Recent developments in nanostructured polyhedral oligomeric silsesquioxane-based materials via 'controlled' radical polymerization

摘要

Polyhedral oligomeric silsesquioxane (POSS) compounds consist of unique three-dimensional nanocages with a general composition of (RSiO_(1.5))_n, where R groups are organic moieties for enhanced physical and chemical compatibility of inorganic POSS frameworks with organic systems. Due to their unique size, structure and properties there has been tremendous progress over the last decade or so in the chemistry and applications of POSSs in various fields of materials, nanoscience and nanotechnology. Advances in synthetic polymer chemistry, particularly the advent of 'controlled' radical polymerization (CRP), namely atom transfer radical polymerization, reversible addition-fragmentation chain transfer and nitroxide-mediated polymerization, have enabled polymer chemists to integrate inorganic POSS nanocages into well-defined copolymers of almost any architecture, thus generating nanostructured materials with controlled molar masses and compositions, and well-defined and tunable morphologies. Thus, these new strategies of employing POSS nanocages in polymer chemistry could lead to potential new applications in various areas of nanoscience and nanotechnology. The present paper covers recent trends and developments over the last five years or so in POSS-based nanostructured materials via CRP. Also included is the combined CRP and 'click' chemistry approach to achieve POSS-containing well-defined hybrid copolymers.