121st General Meeting of the KCS

Type Poster Presentation
Area Physical Chemistry
Room No. Event Hall
Time 4월 20일 (금요일) 11:00~12:30
Code PHYS.P-162
Subject Spatial distribution of Nanoparticles in Polymer Thin Films and its Effects on Dynamics and Thermodynamics
Authors JINKWAN JUNG, Bong June Sung*
Department of Chemistry, Sogang University, Korea
Abstract In the way that polymers confined on short length scale shows different properties to bulk, polymer thin film have been extensively studied in. In many researches, nanoparticles (NPs) are introduced in thin film as probe or purpose of tuning properties. Especially, when polymer thin films are embedding nanoparticles, such polymer thin films may be used as DNA, chemical sensors and catalysts. Because the viscosity and glass transition of polymer thin films influence their applicability, understanding the effects of NPs on the rheological properties of polymer thin films has been an issue of importance. Recent experiments showed that the glass transition temperature (Tg) of thin films depends on how NPs are distributed in thin film. Also, another study showed that according to size of polymer, Tg is changed up to 50 K. In this work, therefore, we perform extensive molecular dynamics simulations to investigate how intermolecular interactions between NPs and polymers, the size, concentration and the spatial arrangement of NPs would affect the rheological properties of polymers. We find that if the intermolecular interaction is very attractive between NPs and polymers, NPs are located mostly at the film center. On the other hand, when the interaction is not very attractive, NPs are located at the interfacial region. We also find that as the size of NPs is decreased, the location of NPs is likely to be shifted to the interfacial region. Interestingly, we find that this bifurcation behavior is energy driven process. More interestingly, in terms of dynamics, large NPs at the film center slow down the polymer diffusion significantly, while small NPs at the film surface hardly affect on the mobility of polymer.
E-mail erjk0719@daum.net