Preparation of porous films with tadpole-shaped POSS-poly(fluorinated acrylate)s

Well-defined tadpole-shaped hybrid copolymers including POSS-poly (trifluoroethyl acrylate) (POSS-PTFEMA), POSS-poly(trifluoroethyl acrylate-b-methyl methacrylate) (POSS-PTFEMA-PMMA) and POSS-poly (methyl methacrylate-b-trifluoroethyl acrylate) (POSS-PTFEMA-PMMA) were used as precursors for the formation of well-ordered honeycomb porous films via breath figure method, and the film morphologies were characterized by scanning electron microscope (SEM). The effects for porous formation including molecular architectures, solvents utilized, solution concentrations and substrates selection were investigated, and the hydrophobic and oleophobic properties along with thermal resistance were also analyzed simultaneously. It was found that all of the three hybrid copolymers were good candidates for honeycomb films and could form highly ordered porous structures under solution concentrations ranging from 5 mg/mL to 30 mg/mL, and the pore sizes increased with the solution concentrations. The regularity of pore structures would also increase with the inducing of TFEMA groups. Compared with dichloromethane, toluene and tetrahydrofuran, chloroform was proven to be the robust solvent to form the well-ordered porous film owing its suitable volatility as well as the solubility for the hybrid copolymer. With the substrate changed from the glass slide to silicon wafer, the average pore sizes decreased, accompanying a reduction of regularity. The obtained films were proven to have well heat-resistance, hydrophobicity and oleophobicity, with contact angles for water in the range of 98°∼116° and 43° ∼66° for dihexyl.