Thymol在不同醇解度PVA/thymol膜中的释放动力学模拟

目的利用分子动力学定性定量地探讨PVA醇解度对thymol释放过程的影响,尝试从微观角度直观地展示thymol在PVA/thymol新型抗菌包装膜中的释放过程,揭示微观释放机理。方法利用Material Studio软件构建不同醇解度的PVA/thymol体系,模拟thymol分子动态释放过程,分别从高分子链运动性、自由体积分数以及扩散系数等角度对比分析thymol在不同醇解度PVA体系中的释放过程。结果 thymol分子在完全醇解的PVA体系中的扩散系数最小,醇解度为88%的体系中最大,醇解度为78%的次之;thymol分子在PVA体系中作缓慢蠕动而非跳跃运动。结论基质材料醇解度的差异对包装材料中抗菌剂的释放过程有较大影响。

Release Dynamics Simulation of Thymol from PVA-based Antibacterial Film with Different Alcoholysis Degrees

Molecular dynamics simulation was used to qualitatively and quantitatively discuss the effect of alcoholysis degree on thymol release process in PVA-based antibacterial film to visually exhibit the release process of thymol from the novel PVA/thymol antibacterial packaging film on microscopic level and reveal the release mechanism. PVA/thymol systems with different alcoholysis degrees were constructed by the software Material Studio to simulate the dynamic molecular release of thymol. Antimicrobial releasing process was analyzed considering different parameters, such as the movement of polymer chains, free volume fraction, and diffusion coefficient. The results showed that the diffusion coefficient of thymol molecule was the minimum in completely alcoholized PVA system, the maximum in 88% PVA system, followed by in 78% PVA system. It also showed the motion of thymol molecule in the PVA system was slowly creeping rather than jumping. The difference in alcoholysis degree of the matrix material had influence on the release of antibacterial agents in packaging materials.