高聚物薄膜表面堆起结构的变温原子力显微术研究

利用原子力显微镜研究了不同温度（室温至58℃）及扫描速率（1—20μm/s）对高聚物PtBuA薄膜（厚度为133nm）表面上形成的突起结构和周期状堆起结构的影响.发现较快的扫描速率或较低的温度易产生随机的团状突起，较慢的扫描速率或较高的温度则易形成周期状突起结构（周期宽度约为100nm），且温度和扫描速率对周期状堆起结构的影响定性满足高聚物的时温等效关系.此外,当温度低于高聚物的玻璃化转变温度Tg时，表面粗糙度随扫描次数的增加而增加；高于Tg时，表面粗糙度基本不变.实验表明堆起结构的形成需要高聚物有较大的 关键词： 高聚物 原子力显微术 纳米技术

Bundle structure formation on polymer film by varying temperature AFM scanning

The bump and bundle structures formed by atomic force microscopic tip scanning on 133nm thick PtBuA films were examined from room temperature to 58℃ with various scanning velocities of 1—20μm/s. It was observed that the bump structures were readily created at low temperature and high scanning velocity, while the bundles were created at high temperature and low scanning velocity. The period of bundles was about 100nm. The effects of temperature and scanning velocity could be explained by the equivalence of temperature and time of viscoelasticity of the polymer. The roughness increased with the scanning numbers at low temperatures while kept almost the same at high temperatures. All the above results indicated that the bump and bundle structure could be formed more frequently on the polymer surface at glassy state due to its larger modulus, smaller adhesion and weaker relaxation, as compared to its rubber state.