To tailor properties of polymer composites are very important for their applications.Very small concentrations of nanoparticles can significantly alter their physical characteristics.In this work,molecular dynamics si...To tailor properties of polymer composites are very important for their applications.Very small concentrations of nanoparticles can significantly alter their physical characteristics.In this work,molecular dynamics simulations are performed to study the thermodynamic and structural properties of polystyrene/C60(PS/C60)composites.The calculated densities,glass transition temperatures,and coefficient of thermal expansion of the bulk PS are in agreement with the experimental data available,implying that our calculations are reasonable.We find that the glass transition temperature Tg increases accordingly with an added concentration of C60 for PS/C60 composites.However,the self-diffusion coefficient D decreases with increase of addition of C60.For the volumetric coefficients of thermal expansion(CTE)of bulk PS and PS/C60 composites,it can be seen that the CTE increases with increasing content of C60 above Tg(rubbery region).However,the CTE decreases with increasing content of C60 below Tg(glassy region).展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11704329)the Scientific Research Fund of Sichuan Provincial Education Department of China(Grant No.15ZB293)+1 种基金the Pre-Research Project of Yibin University of China(Grant No.2019YY06)the Open Research Fund of Computational Physics Key Laboratory of Sichuan Province at Yibin University of China(Grant No.JSWL2014KF02).
文摘To tailor properties of polymer composites are very important for their applications.Very small concentrations of nanoparticles can significantly alter their physical characteristics.In this work,molecular dynamics simulations are performed to study the thermodynamic and structural properties of polystyrene/C60(PS/C60)composites.The calculated densities,glass transition temperatures,and coefficient of thermal expansion of the bulk PS are in agreement with the experimental data available,implying that our calculations are reasonable.We find that the glass transition temperature Tg increases accordingly with an added concentration of C60 for PS/C60 composites.However,the self-diffusion coefficient D decreases with increase of addition of C60.For the volumetric coefficients of thermal expansion(CTE)of bulk PS and PS/C60 composites,it can be seen that the CTE increases with increasing content of C60 above Tg(rubbery region).However,the CTE decreases with increasing content of C60 below Tg(glassy region).
