两亲性嵌段共聚物在选择性溶液中吸附行为的理论研究

Theoretical Study of the Adsorption Behaviors of Amphiphilic Copolymers in Selective Solutions

通过自洽场理论方法研究了在圆形孔道以及水平基板受限情况下两亲性嵌段共聚物在选择性稀溶液中的自组装形态,考察受限管壁、管壁极性以及基板间距对聚合物吸附行为的影响.中性圆形孔道中,随着溶剂对疏水链的排斥作用增强和对亲水段的亲水作用增大,聚合物以蘑菇形状吸附于管壁上.疏水链、亲水链与溶剂的相互作用差异性越大,越容易产生吸附现象.在亲水性孔道中,吸附现象有所缓解,随着管壁对亲水段吸引作用的增强,聚合物在管壁附近形成规则排列的球状胶束.当疏水链、亲水链与溶剂的相互作用相差非常大时,即使管壁对亲水嵌段的吸附作用增强,也不能消除聚合物吸附现象.在中性水平基板中,随着基板间距的增加,两亲性嵌段共聚物在基板附近依次出现球状胶束-蘑菇状胶束-单层球状胶束-高分子刷-双层球状胶束-对称高分子刷的自组装形态.

The self-assemble morphologies of amphiphilic diblock copolymers in dilute selective solutions confined in circular tubes and horizontal slits were investigated by self-consistent field theory （SCFT）,which were affected by the confinements, the hydrophilc-lipophilic properties of tile walls and the spacing between substrates. In neutral circular tubes, with the increase of the repulsion interaction between solvent and hydrophobic blocks and the attraction interaction between solvent and hydrophilic blocks, tt^e copolymer adsorbed on the walls assembling as mushroom shapes. The more intense tile two interactions, the easier the adsorption phenomena of the amphiphilic diblock copolymers. In hydrophilic tubes,the adsorption phenomena eased,and the spherical micelles arranged regularly near the walls with the increase of the interaction between walls and hydrophilic segments of the copolymer. When the differences between the hydrophobic cbain and hydrophilic chain interactions with the solvent were very large, the adsorption phenomena of the copolymers could not be eliminated, even though the adsorption interaction between the wall and the hydrophilic blocks was enhanced. In neutral horizontal substrates, as the substrate spacing was increased, amphiphilie diblock copolymers sequentially appeared as spherical micelles-mushroom-like micelles-single spherical micelles- polymer brush-double spherical micelles-symmetrical polymer brushes near the substrates.