基于分子动力学模拟研究废食用油-老化沥青的扩散行为

Research on Diffusion Behavior of Waste Edible Oil-Aged Asphalt Based on Molecular Dynamics Simulation

为了解废食用油在老化沥青中的扩散行为,利用Materials Studio(MS)分子动力学模拟软件对废食用油-老化沥青的扩散体系进行研究。以沥青四组分的分子模型和废食用油中主成分的分子模型为基础分别建立老化沥青分子模型和废食用油分子模型,并对其所建立的分子模型进行优化处理,在此基础上建立废食用油分子与老化沥青分子的界面模型,最后根据扩散体系的MSD(Mean Square Displacement)曲线来计算扩散系数,以此来表征其扩散能力。结果表明:建立的老化沥青分子模型和废食用油分子模型经过优化处理后均能表征这2种材料的特性。根据MSD曲线计算得到老化沥青和废食用油的扩散系数分别为2.1225×10^(-9) m^(2)/s和4.3107×10^(-9) m^(2)/s,其结果表明这2种物质的分子移动均较为活跃,可以在短时间内将体系结构中的微观空隙填充,故基于废食用油的沥青再生剂具有良好的扩散能力。

To understand the diffusion behavior of waste edible oil in aging asphalt,the diffusion system of waste edible oil and aging asphalt was studied using Materials Studio(MS)molecular dynamics simulation software.Based on the molecular model of the four components of asphalt and the molecular model of the main components in the waste edible oil,the aging asphalt molecular model and the molecular model of waste edible oil were established respectively,and the molecular models established were optimized and established on this basis the interface model between waste edible oil molecules and aging asphalt molecules,and finally the diffusion coefficient is calculated according to the MSD(Mean Square Displacement)curve of the diffusion system to characterize its diffusion ability.The results show that the established molecular model of aged asphalt and waste edible oil can characterize the properties of these two materials after optimization.According to the MSD curve calculation,the diffusion coefficients of aged asphalt and waste edible oil are 2.1225×10^(-9) m^(2)/s and 4.3107×10^(-9) m^(2)/s,respectively.The results show that the molecular movement of these two substances is relatively active and can be the microscopic voids in the system structure are filled in a short time,so the asphalt regenerant based on waste edible oil has good diffusion ability.