Accurate Measurement Of Characteristic Values Of Three Kinds Of Single Walled Carbon Nanotubes Reference Material

Because of its unique structure and excellent physical and chemical properties, Single walled carbon nanotubes(SWCNTs) are widely used in many kinds of fields, such as materials engineering, field effect transistors(FET), biomedicine and electronic devices, etc.The further research on the characteristic value of SWCNTs is helpful to promote the wide application of SWCNTs in various fields. With the development of SWCNTs from basic research to applied research, the accurate measurement of each characteristic value of SWCNTs is becoming more and more important.There are hundreds kinds of SWCNTs with different structures, which can be described by the chiral indices(n, m). The differences of length of SWCNTs and contents of ingredients would lead to changes in performance.The research is divided into four parts.1. The accurate measurement of Chiral index is studied during the process of preparation of SWCNTs chiral reference materials(RM). The measurement method includes fluorescent spectrometry and UV-Vis-NIR absorption spectroscopy. In order to ensure the accuracy of chiral index measurement, equipments used to identify the chiral SWCNTs must be calibrated at first. Calibration procedure of UV-Vis-NIR absorption spectroscopy has been finished, but calibration procedure of fluorescent spectrometry has not been established. In order to ensure the accuracy of chiral identification, calibration procedure of fluorescent spectrometry was established in this paper. The accurate measurement method is another important factor for accurate measurement of Chiral index. Larger errors were always produced by single measurement method. Therefore, the development of chiral reference materials of SWCNTs was carried out using the method of combining Fluorescence spectrum method and UV-Vis-NIR absorption spectrum.2. The accurate measurement of constituent content in SWCNTs is studied during the process of preparation of SWCNTs constituent content reference materials(RM). The accurate measurement of constituent content in SWCNTs includes the accuracy of measuring equipment and the accuracy of measuring method. In order to ensure the accuracy of measurement, Farmar and Calcium oxalate RM were used to calibrate the measuring equipment. In order to ensure the accuracy of constituent content measurement, a new data processing method that is differential method of thermal weight loss curve is proposed. The new method was used to measure the content of water, amorphous carbon, SWCNTs and ash in SWCNTs sample. And Raman and Inductively coupled plasma mass spectrometry(ICP-MS) are used to verify the accuracy of the new method.3. The accurate measurement of length of SWCNTs is studied during the process of preparation of SWCNTs length reference materials(RM). The measuring equipment is an scanning electron microscope(SEM) which was calibrated by dard grid. Due to the length of SWCNTs is not consistent in the SEM image, the only accurate value can not be determined,so a processing method about a large number of data was carried out. The results indicated that the length of SWCNTs is not unique, a new expression method of length is established,and the length of SWCNTs is expressed by the peak with the half peak width of the histogram.4. In view of the influence of different moisture content on the properties and structure of SWCNTs, thermal gravimetric analysis(TGA) and Raman spectrometry were used to analysis the existed forms of moisture in SWCNTs. And emphasis was focused on the analysis of the influence of different moisture content on the structure and spectral properties of SWCNTs.