Block Copolymer-Directed Assembly of Mesoporous Inorganic Architectures

Mesoporous inorganic thin films represent a field of research with growing importance in applications such as sensing, optics, photovoltaic cells and protective coatings. Block copolymers (BCPs) are ideal candidates in the structure-directed assembly of mesoporous inorganic materials. When combined with well-established inorganic sol-gel chemistry methods, BCP micelles enable solution deposition of mesoporous inorganic architectures with controlled porosity, pore sizes and pore arrangement for a broad library of materials. This thesis focused on the use of the BCP poly(isobutylene)-blockpoly(ethylene oxide) (PIB-b-PEO), which is particularly suitable for co-assembly due to the high chemical incompatibility of the two blocks, enabling facile synthesis of well-ordered mesoporous materials. Specific stages of the process were examined to improve material characteristics. The addition of homopolymers in solution enabled the tuning of the material pore size and the pore connectivity. An environmentally friendly alternative for BCP template removal was developed using non-ozone generating UV light. The functionality of the mesoporous film was altered via post-synthetic grafting methods, allowing for the preparation of low refractive index antireflective coatings which maintained their performance at extreme humidity levels. Finally, the aluminosilicate sol recipe was modified to pursue improved mechanical characteristics and scratch resistance, while still maintaining low refractive index and high porosity. In each part of this work, ellipsometric porosimetry (EP) facilitated comprehensive thin film characterisation, enabling measurement of porosity, pore size, pore connectivity and mechanical properties. The results achieved through this work offer potential for the efficient preparation of functional and durable porous coatings with finely tuned characteristics