题目:Mobility Gradient of Polymer Chains at Solid Interface
报告人:Prof. Keiji Tanaka（田中敬二教授）
Polymer composites including inorganic nano-fillers have been widely used in a variety of engineering fields. The performance and functionality of the composites are closely related to the quality of the interface between the polymer and the inorganic material. In this talk, the local conformation of rubbery chains in direct contact with a quartz substrate was discussed on the basis of interface-sensitive sum-frequency generation (SFG) spectroscopy. When the film was thermally annealed, all rubber chains at the interface changed their conformation to one with a lower energy state, accompanied by the randomization of both the main and side chain parts. The presence of the mobility gradient of chains in the interfacial region is found. The segmental relaxation of chains at the interface could be slower than that of bulk chains by more than 10 orders.