On his first day back at HKUST, Wu Bin was quickly called to the office by Director Jiang and asked him to start preparing for graduation.

"Ah, so fast?" Wu Bin thought that there would be a buffer period or something, but he didn't expect that Director Jiang would tell him about graduation as soon as he came back.

"What's the point of delay, and I mean you can start working on your dissertation, do you think it's going to be soon?" Director Jiang asked Wu Bin.

"Not really." Wu Bin shook his head.

"Then you can start preparing." After speaking, Director Jiang added: "But don't think that just because you can graduate, you can write a random errand." ”

"Of course not." Wu Bin hurriedly shook his head.

"Well, I'm sure you're not the one who would do such a thing, so go ahead and get busy with yours."

Walking all the way back to the laboratory with the question of what topic to choose as a graduation thesis, Wu Bin was about to change his clothes, when he heard Feng Jinhui call out to him and said: "Two days ago, people from the scientific examination department were looking for you, and I said that you were not there, so he left a phone number for me." ”

"People from the scientific research department are looking for me?" Wu Bin asked very surprised.

The Department of Scientific Archaeology is a very distinctive department of HKUST, which uses modern technology to analyze ancient remains to obtain a wealth of potential information, and then combines archaeological methods to explore human history.

"But I don't think I've had any interaction with anyone in this department......

But since everyone was looking for them, maybe there was something urgent to find him, so Wu Bin picked up his mobile phone and called the other party.

On his first day back at HKUST, Wu Bin was quickly called to the office by Director Jiang and asked him to start preparing for graduation.

"Ah, so fast?" Wu Bin thought that there would be a buffer period or something, but he didn't expect that Director Jiang would tell him about graduation as soon as he came back.

"What's the point of delay, and I mean you can start working on your dissertation, do you think it's going to be soon?" Director Jiang asked Wu Bin.

"Not really." Wu Bin shook his head.

"Then you can start preparing." After speaking, Director Jiang added: "But don't think that just because you can graduate, you can write a random errand." ”

"Of course not." Wu Bin hurriedly shook his head.

"Well, I'm sure you're not the one who would do such a thing, so go ahead and get busy with yours."

Walking all the way back to the laboratory with the question of what topic to choose as a graduation thesis, Wu Bin was about to change his clothes, when he heard Feng Jinhui call out to him and said: "Two days ago, people from the scientific examination department were looking for you, and I said that you were not there, so he left a phone number for me." ”

"People from the scientific research department are looking for me?" Wu Bin asked very surprised.

The Department of Scientific Archaeology is a very distinctive department of HKUST, which uses modern technology to analyze ancient remains to obtain a wealth of potential information, and then combines archaeological methods to explore human history.

"But I don't think I've had any interaction with anyone in this department......

But since everyone was looking for them, maybe there was something urgent to find him, so Wu Bin picked up his mobile phone and called the other party.

"Hello, who is it?" A man's voice came to mind on the other end of the line.

"Hello, I'm Wu Bin, Teacher Feng said you came to me?"

"Oooh! Wu Bin, yes, I looked for you, it was not convenient on the phone, how about we go to the restaurant to talk? ”

"Russia...... Okay. ”

So Wu Bin stepped on the bicycle with a little inexplicability, and soon came to the restaurant that he had agreed with the person on the phone.

"Over here, classmate Wu Bin."

As soon as Wu Bin parked the car, he saw a boy with glasses waving at the door of the restaurant.

"Hello, are you looking for me?" Wu Bin walked over and asked.

"Yes, let me introduce myself first, my name is Xie Hui, I am a doctoral student in the Department of Science and Technology Archaeology, the way I found you is a little reckless, please forgive me."

"Oh, it's okay, it's okay, so you're looking for me?"

"Let's go in and talk."

After walking into the restaurant, Xie Hui ordered a Coke for Wu Bin, and he sat opposite him with a cup of milk tea.

"Then I'll get straight to the point." Putting down the milk tea, Xie Hui looked at Wu Bin and asked, "I don't know if you know anything about murals?" ”

"What kind of mural?" Wu Bin asked.

"Architectural frescoes, cave frescoes, tomb frescoes, and so on."

"Oh~ I've heard of it, and then what?"

"There is a lot of information recorded in the murals, which is a valuable wealth in the history of human social development, from the murals of the Shiyuan site 4,200 years ago to the Tang, Song, Yuan, Ming and Qing dynasties have found tomb murals."

"Especially the Tang Dynasty! Both in quantity and quality, it is very superior! ”

"Uh-oh." Wu Bin continued to listen patiently.

"But now we are facing a very troublesome problem, that is, a large number of tomb murals have a lot of diseases and need to be repaired urgently, and recently our research has found that graphene plays an important role in the conservation of murals!"

'Oh~'

Speaking of which, Wu Bin finally understood a little bit about the reason why this Dr. Xie came to him.

Seeing Wu Bin's expression of understanding, Xie Hui continued: "Because the structure of the mural mainly includes a layer of pigment, white ash, grass and mud and brick walls from the outside to the inside. ”

"The main component of the white ash layer is calcium carbonate. Therefore, after a long time, the white ash layer is easy to fail, resulting in damage to the surface of the mural, so it needs to be protected urgently. ”

"What protection measures did you do before?" Wu Bin asked curiously.

"That's right, at present, mural protection materials are mainly divided into two categories: organic and inorganic materials, but organic protection materials are not compatible with the mural itself, and they are easy to age and even become brittle and yellow after long-term use, which is not what we want to see."

"At the same time, because the membrane formed by the organic material is not breathable, the comparison will eventually swell and pulverize, which is an irreparable fatal injury to the mural!"

"Oh~" Wu Bin continued to nod, and took out a booklet from his pocket and began to take notes.

Seeing Wu Bin taking notes, Xie Hui was a little surprised, but he was more appreciative, so he slowed down his speech a little and said: "Compared with organic materials, inorganic protective materials like calcium hydroxide have the advantages of good compatibility and aging resistance. ”

Watching Wu Bin quickly write a few lines, Xie Hui continued: "After being applied to the surface of the mural, calcium hydroxide will react with carbon dioxide in the air, thereby generating calcium carbonate and fusing with the white ash layer, thereby further improving the strength of the white ash layer and playing a better protective role." ”

"Huh? Isn't that the problem already solved? Wu Bin looked up and asked.

"If it were that simple, I wouldn't have to be so anxious to look for you, and what I'm just talking about is just a paper by Keplain in 2000, in which he wrote that if you use nano-calcium hydroxide to protect the frescoes. Due to the size effect of nanometers, the chemical and physical properties of calcium hydroxide will be changed, the surface activity and stability will be greatly increased, and the protection effect will be significantly improved. ”

However, this idea is really difficult to ...... Oh no, it's difficult. ”

After coughing lightly, Xie Hui took a sip of milk tea and continued: "Since the publication of this paper, inorganic nanomaterials have been a new research direction for mural protection materials, but we have tried methods such as aqueous solution method, alcohol solution method, microemulsion method and calcium metal method to synthesize nano calcium hydroxide, but none of them. ”

Xie Hui sighed as he spoke, "These synthetic calcium hydroxide are not only too large in size, but also have the disadvantages of poor permeability, poor stability, difficult purification, complex operation, and high cost. ”

Wu Bin couldn't help but want to roll his eyes when he heard this, isn't this the legendary uselessness......

Looking at Wu Bin's speechless expression, Xie Hui laughed awkwardly twice and continued: "But our research is not for nothing. ”

"We found that the fundamental reason why the problems of slow carbonization and low reinforcement strength of calcium hydroxide have not been effectively solved is that the kinetic law of calcium hydroxide nucleation growth has not been clarified, so it is difficult to achieve effective breakthroughs in key technologies such as controllable preparation of nano calcium hydroxide."

Hearing this, Wu Bin nodded with some understanding and began to calculate this information in his mind.

"And then?"

"Oh, now our research group has come up with a new idea to introduce graphene quantum dots to solve this problem."

Hearing this, Wu Bin suddenly snapped his fingers and said, "Do you want to use the salted fish effect of graphene quantum dot surfactant to regulate the nucleation growth kinetic rate of calcium hydroxide?" ”

After a long time, he swallowed a mouthful of saliva and said, "I knew it was right to look for you!" ”

"That's right, we just want to achieve a controlled synthesis of calcium hydroxide nanomaterials."

"So you're looking for me to work on this project?" Wu Bin asked.

"That's right, I've read two papers you published on graphene preparation, and found that your ideas have the potential to solve our current difficulties."

"Okay, I'll join your group!" Wu Bin nodded.