How to make indelible ink at home. Why is the ink color traditionally blue in pens, but 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 the writing of secret letters is interesting in modern times, as well. invisible ink exists and can be made at home.

The purpose of our work: the 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 about the properties of different substances. Make cute 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.

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

From history In ancient times, people made ink from ... cuttlefish. Cuttlefish and octopuses have a special ink bag, from which the animals release an “ink bomb” in a moment of danger - for disguise. Based on these ink bags, they 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 marks. But if such a letter is slightly moistened with a solution of iodine, then you can read it.

From the history of V. I. Lenin dipped a pen into milk and wrote to them on a piece of white paper. The milk was allowed to dry, after which there was no trace of the letters. Then Ilyich heated the paper over the glass of the lamp, and the writing on it clearly showed through.

From history Back in the last century, the great inventor Edison came up with ink for the blind. It was worth writing a text with them and waiting a bit, as the paper in those places where the letters were inscribed hardened and rose, forming a relief.

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

Types of ink Chemical ink Photosensitive ink Fluorescent ink Thermal ink Moisture sensitive ink

The use of invisible ink in modern times

Preparation of invisible ink from lemon Equipment: lemon, cup, brush, paper. Squeeze the juice from the lemon 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 in lemon solution is faintly visible on white paper. When heated, weakly pronounced letters appear, which is not entirely good. The smell of lemon is almost not felt.

Preparation of invisible ink from onions Equipment: onion, gauze, cup, brush, paper. Apply onion juice with a brush on paper, wait for drying. When dried, onion juice is a little noticeable on paper, and has a not very pleasant smell. We will manifest in the same way - by heating. Onion juice darkens when exposed to heat, and the ink becomes visible, turning brown.

Conclusion: Sympathetic onion ink is not ideal, due to the strong smell.

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

Conclusion: milk is ideal for cryptography, no traces remain on paper at all, not without reason Lenin and his associates used this method.

Preparation of invisible ink from soda Equipment: soda, cup, 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. A secret letter is also very simple: 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 is the best!

Conclusion: this sympathetic ink has a long shelf life, there is no smell, the inscription appears best when heated.

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

Conclusion: the inscription with rice water is clearly visible on white paper, so this is ideal for cryptography. The letters are clearly visible. The smell of the broth is almost not felt. Easy to prepare, but not stored for long. Dries quickly, bright blue color.

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

Conclusion: the inscription with copper sulphate 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, cup, brush, paper. We intensively mixed the mixture of oil, ammonia and water until a homogeneous mass was obtained. The inscription was applied with a brush on a sheet of paper, the paper was dried in the air. Then the paper was dipped into the water. Immediately, transparent patterns appeared on the sheet of paper.

Conclusion: the inscription is clearly visible on paper. The letters are clearly visible. There is a smell of ammonia. 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, slightly pronounced Quick preparation, medium shelf life Medium onion Slightly noticeable on paper Yes, strongly pronounced Long cooking Medium soda On white it is imperceptible, on yellow it is very noticeable No Easy to use, not spoils Pronounced 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 congee Weakly visible on paper None Long cooking time, short shelf life Highly pronounced blue vitriol Little visible on paper Weakly pronounced Quick preparation and long storage, quickly developed Highly pronounced Wiedemann's solution Weakly visible on paper Weakly pronounced Long cooking time, long shelf life, long cooking time Above average

Conclusions During the experiment, it was found that the most suitable home-made invisible ink can be considered soda or starch ink. They can even be refilled in a fountain pen, as they do not deteriorate. And this ink appears brighter and more uniform than other invisible inks that I have obtained and examined.

Safety precautions You can write and read spy emails only if you strictly observe safety precautions!!! 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 you need to immediately destroy all evidence!

Conclusion We have solved all the tasks assigned to us: - learned what invisible ink is; - studied the history of invisible ink; - learned about the types of invisible ink and how to obtain them; - found out that it is easiest to make heat-sensitive ink at home; - created sympathetic ink from easily available household substances. Based on our observations, we concluded that inks made from different substances need different ways of developing them.

Thank you for your attention!

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Full title of 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 tasks of the work
1.3. Research methods

Main part……………………………………………………… 5 - 9

2.1. History of steganography and cryptography methods

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 baking soda.

3.5. Preparation of invisible ink from rice water.

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

3.7. Preparation of moisture sensitive ink.

4. Safety precautions……………………………………………………. sixteen

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

6. References…………………………………………………………. nineteen

7. Applications…………………………………………………………………. 21

Introduction

Relevance of the research topic

Mobile phones have become part of our lives, like televisions or computers. Children's exposure to cell phones increasingly occurs in early childhood.

Personally, I got a cell phone in the first grade of school. My parents gave me my first phone. 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 not only write 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 becomes more important and more difficult. I became 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 became interested: 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 the research work

Hypothesis: we assume thatwriting secret letters is also interesting in modern times, because.invisible ink exists and can be made 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 about the properties of different substances.
Make cute 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. Literature analysis

2. Experiment

3. Surveillance

4. Statistical (processing of received data)

Main part

History of steganography and cryptography methods

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, necessitated a way to hide the contents of written messages from outsiders. There are two main ways of classifying information - steganography and cryptography. Steganography is the concealment of the very fact of the transmission of information. Cryptography is the concealment of the meaning of transmitted information.

Wars contributed to the development of cryptography. Written orders and reports were necessarily encrypted so that the capture of couriers would not allow the enemy to obtain important information.

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

ink

The term "sympathetic" itself was first introduced by the French chemist Lemery in 1675. He gave this name to an aqueous solution of "lead sugar". This was the name of 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 Greek means - sensual, susceptible to influence. Since invisible ink becomes visible only under certain conditions, that's why it got its name.

But there is another assumption. 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 a magnet and iron correspond ("sympathize") with each other, and therefore attract. Or amber corresponds to 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 octopus cousins have a special ink sac from which the animals release an "ink bomb" in a moment of danger - for disguise. Based on these ink bags, they 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 marks. But if such a letter is slightly moistened with an iodine solution, then blue letters appear.
As a child, little Lenin was nicknamed "The Magician" by children. He dipped a clean quill in milk and wrote with it on a piece of white paper. The milk was allowed to dry, after which there was no trace of the letters. Then Ilyich heated the paper over the glass of the lamp, and the writing on it clearly showed through. Twenty years later, in a St. Petersburg prison, Lenin again recalled his childhood. He broke a loaf of black bread, molded inkwells from the crumb, collected a white liquid in them and wrote with it between the lines in books. When the overseer called the authorities to stare at the whims of the German spy, Lenin put the inkwell in his mouth.

The history of ink keeps a lot of interesting things. Back in the last century, the great inventor Edison came up with ink for the blind. It was worth writing a text with them and waiting a bit, as the paper in those places where the letters were inscribed hardened and rose, forming a relief.

Types of sympathetic ink

All sympathetic ink can be divided into appearing and disappearing. The developed ink does not leave a mark on the paper after it dries. Inscriptions or images made with such ink become visible (appear) 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 power, turning into a blank sheet of paper. It's disappearing ink.

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

chemical ink

Chemical inks contain colorless or slightly 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 inks are inks that can appear or disappear when exposed to light. This group includes inks that "disappear" when illuminated and appear again in the dark.

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

Fluorescent ink

This group of inks contains substances capable of luminescence when exposed to ultraviolet radiation. For the development of such ink, the inscription is illuminated with an ultraviolet lamp. After the termination of the ultraviolet, the inscription disappears. Luminescent ink is actively used by the police and special services, as well as students and schoolchildren - during tests or exams. This group of inks belongs to our time.

Thermal ink

The composition of heat-sensitive sympathetic ink includes substances that turn 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 paper is ironed with a hot iron, held over a flame or a very hot electric stove.

Moisture sensitive ink

Invisible inscriptions or images made with moisture-sensitive ink are developed by water or steam.

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 the sticky substance of plants.

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 components almost any substance - blood, saliva, plant juices, soap solutions, acids, bases, salts, salt, sugar, starch, etc. It depends only on the imagination and professionalism of the chemist. Although those specialists who are engaged in methods of manifestation of externally invisible recordings do not stand still.

The use of sympathetic ink is currently 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 on a bribe. This method is still used today.

Also, luminescent elements are present in banknotes, the authenticity of banknotes is checked using an ultraviolet lamp.

And in Japan they made ink that disappears from paper after two days. They are convenient to use when working with a book when you need to make notes and underline. Such pens have already been put up for sale and are even produced by Russian firms. It would be great 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 inks are even used in the inkjet industry. These include: -sympathetic ink, which appear under the influence of ultraviolet radiation;

- disappearing ink, which discolor when heated;

- fluorescent inkthat glow in the dark;

- silver ink, conducting electrical impulses;

- textile ink, which print excellently on fabric;

latex , which include polymers made of artificial latex.

These inks are the future of inkjet printing. Some of these species are already commercially available. These inks appear when heated, treated with reagents.

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

Practical part

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

I decided to try. Here are some recipes that every child can use to make disappearing ink.

1. Making Invisible Lemon Ink

For research, we needed: a lemon, a glass, a brush, paper. Squeeze the juice from the lemon into a glass, add the same amount of water. Dip the brush in a solution of lemon juice and water and write something on paper. After the inscription is made, it must be allowed to dry. To develop the inscription, it is necessary 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, not noticeable when

drying, but dries for a long time, appears as a slightly yellow-brown tint of letters.

Conclusion : Lemon grout is barely visible on white paper, so it's ideal for cryptography. When heated, weakly pronounced letters appear, which is not entirely good. The smell of lemon is almost 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 onion juice with a brush on paper, wait for drying. When dried, the onion juice is a little noticeable on paper, and has a not very pleasant smell, which makes this ink imperfect. We will manifest in the same way - by heating. Onion juice darkens when exposed to heat, and the ink becomes visible, turning brown.

Conclusion A: Sympathetic bow ink is not perfect, because of the strong smell.

3.3 Preparation of invisible ink from milk

Pour milk into a glass. Dip the brush in milk and write it on a piece of white paper. Let the milk dry. From the letters there will be no trace, no smell. Then heat the paper over the candle, and the writing 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 non-uniform, and using a candle is not very convenient and unsafe because you are constantly afraid that the leaf might catch fire, it is much more convenient to use an iron. But the experiment made it possible to prove that the inscription appears from exposure to any heat.

Conclusion : milk is ideal for cryptography, no traces remain on paper at all, not without reason 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 spoiling. This is their advantage over the method of writing with milk or lemon and onion juices. For the convenience of writing with this ink, it is best to fill a fountain pen. But I used, as in previous recipes, a brush. Immediately behind the brush, the water evaporates, and there seems to be nothing on the sheet of paper. The secret writing is also very simple: by exposure to 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 is the best!

Conclusion : This sympathetic ink has a long shelf life, no smell, the inscription is best displayed when heated.Easy to prepare, long shelf life, dry faster, brighter color.

3.5. Preparation of invisible ink from rice water

Let's prepare the rice water first. We write with a brush on white paper, after drying there are no visible marks 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 alcohol solution of iodine and smeared it on the other side, we saw that the letters also appeared. You can simplify the version of these inksand take a saturated solution of starch in water. I used, as in previous recipes, a brush. To read the inscription, the paper should be treated with a weak solution of iodine. As you know, under the influence of iodine, starch turns blue.

Conclusion : The rice water lettering is clearly visible on white paper, so it is ideal for cryptography.Rice contains starch, and starch gives itself out completely in the presence of iodine.The letters are clearly visible. The smell of the broth is almost not felt.Easy to prepare, but not stored for long, dry quickly, color is blue and brighter.

3.6. Preparation of invisible ink with copper sulphate solution

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

Conclusion : copper sulphate inscription is clearly visible on paper, so it is ideal for cryptography. The letters are clear enough.their color is bright blue.

3.7. Preparing Moisture Sensitive Ink

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

Conclusion : the inscription is clearly visible on paper, so it is ideal for cryptography. The letters are clear 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 compile a generalizing table.

Ink Composition	Visibility	Smell	Ease of use	Manifestation
lemon	Moderately noticeable on paper	Yes, mild	Fast preparation, medium shelf life	The average
onion	Hard to see on paper	Yes, very pronounced	Long cooking	The average
soda	On white it is invisible, on yellow it is very noticeable	Not	Easy to use, does not deteriorate	Pronounced
milk	Not visible on paper	Not	Short shelf life	Above average
soda	Not visible on paper	Not	They can be stored for a very long time without spoiling.	The brightest
rice water	Looks good on paper	Not	Long cooking time, short shelf life	Pronounced
blue vitriol	Hard to see on paper	Weakly expressed	Fast preparation and long storage, quickly developed	Pronounced
Wiedemann's solution	Hard to see on paper	Weakly expressed	Long cooking time, long shelf life, long cooking time	Above average

Conclusion. The most suitable homemade invisible inks are baking soda or starch inks. They can even be refilled in a fountain pen, as they do not deteriorate. And this ink appears brighter and more uniform than other invisible inks that I have obtained and examined. Thus, invisible inks made from soda and starch are the best in our experiment.

Safety

It is possible to write and read spy letters only strictly observingsafety precautions !!!

1. If you do not want to iron a letter with letters appearing from heat, but with a mysterious look move it over a candle flame, make sure that the paper does not flare up in your hands. And, of course, do not 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 fascinating process.We have solved all the tasks set before us:

Learned what invisible ink is;

Studied the history of invisible ink;

Learned about the types of invisible ink and how to obtain them;

We found out that it is easiest to make heat-sensitive ink at home;

Created "magic" sympathetic ink from easily available household substances.

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

Not all types of sympathetic (invisible) inks can be obtained at home, mostly only heat-sensitive inks. Since they are easy to develop at home by exposure to heat. Sympathetic ink, which requires chemicals or chemical developers, can only be obtained in a special chemical laboratory.

You can develop invisible recordings at home using candles, lamps, irons, but the most convenient and safe way is using an iron.

During the experiment, it was found that the most suitable home-made invisible ink can be considered soda or starch ink. They can even be refilled in a fountain pen, as they do not deteriorate. And this ink appears brighter and more uniform than other invisible inks that I have obtained and examined. Thus, invisible inks made from soda and starch are the best in our experiment.

Based on our observations, we concluded that inks made from different substances need different ways of developing them. During the experiment, we turned to various sources of information: books, manuals, but mainly the Internet. It is not possible to describe in this paper all methods of preparing sympathetic ink. We have only been able to experiment with substances that are easily found in the home. We have found many recipes that require chemicals that we did not have. But we know for sure that we will continue experiments to create new types of sympathetic ink.

In the course of work, we were convinced 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 their own experiments. We invite you to use our recipes for invisible ink for secret correspondence.

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

Bibliography

Aleksinsky VN Entertaining experiments in chemistry. – M.: Enlightenment, 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. A book on chemistry 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 rewarding activity! And why, you ask, should they be made, 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 he will then draw letters and numbers on paper with his ink, or simply squiggles that he alone understands! And the benefits of such an activity are obvious! Firstly, children love to learn something new and literally “absorb” any information received. Secondly, you must agree that spending time in this way is much more useful than sitting near the TV or computer!

But before proceeding to the description of the ink recipe and how to prepare it, let's dive into history a bit and find out how and when they appeared.

According to archaeologists, the very first ink appeared in ancient Egypt. It was there during the excavations that their oldest cooking recipes were found. According to the description found, scientists managed to find out that the Egyptians used gum to make ink - a thick and sticky juice that is released from cherries or acacias and ash that remained after the burning of 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 III century BC, the Greeks and Romans used several types of ink and even made red! 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 true, now it seems not accidental that in educational institutions only teachers can write with a red pen! This, of course, is a joke and was just 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 grapevine. The ink that was found during the excavations of one ancient Roman city consisted of soot, which was diluted in oil.

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

Well, let's try and prepare the ink. Moreover, on gall ink, their ancient history ends and modern begins. Already in the 19th century, they began to produce alizarin ink, then the natural dye (Marena root) was replaced with a synthetic one, and the next step was fully synthetic modern aniline ink. It is impossible to make these at home. Therefore, we will consider simple recipes and prepare ink from the available ingredients.

● Gall ink

You will need:

Galls (growths on oak branches and leaves)

metal can

Copper sulfate (solution)

Cooking method:

Put 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 iron sulfate solution to the jar to the consistency of ink and insist for several hours

Ink ready

● Oak bark mortar ink

You will need:

oak bark

Iron vitriol (solution)

Cooking method:

Plane oak bark

Boil the chips in water for 15-20 minutes

When the water darkens and becomes dark brown, it is necessary to strain it from the chips.

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 hard to make ink! It remains only to figure out what can be used as an inkwell! Good luck with your experiments!

A few years ago, when I became interested in CISS, I downloaded (for personal use) everything related to CISS from the Internet like a vacuum cleaner, without noting the 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 those who want to conduct such experiments, but for acquaintance, I think it will be useful.

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

1) Recipe of the Institute of Microelectronics and Informatics RAS
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 was widely used. The main component is black chrome dye used in the production of felt boots and tarpaulin boots. Of course, not the most accessible chemical, but if you wish, you can get it. The dye is dissolved in distilled water until completely saturated (i.e., dissolved in water heated to 60-70 degrees "up to the stop" and allowed to cool). After that, glycerin is added. 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 carefully filtered.

Comment: Failed to try. 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, such as foreign-made ink, is suitable. You can also use domestic ones, but only after careful filtration. The cartridge can withstand at least 10 refills with such ink.
Comment: I have not tried and do not intend to, Isoproryl alcohol is a highly toxic substance! There are ways and easier to ruin your health!

3) Recipes of Yachen P. A.) I found in the Radio Amateur magazine 8/96 p. 9 a recipe for preparing ink for an inkjet printer: "INK COMPOSITION. Take the Rainbow ink, add 30% (by volume) ethyl alcohol and 5% glycerin to it. 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 - up to 80. "

Comment:It was on the basis of this recipe that the first experiments were carried out, thanks, Yakhen!
B.) (violet with smoothed dots) Take the Rainbow ink, add 2-3% (by volume) of ethyl alcohol to it. Boil the resulting mixture for 10-15 minutes over low heat and filter through a layer of cotton wool. Comment: The print is really blurry, but you can't leave a cartridge filled with such ink in the printer - they will leak out!

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

Comment: Let's start in order:
It is not necessary to boil the ink at all, moreover, during boiling, part of the alcohol and water will evaporate and, consequently, the viscosity will change!
I DO NOT recommend filtering through cotton wool, it is better to take paper filters at 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 in stages and recipes:

You will need:
Necessary equipment: several flat-bottomed flasks, a measuring cylinder or beaker, glasses, a funnel, ready-made ink containers, 20 ml syringes (if something is missing, any household utensils will do), paper filters with a pore size of 0.9 microns or less ideally 0.3 microns, but you can filter with such) 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 inks for pens can be Parker, for example:-))), alcohol, glycerin, distilled water (if not, boiled water is fine), 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 paint!!! It contains adhesive components that will instantly clog the head!
If you use ink not named in the recipes, they should be boiled, if during boiling they coagulate (coagulate, form a precipitate), such ink cannot be used!
Ink preparation steps
a) prepare the components in the specified way
b) mix all the components named in the recipe in the exact proportion
c) filter the mixture through a filter by gravity or with a pump.
d) fill in the cartridge

| Message Sent 01 April 2006 - 11:38

Continuation

Recipes:(In order of experimentation and improvement)

"Black" ink

*quoted because our domestic black ink RAINBOW
on closer inspection they are somewhat green in color.

№1
1. 27% black "rainbow" ink reduced to 50% by volume
2. 18% alcohol
3. 55% glycerin
4. Characteristics: pale dark green print flowing from the print head

№2
1. 44% black "rainbow" ink reduced to 35% by volume
2. 18% alcohol
3. 35% glycerin
4. 3% AJAKS
Characteristics: rich dark green printing, almost no flow.

№3
1. 47% black "rainbow" ink reduced to 25% by volume
2. 20% alcohol
3. 30% glycerin
4. 3% AJAKS
Characteristics: almost black printing with a shade of dark green, does not flow.

№4
1. 40% black ink "PARKER Quink" stripped down to 30% by volume
2. 30% alcohol
3. 30% glycerin

Characteristics: Intense dark gray print with green tint, almost no bleed
print quality is good (letters are clearer)

purple ink
№1
1. 27% purple rainbow ink
2. 18% alcohol
3. 55% glycerin
Characteristics: pale purple print flowing from serpentine and print head.

№2
1. 45% purple "rainbow" ink reduced to 50% by volume
2. 16% alcohol
3. 35% glycerin
4. 4% AJAKS remedy
Characteristics: purple, slightly blurry print, flowing from the print head.

№3
1. 30% purple "rainbow" ink reduced to 20% by volume
2. 40% alcohol
3. 30% glycerin

Characteristics: high-quality purple, printing, almost no flow.

№4
1. 38% violet "rainbow" ink reduced to 10% by volume
2. 37% alcohol
3. 25% glycerin
4. AJAKS tool can be omitted
Characteristics: dark purple, printing, do not flow.

| Message Sent 01 April 2006 - 11:40

Continuation

Design your recipe!

1. the choice of dye: first of all, the dye that you will use in your recipe should be water-soluble and not pigmented, to check this - drop it on a piece of plain (80g / m) paper, if it soaks it and will stain it on the reverse side, then it will most likely fit. If the ink (dye) remains on one side, and an uncolored liquid appears 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 one more thing - if you decide to choose the colors of Cyan Magnetta Yello (for a color cartridge), don't try it - even the manufacturers of cartridge refills did not succeed, unless you want to constantly print in one color - orange, for example. In the latter case, use Easter or food coloring after boiling and filtering. Attention! If you are using food coloring or other tinting mixtures, read the ingredients on the packaging carefully! Dyes containing molasses, sugar, glue and other foreign components (in addition to 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 in a certain amount of "native ink" ", for example, 3 ml and note the time for which the ink will flow out - this is the ideal to which it will be necessary to adjust the viscosity of home-made ink. 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 products (the latter is preferable because it lowers the viscosity without changing the density of the ink) If you do not have "native ink" left - the viscosity should be about 3 ml in 10 min.

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

Suggested the 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 paper there is a rather deep trace, according to which you can read what is written without resorting to backlighting. How would you fill the printer with such ink? :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. They glow in ultraviolet light, they are not visible in white light.
I met a set of "photos", i.e. with light flowers.
IMHO, it will be not only not easy, but also not profitable.

| Message Sent 05 April 2006 - 19:41 yuha

V&W, I should have posted in this thread about "viscosity".
Anyway.
I support the idea and method of controlling "fluidity" by drop by drop method. Especially since it's professional.
I'll experiment in the next few days.

| Message Sent 07 April 2006 - 22:46 SPAWN

There is an idea to make "invisible" ink. They become visible under the influence of radiation.
Suggested the 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 paper there is a rather deep trace, according to which you can read what is written without resorting to backlighting. How would you fill the printer with such ink? biggrin.gif

I have been visited by a similar idea for a long time, only not "invisible" but transparent fluorescent
visible under ultraviolet light.
Recently C 42 (my little polygon :P) has appeared, it remains 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 coloring (edible), it would be possible to decorate cakes - nice and you can make money on it B)

| Message Sent 15 April 2006 - 01:46

Need a confectionery printer to print on food paper DECOJET EVOLUTION
Decojet Evolution uses wafer or sugar paper and edible ink for printing. In addition, a special carrier, Shocotransfer, is offered for transferring images to chocolate.

The preparation of ink is not associated with 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 dishes, copper or iron cauldrons both for making ink and for filtering, and, finally, glass bottles are needed into which ready-made ink is poured.

In addition to ordinary writing inks, special inks are also produced for copying, hectograph, glass, drafting, linen marks, etc. The production of ink can also include the manufacture of inks for typewriters, stamp pads, etc., since they are in their composition similar to ink.

All manufactured inks must meet the following requirements. They should not act corrosively on the pen, should not give sediment in the inkwell, should not contain highly toxic substances. The ink should flow easily from the pen and be free of insoluble solids so that the finest line can be drawn. In addition, they must be durable and must not be moldy.

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

The ink of the first group is still the most widely used and, moreover, the cheapest. They are prepared mainly from tannic and gallic acids or from substances containing tannin.

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

ink nuts are painful growths on oak leaves, resulting from an injection of a nutcracker.

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

In the manufacture of ink, the main work is the preparation of tannin extracts obtained from the raw material with the help of water; at present, 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, with tannins, can form insoluble compounds. It is best to use rain, snow or distilled water. As thickeners for the preparation of ink, glycerin, gum arabic, gelatin, dextrin, etc. are used. To protect against mold, carbolic acid, salicylic acid, creosote, etc. are used.

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

To improve the quality of ink, ink, etc., it is recommended to add to coloring liquids small amounts of aliphatic volatile organic compounds that contain at least 4 carbon atoms per molecule, such as valeric or caproic acid, alcohol, ether and ketones.

Manufacturing
ink at home
conditions

4th grade student

municipal budgetary educational institution "Lyceum"

Karasev Prokhor Timofeevich

Work manager

Gubina Marina Nikolaevna,

primary school teacher MBOU "Lyceum"

2017

Content

Introduction

Theoretical part

4-9

1.1. The 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 "Soot and oil mixture"

10-11

2.1.2. Recipe No. 2 "Decoction of oak bark, iron sulfate solution, PVA glue"

11-12

2.2. Developing ink

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

2.2.5. Recipe No. 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 the work and conclusions

16-17

Bibliography

Introduction

Last year, pen ink leaked from my jeans pocket. The clothes were ruined, but the "stain" made me wonder: what is the ink made of? What were they made from before? When did ink first appear? Can you make ink at home? Thus, the theme of this project was born.

This work seems 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, inks were made from naturally occurring ingredients, so these inks are more environmentally friendly.

Objective of the project : study the history of ink, 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 stable ink.

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

Hypothesis The project lies in the fact that at the present stage it seems possible to produce ink according to a number of preserved old recipes and find application for them.

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

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

Project object: ink.

Project subject: ink making process.

1. Theoretical part

1.1. The history of the invention of ink

Before presenting recipes for making ink, it is necessary to define what ink is. For this, I turned to the “Dictionary of the Russian Language” by S.I. Ozhegov 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 was subjected to deetymologization very early: ink of different colors has been known since ancient times. "Ink is a coloring liquid for writing." “Ink is a liquid dye suitable for writing and / or creating any images using 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 making ink

Note

Ancient Egypt

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

called "Cyperus Papyrus"

Black ink was used by people of various backgrounds.

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

A mixture of soot and oil

Already known in ancient Greece and China

Ancient Rome

A mixture of soot and oil

Used in painting and writing. Ancient Roman artists made ink from fruit pits, vines, softwood, soot, charcoal, and bone charcoal. Interestingly, even to this day the best black paint is prepared from the soot obtained by burning grape seeds.

Purple and cinnabar - Red "court ink", which was used only for state documents. Even an imperial decree was born, forbidding the use of red ink outside the imperial court under pain of death.

This ink was guarded by special guards. 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 been preserved, consisting almost entirely of the shells of the brandaris mollusk. The bodies of mollusks were removed from the shells and placed in salt water. Then, for three or four days, they dried in the sun, then boiled, and as a result, out of every ten thousand mollusks, they received ... only one gram of paint!

Ancient Russia

Soot with gum (cherry glue), diluted in plain water

This is the so-called "smoked" ink.

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

Their recipe is:

"part of the oak bark, the other alder, half ash, and this put a full vessel of iron or clay and cook with water until the water boils, not all of it is boiled, and the rest of the water is stuck in the vessel, and the packs pour water, boil it on the skin, and put fresh bark and then cook without bark, and put the tin into the boards, tie it up and put the iron in and interfere, and on the third day write.

Ink nut juice, iron sulfate*, glue

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

Germany 1855

german teacherChristian-August Leonhardi invented alizarin ink

Leonhardi's ink was also made from ink nuts, but the inventor added a substance called krapp to them. Krapp is extracted from the roots of the oriental madder plant. Later, a synthetic substitute for krappa was found, and ink nuts were replaced with gallic acid similar in composition to them. So alizarin ink began to be made entirely from artificial substances. Making them has become 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.

Pale gray ink had the following property: as soon as they wrote the 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.

Comparing different ways of making ink, you can do the following:findings :

1. The composition of the 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 lengthy.

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, resistance, etc.).

1.2. Ink Requirements

The main requirements for ink are: :

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

2. The ink should come off the pen easily and be free of insoluble solids so that the finest line can be drawn.

3. In addition, they must be durable and must not be moldy.

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

Additional ink requirements may apply :

1.increased water resistance or resistance to certain solvents;

2.increased thermal, light, frost resistance;

3. the possibility of mixing different colors of the same type of ink to obtain a given shade.

The list of possible additional requirements is not exhausted by the given requirements.

1.3. Disappearing and developing ink

As follows from the above material, the ink was used and is being usedinthe field of writing and paperwork and / or other paper media. In addition, one of the important requirements for ink is its stability, i.e. the ability to maintain the brightness of color in any conditions. However, in the course of studying scientific sources, I found recipes for disappearing and appearing ink.

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

Developing ink is a special type of ink widely used and used in "secret" correspondence. The text written with such ink is developed under the influence of heat, processing with special reagents or in ultraviolet or infrared rays. There are many recipes for such ink.

It is believed that the "secret" ink, which does not leave marks 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 in ancient times. In the 1st century ADPhilo of Alexandria described a method for making "secret" ink fromjuice of ink nuts,for the development of which a solution of iron-copper salt was used.

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

The secret of cryptographyPliny the Elder was to useplant juice. 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 decoction of seaweed, apparently containing iodine, to develop writing.

In the 15th century, a Swiss physician and scientistParacelsus made a drawing of a landscape that, 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 containing an aqueous solution of cobalt chloride was found in her hotel room, which was one of the pieces of evidence in the exposure of her espionage activities. Cobalt chloride can be successfully used for cryptography: the 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 pass secret information to each other. The secret text, written in milk between the lines of a seemingly harmless ordinary letter, appeared 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 St. Petersburg mayor Khrenov. Zasulich was acquitted by a jury, but the gendarmes tried to arrest her again as she left the courthouse. However, she managed to escape, informing her friends in advance about the plan to escape at the end of the trial, whatever his decision. A note asking to bring some of the clothes contained information on the back of the sheet, written in an aqueous solution of ferric chloride.FeCl 3 . Zasulich took this substance as a 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 the iron thiocyanate complex.

Members of a secret organization"Black redistribution" also used invisible ink in correspondence. Secret letters were written with a dilute aqueous solution of blue vitriol. 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 cryptography. To develop the letter in these cases, it is enough to hold the paper for several minutes over the fire.

DuringWorld War II the military has used a variety of substances to covertly transmit military reports, including copper sulfate (manifested as sodium iodide), ferrous sulfate (sodium carbonate), sodium chloride, i.e. common table salt (manifested by silver nitrate). Often vials with such substances were hidden in completely unexpected places - keys, door handles, 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 treat the "letter" with a mixture of magnesium sulfate, hydrogen peroxide and several other substances, after which the hidden message appeared in orange.

Today, there are special inks that appear only 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 cheat sheets. A number of household chemicals glow under ultraviolet light, so they can also be used as inks. For development, you can use ultraviolet flashlights, miniature currency detectors, and even parts of copiers (there are often used lamps with an ultraviolet radiation spectrum).

2.Practical part

After analyzing the studied theoretical material, let's move on to the experimental part of my project. As the main criteria for choosing one or another recipe for making ink, I identified the following:

1) the ink must be safe to manufacture and use

2) the constituent components of the ink must be available

3) The ink must be environmentally friendly

4) ink must have scope

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

1) preparation of components necessary for the manufacture of ink

2) production of ink according to the recipe;

3) the use of the received ink on the letter.

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

2.1. Resistant ink

When studying theoretical sources, several recipes for stable ink were identified. For the study, 2 recipes were selected, since the constituent components of this ink are available, safe, and the ink manufacturing process itself is simple.

2.1.1. Recipe No. 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 experimentally to 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 writing something with such thick ink seemed rather difficult. By adding another part of vegetable oil, I got a more liquid ink, which easily came off the pen, but left blots and smeared. It was decided to add 1 more part of soot to this mass. At a ratio of 1 part soot to 1.5 parts vegetable oil, ink was obtained that easily left the pen and did not cause difficulties in writing.

Table number 2

Components

ink

Ratio

components

Ink Requirements

Do not corrode the pen

Doesn't leave sediment

in an inkwell

Easily come off

pen

Color saturation

Soot,

vegetable

butter

1:1

1:2

2:3

2.1.2. Recipe number 2 "Decoction of oak bark,

ferrous sulfate solution, PVA glue "

The manufacturing process for this ink recipe is more complex and time consuming. First I prepared a decoction of oak bark. To do this, poured oak bark (1 tsp) bought at the pharmacy with 200 ml of cold water, 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 decoction of oak bark, a solution of iron sulfate and PVA glue. The resulting mixture turned out to be too thick and viscous and hardly left the pen, so it was decided to add one more part of the decoction of oak bark to the resulting composition. After that, the ink mass became suitable for use.

Table No. 3

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

Components

ink

Ratio

components

Ink Requirements

Do not corrode the pen

Doesn't leave sediment

in an inkwell

Easily come off

pen

You can carry the thinnest line

Color saturation

A decoction of oak bark, a solution of iron sulphate,

PVA glue

1:1:1

2:1:1

2.2. Developing ink

In the sources I analyzed, a significant number of recipes for developing ink were found. Most of the components of this ink are readily 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 the manufacture and use of these inks is that they have an unpleasant odor and cause tearing.

write heat up

2.2.2. Recipe number 4 "Lemon juice"

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

write heat up

2.2.3. Recipe number 5 "Concentrated baking soda solution"

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

write heat up

2.2.4 Comparative analysis of the above inks

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

Components

ink

Ratio

components

Ink Requirements

Do not corrode the pen

Doesn't leave sediment

in an inkwell

Easily come off

pen

You can carry the thinnest line

Color saturation

onion juice

1:1

+ -

Lemon juice

1:2

+ -

Concentrated baking soda solution

2:1

+ -

2.2.5. Recipe No. 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. We heat the resulting starch solution over low heat for 10-15 minutes, mixing thoroughly and breaking up 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 draw a “message to a friend” on paper. When the paper dries, the pattern will "disappear".

6. To manifest it, you will need "iodine water" (20-30 drops of iodine per half a glass of water): spray paper with a message with iodine water.

result 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 by underground revolutionaries for a long time. 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

Change in ink quality when changing the fat content of milk

Mass fraction of milk fat

Ink Requirements

Not

corrode pen

Does not leave sediment in the inkwell

Easily come off

pen

You can carry the thinnest line

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 pen with a thin pointed tip was used in the experimental part of the study. Thus, a thin line was drawn, the ink easily left the pen, however, when heated, not all of the text appeared, but for the most part only the final part of the text, since by the end of the work, milk droplets accumulate on the pen and the drawn lines become thicker.

It is also interesting to note that not all "milk" ink appeared. It was assumed that the higher the mass fraction of milk fat, 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 mass fraction of fat 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 tip nib. The results of the experiment showed that with an increase in the mass fraction of milk fat, the color saturation of "milk" ink increases. However, as in the first experiment with "milk" ink, the ink from "Toptyzhka" milk did not appear as clearly as the ink from milk with a similar mass fraction of fat.

The recipes for "milk" ink indicated that they appeared when heated under a lamp, on a battery, or when paper was 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 "milk" ink, other inks can also be used. One of the most affordable is ink made from onion juice.

2.3. Disappearing ink

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

Recipe number 8 "Dextrin, alcohol solution of iodine"

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

For the manufacture of dextrin, starch, a heating device, and baking dishes are needed. An oven is usually used as a heating device. Dishes - the most convenient is a baking sheet from the oven, but you can also use a frying pan. 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 stand for an hour and a half. It needs to be stirred well from time to time so that it does not melt and does not gather into lumps. The resulting dextrin is usually yellowish brown in color. Starch may not completely decompose, but this does not affect the quality of dextrin and its properties. Then 1 tsp. I mix dextrin with 50 ml of an alcohol solution of iodine, and the ink is ready.

Table No. 6

"The Qualities of Disappearing Ink"

Components

ink

Ratio

components

Ink Requirements

Do not corrode the pen

Doesn't leave sediment

in an inkwell

Easily come off

pen

You can carry the thinnest line

Color saturation

Dextrin, alcohol solution of iodine

1 hour the spoon

Dextrin: 50 ml alcohol solution of iodine

3. Results of the work and conclusions

In the course of the study, 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 those natural materials that were available in each particular territory, and improved in connection with the development of science and technology.

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

All inks I've made have been evaluated on the following ink criteria: availability, safety, color saturation and fastness, and ease of use. The maximum score for each criterion is 10 points, the minimum score is 1 point. To the maximum extent corresponding to these requirements, is "milk" ink, then the ink made from soot and vegetable oil. The ink that least meets the requirements for them is ink made from a solution of copper sulphate.

Thus, all the tasks of the project are solved, the goal is achieved. The hypothesis put forward by me at the beginning of the project was confirmed.

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

4. List of references

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

Ozhegov S.I. Dictionary of the Russian language. - Ed., 24th revision - M .: Mir and education, 2003. - 895 p.

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

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

Nemirovsky E.L. Journey to the origins of Russian book printing. - M.: Enlightenment, 1991. - 224 p.

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

How to prepare invisible ink? /U. Scanwordenok. - 2011. - No. 9. - S. 56.

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