摘要
基于ReaxFF力场利用LAMMPS软件建立毕兹分子(QNB)的模型,模拟微观条件下等离子体降解毕兹的反应机理。通过模拟考察300 K恒温条件下毕兹在活性粒子作用下的行为。研究表明毕兹在O自由基作用下降解主要通过苯环活化开环、羟基夺氢反应以及奎宁环中N—O键的形成3个过程,·HO_(2)、O_(2)、NO、NO_(2)这4种活性粒子在模拟中基本未对毕兹分子造成任何破坏。利用ReaxFF MD分子模拟方法对常温环境下等离子体降解毕兹反应机理研究的一个尝试,可为相关的毒剂降解试验机理分析、理论研究提供一定的参考。
In this paper,we analyze the mechanisms of interactions between reactive plasma species(·O,·OH,O_(2),·HO_(2),NO,and NO_(2)) and 3-quinuclidinyl benzilate using a reactive force field molecular dynamics(ReaxFF MD) simulation methodology.ReaxFF reaction molecular dynamics combines two methods of quantum mechanics and classical statistical mechanics,which can judge the breaking and formation of important chemical bonds.The behavior of 3-quinuclidinyl benzilate under the action of active particles at 300 K is investigated by the simulation,with the help of OVITO,ORIGIN,and other software to visualize its simulation calculation results.The results show that the final degradation products mainly include carbon dioxide,water,and quinuclidine.Besides,only reactive oxygen species(·O and ·OH) have a series of chemical reactions with 3-quinuclidinyl benzilate,leading to the destruction of 3-quinuclidinyl benzilate.The pathway between O free radicals and 3-quinuclidinyl benzilate can be divided into three stages:benzene ring-opening,hydrogen abstraction reaction,and the formation of N—O bond in quinine ring.Under the condition of sufficient O and OH free radicals,the degradation efficiency can be significantly improved,and the activity of O free radicals is higher,resulting in more thorough cracking.The existence of OH free radicals alone will form a large number of clusters,which is not conducive to the reaction.Furthermore,the four free radicals(·HO_(2),O_(2),NO,and NO_(2)) do not cause any damage to the structure of 3-quinuclidinyl benzilate in the simulation.This work is an attempt to apply the reactive force field molecular simulation method to study the mechanism between reactive plasma species and 3-quinuclidinyl benzilate at room temperature.It can provide a reference for an in-depth understanding of the mechanism and related experimental and theoretical studies.
作者
程礼盛
牟凯达
宋立健
王晨晖
刘晗
CHENG Li-sheng;MOU Kai-da;SONG Li-jian;WANG Chen-hui;LIU han(College of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing 100029,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2021年第6期2813-2819,共7页
Journal of Safety and Environment
关键词
环境工程学
低温等离子体
自由基
毕兹
降解
反应分子动力学
environmental engineering
low-temperature plasma
free radical
3-quinuclidinyl benzilate
degradation
ReaxFF molecular dynamics
