摘要
为实现对PEO-b-PS薄膜微相分离形貌和纳米结构的调控,通过原子转移自由基聚合制备了不同嵌段结构的PEO-b-PS,使用原子力显微镜研究了嵌段结构及热处理条件对溶液旋涂制备的PEO-b-PS薄膜微相分离形貌的影响.结果表明:PEO-b-PS薄膜发生微相分离后呈现PS锥状突起的分散形貌;提高热处理温度使微相分离加快,相分离程度提高,PS微区尺寸增大;延长热处理时间使PS锥状突起更加明显;PEO链长一定时,PS链长增加导致PS锥状微区数量和尺寸增加;PS链长一定时,PEO链长增加使PS锥状微区数量减少;嵌段比一定时,嵌段共聚物分子量增加使PS微区尺寸增大.通过调节PEO-b-PS嵌段结构和薄膜的热处理条件,可以实现对PEO-b-PS薄膜微相分离结构的控制.
To adjust microphase separation morphologies and nanostructures in the thin films of diblock copoly- mers of ethylene oxide and styrene （PEO- b -PS）,the PEO- b- PS with different block lengths and ratios were synthesized by using atom transfer radical polymerization （ATRP）technique. The block eopolymers were dissolved in THF and PEO - b - PS thin films were prepared by spin coating. The measurements of AFM were conducted to investigate the effects of block structure and heat treatment on the microphase separation morphol- ogies of PEO - b - PS thin films. It was found that the microphase separation occurred in PEO - b - PS films, with cone-shaped PS microphases projecting from the surface of the films. The higher the heat treatment tem- perature was, the quicker the microphase separation developed, and the larger the PS microphase regions were. As the heat treatment process prolonged, the cone-shaped morphology of PS microphases became clearer. When the chain length of PEO block .in PEO - b - PS was fixed, the longer chain length of the PS block led to increa- ses in both the number and the size of cone-shaped PS microphase regions. With the same chain length of PS block in PEO - b - PS, the increase of chain length of PEO block led to the decrease of the number of cone- shaped PS microphases. Also, the increase of molecular weight of PEO - b - PS made cone-shaped PS mi- crophase become larger. The microphase separation structures of PEO - b - PS thin films could be adjusted by controlling the block structures of PEO - b - PS and the heat treatment conditions.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2012年第4期99-103,共5页
Materials Science and Technology
基金
国家自然科学基金资助项目(20674032)
