CH_(4)在PVDF中渗透行为及机理的分子模拟研究  

Molecular Simulation of Permeation Behavior and Mechanism of CH_( 4) in PVDF

作　　者：张学敏[1,2] 王品 李厚补 周腾 肖春红 冯金茂 钟明强 ZHANG Xuemin;WANG Pin;LI Houbu;ZHOU Teng;XIAO Chunhong;FENG Jinmao;ZHONG Mingqiang(School of Materials Science and Engineering,Chang’an University,Xi’an 710064,China;Zhejiang Weixing New Building Materials Co,Ltd,Linhai 317000,China;State Key Laboratory of Performance and Structural Safety for Petroleum Tubular Goods and Equipment Materials,CNPC Tubular Goods Research Institute,Xi’an 710077,China;School of Materials Science and Engineering,Zhejiang University of Technology,Hangzhou 310014,China)

机构地区：[1]长安大学材料科学与工程学院,西安710064 [2]浙江伟星新型建材股份有限公司,浙江临海317000 [3]中国石油集团石油管工程技术研究院石油管材及装备材料服役行为与结构安全国家重点实验室,西安710077 [4]浙江工业大学材料科学与工程学院,杭州310014

出　　处：《中国塑料》2021年第3期97-104,共8页China Plastics

基　　金：国家自然科学基金(51304236,51504037);长安大学中央高校基本科研业务费专项基金(300102310201);国家级大学生创新创业训练计划项目(S202010710156)。

摘　　要：采用巨正则蒙特卡洛法(GCMC)和分子动力学法(MD)相结合的方法模拟研究了典型气体CH_(4)在聚偏氟乙烯(PVDF)中的吸附扩散行为,探讨了温度及压力对气体吸附扩散能力的影响,分析了CH_(4)在PVDF中的吸附位点及扩散轨迹。模拟结果表明,CH_(4)在PVDF中的溶解系数、渗透系数随温度的升高先增大后减小,随压力的升高而增大;扩散系数和自由体积分数均随温度和压力的升高而增大;吸附过程中,CH_(4)在PVDF内呈现有选择性地聚集吸附,且多吸附于模拟晶胞中的低势能区;随后,PVDF内的CH_(4)分子在以空穴形式存在的自由体积之间进行扩散,温度越高、压力越大,扩散能力越强。The adsorption and diffusion behavior of CH_(4) in poly(vinylidene fluoride)(PVDF)was studied by a combination of molecular dynamics(MD)and Grand Canonical Monte Carlo(GCMC)simulations.The effects of temperature and pressure on the adsorption and diffusion capabilities of CH_(4) were discussed,and the adsorption sites and diffusion paths of CH_(4) in PVDF were analyzed.It was found that the solubility coefficient and permeability coefficient of CH_(4) in PVDF increased at first and then tended to decrease with an increase in temperature.However,these two parameters always increased with an increase in pressure.As the temperature and pressure increased,the diffusion coefficient and fractional free volume increased.The simulated results indicated that the CH_(4) molecules exhibited a selectively aggregated adsorption in PVDF,and they were mostly absorbed in the low potential region of the simulated cell.The CH_(4) molecules in PVDF diffused within the free volumes in the form of cavities.The higher temperature and greater pressure can result in a better diffusion capability.

关 键 词：聚偏氟乙烯 渗透 吸附 扩散 分子模拟 

分 类 号：TQ325.4[化学工程—合成树脂塑料工业]