Search

[Objective] The study aimed to investigate the effect of macular pollutants on the release of pyrolytic products from cigarette paper, and provide a method basis for the classification of macular pollutants. [Method] The pyrolytic particulate matter of different cigarette papers was captured by a self-built temperature-controlled pyrolytic device. The differences in pyrolytic components of different cigarette paper samples were analyzed by using GC-MS. And the classification of macular pollutants was achieved using principal component and cluster analysis based on the differences in pyrolytic products. [Result] The different pollutants changed the microscopic surface morphology of cigarette paper fibers. And the pyrolytic products chromatograms of all the contaminated cigarette papers exhibited a similarity of less than 0.417 when compared with that of blank cigarette papers. A total of 78 kinds of pyrolytic products were detected in the blank cigarette papers, including ketones, phenols, benzene derivatives, aldehydes, furans, alcohols, heterocycles and other chemicals, etc. Moreover, the pyrolytic products released from contaminated cigarette paper not only had common components with blank cigarette paper, but also had many unique pyrolysis components, and there were significant differences in the number and content distribution of various pyrolysis components. Specifically, after the contamination of Premalube red and Nordic grease, the phenolic compounds in the pyrolytic products significantly reduced from 36.07% to 5.58% and 8.32%, respectively. Meanwhile the release of hydrocarbons remarkably increased, but the composition and distribution of hydrocarbon substances exhibited significant differences. Flavor and sugar contaminants reduced the content of aldehydes, ketones, phenols, benzene rings and heterocyclic pyrolytic components in the pyrolytic products, but their own unique propylene glycol/glycerol solvents or esters could release to the particulate matter during the heating process through the evaporation. Principal component analysis based on pyrolytic products showed that cigarette papers contaminated with different pollutants could be effectively distinguished from the blank sample. Hierarchical clustering analysis also showed that samples contaminated with grease could be classified into one, and cigarette papers contaminated with flavor and sugar could be grouped into another one. [Conclusion] The results in the study would be beneficial for the classification and identification of macular pollutants source based on the differences in pyrolytic products that were captured by self-built temperature-controlled pyrolytic device and analyzed by multiple statistical methods. [ABSTRACT FROM AUTHOR]

As a new type of reversible phase change material, vanadium dioxide (VO2) has shown great potential in development with the regulation of its phase change temperature (TMIT) and were extensively studied. The experiment in this study focuses on exploring the effect of germanium ions on TMIT of VO2 thin films and trying to explain the internal mechanism. A series of VO2 films containing different ratios of germanium ions were deposited on polished alumina sheets. The characterization results show that germanium ions contribute to increasing TMIT (maximum TMIT is 84. 7 ℃). The main reason for this increase is that germanium ion enhances the stability of monoclinic V-V dimer by increasing the stability of monoclinic V-V dimer, which makes the transition from low-temperature monoclinic state to tetragonal rutile state more difficult. [ABSTRACT FROM AUTHOR]