The Efficiency of Dispersing Nano-silica Particles in Epoxy Resin Using Zirconia Ball Media by Mechanical Stirring

This paper explores the efficiency of dispersing nano-silica particles in epoxy resin using zirconia ball media by mechanical stirring. Stirring speed (RPM), the time of milling and temperature are the main parameters studied at a fixed media: total silica-epoxy volume ratio. The results show that ball media and heating aid dispersion. The stir speed and duration affects the nano-silica dispersion, given that all the other conditions (zirconia ball media to nano-silica-epoxy ratio and intermittent heating) remain constant. At low stirring speed, short stirring duration is more suitable. On the reverse, higher stirring duration is the more suitable condition to disperse nano-silica at high stirring speed of 500 rpm.Keywords: Dispersing Nano-Silica Particles, Epoxy Resin, Zirconia Ball Media, Mechanical Stirring

Nano silica dispersion in epoxy: the investigation of heat, milling speed and duration effect

Nano composites are a promising development but the challenge of homogenous and discrete dispersion of the nano fillers are barriers that must be overcome before they can be effectively implemented. Although the common dispersion methods such as particle surface modification, comprehensive milling metrologies and the usage of solvents bear results, these are time consuming and not cost effective. In this paper, we explore the efficiency of coupling the usage of ball-media and heat on the dispersion of nano silica in epoxy. No solvents are involved. The effects of milling speed and duration are also studied albeit under a fixed ball media : silica-epoxy volume ratio of 3:5. The experiment set-up involves a simple 3-blade mixer, round bottom flask and 60 ? m zirconia ball. At nano silica loading of 10 wt % the nano silica clusters are systematically reduced from 1.5 - 2 ? m to 100 - 200 nm with the usage of ball media and application of heat. At the optimum milling speed and duration of 500 rpm for 5 hours, the aggregate sizes were further reduced to 30 - 70 nm, which is almost a discrete dispersion

An optimized sol–gel synthesis of stable primary equivalent silica particles

An optimized synthesis of nanometer silica particles via hydrolysis and condensation of tetraethylorthosilicate (TEOS) is described. At the optimum experimental conditions, homogeneous and stable silica nanoparticles with mean particles size of 7.1 ± 1.9 nm were obtained. The particle size is in a good agreement with primary particles. The size, size distribution (SD) and the yield of silica were controlled by the concentration of the reactants, ammonia feed rate, temperature and mixing mode. The increase in TEOS concentration resulted in bigger and multi-model distributed powder, while high temperature and magnetic agitation produced a highly aggregated powder. However, higher H2O/TEOS ratio and lower ammonia concentration at slower feed rate produced particles in the range of 10–14 nm. It was also found that the concentration of silanol group increased significantly with the decrease in particle size, especially below 40 nm. The optimized technique developed is simple and reproducible, affording a high yield of ∼75% of nanometer silica in a primary size range