I Have a Research Support System

"The new materials we synthesize should also characterize their basic properties, such as molecular weight, elemental analysis, etc." Xu Qiu said:

"That's right, but it's too troublesome to test it every time the synthesis is completed. Generally, the batch with the best performance will be tested." Chen Wanqing said:

"Make an appointment on the instrument sharing platform of the Department of Materials, first use gel chromatography GPC to test the molecular weight, in addition to the hydrogen spectrum, carbon spectrum, and elemental analysis of nuclear magnetic resonance NMR.

Some materials can also be characterized by infrared spectroscopy and Raman spectroscopy, but our materials do not need it. "

"The characterization of new materials is so troublesome." Xu Qiu sighed.

"Yes, if you published an article in the early years, if you were reporting a new material, you wouldn't be able to publish all the representations," Chen Wanqing said:

"It is much more relaxed now. These characterization results usually do not need to be analyzed in the main text, but can be given in the supporting information.

By the way, I received an email a few days ago. The department can sign up for instrument training at the beginning of the semester. You can reply to the email to sign up. "

"Is there?" Xu Qiu asked doubtfully:

"I had a class meeting yesterday, and I just checked my inbox, but I didn't see any relevant emails."

Chen Wanqing thought for a while, and suddenly said: "I forgot that you are still an undergraduate, this training is for graduate students.

But it's not a big problem, anyway, I'm here, so if we make any signs, we'll go together. "

After the second batch of synthesized material was filtered, the two put them into a Soxhlet extractor and began extraction.

Then put the first batch of dried materials into the sealed tank where the monomers were stored for temporary storage.

After confirming the safety of water, electricity and gas, close the laboratory.

…………

The next day, the two came to Zhang Jiang's laboratory again.

The Soxhlet extraction of the second batch of materials has been completed, and it only needs to be dried in a vacuum oven.

Compared with the oven in the laboratory, the vacuum oven is relatively small.

The length, width and height of the former are more than one meter, while the latter is almost the size of a microwave oven.

Because the inside of the oven will release a lot of heat to maintain the temperature, there is a certain degree of danger.

On the one hand, accidental touch by the human body can cause burns, and on the other hand, there is also a hidden danger of fire.

According to laboratory safety regulations, it is not allowed to pile up items around the oven, especially combustible materials such as solvents, so its footprint will be relatively large.

Fortunately, Zhang Jiang's laboratory has a very large area, so this is not a problem.

In the case of a vacuum oven, in addition to the heating function of an ordinary oven, it also integrates a vacuum function, which can be connected to a vacuum pump to evacuate its internal cabin.

In this way, there is no need to worry about the sample reacting with oxygen while heated.

And the lower the vacuum, the lower the boiling point of the solvent.

Using a vacuum oven can quickly dry solvents with a boiling point over 100 degrees Celsius at a lower temperature, such as 70 degrees Celsius.

After placing the second batch of samples in a vacuum oven, the two returned to the A501 office.

Today is a day of paddling.

It takes Zhangjiang Handan two hours to commute back and forth, four hours to wait for drying, and only fifteen minutes for the experimental operation.

That is to say, it took a day's time to do only fifteen minutes of work.

Chen Wanqing sat at his desk and used the computer to catch up on dramas. After Xu Qiu finished his one-hour daily document reading task, he opened the starting point and started reading novels.

It is not easy for him to enter the simulation laboratory with his senior sister.

...

Four hours later.

The second batch of samples was dried, and Xu Qiu weighed it with a balance, and it was more than 120 mg.

At the beginning, the total mass of the monomers fed was more than 160 mg.

The calculated yield is roughly 85%, which is already very high.

The first batch of samples only obtained more than 60 mg, and the yield was less than 50%.

When calculating the yield here, you cannot directly divide 120 by 160.

The trimethyltin and bromine groups connected to both ends of the fed monomer will fall off after the condensation reaction, and this part should be deducted.

Therefore, the effective fraction of the monomeric starting material has a mass of only about 140 mg.

Xu Qiu carefully transferred the sample to a glass bottle with tweezers and weighing paper, marked it with a marker pen as "PBT4T-2", and wrapped the glass bottle with aluminum foil.

After completion, take both batches of samples and return to Handan Campus.

Although the monomer raw material is toxic, it becomes a polymer after synthesis, and the toxicity is almost zero.

And the samples came in bottles and trash bags, so carrying them on the school bus wasn't a problem.

...

In the evening, Xu Qiu "took" the glove box from Wu Feifei's hands.

He was not sure about the solubility of the product and what solvent to use, so he tried two solvents, chloroform and chlorobenzene, and prepared 1 ml of each solution.

Two batches of samples, two solvents, a total of four sets of solutions.

The polymer donor concentrations were 5 mg/ml (chloroform) and 8 mg/ml (chlorobenzene).

The acceptor material is PC[60]BM, and the mass ratio of donor to acceptor is 1:1.

Obviously, it is impossible to continue making devices tonight, and the solution can be stirred overnight. Xu Qiu did not adjust the temperature of the heating table to too high, but only adjusted it to 45 degrees Celsius.

He also helped the senior sister prepare four sets of solutions according to the same conditions, and put them together on the heating and stirring table.

After all was done, it was already nine o'clock.

Xu Qiu left the glove box and called Wu Feifei.

She glared at Xu Qiu and took over the glove box from him.

Xu Qiu hurriedly slipped away, he was at fault for this matter, at the time he acted emotionally and rationalized, saying that the solution could be prepared in half an hour, but it took nearly an hour and a half.

The main reason is that it took a lot of time to weigh the polymer. The polymer will be adsorbed on the bottle wall and tweezers. It should be electrostatically adsorbed and it is difficult to pick it up.

Back at the desk, Xu Qiu invited her senior to go for a night run together, and the other party readily agreed.

This semester, the two will go out for a few laps together when they have time at night.

Chen Wanqing was out of breath from the first two steps, and now she can chat with Xu Qiu while running.

After jogging for two kilometers, the two came to the lawn next to the first floor of the material to move their bodies and stretch the ligaments to relieve the muscle soreness the next day.

After exercising, Xu Qiu returned to the laboratory, went to the glove box to check the solution he had prepared, and it seemed that there was nothing wrong with it.

However, he once again got a supercilious look from Wu Feifei.

Because Xu Qiu had class on Friday morning, before he left, he asked his senior sister to help him prepare some substrates when he was making devices tomorrow.

...

Back in the dormitory, Xu Qiu had no choice but to take a shower again before the student bathroom opened.

He entered the simulation laboratory, and his progress was still at the state of his last practice throwing reaction.

A few days ago, he had been going to Zhangjiang to do synthesis. He needed to stand up for continuous experiments, and he had to spend an hour a day reading literature and exercising. At night, he had no energy, so he didn't continue the experiment in the simulation laboratory.

Although he paddled all day today, Xu Qiu still found an excuse for himself:

Tomorrow, we can get the result of photoelectric performance by making the device, so let’s wait for the result to come out.

After a glance, he exited the simulation laboratory.

Thanks to Lan Shiyu for the 500 starting point reward, and brother Wuming Yi 1 for the 100 point reward.