Gold/semi-fluorinated Block Copolymer Nanocomposites Developed in Thin Film with Annealing

The self-assembly of block copolymers (BCPs) into a nanostructure with novel morphology and property has attracted an increasing interest as a new approach for materials science, chemical synthesis, and nanofabrication [1,2]. Recently, rod-coil block copolymers have received a great deal of attention since they offer an attractive strategy for the organization of many highly functional rod-like polymers such as helical biopolymers and conducting polymers with rigid π-conjugated backbones [3]. In particular, block copolymers containing conducting polymer segments, such as polyfluorene, poly(phenylene vinylene), have received much attention because of their prompt application to a wide variety of optoelectric devices. On the other hand, fluorinated block copolymers are of growing interest due to their unique properties such as very low surface energy and oil/water repellence, which cannot be achieved by corresponding non-fluorinated materials [4]. The unique properties of fluorinated polymer may be transferred to other polymeric materials by copolymerization. Polymeric nanocomposites are commonly defined as a binary mixture of functional inorganic nanomaterials dispersed in a polymeric matrix. The stabilization of nanoparticles (NPs) with polymers has been investigated by a number of groups [5,6]. Although innumerable research articles were shown in the literature for the self-assembly of BCPs and the morphological development of the hybrid films of BCPs and NPs [7-9], few works have been reported for the block copolymers of π-conjugated and fluorinated polymers which have potential applications to optical and microelectonics devices. In this work, semifluorinated BCP micelles are used as a template for composites to generate welldispersed NPs with uniform size and shape without severe aggregation. Three different annealing modes of Au-loaded block copolymeric thin films were employed: in solvent vapor, in supercritical CO2 at 70 C and in a vacuum oven at 150 C.