分子链长影响NO2氧化PPS低聚物的密度泛函理论研究
Density functional theory study on the effect of molecular chain length on NO2 oxidation of PPS oligomers
王庞子钦 1刁永发 1李子航1
作者信息
- 1. 东华大学环境科学与工程学院,上海 201620
- 折叠
摘要
建立了聚合度为2～10的聚对苯硫醚(PPS)分子链模型,运用密度泛函理论优化了不同长短分子链模型的几何结构,并计算了相应的反应活化能与电子性质.结果表明,对于聚合度大于6的PPS分子链模型,其几何结构参数与实际PPS滤料差异较小,且S原子的马利肯电荷量波动不超过0.6％.对NO2与PPS发生氧化反应的研究结果显示,NO2中的1个O原子会与PPS中的S原子生成新的化学键,故S原子的电子性质会对反应的发生有更加显著的影响.对反应活化能的研究发现NO2氧化聚合度大于6的PPS所需活化能稳定并保持在约143 kJ·mol-1.因此,探究NO2氧化PPS滤料的反应机理时,聚合度为7的聚对苯硫醚分子模型在保证计算精度的同时也大大降低了计算工作量.
Abstract
Molecular chain models of polyphenylene sulfide(PPS)with polymerization degrees ranging from 2 to 10 were constructed.The geometries of the models,representing various lengths of molecular chains,were optimized using density functional theory.Subsequently,the activation energies and electron-ic properties of the reactions were computed.The findings indicated that the geometrical parameters of the PPS molecular chain model,with a polymerization degree exceeding 6,closely resemble actual PPS filters.Furthermore,the fluctuation in Mulliken charge of S atoms did not exceed 0.6％,and the variation in Mayer bond order was more consistent.The investigation revealed that the C—S bond and C—H bond are weaker links in the molecular chain,susceptible to disruption under harsh conditions.Analysis of the oxi-dation reaction between NO2 and PPS revealed the formation of a chemical bond between O atom in NO2 and S atom in PPS,emphasizing the influence of the electronic properties of PPS on the reaction.The acti-vation energy for polyphenylene sulfide oxidation,with a polymerization degree greater than 6,remained constant at approximately 143 kJ·mol-1.Employing a molecular model of polyphenylene sulfide with a polymerization degree of 7 enhances the precision and reduces the computational workload in studying the oxidation reaction mechanism of PPS subjected to NO2.Selecting the appropriate length of the PPS molec-ular chain is crucial for investigating damage caused by flue gas components in PPS filter media and advan-cing filter media development further.
关键词
密度泛函理论/聚苯硫醚/分子链/二氧化氮/活化能Key words
density functional theory/polyphenylene sulfide/molecular chain/nitrogen dioxide/activation energy引用本文复制引用
基金项目
China National Key R&D Program during the 13th Fiveyear Plan Period(2018YFC0705300)
Fundamental Research Funds for the Central Universities(2232017A-09)
出版年
2024
NETL
NSTL
万方数据