How to make indelible ink at home. Why is ink color traditionally blue in pens, and black in printed texts? Equipment and materials

Petrovsky Vadim

How to write a letter so that only the person to whom it is addressed can read it?

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Hypothesis, we assume that writing secret letters is interesting in modern times, because invisible ink exists and can be prepared at home.

The purpose of our work: preparation of invisible ink at home. Tasks Find information on a topic of interest in additional reference literature, study the history of the origin of ink. Expand knowledge of the properties of different substances. Make sympathetic ink at home. To popularize knowledge of cryptography among classmates by making recommendations for making invisible ink. Subject of research: substances that disappear when applied to paper and appear on it under certain conditions. Research object: invisible ink.

Basic concepts Steganography is the concealment of the very fact of information transfer. Cryptography is the concealment of the meaning of the transmitted information. Sympathetic (invisible) ink is ink whose records are initially invisible and only become visible under certain conditions (heating, lighting, chemical developer, etc.).

From history In ancient times, people made ink from ... cuttlefish. Cuttlefish and octopuses have a special ink sac, from which animals, at the moment of danger, release an “ink bomb” - for disguise. On the basis of these ink sacs, we learned how to prepare ink for writing.

From history Secret agents of Ivan the Terrible wrote their reports with onion juice. The letters became visible when the paper was heated.

From history, the Chinese emperor used invisible ink from rice water for his secret inscriptions, which, after drying, did not leave any visible traces. But if such a letter is slightly moistened with iodine solution, then you can read it.

From history V. I. Lenin dipped a pen in milk and wrote to them on a piece of white paper. He allowed the milk to dry, after which not a trace remained of the letters. Then Ilyich heated the paper over the glass of the lamp, and what was written was clearly visible on it.

From history Back in the last century, the great inventor Edison invented ink for the blind. It was necessary to write a text with them and wait a little, as the paper in those places where the letters were inscribed, hardened and rose, forming a relief.

Types of ink Developing ink does not leave a trace on the paper after it dries. Inscriptions or images made with such ink become visible (developed) only when special conditions are created. Disappearing ink, which initially has color, is clearly visible during writing, and becomes discolored under the influence of time or substances in the air.

Kinds of ink Chemical ink Photosensitive ink Luminescent ink Heat sensitive ink Moisture sensitive ink

The use of invisible ink in modern times

Preparation of invisible ink from lemon Equipment: lemon, cup, brush, paper. Squeeze lemon juice into a glass, add the same amount of water. Let's write something on paper and let it dry. To develop the inscription, iron it with a hot iron. Citric acid darkens when exposed to temperature and thus my ink becomes visible.

Conclusion: the inscription with a lemon solution is faintly visible on white paper. When heated, weakly pronounced letters appear, which is not very good. The smell of lemon is practically not felt.

Preparation of invisible ink from onions Equipment: onion, gauze, glass, paintbrush, paper. Apply the onion juice with a brush to the paper, wait until it dries. When dry, the onion juice is slightly visible on the paper, and has a not very pleasant smell. We will develop in the same way - by heating. Onion juice darkens when exposed to heat, and the ink becomes visible and takes on a brown tint.

Takeaway: The sympathetic onion ink isn't perfect due to the strong smell.

Preparation of invisible ink from milk Equipment: milk, glass, brush, iron, candle, paper. Pour milk into a glass. Dip the brush in milk and write on a piece of white paper. Let the milk dry. There will be no trace or smell of the letters. Then heat the paper with an iron, and the written text will appear on it, since the milk will change color when heated.

Conclusion: milk is ideal for secret writing, no traces remain on paper at all, it was not for nothing that Lenin and his associates used this method.

Preparation of invisible ink from soda Equipment: soda, glass, brush, paper. It is necessary to prepare a saturated solution of ordinary baking soda in water. Immediately behind the brush, the water evaporates, and there seems to be nothing on the sheet of paper. The secret letter also manifests itself very simply: under the influence of heat. When heated with an iron, dark brown text appears. Moreover, this text turned out to be the brightest and most uniform of all the previous ones. This invisible ink turned out to be the best!

Conclusion: these sympathetic inks have a long shelf life, there is no smell, the inscription is best shown when heated.

Preparation of invisible ink from rice water Equipment: rice water, iodine solution, glass, brush, paper. First, let's prepare the rice water. We write with a brush on paper, after drying there are no visible traces left. To read the inscription, the paper should be treated with a weak iodine solution. As you know, under the influence of iodine, starch turns blue.

Takeaway: The rice-water writing is clearly visible on white paper, so it is ideal for cryptography. Letters appear quite clearly. The smell of the broth is practically not felt. Easy to prepare, but not stored for long. Dries quickly, the color is bright blue.

Preparation of invisible ink with a solution of copper sulfate Equipment: copper sulfate, ammonia solution, a glass, a brush, paper. We have prepared a saturated solution of copper sulfate. The drawing was applied with a brush to a sheet of porous paper, dried in air, and the image was developed with a 10% solution of ammonia (ammonia). The image on the paper instantly turned a bright blue.

Conclusion: the inscription with copper sulfate is clearly visible on paper. The color of the letters is bright blue. The smell of ammonia is, of course, very unpleasant. Therefore, they are not ideal for cryptography.

Preparation of moisture-sensitive ink Equipment: linseed oil, ammonia solution, water, glass, brush, paper. We intensively mixed a mixture of oil, ammonia and water until a homogeneous mass was obtained. With a brush, they wrote an inscription on a sheet of paper, dried the paper in the air. Then they dipped the paper into the water. Immediately, transparent patterns appeared on the sheet of paper.

Conclusion: the inscription is clearly visible on paper. Letters appear quite clearly. The smell of ammonia is felt. It takes a very long time to prepare. Therefore, they are not ideal for cryptography.

Conclusions Ink composition Visibility Odor Ease of use Manifestation lemon Moderately noticeable on paper Yes, mildly pronounced Fast preparation, medium shelf life Medium onion Slightly visible on paper Yes, strongly pronounced Long-term preparation Medium soda Invisible on white, strongly noticeable on yellow No Convenient to use, not spoils Distinct milk Not noticeable on paper No Short shelf life Above average soda Not noticeable on paper No Can be stored for a very long time without spoiling. The brightest rice broth Weakly visible on paper No Long cooking, short shelf life Strongly expressed copper sulfate Weakly visible on paper Weakly expressed Fast preparation and long storage, quickly manifesting Strongly pronounced Wiedemann solution Weakly visible on paper Weakly expressed Long cooking, long shelf life, long cooking Above the average

Conclusions In the course of the experiment, it was found that the most suitable homemade invisible ink can be considered ink from soda or starch. They can even be tucked into a fountain pen as they will not deteriorate. And this ink appears brighter and more uniform than other invisible inks that I received and researched.

Safety measures It is possible to write and read spy letters only strictly observing safety measures !!! 1. Be careful when working with a hot iron. And, of course, don't forget to turn it off! 2. Solutions of copper sulfate and ammonia are poisonous, they should not be drunk, even if all evidence must be destroyed immediately!

Conclusion We have solved all the tasks set before us: - learned what invisible ink is; - studied the history of the emergence of invisible ink; - learned about the types of invisible ink and how to obtain them; - found out that the easiest way is to make heat-sensitive ink at home; - created sympathetic ink from substances readily available in household use. Based on the observations made, we concluded that different ways of their development are needed for inks made from different substances.

Thank you for the attention!

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Full title of the work	"How to make invisible ink
Direction	Chemistry
	Petrovsky Vadim Alexandrovich

Locality	the village of Ermakovskoe
Name of the educational institution	MBOU "Ermakovskaya secondary school No. 2"
Class	4th grade
Place of execution	Home, school
Supervisor	Klepets Elena Alexandrovna

1. Introduction ……………………………………………………………………… 3 - 4

1.1. Relevance of the research topic
1.2. Purpose and objectives of the work
1.3. Research methods

Main part ……………………………………………………… 5 - 9

2.1. History of steganography and cryptography

2.2. Types of sympathetic ink

3. Practical part ……………………………………………………… 10 - 13

3.1. Preparation of invisible ink from lemon.

3.2. Preparation of invisible ink from onions.

3.3. Preparation of invisible ink from milk.

3.4. Preparation of invisible ink from soda.

3.5. Preparation of invisible ink from rice water.

3.6. Preparation of invisible ink from a solution of copper sulfate.

3.7. Preparation of moisture-sensitive ink.

4. Safety precautions …………………………………………………. 16

5. Conclusion ……… ... …………………………………………………… ..17 - 18

6. References …………………………………………………………. 19

7. Appendices ………………………………………………………………. 21

Introduction

Relevance of the research topic

Mobile phones have become a part of our lives, like televisions or computers. Acquaintance of children with a cell phone increasingly occurs in early childhood.

Personally, I got a cell phone in the first grade of school. The very first phone was given to me by my parents. First of all, the phone was purchased as a means of constant communication with me outside the home. As I grew older, my phone became more functional. I can write not only messages, but also use e-mail on the Internet.

But everything that is sent using the phone and the Internet becomes open, public. This fact in the modern world is a real "disaster" for many people.

Therefore, people try to hide this or that information from others. As civilization develops, information becomes more and more, and the need to hide it is more and more important. I'm interested in how to write a letter so that only the person to whom it is addressed can read it?

For the first time I learned about "invisible ink" from the cartoon "Fixies" and I wondered: what is "invisible ink" and can it be made at home without special equipment and devices? It would be great to learn the secrets of this ink, and learn how to use it!

1.2. The purpose and objectives of research work

Hypothesis: we assume thatwriting secret letters is also interesting in modern times, becauseinvisible ink exists and can be prepared at home.

The purpose of our work:making invisible ink at home and writing invisible words with it.

Tasks:

Find information on a topic of interest in additional reference literature, study the history of the origin of ink.
Expand knowledge of the properties of different substances.
Make sympathetic ink at home.
To popularize knowledge of cryptography among classmates by making recommendations for making invisible ink.

Subject of study:substances that disappear when applied to paper and appear on it under certain conditions.

Object of study:invisible ink.

1.3. Research methods

1. Analysis of the literature

2. Experiment

3. Observation

4. Statistical (processing of the received data)

Main part

History of steganography and cryptography

From additional sources, I learned that with the spread of writing, people had a need for the exchange of letters and messages, which, in turn, caused the need to create a way to hide the contents of written messages from outsiders. There are two main ways to classify information - steganography and cryptography. Steganography is a concealment of the very fact of information transfer. Cryptography is the concealment of the meaning of the transmitted information.

The development of cryptography was facilitated by wars. Written orders and reports were necessarily encrypted so that the capture of couriers did not allow the enemy to receive important information.

Protecting data with encryption is one possible solution to the security problem. Encrypted data is only made available to those who know how to decrypt it, and therefore stealing encrypted data is completely pointless for unauthorized users.

ink

The term "sympathetic" itself was first coined by the French chemist Lemery in 1675. He gave this name to an aqueous solution of "lead sugar". This was the name of the acetic-lead salt, which in those days was used in significant quantities for dyeing and calico printing. The ink was developed by heating or treatment with hydrogen sulfide. So why did the famous scientist call invisible ink sympathetic?

According to the first version, the word "sympathetic" in translation from Greek means - sensual, susceptible to influence. Since invisible ink becomes visible only under certain conditions, that's why they got this name.

But there is another suggestion. The term "sympathetic" originated from the word "sympathy". In the 18th century, the French understood sympathy as the natural correspondence of things to each other.. Moreover, they found this correspondence in the most unexpected and absurd properties. For example, they believed that the magnet and iron correspond ("sympathize") with each other, therefore they are attracted. Or amber matches straw, because they are the same color.

One of the most common steganography techniques is the use of sympathetic (invisible) ink.Sympathetic (invisible) ink is ink whose records are initially invisible and become visible only under certain conditions (heating, lighting, chemical developer, etc.).

In ancient times, people made ink from ... cuttlefish. Cuttlefish and their cousins, the octopuses, have a special ink sac, from which animals, at the moment of danger, release an “ink bomb” - for disguise. On the basis of these ink sacs, we learned how to prepare ink for writing.

During the Middle Ages, recipes for simple sympathetic ink were widely used for diplomatic correspondence. Secret agents of Ivan the Terrible wrote their reports with onion juice. The letters became visible when the paper was heated.

The Chinese emperor used invisible ink from rice water for his secret inscriptions, which, after drying, did not leave any visible traces. But if such a letter is slightly moistened with iodine solution, then blue letters appear.
In the childhood of little Lenin, the children were nicknamed "The Magician". He dipped a clean quill pen in milk and wrote to them on a piece of white paper. He allowed the milk to dry, after which not a trace remained of the letters. Then Ilyich heated the paper over the glass of the lamp, and what was written was clearly visible on it. Twenty years later, in a St. Petersburg prison, Lenin again recalled his childhood. He broke a loaf of black bread, sculpted inkwells from the crumb, collected white liquid in them and wrote with it between the lines in books. When the warden summoned his superiors to gawk at the quirks of the German spy, Lenin thrust an inkwell into his mouth.

The history of ink keeps many interesting things. Back in the last century, the great inventor Edison invented ink for the blind. It was necessary to write a text with them and wait a little, as the paper in those places where the letters were inscribed, hardened and rose, forming a relief.

Types of sympathetic ink

All sympathetic inks can be divided into emerging and disappearing. The developing ink does not leave a mark on the paper after it dries. Inscriptions or images made with such ink become visible (developed) only when special conditions are created. But there are substances that initially have a color, are clearly visible during writing, and become discolored under the influence of time or substances in the air. In this case, the document loses its validity, turning into a blank sheet of paper. This is a disappearing ink.

Depending on the nature of the interaction of substances, all invisible ink can be divided into the following types.

Chemical ink

Chemical ink contains colorless or weakly colored substances that can react with other substances to form brightly colored products. The ink solution is applied to paper and dried at room temperature. The resulting latent image is developed with a solution of another substance (developer) using a spray bottle or cotton swab. Sometimes the developer is a gaseous substance.

Photosensitive ink

Photosensitive ink is ink that can appear or disappear when exposed to light. This group includes ink that "disappears" under lighting and reappears in the dark.

Photosensitive ink is applied to paper and air dried. The inscription is developed or removed, illuminating it with bright sunlight.

Luminescent ink

This group of inks contains substances that are luminescent when exposed to ultraviolet radiation. To develop such inks, the inscription is illuminated with an ultraviolet lamp. After the termination of the action of ultraviolet radiation, the inscription disappears. Luminescent ink is actively used by the police and special services, as well as by students and schoolchildren - during tests or exams. This group of ink dates back to our time.

Heat sensitive ink

Thermosensitive sympathetic ink contains substances that transform into colored compounds when heated. In many cases, coloration results from the interaction of ink components with paper. The ink is applied to paper and dried at room temperature. The inscriptions and drawings made by them are invisible. They appear when heated to 120-180 ° C, for example, if you iron the paper with a hot iron, hold it over a flame or a highly heated electric stove.

Moisture Sensitive Ink

Invisible writing or images made with moisture-sensitive ink are developed by water or water vapor.

Another classification method is determined by the nature of the ink, which can be based on:

1) blood and body secretions (sweat, saliva, urine);

2) food solutions and juices of fruits, vegetables and plants;

3) chemicals (acids, bases and salts);

4) a variety of substances, including soap solutions and plant gum.

2.3. The use of invisible ink in modern times

The composition of modern sympathetic ink can include, both in pure form and in the form of constituent parts, almost any substance - blood, saliva, plant juices, soap solutions, acids, bases, salts, salt, sugar, starch, etc. It only depends on the imagination and professionalism of the chemist. Although, those specialists who are engaged in methods of manifesting externally invisible records do not stand still.

The use of sympathetic ink in our time is developing in several directions.

One of them and the most famous is the use of luminescent ink by the police when marking money to catch criminals in a bribe. This method is still used today.

Luminescent elements are also present in banknotes; the authenticity of the banknotes is checked using an ultraviolet lamp.

And in Japan, ink was made that disappears from paper in two days. They are convenient to use when working with a book when you need to make notes and underlines. Such pens are already on sale and are even produced by Russian firms. It would be very cool to use such pens at school, for solving in a column in the margins, and the teacher can see the solution, and then the notebook is neat.

Invisible ink is even used in inkjet printing. These include: -sympathetic ink, which appear under the influence of ultraviolet radiation;

- disappearing inkwhich discolor when heated;

- fluorescent inkthat glow in the dark;

- silver inkconducting electrical impulses;

- textile inkthat print excellently on fabric;

Latex , which include synthetic latex polymers.

These inks are the future of inkjet printing. Some of these types are already commercially available. This ink appears when heated, treated with reagents.

Thus, the properties of sympathetic ink are not forgotten, they are used in the modern world, opening up prospects for steganography and paper saving.

Practical part

How to make disappearing ink at home? Some of them require chemicals that I don't have. But it turned out that there are several methods available for preparing invisible and disappearing ink that can be easily applied at home.

I decided to give it a try. Here are some recipes every kid can use to make disappearing ink.

1. Preparation of invisible ink from lemon

For research we needed: a lemon, a glass, a paintbrush, paper. Squeeze lemon juice into a glass, add the same amount of water. Dip the brush in a solution of lemon juice and water and write something down on paper. After the inscription is made, it must be allowed to dry. To develop the inscription, you need to heat a piece of paper, for example, iron it with a hot iron. Citric acid darkens when exposed to temperature and thus my ink becomes visible. Lemon juice smells good, is not noticeable when

drying, but dries for a long time, manifests itself as a weak yellow-brown tint of letters.

Output : Lemon solution is faintly visible on white paper, so it is ideal for secret writing. When heated, weakly pronounced letters appear, which is not very good. The smell of lemon is practically not felt.

3.2. Making invisible ink from onions

For the experiment, we need the same as for the previous one. Take half an onion, grate it on a fine grater and squeeze the juice through a piece of gauze into a glass. Apply the onion juice with a brush to the paper, wait until it dries. When dry, the juice of the onion is slightly visible on the paper, and has an unpleasant odor, which makes this ink imperfect. We will develop in the same way - by heating. Onion juice darkens when exposed to heat, and the ink becomes visible and takes on a brown tint.

Output : Sympathetic onion ink is not perfect because of the strong smell.

3.3 Making invisible ink from milk

Pour milk into a glass. Dip the brush in milk and write on a piece of white paper. Let the milk dry. There will be no trace or smell of the letters. Then heat the paper over a candle, and what is written will appear on it, since the milk will change color when heated. The milk really changed color, but the color of the inscription turned out to be heterogeneous, and it is not very convenient and unsafe to use a candle because you are constantly afraid that the leaf may catch fire, it is much more convenient to use an iron. But the experiment made it possible to prove that the inscription appears from the influence of any heat.

Output : milk is ideal for secret writing, there are no traces on paper at all, it was not for nothing that Lenin and his associates used this method.

3.4 Preparation of invisible ink from soda

It is necessary to prepare a saturated solution of ordinary baking soda in water. This ink can be stored for a very long time without deterioration. This is their advantage over the method of writing with milk or lemon and onion juices. For ease of writing, this ink is best filled with a fountain pen. But I used, as in the previous recipes, a brush. Immediately behind the brush, the water evaporates, and there seems to be nothing on the sheet of paper. The secret letter also manifests itself very simply: by the influence of heat. When heated with an iron, dark brown text appears. Moreover, this text turned out to be the brightest and most uniform of all the previous ones. This invisible ink turned out to be the best!

Output : This sympathetic ink has a long shelf life, no odor, the inscription is best shown when heated.Easy to prepare, shelf-stable, dry faster, brighter color.

3.5 Preparation of invisible ink from rice water

First, let's prepare the rice water. We write with a brush on white paper, after drying there are no visible traces left. The letter was smeared with an alcohol solution of iodine and we got letters. But all the paper turned dark brown and it was inconvenient to read. Then we made a weak alcoholic solution of iodine and smeared on the other side, we saw that the letters also appeared. You can simplify the version of this inkand take a saturated solution of starch in water. I used a brush, as in the previous recipes. To read the inscription, the paper should be treated with a weak iodine solution. As you know, under the influence of iodine, starch turns blue.

Output : The rice-water lettering is clearly visible on white paper, making it ideal for cryptography.Rice contains starch, and starch - gives itself out completely in the presence of iodine.Letters appear quite clearly. The smell of the broth is practically not felt.Easy to prepare but short-lived, dry quickly, blue and brighter.

3.6. Preparation of invisible ink with a solution of copper sulfate

We have prepared a saturated solution of copper sulfate. The drawing was applied with a brush to a sheet of porous paper, dried in air, and the image was developed with a 10% solution of ammonia (ammonia). The image on the paper instantly turned a bright blue.

Output : Copper sulfate is clearly visible on paper, making it ideal for secret writing. Letters stand out clearly enoughtheir color is bright blue.

3.7. Preparation of moisture sensitive ink

The method of obtaining moisture-sensitive ink turned out to be very interesting for me. To obtain them, we prepared a Wiedemann solution. For this, linseed oil, a 25% solution of ammonia and water were mixed in a volume ratio of 1: 20: 100. We mixed the mixture vigorously until a homogeneous system was obtained. With a brush, they applied an inscription on a sheet of porous paper, dried the paper in the air. Then they dipped the paper into the water. Immediately, transparent patterns appeared on the sheet of paper.

Output : The lettering is clearly visible on paper, so it is ideal for secret writing. Letters appear clearly enough. The smell of ammonia is, of course, very unpleasant.It takes a very long time to prepare.Therefore, they are not ideal for cryptography.

Thus, we conducted a study of sympathetic ink, made the appropriate conclusions, on the basis of which we will draw up a summary table.

Ink composition	Visibility	Smell	Ease of use	Manifestation
lemon	Moderately visible on paper	Yes, mild	Fast preparation, medium shelf life	The average
onion	Poorly visible to paper	Yes, strongly pronounced	Long-term cooking	The average
soda	Invisible on white, strongly noticeable on yellow	No	Easy to use, does not deteriorate	Pronounced
milk	Not noticeable on paper	No	Short shelf life	Above the average
soda	Not noticeable on paper	No	They can be stored for a very long time without spoiling.	The brightest
rice water	Visible on paper	No	Long cooking time, short shelf life	Pronounced
copper sulfate	Poorly visible to paper	Weakly pronounced	Fast preparation and long storage, quick manifestation	Pronounced
Wiedemann's solution	Poorly visible to paper	Weakly pronounced	Long cooking time, long shelf life, long cooking time	Above the average

Output. The most suitable homemade invisible ink is soda or starch ink. They can even be tucked into a fountain pen as they will not deteriorate. And this ink appears brighter and more uniform than other invisible inks that I received and researched. Thus, invisible ink made from soda and starch is the best in our experiment.

Safety engineering

You can write and read spy letters only by strictly observingsafety engineering !!!

1. If you do not want to iron a letter with letters that appear from the heat, but with a mysterious look drive it over the flame of a candle, make sure that the paper does not burst into flames in your hands. And, of course, don't forget to turn off the iron!

2. Solutions of copper sulfate and ammonia are poisonous, they should not be drunk, even if all evidence must be destroyed immediately!

Conclusion

Learning the secrets of cryptography is a fun process.We have solved all the tasks assigned to us:

Learned what invisible ink is;

Studied the history of the origin of invisible ink;

Learned about the types of invisible ink and the methods of obtaining them;

Found out that the easiest way to make thermosensitive ink at home;

Created "magic" sympathetic ink from substances readily available in household use.

So, we have achieved the goal that we set for ourselves at the beginning of the study.
We fully confirmed our hypothesis that you can make invisible ink yourself at home.from substances readily available in household use. Moreover, even a child can cope with this, since I am 10 years old, and I easily coped with it.

Not all types of sympathetic (invisible) inks can be obtained at home, generally only heat-sensitive inks. Since they are easy to manifest at home by exposure to heat. Sympathetic inks that require chemicals or chemical developers can only be obtained from a dedicated chemical laboratory.

You can show invisible records at home using a candle, a lamp, an iron, but the most convenient and safe way is with an iron.

In the course of the experiment, it was found that the most suitable homemade invisible ink can be considered ink from soda or starch. They can even be tucked into a fountain pen as they will not deteriorate. And this ink appears brighter and more uniform than other invisible inks that I received and researched. Thus, invisible ink made from soda and starch is the best in our experiment.

Based on the observations made, we concluded that different ways of their development are needed for inks made from different substances. In the course of the experiment, we turned to various sources of information: books, manuals, but mainly the Internet. It is impossible to describe all methods of making sympathetic ink in this work. We were able to conduct experiments only with substances that can be easily found in the house. We have found many recipes that require chemicals that we did not have. But we know for sure that we will continue to experiment on creating new types of sympathetic ink.

During the work, we made sure that the experiment is very interesting and exciting. I shared the results of my research with my classmates and I really hope that this will inspire them to experiment on their own. We suggest you also use our recipes for invisible ink for secret correspondence.

We plan to continue working on the Invisible Ink theme. The modern world is developing.Now more and more computer steganography is used. Perhaps this topic will become the subject of my future research.

Bibliography

Aleksinsky V.N. Amusing experiments in chemistry. - M .: Education, 1995.
Lavrova S.A. Riddles and secrets of ordinary things. - Ed. "White City", 2006.
Lavrova S.A. My first book. Entertaining chemistry for kids. - Ed. "White City", 2009.
Stepin B. D., Alikberova L. Yu. Chemistry book for home reading. - M .: Chemistry, 1994.
What? What for? Why? Big book of questions and answers / Per. K. Mishina, A. Zykova. - M .: Eksmo, 2007.

Other sources of information:

Making your own ink can be a fun and very rewarding experience! And why, you ask, do them, because every house is already full of ballpoint pens and pencils? Of course, today you won't surprise anyone with ink, but just imagine how many emotions their creation will bring to your child! With what enthusiasm and curiosity he will take part in this process and with what joy - then print letters and numbers on paper with his ink, or just squiggles that are understandable to him alone! And the benefits of such an activity are obvious! First, children love to learn something new and literally "absorb" any information they receive. Secondly, you must admit that spending time in this way is much more useful than sitting near a TV or computer!

But before proceeding with the description of the ink recipe and the method of their preparation, let's plunge a little into history and find out how and when they appeared.

According to archaeologists, the very first ink appeared in ancient Egypt. It was there that during the excavations their oldest recipes were found. According to the description found, scientists managed to find out that for the manufacture of ink the Egyptians used gum - a thick and sticky juice that is secreted from cherries or acacia and ash, which remained after burning papyrus or its roots. By the way, scientists also managed to find out that about two and a half thousand years ago, the same ink was used in China.

Already in the 3rd century BC, the Greeks and Romans used several types of ink and even made red ones! They were intended for special occasions and were considered sacred in those distant times. Only the emperor had the right to write in red ink. Isn't it, now it seems not accidental that in educational institutions only teachers can write with a red pen! This, of course, is a joke and it was just as a small digression, but now let's go back to the third millennium BC and find out what ink was made of then. For this, people used fruit seeds, soot, charcoal and grapevines. The ink that was found during the excavations of an ancient Roman city consisted of soot, which was diluted in oil.

A little later, ink appeared, made on the basis of a decoction of peel from green chestnuts or walnuts, then from nuts that cover the leaves of oak - galls. These nuts are a kind of growths that form on oak branches and leaves. In these galls, larvae of nutcracker insects develop. To prevent the ink from washing off, they used a fixative - again the same gum that was used by the ancient Egyptians. Surprisingly, the manuscripts that have survived to this day, which were made with gallic ink, have not yet lost their brightness and clarity! By the way, in our time, some graphic artists use such ink to create their unique works and, of course, make them on their own.

Well, let's try and prepare ink. Moreover, on gallic ink their ancient history ends and the modern one begins. Already in the 19th century, alizarin ink began to be produced, then the natural dye (madder root) in them was replaced with a synthetic one, and the next step was completely synthetic modern aniline ink. It is impossible to make such at home. Therefore, we will look at simple recipes and prepare ink from the available ingredients.

● Gallic ink

You will need:

Gauls (growths on oak branches and leaves)

Metal can

Copper sulfate (solution)

Cooking method:

Fold the galls in a metal jar and fill with water so that it completely covers them

When the water darkens a little, add a small amount of ferrous sulfate solution to the jar to the consistency of ink and leave for several hours

Ink ready

● Ink from oak bark solution

You will need:

Oak bark

Iron vitriol (solution)

Cooking method:

To shave off the oak bark

Boil the chips in water for 15-20 minutes

When the water darkens and turns dark brown, it is necessary to strain it from the shavings.

Add a solution of ferrous sulfate to the broth until a black color is obtained, insist for several hours

Ink ready

As you can see, it's not that difficult - making ink! It remains only to figure out what can be used as an inkwell! Good luck with your experiments!

Several years ago, when I became interested in the CISS, I downloaded (for personal use) everything related to the CISS as a vacuum cleaner from the Internet, without noting the original source and authors.
Now I regret it.
It turned out to be a large archive, I decided to post some articles and photos on the forum.
I think it will be interesting for beginners.

I found an article in my archive about experiments with ink and recipes.
I doubt that there will be people willing to conduct such experiments, but for familiarization, I think it will be useful.

First, I will list the recipes that I found on the net (you probably already met them)

1) Recipe of the Institute of Microelectronics and Informatics of the Russian Academy of Sciences
The recipe was developed at the Institute of Microelectronics and Informatics of the Russian Academy of Sciences for the Canon BJ 300 printer where it became widespread. The main component is black chrome dye, used in the production of felt boots and tarpaulin boots. Of course, not the most affordable chemical, but if you want, you can get it. The dye is dissolved in distilled water until it is completely saturated (that is, it is dissolved in water heated to 60-70 degrees "until it stops" and allowed to cool). Then add glycerin. Unfortunately, the proportion of glycerin can only be specified for Canon BJ 300 printers with a resolution of 300 dpi - 40%. Glycerin is added to increase the viscosity of the ink. Obviously, its proportion will have to be selected empirically. Before use, the composition is recommended to be thoroughly filtered.

A comment: Failed to try because I could not get this dye, but I can say that the print will most likely be grayish in color, since the dye is water-soluble.

| Message Sent 01 April 2006 - 11:32

Continuation

2) Composition, for Canon BJC-250 40% isopropyl alcohol, 40% medical glycerin and 20% dye. As the latter, any liquid, water- and alcohol-soluble dye is suitable, for example, foreign-made ink. You can also use domestic ones, but only after thorough filtration. The cartridge can withstand at least 10 refills with such ink.
Comment: I have not tried it and I am not going to, Isoproryl alcohol is a highly toxic substance! There are ways and easier to spoil your health!

3) Recipes by Jahen P. A.) I found a recipe for preparing ink for an inkjet printer in the magazine "Radio Amateurs" 8/96 p. 9: "INK COMPOSITION. Take" Rainbow "ink, add to them 30% (by volume) ethyl alcohol and 5% glycerin. The resulting mixture boil for 10-15 minutes on low heat and filter through a layer of cotton wool. Domestic printheads can withstand 30 ... 35 refills, and imported ones - up to 80. "

A comment: It was on the basis of this recipe that the first experiments were carried out, thank you Yahenu!
B.) (purple with smoothed dots) Take "Rainbow" ink, add 2-3% (by volume) ethyl alcohol to them. Boil the resulting mixture for 10-15 minutes over low heat and filter through a layer of cotton wool. Commentary: The print is really fuzzy, but you cannot leave a cartridge filled with such ink in the printer - they will leak!

Quote: I tested homemade ink. 5% glycerin turned out to be not enough - the ink was flowing, 20% glycerin was the optimal solution. The color turned out to be not black, but gray towards dark green. Quite waterproof. He boiled the ink for one minute, then waited until it cooled to room temperature, filtered it and filled it into the cartridge. More about glycerin. From the letters that I receive, the following conclusions can be drawn: for printers with a resolution of 300 dpi, 40-50% glycerin to the total volume is needed (that is, almost 1/1 is ink / glycerin, plus a little alcohol). 600 dpi printers require 5-20% glycerin.

A comment: Let's start in order:
It is not at all necessary to boil the ink, in addition, during boiling, some of the alcohol and water will evaporate and, therefore, the viscosity will change!
I DO NOT recommend filtering through cotton wool, it is better to take paper filters for 0.9-0.5 (see below) 40-50 ... 5-20 but how much exactly? For which model? (see below)

| Message Sent 01 April 2006 - 11:34

Continuation

And now I bring my technology by stages and recipes:

You will need:
Necessary equipment: several flat-bottomed flasks, a measuring cylinder or beaker, glasses, a funnel, containers for ready-made ink, 20 ml syringes (if something is not available, any household utensils will do), paper filters with a pore size of 0.9 microns or less ( ideally 0.3 microns, but you will wash with such a filter) Preparation of dishes: wash with soap, wipe dry, scald with boiling water.
Required reagents: GAMMA "rainbow" ink of any desired color (or other water-soluble ink for pens can be Parker, for example :-))), alcohol, glycerin, distilled water (if not, boiled water is suitable), it is also desirable to have a glass cleaner "Ajaks professional" - a transparent bottle with a spray, the liquid itself is blue.
Attention DO NOT use stamp ink !!! It contains adhesive components that will instantly clog the head!
If you use ink not named in the recipes, it should be boiled, if during boiling they curl (coagulate, form a precipitate), such ink cannot be used!
Stages of preparation of ink
a) prepare the components in the specified way
b) mix all the ingredients named in the recipe in the exact proportion
c) filter the mixture through a filter by gravity or with a pump.
d) refill the cartridge

| Message Sent 01 April 2006 - 11:38

Continuation

Recipes:(In order of progress of experimentation and improvement)

"Black" ink

* taken in quotes because our domestic black ink RAINBOW
on closer inspection are somewhat green.

№1
1.27% black ink "rainbow" evaporated to 50% by volume
2.18% alcohol
3.55% glycerin
4. Features: faint dark green printing flows from the print head

№2
1.44% black ink "rainbow" evaporated to 35% by volume
2.18% alcohol
3.35% glycerin
4.3% AJAKS remedy
Characteristics: deep dark green print, almost no flow.

№3
1. 47% black ink "rainbow" evaporated to 25% by volume
2.20% alcohol
3.30% glycerin
4.3% AJAKS remedy
Characteristics: almost black print with a shade of dark green, no flow.

№4
1. 40% black ink "PARKER Quink" evaporated to 30% by volume
2.30% alcohol
3.30% glycerin

Characteristics: rich dark gray with a tint of green printing, almost no flow
print quality is good (letters are clearer)

Purple ink
№1
1.27% purple rainbow ink
2.18% alcohol
3.55% glycerin
Features: pale purple print, flowing from snake and print head.

№2
1.45% purple ink "rainbow" evaporated to 50% by volume
2.16% alcohol
3.35% glycerin
4.4% AJAKS remedy
Characteristics: purple, slightly fuzzy printing, flowing from the print head.

№3
1.30% purple rainbow ink evaporated to 20% by volume
2.40% alcohol
3.30% glycerin

Characteristics: high quality purple, print, almost no flow.

№4
1.38% purple ink "rainbow" evaporated to 10% by volume
2.37% alcohol
3.25% glycerin
4. AJAKS can be omitted
Features: deep purple, print, non-flowing.

| Message Sent 01 April 2006 - 11:40

Continuation

Develop your own recipe!

1. choice of dye: first of all, the dye that you will use in your recipe must be water-soluble and not pigment, to check it - drop it on a piece of ordinary (80g / m2) paper, if it soaks and stains it on the back side, then it will most likely work. If ink (dye) remains on one side, and an uncolored liquid emerges on the other side, such a dye cannot be used! I must say right away: most building tinting, as well as tinting for car paints are not suitable. And yet - if you are thinking of choosing the colors of Cyan Magnetta Yello (for a color cartridge), it is better not to try - this did not work even with the manufacturers of cartridge refills, unless you want to constantly print in one color - orange, for example. In the latter case, use Easter or food paints after preliminary boiling and filtration. Attention! If you use food coloring or other mixtures for tinting, carefully read the composition on the package! Dyes containing molasses, sugar, glue and other extraneous components (besides the dye) are not suitable!

2. determination of the viscosity of the finished ink: After the ink is ready, it is necessary to compare their viscosity with the "native ink" for this we take any syringe, for example, 5 ml, put on a needle, turn it over, quickly pour a certain amount of "native ink" ", for example, 3 ml and we note the time for which the ink will flow out - this is the ideal to which the viscosity of homemade ink will need to be adjusted. Attention, determine the viscosity of your ink on the same syringe under the same conditions! .If the viscosity is low, add glycerin, increase the concentration (by evaporation) of the original ink If it is high, add alcohol, AJAKS means (the latter is preferable because it lowers the viscosity without changing the density of the ink) If you have no "native ink" left, the viscosity should be about 3 ml in 10 min.

| Message Sent 02 April 2006 - 10:00 P $ ux

I thought of a Chinese toy "Magic Pen". On the one hand there is a paste with "invisible" ink, on the other - a flashlight, in the light of which the ink glows blue. So - from the pen on the paper there is a rather deep mark on which you can read what was written without resorting to backlighting. How can I put this ink into the printer? : D

| Message Sent 05 April 2006 - 19:31 Episode

P $ ux (Apr 2 2006, 10:00 AM) wrote:

There is an idea to make "invisible" ink.

These inks are commercially available. Designed for applying security marks on documents, decorating evening clubs, discos, etc. Glow in ultraviolet light, they are not visible in white light.
Met a set of "photos", i.e. with light colors.
IMHO, it will be not only not easy to do it yourself, but also not profitable.

| Message Sent 05 April 2006 - 19:41 Yuha

V & W, I should have posted on this topic about "viscosity".
Anyway.
I support the idea and method of controlling "fluidity" by the drop-by-drop method. Moreover, this is a professional way.
One of these days I will experiment.

| Message Sent 07 April 2006 - 22:46 SPAWN

There is an idea to make "invisible" ink. They become visible under the influence of radiation.
I thought of a Chinese toy "Magic Pen". On the one hand there is a paste with "invisible" ink, on the other - a flashlight, in the light of which the ink glows blue. So - from the pen on the paper there is a rather deep mark on which you can read what was written without resorting to backlighting. How can I put this ink into the printer? biggrin.gif

A similar idea has been coming to me for a long time, only not "invisible" but transparent fluorescent
which are visible under ultraviolet light.
Recently appeared C 42 (my little polygon: P) left to find ink.
I think in a joke store maybe.

| Message Sent 14 April 2006 - 23:09 delfin

How about edible pictures? I heard that there is edible paper (either rice or corn), how about making ink from food dyes (edible), it would be possible to decorate cakes - cute and you can make money on it B)

| Message Submitted 15 April 2006 - 01:46

Need a pastry printer to print on DECOJET EVOLUTION food grade paper
Decojet Evolution uses wafer or sugar paper and edible ink for printing. In addition, a special medium, Shocotransfer, is offered for translating images into chocolate.

The preparation of ink is not connected with the factory equipment, and therefore in small industries it is possible to successfully produce ink that meets all the requirements for them. Old barrels or vats can serve as utensils, copper or iron pots both for making ink and for filtering, and, finally, glass bottles are needed into which the finished ink is poured.

In addition to ordinary writing ink, special inks are also produced for copying, hectograph, steklograph, sketching, linen marks, etc. look like ink.

All manufactured inks must meet the following requirements. They should not act in a corrosive manner on the pen, should not leave sediment in the inkwell, and should not contain highly toxic substances. The ink must run off the pen easily and be free of insoluble particulate matter so the finest line can be drawn. In addition, they must be strong and free from mold.

The currently used ink (1925) can be divided into two groups. The largest and most important group is formed by black ink containing tannic acid. Inks of the second group do not contain tannic acids.

Inks of the first group are still the most commonly used and, moreover, the cheapest. They are prepared mainly from tannin and gallic acids or from substances containing tannins.

Solutions of tannins with iron salts give a colored liquid, which is the basis for numerous simple and cheap recipes for all kinds of ink. Of the tannins of vegetable origin, ink nuts, knopers, horse chestnut, willow and pine bark, Persian berries (Avignon pear), blackthorns, etc. are most often used for this purpose.

Ink nuts are painful growths on oak leaves, resulting from a stab of a nutcracker.

Knopers are also painful growths on the cups of oak acorns. The cheapest is the use of used and re-dried tanning bark. Such bark contains a sufficient amount of tannin for the preparation of ink.

In the manufacture of ink, the main work is the preparation of extracts of tannins, obtained from the raw material using water; nowadays, however, factory-made tannic extracts are often used, as well as chemically pure tannic acid. Tannin, which is commercially available as a yellowish-white or brownish powder, is quite suitable for making small quantities of ink.

The water used for the manufacture of ink must not contain foreign impurities, which can give insoluble compounds with tannins. It is best to use rain, snow or distilled water. Glycerin, gum arabic, gelatin, dextrin, and other substances are used as thickeners for the preparation of ink. To prevent mold growth, carbolic acid, salicylic acid, creosote, etc. are used.

With the development of the colorful aniline industry, ink production has been simplified to the extreme. By simply dissolving the corresponding aniline ink in water, ink of any shade is obtained, and the proportions of the ink are determined depending on the desired intensity of one or another ink color.

To improve the quality of ink, ink, etc., it is recommended to add small amounts of volatile organic compounds of the aliphatic series, which contain at least 4 carbon atoms in the molecule, to coloring liquids, for example, valeric or nylon acid, alcohol, ether and ketones.

Manufacturing
home ink
conditions

4th grade student

municipal budgetary educational institution "Lyceum"

Karasev Prokhor Timofeevich

Work manager

Gubina Marina Nikolaevna,

primary school teacher MBOU "Lyceum"

2017 year

Content

Introduction

Theoretical part

4-9

1.1. History of the invention of ink

4-6

1.2. Ink requirements

1.3. Disappearing and developing ink

7-9

Practical part

10-16

2.1. Resistant ink

2.1.1. Recipe No. 1 "A mixture of soot and oil"

10-11

2.1.2. Recipe No. 2 "Broth of oak bark, solution of ferrous sulfate, PVA glue"

11-12

2.2. Developing ink

2.2.3. Recipe No. 5 "Concentrated baking soda solution"

2.2.5. Recipe # 6 "Spy Ink"

13-14

14-15

2.3. Disappearing ink

2.3.1. Recipe No. 8 "Dextrin, alcohol solution of iodine"

15-16

Results of work and conclusions

16-17

Bibliography

Introduction

Last year, pen ink leaked in my jeans pocket. The clothes were tainted, but the "stain" made me wonder: what is the ink made of? What were they made of before? When did the first ink appear? Can ink be made at home? This is how the topic of this project arose.

This work seems to be relevant, since at the present stage, ink is usually produced at specialized chemical plants and factories. Chemical production causes serious damage to the environment and human health. In the past, ink was made from natural ingredients, which makes it more environmentally friendly.

Objective of the project : to study the history of the appearance of ink, to make ink at home.

Project objectives :

1. Learn the history of origin and recipes for making ink.

2. Make ink according to the recipe at home.

3. Identify the most resistant ink.

The stated goal and objectives of the project determinedmethods used in this work, namely: analysis and synthesis of theoretical material, descriptive method, observation, experiment.

Hypothesis of the project lies in the fact that at the present stage it seems possible to make ink according to a number of surviving old recipes and find their application.

Theoretical significance the project consists in finding recipes for making ink at home from ancient times to the present day.

Practical value of the project is to determine the scope of practical application of ink at the present stage.

Project object: ink.

Project subject: the process of making ink.

1. Theoretical part

1.1. History of the invention of ink

Before presenting recipes for making ink, you need to determine what ink is. To do this, I turned to the "Dictionary of the Russian language" S.I. Ozhegova and to Internet resources.

In Russian, the wordink from the word black (also in a number of other languages: Fin.musta , Swede,black ), but this word very early underwent de-etymologization: inks of different colors have been known since ancient times. "Ink is a coloring liquid for writing." “Ink is a liquid dye suitable for writing and / or creating images with writing tools and stamps. From these definitions, it follows that ink is primarily intended for writing, therefore, the first ink was created in ancient times.

After analyzing various ink recipes found in scientific publications and Internet resources, I presented them by the time of invention in the table “Historical stages of the invention of ink ”.

Table No. 1

Epoch

Composition and method of manufacturing ink

Note

Ancient Egypt

The root of the reed that grows in the stagnant waters of the Nile,

called "Cyperus Papyrus"

Black ink has been used by people of different origins.

Red ink was considered sacred and was available for use only by clergy and emperors.

A mixture of soot and oil

Were already known in ancient Greece and China

Ancient Rome

A mixture of soot and oil

It was used in painting and writing. Ancient Roman artists made ink from fruit seeds, grapevines, softwood, soot, charcoal and bone charcoal. Interestingly, until now, the best black paint is made from soot obtained from burning grape seeds.

Purpure and cinnabar - Red “court ink”, which was used to write only state documents. Even an imperial decree was born, forbidding the use of red ink outside the imperial court on pain of death.

This ink was guarded by a special guard. The process of obtaining purple was very laborious. At first, literally hundreds of thousands, millions of shells were collected. In southern Italy, a "shell mountain" has survived, consisting almost entirely of the shells of the Brandaris mollusc. The bodies of the molluscs were removed from the shells and placed in salt water. Then they dried it in the sun for three to four days, then boiled it, and as a result, out of every ten thousand shellfish they got ... only one gram of paint!

Ancient Russia

Soot with gum (cherry glue), diluted with ordinary water

This is the so-called "smoked" ink

From a decoction of the bark of tanning plants - "Boiled Ink", XVcentury

Their recipe is as follows:

"part of the oak bark, the other alder, half of the ash, and this overlay is full of a vessel of iron or clay, and boil with water, not all of the water will boil, and the rest of the water is stuck into the oprishny vessel, and packs of water are boiled for that skin, and overlap with fresh bark and then cook without bark, and put a gesture in the circuit board, tying it up and put in the iron and interfere, and on the third day write. "

Ink nut juice, iron vitriol *, glue

With this method, the ink was thick, durable, and cheap. But they do not turn black immediately, but 10-12 hours after they write something with them. Ink nuts do not appear on all types of oak, so oak bark was often used instead of mix. It needs to be cut, boiled in water for 15-20 minutes, until the liquid turns dark brown, filtered and added with a solution of ferrous sulfate to obtain black ink. If ferric chloride is added instead of vitriol, the ink will be dark blue.

Germany 1855

German teacherChristian Augustan Leonhardi invented alizarin ink

Leonhardi ink was also made from ink nuts, but the inventor added a substance called crappin to them. Crapp is obtained from the roots of the oriental madder plant. Later, a synthetic substitute for speck was found, and ink nuts were replaced with gallic acid, similar in composition. So alizarin ink began to be made entirely of artificial substances. Making them became easier and cheaper.

USA 1900s

Everyone knows the great inventorT. Edison ... He invented the phonograph, the carbon filament light bulb, and many other wonderful things, including ink for the blind.

Ink of a pale gray color had such a property: as soon as they wrote a text, the paper on which the letters were inscribed rose, hardened and formed a relief. The blind easily "read" these raised letters with their sensitive fingers.

By comparing different methods of making ink, you can do the followingconclusions :

1. The composition of ink for a long time (before the active development of the chemical industry) included only components of natural origin.

2. The process of making ink was quite laborious and time-consuming.

3.Inkdifferent colors were used by people of different classes and were used in the fields of human activity.

4.Any ink contains the following main components:

solvent (usually pure or distilled water);

coloring matter (vegetable or chemical origin);

modifiers * (for example, viscosity, wettability, durability, etc.).

1.2. Ink requirements

The following basic requirements are imposed on ink :

1. They should not act in a corrosive manner on the pen, should not give sediment in the inkwell, should not contain highly toxic substances.

2. Ink must run off the pen easily and be free of insoluble particulate matter so that the finest line can be drawn.

3. In addition, they must be strong and free of mold.

4. Special attention is paid to color saturation and durability for a long time under normal storage conditions, relative cheapness, availability and safety of components and finished ink.

Additional requirements may apply to ink :

1.increased water resistance or resistance to certain solvents;

2.increased thermal, light, frost resistance;

3. The ability to mix different colors of the same type of ink to obtain a given shade.

The list of possible additional requirements is not limited to the above requirements.

1.3. Disappearing and developing ink

As follows from the above material, ink has been and is appliedvthe sphere of writing and execution of documents and / or other paper carriers. In addition, one of the important requirements for ink is its stability, i.e. the ability to maintain the brightness of color in all conditions. However, in the course of studying scientific sources, I found recipes for disappearing and emerging ink.

A characteristic feature of all disappearing ink is the loss of color by the ink composition. The time for the disappearance of such ink is from 1-2 days to 2 weeks.

Developing ink is a special kind of ink widely used and used in "secret" correspondence. Text written with such ink appears under the influence of heat, treatment with special reagents, or in ultraviolet or infrared rays. There are many known recipes for such ink.

It is believed that "secret" ink, which does not leave traces on paper and appears when heated or wetted with a certain solution, first appeared in the 17th century in France.

But ink for secret correspondence, that is, sympathetic, was used even in ancient times. In the 1st century ADPhilo of Alexandria described a method of making "secret" ink fromjuice of ink nuts,for the development of which a solution of iron-copper salt was used.

Romanpoet Ovid suggested using for writing textmilk,manifested after sprinkling it with soot powder.

Secret of cryptographyPliny the Elder was to usesap of plants. Chinese emperorQing Shi Huang (249-206 BC), during whose reign the Great Wall of China appeared, used thick rice water for his secret letters, which, after drying the written hieroglyphs, does not leave any visible traces. If such a letter is slightly moistened with a weak alcohol solution of iodine, then blue letters appear. And the emperor used a brown seaweed broth, apparently containing iodine, for the manifestation of the letter.

In the 15th century, a Swiss physician and scientistParacelsus made a drawing of a landscape, which, when heated, turned from "winter" into "summer": bare branches of trees were covered with green foliage.

Secret agentsIvan the Terrible wrote their reports with onion juice. The letters became visible when the paper was heated.

Famous spyMata Hari also used secret ink. When she was arrested in Paris, a vial of an aqueous solution of cobalt chloride was found in her hotel room, which became one of the pieces of evidence in the exposure of her espionage activities. Cobalt chloride can be successfully used for secret writing: letters written with its solution containing 1 g of salt in 25 ml of water are completely invisible and appear, turning blue, when the paper is slightly heated.

Secret ink was widely used in Russia by underground revolutionaries. The revolutionaries used cryptography to transfer secret information to each other. The secret text, written in milk between the lines of an outwardly harmless ordinary letter, was revealed when the paper was ironed with a hot iron. The tsarist secret police knew about this secret correspondence and successfully read it.

In 1878Vera Zasulich shot at the Petersburg mayor Khrenov. The jury acquitted Zasulich, but the gendarmes tried to arrest her again as she left the courthouse. However, she managed to escape, informing her friends in advance of the plan to escape at the end of the trial, regardless of any of his decisions. A note with a request to bring some of the clothes contained information on the back of the sheet, written with an aqueous solution of ferric chlorideFeCl 3 ... Zasulich took this substance as medicine. Such a note can be read by treating it with a cotton swab moistened with a dilute aqueous solution of potassium thiocyanate: all invisible letters will turn blood red due to the formation of an iron thiocyanate complex.

Members of a secret organization"Black redistribution" also used invisible ink in correspondence. The secret letters were written with a diluted aqueous solution of copper sulfate. The text written in such ink appeared if the paper was held over a bottle of ammonia. The letters turn bright blue due to the formation of the copper ammonia complex.

Lenin used lemon juice or milk for secret writing. For the manifestation of the letter in these cases, it is enough to hold the paper for several minutes over the fire.

DuringWorld War II The military used various substances for the covert transmission of military reports, including copper sulfate (manifested by sodium iodide), ferrous sulfate (sodium carbonate), sodium chloride, i.e. common table salt (manifested by silver nitrate). Often, bubbles with such substances were hidden in completely unexpected places - keys, doorknobs, switches, etc.

In 2006, two researchers from the University of Michigan uncovered the secret of invisible messages used by Germanspecial services (Stasi). A sheet of paper impregnated with cerium oxalate was placed between two blank sheets of white paper. After that, a message was written on the top sheet, which was then transferred to the bottom sheet. For the message to appear, it was necessary to process the "letter" with a mixture of magnesium sulfate, hydrogen peroxide and several other substances, after which the hidden message appeared in orange.

Today there is a special ink that only develops under ultraviolet light, which is used in the manufacture of paper money. Another area of application of such ink is various public events, discos in nightclubs as passes, a pen for making school cribs. A number of household chemicals glow in ultraviolet light, so they can also be used as ink. For development, you can use ultraviolet flashlights, miniature currency detectors and even parts of copiers (lamps with an ultraviolet spectrum of radiation are often used there).

2.Practical part

Having analyzed the studied theoretical material, let's move on to the experimental part of my project. I have identified the following as the main criteria when choosing a particular recipe for making ink:

1) ink must be safe to manufacture and use

2) the constituent components of the ink must be available

3) ink must be environmentally friendly

4) the ink must have a scope

During the experiment, I will adhere to the following plan:

1) preparation of the components necessary for the manufacture of ink

2) manufacture of ink in accordance with the recipe;

3) the use of the received ink for writing.

Since in the theoretical part of the project it was determined that all existing inks can be classified into persistent, emerging and disappearing, I will produce ink in accordance with this classification.

2.1. Resistant ink

While studying theoretical sources, several recipes for resistant ink have been identified. For research, 2 recipes were selected, since the constituent components of this ink are available, safe, and the process of making the ink itself is simple.

2.1.1. Recipe number 1 « A mixture of soot and oil "

In the sources available to me, the ratio of the components of this recipe was not found, therefore it was decided to experimentally establish the necessary proportion of the components (soot and vegetable oil). I suggested that you first mix the components in a 1: 1 ratio. However, the resulting mixture turned out to be too thick and did not come off the pen well, so it was rather difficult to write anything with such thick ink. By adding another part of vegetable oil, I got a thinner ink that easily came off the pen, but left blots and smudged. It was decided to add 1 more part of soot to this mass. With a ratio of 1 part soot to 1.5 parts vegetable oil, ink was obtained that easily came off the pen and did not cause difficulties in writing.

Table No. 2

Components

ink

Ratio

components

Ink requirements

Do not corrode the feather

No sediment

in the inkwell

Easy to get off

from the pen

Color saturation

Soot,

vegetable

butter

1:1

1:2

2:3

2.1.2. Recipe number 2 "Broth of oak bark,

solution of ferrous sulfate, PVA glue "

The manufacturing process for this ink recipe is more complicated and time consuming. First, I prepared a decoction of oak bark. To do this, he poured 200 ml of cold water bought in a pharmacy (1 tsp), brought to a boil, boiled for 20 minutes. Then the resulting broth was cooled, filtered. To make a solution of ferrous sulfate, I used the ratio of water and salt presented on the package (1: 1). Then he mixed in equal proportions a filtered broth of oak bark, a solution of ferrous sulfate and PVA glue. The resulting mixture turned out to be too thick and viscous and could hardly come off the pen, so it was decided to add another part of the oak bark broth to the resulting composition. After which the ink mass became suitable for use.

Table No. 3

"Changing the quality of ink when changing the ratio of the composition of the components"

Components

ink

Ratio

components

Ink requirements

Do not corrode the feather

No sediment

in the inkwell

Easy to get off

From the pen

The thinnest line can be driven

Color saturation

Decoction of oak bark, solution of ferrous sulfate,

PVA glue

1:1:1

2:1:1

2.2. Developing ink

A significant number of developing ink recipes have been found in the sources I have analyzed. Most of the components of this ink are available and safe to use.

2.2.1. Recipe No. 3 "Onion Juice"

The recipe for such ink is quite simple: you just need to peel the onion (preferably large and juicy) and squeeze the juice out of it manually or using a press. The only difficulty in making and using these inks is that they have an unpleasant odor and cause watery eyes.

writing heat

2.2.2. Recipe No. 4 "Lemon Juice"

Similar to the ink described above - ink made from lemon juice. They are also available and easy to make and use.

writing heat

2.2.3. Recipe number 5 "Concentrated baking soda solution"

I have also tested ink made from a concentrated baking soda solution. In order to make this ink, it is necessary to dissolve a significant amount of baking soda in water. In my experiment, the ratio of water to baking soda was2:1.

writing heat

2.2.4 Comparative analysis of the above described inks

Table No. 4 "Comparative table of the qualities of developing ink"

Components

ink

Ratio

components

Ink requirements

Do not corrode the feather

No sediment

in the inkwell

Easy to get off

from the pen

The thinnest line can be driven

Color saturation

Onion juice

1:1

+ -

Lemon juice

1:2

+ -

Concentrated baking soda solution

2:1

+ -

2.2.5. Recipe number 6 Spy Ink

1.Pour one tablespoon of starch into a metal bowl or small saucepan.

2.Pour one glass of cold water and mix thoroughly.

3.Heat the resulting starch solution over low heat for 10-15 minutes, stirring thoroughly and breaking lumps, do not allow boiling.

4. We will see how the solution thickens and becomes like a liquid colorless jelly.

5. The paste is ready - this is the "ink". They can be used to draw a "message to a friend" on paper. When the paper is dry, the pattern will “disappear”.

6. To develop it, you need “iodine water” (20-30 drops of iodine in half a glass of water): the paper with the message must be sprayed with a spray bottle with iodine water.

result the next day

2.2.6. Recipe No. 7 "Ink from milk"

The recipe for this ink has been known for a long time; this ink has been used for a long time by underground revolutionaries. However, none of the recipes indicated the fat content of milk, so it was decided to try milk with different mass fractions of fat as ink. The results of the experiment are shown in the table.

Table No. 5

Changes in the quality of ink when changing the fat content of milk

Mass fraction of milk fat

Ink requirements

Not

eat a feather

No sediment in the inkwell

Easy to get off

from the pen

The thinnest line can be driven

Color saturation

1,8%

3,2%

10%

Since one of the requirements for ink is the ability to draw the thinnest line with such ink, a nib with a thin pointed end was used in the experimental part of the study. Thus, a thin line was drawn, the ink easily came off the pen, however, when heated, not all of the text appeared, but mostly only the final part of the text, since by the end of the work, droplets of milk accumulate and the drawn lines become thicker.

It is also interesting to note that not all of the milky ink was developed. It was assumed that the higher the fat mass fraction of milk, the brighter the "milk" ink appears when heated. Therefore, it is not surprising that the text written with 1.8% milk did not appear at all. As the mass fraction of fat increases from 3.2% to 6%, the text becomes brighter. However, the text written with Toptyzhka milk with a fat mass fraction of 3.2% practically did not appear. Only some elements of the letters are faintly visible.

It was decided to re-experiment with milky ink using a wide nib. The results of the experiment showed that with an increase in the mass fraction of milk fat, the color saturation of the "milk" ink increases. However, as in the first experiment with “milk” ink, ink from “Toptyzhka” milk did not appear as clearly as ink from milk with a similar mass fraction of fat.

Milky ink recipes indicated that they appear when heated under a lamp, on a battery, or when paper is steamed with an iron. It should be noted that the text written with this ink appeared only under the influence of the heat of a hot iron.

In addition to milky ink, other inks can also be used. Some of the more readily available are ink made from onion juice.

2.3. Disappearing ink

Of all the recipes for endangered ink I found, one was chosen for the experimental part of the study for reasons of affordability and safety.

Recipe number 8 "Dextrin, iodine alcohol solution"

The only difficulty in making this ink was the dextrin production. Turning to the Internet resources, I found out that "dextrin is a polysaccharide obtained by thermal processing of potato or corn starch."

For the manufacture of dextrin, starch, a heating device, and dishes for calcination are needed. An oven is usually used as a heating device. Dishes - a baking sheet from the oven is most convenient, but you can also use a frying pan. The starch is evenly distributed over the surface and placed in the oven at the very top. I bring the temperature in the oven to 200C and hold it for an hour and a half. It must be mixed well from time to time so that it does not melt and collect into lumps. The resulting dextrin is usually yellowish brown in color. The starch may not completely decompose, but this does not in any way affect the quality of dextrin and its properties. Then 1 tsp. I mix dextrin with 50 ml of iodine alcohol solution, and the ink is ready.

Table 6

"Quality of Disappearing Ink"

Components

ink

Ratio

components

Ink requirements

Do not corrode the feather

No sediment

in the inkwell

Easy to get off

from the pen

The thinnest line can be driven

Color saturation

Dextrin, iodine alcohol solution

1h spoon

Dextrin: 50 ml of iodine alcohol solution

3.Results and conclusions

In the course of my research, I was able to establish that the first ink was invented in ancient times. The recipes for making ink were constantly changing in accordance with the natural materials that were available in each specific area, and improved in connection with the development of science and technology.

A variety of recipes for making ink have come down to us. Their study made it possible to classify ink into stable, emerging and disappearing. Many inks can be made at home, but not all inks are, in my opinion, safe.

All inks I make have been evaluated according to the following criteria for ink: affordability, safety, color saturation and fastness, ease of use. The maximum score for each criterion is 10 points, the minimum is 1 point. The ones that best meet these requirements are “milk” ink, then ink made from soot and vegetable oil. The least satisfying ink is ink made from a copper sulfate solution.

Thus, all the tasks of the project have been solved, the goal has been achieved. The hypothesis I put forward at the beginning of the project was confirmed.

It seems promising to create a creative project using more ink available for making at home.

4.List of literature

Dietrich A., Yurlin G., Koshurnikova R. Why Much. - M .: Pedagogika, 1988 .-- 384 p.

Ozhegov S.I. Dictionary of the Russian language. - Publishing house, 24th rev. - M .: Peace and education, 2003. - 895 p.

That which no longer exists // School stories. Children's encyclopedia. - M., 2010, No. 10. - S. 35-38.

I get to know the world: Children's encyclopedia. Chemistry / Auth.-comp. L.A. Savina, - M .:ACT, 1997 .-- 448 p.

E.L. Nemirovsky A journey to the origins of Russian typography. - M .: Education, 1991 .-- 224 p.

Yurlin G. About notebook and hag, pencil and desk. - M .: Children's literature, 1983.-64 p.

How to prepare invisible ink? / U. Scanwork. - 2011. - No. 9. - P. 56.

Tereshin A. Nostalgia for the inkwell // Kalina Krasnaya. - 2012. - No. 4. - S.