Dr. Xufeng Dong, Associate Professor, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China

Biography: Dr. Xufeng Dong joined the faculty of School of Materials Science and Engineering in Dalian University of Technology (Dalian) in 2011. Prior to that, he served as a post-doctoral fellow at Dalian University of Technology from 2009-2010. He holds a B.S. in Polymer Science and Engineering (Harbin Institute of Technology 2003), a M. S. in Materials Science (Harbin Institute of Technology 2005), and a Ph.D. in Disaster Mitigation Engineering (Harbin Institute of Technology 2009). He had over 60 peer-reviewed publications. His research interests focused on smart composites, electrorheological elastomers, magnetorheological elastomers, soft matters and biomedical composites.

Speech Title: Enhanced Electrorheological Properties of Elastomers Containing Coupling Agent Modified TiO2 Particles
Abstract: Electrorheological (ER) elastomers are generally made by dispersing dielectric particles in cross-linked polymers. They present reversible change in shear storage modulus in an applied electric field owning to the interaction between polarized particles. However, the ER effect of those EREs is lower than the magnetorheological (MR) effect of most MR elastomers, which limit their applications in practical engineering. As a kind of particles filled polymer composites, the particles/rubber interface may play an important role on the ER effect of EREs, which has been largely overlooked in the past decade. In this study, two coupling agents, 3-(trimethoxysilyl) propylmethacrylate (A174) and triethoxyvinylsilane (VTEO), were used to modify the surface of TiO2 particles to enhance the interface between the particles and the rubber matrix. Bridging structures can be observed for the modified particles filled EREs, indicating enhanced TiO2 particles/silicon rubber interface. Besides, the surface modified TiO2 particles filled EREs present higher crosslink density and higher tensile strength, which are indirect evidences of the enhanced particles/rubber interface. The storage modulus sensitivity of the EREs with the modified particles is higher than that with the unmodified particles. The results indicate the ER effect of the ER elastomers can be improved by enhancing the particles/rubber interface.
Keywords: Electrorheological (ER) elastomers; Coupling agent; Interface; Storage modulus