Amino-functionalized polymethylmethacrylate-co-polyethyleneimine (PMMA-co-PEI) as a template to fabricate nano-silica

Polymer template method is a general and facile to fabricate nano-structural matters. Some amphiphilic polymers or co-polymers were used as templates to synthesize nano-silica. In this contribution, polymethacrylate (PMMA) employed was a commercial hydrophobic acrylate polymer and grafted with a strong hydrophilic polyethyleneimine (PEI, a densely amino-groups polymer) via aminolysis reaction, which was monitored and identified by means of FT-IR. The aminolysis reaction was optimized and the suitable reaction time was 12 h at 110 °C. The obtained copolymer, PMMA-co-PEI was applied as a template to prepare nano-silica spheres that was characterized by a scanning electron microscope (SEM). When the dosage was 1 wt% of purified PMMA-co-PEI, the resultant nano-silica had uniform particle size, and average diameter of 311 nm. When the dosage of PMMA-co-PEI was increased to 2 wt% or 4 wt%, the resultant particles became bigger and inclined to aggregate. Nano-silica afforded by this template method will be a promising material in application of catalysis, energy, biology and chromatographic analysis and the copolymer of PMMA-co-PEI will be a template for producing metal oxide nano-spheres.