聚苯乙烯重氮盐的单组分逐层自组装研究

ULTRATHIN FILMS PREPARED FROM A POLYSTYRENE-BASED POLYMERIC DIAZONIUM SALT VIA LAYER-BY-LAYER SELF-ASSEMbLY

利用聚苯乙烯重氮盐(PS-DAS),通过单组分逐层自组装,得到了厚度可控的超薄膜.采用紫外可见光谱,椭偏仪,原子力显微镜等对自组装膜的增长和表面形貌进行了表征,并对其交联前后的性质进行了研究.结果表明,利用逐层自组装步骤可以制备膜厚均匀增长的PS-DAS膜.组装过程中的吹干步骤对自组装膜的增长起重要作用.在加热条件下,超薄膜可以发生交联反应,得到疏水的表面。

A polystyrene-based polymeric diazonium salt（PS-DAS） was used to demonstrate that its ultrathin films could be prepared through a sequential growth manner.The films were prepared by dipping the substrates in the PS-DAS solution,washing with deionized water,and drying repeatedly.The growing process of untrathin films was monitored by UV-Vis spectroscopy and ellipsometry.The surface morphology and wettability of the films were characterized by AFM and water contact angle measurements.Results showed that PS-DAS could form thin films through uniformly layer-by-layered growth manner by a repeated dipping-coating-drying process.The UV-Vis and ellipsometry results showed that the amount of PS-DAS adsorbed in each dipping cycle was almost the same.In the dipping-washing-drying cycles,the drying step after each deposition was critical for growth of the PS-DAS ultrathin film.After heating treatment,cross-linking occurred in the thin films.The water contact angle changed from 77° to 90.7° after heating,which indicated the decomposition of the diazonium functional groups.The solvent resistance of the PS-DAS ultrathin films was also greatly enhanced by cross-linking.The observations are helpful for understanding the unique self-assembling properties of polymeric diazonium salt which could be used to prepare ultrathin films.