Fabrication of inverse opal structure and its application on the morphological control of block copolymers

Abstract

In this thesis, high-quality inverse opal structure as a template was fabricated via novel technique and its application on morphological control of symmetric diblock copolymers were demonstrated. In chapter 2, two (2D) and three dimensional (3D) inverted opal (IO) structures are conveniently fabricated from a single poly(vinylpyrrolidone) (PVP) incorporated 3D colloidal crystal template by controlling the lift-up speed and temperature of infiltrated silica sol. With room temperature of silica sol and high lift-up speed (6 mm/min), a 3D colloidal crystal structure can be retained after infiltration. Consequently, a 3D IO structure is obtained after calcinations. With -4℃ of silica sol and slow lift-up speed (1.5 mm/min), the solidified silica sol is detached automatically from the substrate, so that 2D IO structure is left to the lifted substrate. Using this simple process, it is possible to fabricate 2D and 3D IOs having various lattice distances from the 3D colloidal template. In addition, the 2D IO films can physically confine smaller particles within the holes and also it is possible to regulate the internal structure of the block copolymer morphology depending on the surface properties of inverted opal. In chapter 3, we demonstrated morphological control of diblock copolymer confined in 2D and 3D IO templates. Using IO templates, we can obtain not only interconnected BCPs particle with uniform size but also various morphologies of BCPs via simple treatment. Moreover, we can easily control the size and morphology of BCPs particle by changing the template with different size. Besides, we observed the cross-section of interconnected BCPs nanoparticles, which showed the detailed inside pattern of particles.