Nafion薄膜表面微结构转变

Surface Microstructure Transformation in Nafion Films

采用旋涂法,以不同表面预处理的硅片为衬底镀上Nafion膜,将硅片上薄膜进行退火处理,得到不同衬底上退火前后的Nafion膜.通过原子力显微镜对薄膜的表面形貌进行了表征和观察,基于慢正电子束的正电子湮没多普勒谱获得薄膜中正电子湮没线性参数S与正电子注入能量E的关系曲线,用接触角测定仪测得不同衬底的Nafion膜表面接触角.研究结果表明,不同预处理的衬底硅片对Nafion膜表面的微结构有影响,热处理引起薄膜中分子链运动,导致退火前后薄膜表面层亲水基的分布发生了转变.

In this paper, Nafion films were spin-coated onto silicon wafers which were subjected to different types of surface pretreatments. Nation membranes were annealed at 150 ℃ for 2 h in a vacuum oven. Surface morphologies and contact angles of the prepared Nafion films were measured by an atomic force microscopy （AFM） and a contact angle instrument, respectively. Meanwhile, the Nation membranes on different substrates were characterized by posi- tron annihilation doppler broadening spectroscopy based on a slow positron beam. Results show that the treatment of substrates has effect on the microstructure of Nafion films, and thermal treatment cause the movement of molecular chain, leading to the rearrangement of hydrophilic groups and hydrophobic segments in Nafion membranes.