Chapter 97: True chloroform extraction

　　 Monday morning, the group meeting.
　　 Wu Feifei's perovskite system has made progress. She uses ammonium chloride as an additive, does not require thermal annealing, and the efficiency has exceeded the standard.
　　 Next, she plans to use experiments to demonstrate the possible reasons for this phenomenon, and intends to do some research on the charge transport mechanism with Tian Qing.
　　 The most critical data, that is, the photoelectric performance has been almost optimized, only need to supplement other characterization experiments.
　　 And her new work is fair, and she can post it with a high probability. It is estimated that she will be able to post another article in less than a month.
　　 Wei Xingsi was very happy on his face, but he still urged Feifei Wu to speed up the progress of the experiment to prevent others from picking peaches.
　　 Duan Yun's experiment this week has not made much progress, and the installation is still under construction.
　　 According to his description, Xu Qiu estimated that his installation would not be successful for a while.
　　 After listening, Mr. Wei changed his face and scowled, saying that he "spends money but doesn't work."
　　 Xu Qiu watched at the speed at which his face changed, and he was amazed.
　　 Chen Wanqing's report is quite satisfactory. Teacher Wei did not comment too much, but asked her to continue to do it according to her ideas.
　　 Finally it was Xu Qiu's turn.
　　 After finishing the report, Mr. Wei commented:
　　 "Yes, this time I followed the format, it doesn't seem to be as strenuous as last time.
　　 In general, I agree with your experimental ideas, but at this stage, we still don’t want to broaden the research direction too much.
　　 Chen Wanqing also has her subject, now you will do it alone.
　　 This semester I will see if I can recruit a few more undergraduates to help you do experiments. Feifei Wu is also short of staff.
　　Let’s do this, don’t do the PBT2T, 3T, 5T system for now, because there are too many variables to control, so focus on the current PBT4T system.
　　 The efficiency is now close to 5%. As a new system, it is already very good.
　　 As for the experimental conditions, shorten the reaction time and use Soxhlet extraction with chloroform to try it. I guess it will have some effect.
　　Also, the two of you must pay attention to safety when doing experiments in Zhangjiang. If you have anything to do, contact me in time. "
　　 "Okay." Xu Qiu and Chen Wanqing said at the same time.
　　……
　　 In the afternoon, the two took the two batches of materials previously synthesized and headed to the Zhangjiang campus.
　　 They first went to the drug warehouse to fetch the pre-ordered color-changing silica gel and used some necessary glass equipment.
　　 then came to the laboratory and found that the four oil baths bought last time had arrived.
　　 was delivered to the drug warehouse on Monday morning, and was placed at the door because no one received it.
　　 There are no people in the whole building, and there are access control and monitoring, so there is no need to worry about losing it.
　　 Entering the A502 laboratory, Xu Qiu put on his lab coat, four layers of gloves, and a gas mask.
　　 gas mask, because the shape resembles a pig’s nose, it is commonly called a pig’s nose.
　　 Its front end is a multi-layer filter device. The one in his hand is equipped with an organic solvent filter, which has a better protection effect.
　　 The other parts are mainly made of rubber, which can completely cover the mouth and nose after wearing.
　　 There are four elastic bands on the mask, connected to a plastic support.
　　 Place the mask on the face and place the plastic support on the back of the neck to complete wearing.
　　 After Xu Qiu put on the gas mask, she felt that the elastic band was very tight, and she felt a little discomfort at the beginning.
　　 It took a few seconds to get used to it.
　　 After he finished the whole set of protection, he found that Chen Wanqing was also playing with the gas mask.
　　 "Sister, are you coming too?" Xu Qiu said.
After 　　 finished speaking, he found that speaking through the gas mask, his voice would become smaller and his voice would become urn-sounding.
　　 "What are you talking about?" Chen Wanqing couldn't hear his voice far away.
　　 Xu Qiu could hear the senior sister's voice clearly, because the gas mask did not cover her ears.
　　 He leaned in front of the senior sister and said again:
　　 "I just said, are you coming too?"
　　 "Hmm," Chen Wanqing nodded and said: "I am still a little worried about you doing the experiment alone."
　　 "Well, then you can stand a little farther and watch, I'll do it." Xu Qiu said.
　　 "By the way, you are good at experimental operations," Chen Wanqing said.
　　 "Needless to say the Soxhlet extraction, I have used it in the "Organic Chemistry Experiment" class for rotary steaming." Xu Qiu said.
　　 "That's good." Chen Wanqing said.
　　……
　　 The two of them took precautions and entered the laboratory.
　　 Xu Qiu took out the sample, wrapped it in filter paper, put it in the extraction tube, and started to build the Soxhlet extraction device, a total of four sets were to be built.
　　 first build a prototype.
　　From bottom to top, they are conical flask, extraction tube, spherical condenser, three-way valve, and balloon.
　　 Then make four nitrogen and insert them above the spherical condenser.
　　 Add about 250 ml of chloroform solvent to each Erlenmeyer flask, and then add a long stir bar.
　　 Pump and exhaust three times to ensure that the closed system is nitrogen atmosphere.
　　 Turn on the condensed water, heat the oil bath to 60 degrees Celsius, reflux the chloroform, and start the extraction.
　　……
　　 All four sets of devices were set up, which took almost an hour.
　　 During this period, Chen Wanqing was not idle either.
　　 First, all the windows in the laboratory were opened to keep the room ventilated~EbookFREE.me~ Then, the color-changing silica gel was put into the vacuum tank where the monomer was previously stored, and then filled with nitrogen for protection.
　　 Next, take out the glass instrument that was previously soaked in the alkali tank, clean it with an ultrasonic cleaner, and put it in the oven.
　　 In addition, she also transferred the trash from several small trash cans in the laboratory to a large trash can.
　　 The so-called large trash can is a cardboard box with a large black trash bag inside, and then transfer the small trash bag inside.
　　The garbage in the laboratory cannot be thrown away at will, and must be thrown into the designated laboratory garbage collection point.
　　 In the early years, school management was not so strict, and the Department of Materials did not have a person responsible for experimental waste. Experimental waste was directly mixed with domestic waste.
　　 Now, supervision is getting stricter.
　　 Not only that, the department also requires each laboratory to conduct regular safety inspections and self-inspections, which requires filling out a lot of forms.
　　Of course, this kind of self-examination is generally useless.
　　 Therefore, departments and schools will organize safety inspections from time to time.
　　 Although it is said to be a surprise inspection, there will be some noise a week before the inspection.
　　The instructors of each research group will ask their students to organize the laboratory in advance to deal with surprise inspections.
　　From the perspective of laboratory safety, more or less has a little effect.
　　 Because it takes time to extract the product with chloroform, Chen Wanqing said:
　　 "Let's dispose of the waste liquid and experimental waste accumulated before, mainly the waste liquid, which must be handled by the School of Pharmacy.
　　 They don’t collect it every day. I checked and they just collected it this afternoon. "
"Ok."
　　 The two tied the mouth of the black garbage bag containing the experimental garbage tightly, placed it neatly on the cart, and pushed it to the designated collection point.