The adsorption capacity of activated carbon is so abnormal that if you throw three or two pieces of activated carbon into a bowl of dark ink, the ink will become watery in the blink of an eye.

There was a bowl in front of Guan Yu. In one hand, Guan Yu took a pen and poured ink into the bowl. In the other hand, he grabbed a handful of charcoal blocks. From time to time, he dropped a few drops of ink into the bowl, and then threw a piece of charcoal in. He watched the charcoal quickly absorb the ink.

Guan Yu enjoyed the game so much that he was amazed.

The successful preparation of activated carbon is a major breakthrough. Having activated carbon means having a super powerful decolorizing agent. Li Mengxi can't wait to see how white the pulp can be when using activated carbon to decolorize.

After a lot of busy work, a new pot of paper pulp was started to boil. When it was getting late, the fire was stopped and the pot was started, and the pulp cooking was completed.

When the paper pulp cooled slightly, Li Mengxi immediately threw the activated carbon bag wrapped in linen into the pot.

After a period of time, the decolorization was completed and dozens of bags of activated carbon were used, estimated to be several kilograms in total.

Li Mengxi and Guan Yu leaned over the pot to take a look, and they could tell at a glance that the pulp in the pot was unprecedentedly clear and transparent.

Seeing how clear the paper pulp was, Li Mengxi's eyes lit up. He raised his head and looked at Guan Yu, whose eyes were also bright.

Immediately, without any communication, Li Mengxi and Guan Yu immediately got busy.

Guan Yu went to get the gauze net for catching the pulp, and Li Mengxi went to get the spoon to hold the pulp, and the tools were found. The two of them cooperated in a tacit understanding, and the pulp and net were collected in one go.

Soon, the paper pulp dried quickly after being baked by fire for a while, and Guan Yu peeled off the new paper.

"Let me see, let me see!" Li Mengxi jumped to see first.

Guan Yu smiled and handed the paper to Li Mengxi.

When you take the paper into your hands, in terms of feel, it is not much different from the paper made before. However, this new paper has no color at all. It is pure and white in color and looks extremely beautiful.

Li Mengxi thinks that the best paper should be the kind of white paper that is as white as wall putty, can reflect light, and has no other colors at all.

This time, activated carbon was used to absorb pigments in the paper pulp. As expected, the paper turned a lot whiter. But looking carefully, Li Mengxi found that although the paper was whiter and no longer variegated, and although the whole body was of the same color, the color of the paper was still a little off.

The color is grayish-yellow, which should be the original color of hemp fiber.

Activated carbon can absorb pigments from other impurities such as colloids, but hemp fiber itself also contains pigments, and the pigments in the fibers are difficult to remove.

This made Li Mengxi dissatisfied again. He scratched his head, how to remove the pigments in cellulose. Activated carbon is a physical color removal method, and activated carbon is almost the strongest physical color removal method.

Since physical means cannot remove the color from cellulose, what about chemical means? Can chemical means remove the color? What chemical means should be used, what is the principle, and what kind of chemicals should be used? Li Mengxi has no idea at all.

Let’s reason again as before, papermaking is a low-level industry. Since it is a low-level industry, it does not use too complex chemical technology, nor does it use too complex chemicals. Since it does not use too complex chemicals, then

Suffice it to say that low-level chemicals are used.

Low-level chemicals include acid and alkali salts, grease, alcohol, and the like.

But in the previous test, acid and alkali were also used. The acid was replaced by acetic acid, and the alkali was replaced by plant ash solution. Both acids and alkali were used, but the pigment in the cellulose could not be removed.

This shows that the chemicals that can remove color in chemistry are not simple acids or bases, but other chemicals.

What will it be……

Guan Yu saw Li Mengxi holding the paper and looking at it for a long time. Seeing Li Mengxi's brows gradually wrinkled, Guan Yu teased, "Xi'er, the paper this time is good enough, right?"

After coming back to his senses, Li Mengxi glanced at the piece of paper in his hand, which was technically a blank sheet of paper. He frowned and said, "Although it's good, it's not the best. It can be better."

Sure enough, it is so again.

Guan Yu knew that Li Mengxi was very picky about paper, and Guan Yu laughed happily.

In Guan Yu's opinion, the paper made in the past was good enough, but it was far from comparable to this time. After using the so-called activated carbon this time, the pulp became clear and transparent, and the paper made was completely jade-white.

The background color was slightly green linen, and the whole paper had no color at all from top to bottom. Guan Yu asked himself, such a good paper, he would be willing to buy it even if it cost five cents.

A piece of paper can be sold for five cents, and the profit from luxury goods is no more than that.

It was getting dark, so Guan Yu continued to make paper while there was still some light. He wanted to finish the entire pot of paper pulp.

Li Mengxi was lying on the side of a short table, his chin resting on his hand, his brows furrowed, and he was thinking.

He was thinking about how to get rid of the remaining pigments in the fiber. The key is chemicals. In addition to acids and bases, what are the common and easily available chemicals? He might as well try them all one by one.

According to previous experience, the glue removal with alkali solution can be done by hard test, so there is a high probability that chemical bleach can also be used to remove the glue.

It is now the end of the Eastern Han Dynasty, and the common chemicals that can be found are limited. The ones that are easy to find are acids and bases. However, it has been determined that acids and bases cannot remove color, so there are not many options left.

Common non-acid and non-alkali substances, Li Mengxi thought of salt water, oil, alcohol, etc.

After thinking about it, Li Mengxi directly eliminated the alcohol. For no other reason, making wine requires food. Food is very precious. If alcohol is used to make paper, it will be wasteful and expensive.

Paper must be low-cost in order to facilitate its promotion. If paper is more expensive than cloth, it will run counter to the original intention of papermaking.

In short, even if alcohol can decolorize, I definitely don’t use it because it’s too damn expensive.

Regarding whether alcohol can decolorize, Li Mengxi really remembered some relevant knowledge. In junior high or high school biology class, there was an experiment on extracting chlorophyll. The experimental steps were to put the fresh leaves into a stone mortar and grind them gently, and then pour some

With high concentration of alcohol, chlorophyll will be dissolved into the alcohol. Then put the filter paper in and you will find that the pigment will be adsorbed to the filter paper, and the pigment will be layered up and down on the filter paper, shallow at the top and deep at the bottom.

Thinking of this, Li Mengxi remembered that alcohol can indeed extract pigments, that is, dissolve pigments in plants into alcohol.

This chapter is not over yet, please click on the next page to continue reading! In the same way, the pigments in chlorophyll can be extracted, and the pigments in hemp fiber should also be extracted.

Li Mengxi realized that it was feasible to use alcohol for chemical decolorization, but the cost was still a big problem.

I vaguely remember that high-concentration alcohol is needed to extract chlorophyll. Similarly, if you want to extract the pigments in hemp fiber, you also need to use high-concentration alcohol. Ordinary wine is already too expensive. Using high-concentration alcohol again will make the cost skyrocketing.

Unless the cost can be reduced, the alcohol decolorization method has no practical value.

Li Mengxi thought hard for a long time, and his brows furrowed deeper and deeper. He thought that alcohol acts as a solvent when extracting pigments, that is, alcohol itself does not participate in the reaction. This means that if there is a way to recycle alcohol, then a barrel of

Alcohol can be reused for one year. A barrel of high-strength alcohol is expensive, but if a barrel of high-strength alcohol can produce hundreds of tons of high-quality pulp, the cost will be spread out. In fact, the cost is not high.

Li Mengxi's brows relaxed. He thought of making an oversized sealed box, filling it with high-strength alcohol, and then stuffing the cooked plant fibers into the alcohol and soaking them for a few days. After a few days, he opened the box and took out the plant fibers.

Come.

Then, you can pour the removed plant fibers into clean water and soak them for a period of time. This process is to soak out the residual alcohol that has penetrated the fibers.

Afterwards, the residual alcohol can be collected by distillation.

After such a process, the pigments in the plant fibers that are difficult to remove will be dissolved in the alcohol. By then, white and reflective paper should be produced.

Li Mengxi took a look at the entire alcohol decolorization process. It requires a sealed decolorization tank, a large amount of alcohol, and a pool of high-strength liquor. This is as luxurious as a wine pool and a forest of meat. How rich you have to be to get a pool of high-strength liquor.
Chapter completed!