Chapter 122: NMR sample delivery

　　 There are two main reasons for using deuterated chloroform as the solvent for testing NMR:
　　 On the one hand, it has good solubility for the sample, on the other hand, its residual signal peak in the NMR test will not interfere with the signal peak of the sample.
　　Before the test, the sample in the NMR tube must be completely dissolved without any solid residue.
　　 Therefore, polymer samples should not be added too much. It is best to set the solution concentration first, and then weigh to confirm the quality of the sample before adding it.
　　 Otherwise, once more samples are added and the solution concentration is too high, you have to reopen a bottle of deuterated chloroform to dilute the solution.
Xu Qiu first weighed his five samples, each of about 4 mg, and added them to the five NMR tubes respectively, and then numbered them on the upper wall of the NMR tubes with a marker, and finally added one milliliter of deuterated chloroform to each, and capped the bottle Stuffed.
　　 One milliliter of solvent can only hold about one-third of the volume of the NMR tube, and the dissolution speed is not fast.
　　 Xu Qiu looked at the dissolution process and found that it was a bit like adding potassium permanganate to the bathtub before taking a bath at home in the early years. The process of dissolving the potassium permanganate, the solid materials gradually dispersed in the solution.
　　 After observing for a while, he pressed the stopper and shook the NMR tube back and forth with the strength of his wrist to accelerate the dissolution of the sample.
After a few minutes.
　　The samples are all processed, even the most difficult to dissolve P2FBT4T-2BO sample can be completely dissolved, and a total of five groups of dark blue solutions are obtained.
　　 However, the solution concentration of about 4 mg/ml is still relatively low.
　　 It is more than enough to test the proton nuclear magnetic resonance spectrum. As for whether the carbon spectrum signal can be measured, it can only be resigned.
　　 Besides, when he checked the polymer material he had synthesized in the glove box, he found a problem.
　　In the previous reaction, because the optimal reaction conditions are not clear, the materials for a single reaction dare not toss too much, and the product of each reaction is only tens of milligrams.
　　 Normally, it takes a few milligrams of materials to prepare a solution.
　　 It takes a few milligrams of materials to do a test.
　　A piece of polymer was dropped during weighing, and several milligrams of material was consumed.
　　 Therefore, except for the P2FBT4T-2OD material that has been reacted several times later, there is still ample margin, and there are not many other materials left.
　　 It seems that I still have to go to Zhangjiang to do synthesis, but I can bring Han Jiaying and train this little helper as soon as possible.
　　……
　　 A total of 8 NMR samples were prepared by the two.
　　 Chen Wanqing took a stack of sticky notes, wrote the sample number, solvent, test type, research group, contact number and other information on the sticky notes, and then inserted it on the NMR tube like a kebab.
　　 Xu Qiu also followed her example, writing his sample information on the label paper, and then poke a hole in the note paper with a nuclear magnetic tube and put it on.
　　 "This labeling method is quite unique, but where did you learn it from the teacher?" Xu Qiu teased.
　　 "You found all of this. When I made an appointment for NMR before, I observed how other people gave samples." Chen Wanqing said:
　　 "This will not pollute the NMR tube, and the note paper is not easy to fall off, and it can leave enough information."
　　 Xu Qiu nodded and said:
　　 "Wait, send samples directly to the aging building?"
　　 "Yes, send the samples to the MRI room, and after registration, they will arrange the tests in the order in which they are sent." Chen Wanqing said.
　　 "In this case, how do we get the sample data, they will specifically notify, and then we go to get it?" Xu Qiu asked:
　　 "There will be no special notice," Chen Wanqing said:
　　"We need to log in to an FTP address on the campus network and find the folder corresponding to the research group that we filled out when sending samples. The specific address and operation method are posted outside their MRI test room.
　　 If the test is completed, they will name the data file with the test time and upload it in the compressed rar format. We can download the corresponding file when we find the corresponding file. It usually takes about a week to wait. "
　　 Xu Qiu subconsciously thought:
　　Such data transmission is not very secure, because other people can see their test data.
　　 I thought about it again, but I was thinking too much.
　　 First of all, the files they upload are read-only, others can only download but cannot modify, so there is no need to worry about the data being tampered with by boring people.
　　Secondly, the samples tested are all with serial numbers, and others don’t know what the samples are.
　　 Besides, the importance of nuclear magnetic test is also average, and it has almost no commercial value. Even if other people get the data, it is meaningless.
　　 After finishing the preparations, the two of them took eight NMR tubes to the NMR test room of the aging building, put them in the beaker specially used to collect samples, registered with the teacher on duty, and completed the sample delivery.
　　……
　　 A few days later, 216 laboratory.
　　 "In addition to the light source test, today's element analysis is our last characterization test." Chen Wanqing said.
　　 "I remember there are transient light absorption spectroscopy, transient fluorescence spectroscopy, don't we do these characterizations?" Xu Qiu said.
　　 "You said TA and TRPL, these two devices are more expensive, Mr. Wei currently has no way to test in Modu." Chen Wanqing said:
　　"TRPL, nanosecond response, with a 515 nm wavelength monochromatic laser device ~ EbookFREE.me ~ almost 200,000 is enough, it's not cheap.
　　 And TA is expensive, nanosecond level response is about one million, femtosecond level response is several million, and there are not many places where TA testing can be done in China. "
　　 "Several millions, it's so expensive, it's almost the price of an electron microscope." Xu Qiu said with emotion:
　　 "It feels that it is not worthwhile for a research group in the direction of materials to buy an instrument like TA. For example, the research group related to optics in the Department of Physics is quite suitable."
　　 "Yes, except for those who specialize in TA, people in other fields buy one and turn it on once or twice a month without losing money." Chen Wanqing said:
　　"A key project of the National Natural Science Foundation of China only has a funding of 3 million. The general project funding is 600,000, and the time is four years. You cannot apply for projects in the same field before the project is completed.
　　 It looks like a lot of 3 million key projects, but the application is extremely difficult. It is all academicians and the Yangtze River who fight with the gods. It is difficult for ordinary people to fight them, and not all the funds can be used to buy equipment.
　　Relatively speaking, the price of TRPL instruments is relatively affordable.
　　 I heard from Teacher Wei before that one of Su Da’s friends has one. They mainly make perovskite quantum dots. If we want to test, we have to go there by ourselves.
　　Senior brother, are you interested in a business trip to Sioux City? "
　　 Xu Qiu thought about the documents he had seen before, and said:
　　" Forget it, I feel that there is no need to test TRPL for the time being, and there is not much useful information.
　　 Fluorescence spectroscopy in the field of organic photovoltaics is mainly used to calculate the fluorescence quenching efficiency of the blend film of the donor and the acceptor. The ordinary steady-state fluorescence spectroscopy is sufficient for now. "
　　 "That's true too."