Chapter 123: victory is in sight

　　 Next, the elemental analysis of the polymer donor material is required.
　　 Xu Qiu’s five materials contain carbon, hydrogen, nitrogen, sulfur, and fluorine.
　　 Ideally, only these five elements are contained. However, in the polymerization reaction, there must be unreacted trimethyltin or bromine end groups, so there will be traces of bromine, tin and other elements remaining in the product.
　　 The element analyzer reserved in the school is tested by the combustion method.
　　 Its basic working principle is that under the action of a composite catalyst, the sample is oxidized and burned at high temperature to obtain gaseous combustion products, and then through the detection of combustion products, the element content in the sample is reversed.
　　 Specifically, the material undergoes high-temperature oxidation and combustion to generate nitrogen, nitrogen oxides, carbon dioxide, sulfur dioxide and water.
　　 Driven by the carrier gas, these combustion products enter the separation detection unit.
　　 The adsorption column in the detection unit can adsorb and retain non-nitrogen compounds.
　　Nitrogen oxides are measured after being reduced to nitrogen.
　　The oxides of other elements are then separated and determined in the order of carbon, hydrogen, and sulfur by adsorption/desorption column adsorption and analysis.
　　Using this method, halogens like fluorine and bromine are difficult to detect. Metal tin is also difficult to detect. Only the proportion of carbon, hydrogen, nitrogen and sulfur in the molecule can be obtained.
　　 Like nuclear magnetic resonance, elemental analysis is also sample delivery, but it does not require special sample preparation, only the original solid sample is required.
　　 "Xu Qiu, do you have too much polymer samples left?" Chen Wanqing prepared the samples in the glove box. She frowned and said, "I almost run out of mine."
　　 "You still have about 20 or 30 milligrams, what are you nervous about." Xu Qiu leaned over and said:
　　"The P2FBT4T-2BO material, which is the most difficult to dissolve before, has a very low yield, only more than 30 mg.
　　 I turned the bottle upside down duang for a long time, and the bottom of the bottle was cleaned before I came up with this sample.
　　 There is nothing left now, and there will be a chance to go to Zhang Jiang to make up a few responses. "
　　 "Hmm..." Chen Wanqing stared at the reagent bottle in her hand, and stopped talking.
　　 "Sister, what's the matter?" Xu Qiu said.
　　 hesitated for a while, she seemed to have made up her mind and said:
　　 "I, I want to ask you to help me synthesize a batch of materials.
　　 The reaction you voted for me before is that the ratio of the two A units is 7:3, and the resulting synthetic product device has the highest efficiency.
　　 I am a little uncertain now, whether the performance of the 7:3 material itself is good, or it is because of the poor performance of the other two materials I synthesized, 3:7 and 5:5. "
　　 "That's it." Xu Qiu began to analyze:
　　 When dealing with the synthesis reaction before, the two did it together. He also observed the other products he synthesized, and it seemed that there was no problem.
　　 In addition, the material yield and molecular weight data are also okay.
　　 From this point of view, in theory, the performance difference of the three materials should not have much to do with whether they are synthesized by themselves.
　　 However, the experimenter in charge of the synthesis experiment can be regarded as an experimental variable.
　　 helped her to vote for three responses. It is not difficult to eliminate the influence of this variable, it is nothing more than spending more time.
　　 "No problem, leave it to me." Xu Qiu didn't think about how long:
　　 "But I have to wait until the light source is tested. I will get all the experimental data and go to Zhang Jiang to write an article while doing synthesis. I can also teach Han Jiaying by the way."
　　 "Okay." Chen Wanqing suddenly opened her eyes and smiled.
　　 "By the way, the light source will be tested next week, this time it won't be all night." Xu Qiu said.
　　 "Fortunately, you reminded me, I almost forgot to ask Teacher Wei to do the light source safety audit. In terms of time, it is the daytime next Thursday." Chen Wanqing said.
　　 "Would you like to bring Han Jiaying this time?" Xu Qiu said.
　　 "Go and ask to see if she is free." Chen Wanqing said.
　　……
　　 At this time, Han Jiaying was sitting at her desk, reading a book carefully.
　　 Xu Qiu discovered that this school girl is more diligent than when he first joined the research group, working six days a week, basically four or five days to see her.
　　 She has gotten acquainted with the people in the laboratory, and Wu Feifei occasionally asks her for help, but the main thing is to help Xu Qiu and the others experiment.
　　 Now she has learned the entire device preparation process.
　　 Although I am not very skilled, it is no problem to operate independently, prepare and test a batch of devices.
　　 As for other means of representation, I haven't learned it yet.
　　 seemed to sense that someone was approaching, she raised her head just to meet Xu Qiu's gaze.
　　 "Han Jiaying, are you free next Thursday?"
　　 "Next Thursday, I will have no class, I will be free all day." Han Jiaying tilted her head and said in confusion:
　　 "Brother, what do you want to do?"
　　 "It's like this, next Thursday from 9 am to 9 pm, Chen Wanqing and I will go to the Magic City synchrotron radiation source for testing," Xu Qiu said:
　　"If you are free, you can come with us. The location is Zhang Jiang.
　　The test time is twelve hours, but if it goes well, the test will end early. "
　　 "So you asked me for an experimental test," Han Jiaying nodded and said, "Of course."
　　 "Okay, first you have to register an account, and then perform a security test~EbookFREE.me~ You can search the answers directly online, and finally take a photo of the user number and record it."
　　 After that, Xu Qiu helped her open the website of the light source, guided him to start the safety test, and then copied the information he had previously checked with a U disk, about the test principle of grazing incidence X-ray diffraction.
　　……
　　 a few days later.
　　 Xu Qiu got the elemental analysis and nuclear magnetic resonance spectroscopy data from the sample test.
　　 Among them, the elemental analysis data is relatively simple. What you get directly is the percentage of carbon, hydrogen, nitrogen, and sulfur in the material, without further data processing.
　　Xu Qiu compares the theories of each element of each material and the percentage content obtained by detection.
　　 In general, the errors of the four elements are not large, about 1-2%, which shows that the synthesis reaction is relatively successful.
　　 As for the NMR spectrum, the sample signal in the hydrogen spectrum is very obvious, but only the obvious solvent signal can be seen in the carbon spectrum. The sample signal is very weak and almost impossible to read.
　　 Of course, this is also expected.
　　 Proton nuclear magnetic resonance spectrum data processing is not difficult.
　　 Import the data file into the analysis software, first calibrate the chemical shift of hydrogen by the signal peak of the deuterated chloroform solvent, and then integrate the signal peak at each chemical shift to obtain the hydrogen content under the corresponding chemical shift.
　　 However, this data is difficult to analyze.
　　The main reason is that the sample tested is a polymer, in which the chemical environment of hydrogen atoms is very complicated, and the signal peaks obtained are mostly broad, and it is difficult to determine the specific attribution of hydrogen.
　　 For such data, just mark the position of the peak, how many peaks, and the number of corresponding hydrogen atoms, and list the data.
　　 Now only the data of the light source is missing, and victory is in sight.