ABSTRACT

Self-assembly of binary block copolymer blends in thin film induced by solvent vapor annealing has been systematically studied. The diblock copolymers polystyrene-b-poly(2-vinylpyridine) with different molecular weights and volume fractions were blended with different molar ratios to cast thin films on silica substrate by spin coating. The films were annealed separately in the vapor of ethanol or toluene over time to induce morphology transformations from spheres, gyroids, and bicontinuous nanostructures, depending on the blending ratio, solvent selectivity, and annealing time, as investigated by atomic force microscopy and X-ray photoelectron spectroscopy. The formation and transformation mechanism of the self-assembly structure are discussed in the context of solvent-copolymer interactions. This study provides new insights into the simple manipulation of self-assembled nanostructures of block copolymer thin films.

摘要

已经系统地研究了溶剂蒸汽退火引起的薄膜中二元嵌段共聚物共混物的自组装。将具有不同分子量和体积分数的二嵌段共聚物聚苯乙烯-b-聚（2-乙烯基吡啶）以不同的摩尔比共混以通过旋涂在二氧化硅基底上流延薄膜。随时间推移，将膜分别在乙醇或甲苯的蒸气中退火，以诱导球形，螺旋形和双连续纳米结构的形态转变，这取决于混合比，溶剂选择性和退火时间，如原子力显微镜和X射线研究光电子能谱。在溶剂-共聚物相互作用的背景下讨论了自组装结构的形成和转化机理。