嵌段共聚物规整纳米多孔薄膜的制备与形貌调控  

Preparation and Morphology Control of Highly Ordered Nanoporous Films from Block Copolymers

作　　者：刘圆圆[1] 唐鹤玮 李倩[1] 王晓琳[1] 

机构地区：[1]清华大学化学工程系膜材料与工程北京市重点实验室,北京100084

出　　处：《高分子学报》2015年第4期466-474,共9页Acta Polymerica Sinica

基　　金：国家高技术研究发展计划(863计划;项目号2012AA03A604);清华大学自主科研计划(项目号20121088039)资助

摘　　要：通过结合嵌段共聚物自组装与非溶剂致相分离法,制备了上表面为高规整纳米直孔薄层,内部为双连续大孔支撑层的非对称薄膜结构,并考察了铸膜液浓度、溶剂挥发时间、凝固浴温度、刮膜厚度等因素对膜形貌的影响,实现对表面结构的有效调控.研究表明铸膜液浓度与挥发时间的影响有协同效应,随着铸膜液浓度的升高,规整表面孔结构所需的挥发时间减小.若铸膜液浓度不变,挥发时间的增大可使膜表面依次完成从非规整孔、规整柱状孔,再到层状孔的转变.凝固浴温度的降低有利于规整表面结构的形成.当刮膜厚度降低时,原有操作条件下的膜表面形貌形成规律将不再适用,为制备更薄的规整纳米多孔薄膜,需降低挥发时间或采用溶剂退火的方法,这一发现扩展了此类新型薄膜材料制备过程的可操作空间.This work demonstrated the combination of the self-assembly of a block copolymer with the wellestablished non-solvent induced phase separation process. Nanoporous films were obtained with well-ordered cylinder pores perpendicular to the film surfaces on top of a non-ordered bicontinous porous layer. Numerous parameters during the film formation process, including the concentration of casting solution, the solvent evaporation time, the temperature of precipitation bath, and the gate height of doctor blade, were systematically investigated to realize the effective control of surface morphology. Voronoi tessellation was first introduced to quantitatively describe the regularity of the surface pattern. It was found that the concentration of casting solution and the solvent evaporation time have synergetic influences on the porous structures. With the increase of concentration,the minimum evaporation time needed for a well-ordered porous surface decreases. If keep the concentration as a constant,the evolution of surface morphologies from non-ordered cylinder pores to ordered cylinder pores, and then to lamellar pores,was observed with the increase of evaporation time. Although lots of combinations of these two parameters can be utilized for the well-ordered structure formation, the mean pore size of the film surface didn＇ t change significantly with the change of film preparation conditions. Besides,the decrease of the temperature of precipitation bath also helped to improve surface pattern regularity. Further study revealed that once the gate height of casting solution was decreased,the evaporation of solvent induced more significant change of casting solution concentration and the solvent composition, resulting in the disappearance of well-ordered cylinder pores. Two ways, including decreasing the solvent evaporation time and applying the solvent annealing process, were proven to be very effective to prepare thinner films with well-ordered nanoporous structures. The above results greatly broaden the operation wind

关 键 词：嵌段共聚物 自组装 非溶剂致相分离 规整纳米多孔薄膜 

分 类 号：TB383.2[一般工业技术—材料科学与工程]