Teacher Xu, Please Take Care of the Reckless Students in Your Class

Extremely humble!

Qu Mingliang is the most humble teacher.

He immediately said, "At the 14 World Materials Conference, a cloud-like, smoke-like, light and ethereal ultra-light substance caused a sensation. This is the lightest solid in the world..."

Wei Minghai, "That's it? Teacher, are you talking about aerogel? The lightest solid in the world, its density is only one-sixth of that of air."

"Put it on the stamens, and the stamens are hardly deformed."

"This kind of thing was made in 1931, it wasn't 14 years old that it was noticed."

Qu Mingliang was dumbfounded, "Mr. Xu told you again?! Mr. Xu, why don't you give any way to survive, teach everything!?"

"Then how did he make this thing? He certainly didn't teach you! You can't get involved, can you?!"

Before he could finish speaking, He Ruohua raised his hand weakly, "Mr. Qu, is the production process divided into two steps?"

"Step [-]: Preparing the wet gel."

"Step [-]: Dry the wet gel by a special technique."

Qu Mingliang's face darkened.

"The most traditional preparation method for wet gels is the sol-gel method."

"The compound containing highly chemically active components is dispersed in a solvent, and undergoes a hydrolysis reaction to generate active monomers, which polymerize to form a sol, which in turn generates a gel with a certain spatial structure."

"The gel produced at this point is somewhat similar to jelly, and then the jelly-like gel is further dried to obtain the aerogel."

"Due to the effect of surface tension, under normal conditions, the volatilization of the liquid in the gel will cause the fragile skeleton of the gel to collapse."

"Drying by freeze-drying can solve this problem. The wet gel is frozen at low temperature and then dried under vacuum."

"Due to the freezing process, the liquid in the gel has been transformed into a solid, which is then detached from the gel skeleton in the form of sublimation in a vacuum environment..."

Qu Mingliang just clenched his molars, "Mr. Xu, Mr. Xu, can't you just keep it and teach less?"

After regaining his senses, Qu Mingliang said with pain, "He Ruohua, do you know why you are in a vacuum environment?"

Qu Mingliang decided that it was impossible for anyone to know this little knowledge point.

Can--

He Ruohua replied indifferently, "In this way, the problem of skeleton collapse caused by liquid volatilization can be avoided, and the aerogel we expect can be obtained."

"These are Teacher Xu's original words, I just repeated them."

"Right? Teacher Qu."

Qu Mingliang, "Pfft—"

All the students, "Uh..."

"Teacher Qu, go ahead! You only said two!"

Qu Mingliang, "Don't say it! Say one, you know, say two, you also know!"

Luo Pingting, "Mr. Qu, but we don't necessarily know about the following three! Tell me about it!"

"What are the remaining three? We're a little curious."

Shi Leiluo said, "Mr. Qu, tell me, do we know?"

Qu Mingliang bit the bullet, "Are you sure that Teacher Xu hasn't talked to you about these five anti-physics things?"

Everyone shook their heads in unison.

Qu Mingliang, "That's weird! Then how did you know?"

Qian Mengmeng, "I said it! Teacher Xu asked a question before, and it will be involved. We asked a few more questions out of curiosity, and Teacher Xu said a few words casually."

Is it casual?

Did you even talk about the production process?

A mask of pain gradually appeared on Qu Mingliang's face.

Classmates, "Mr. Qu, please talk about it!"

.......