(158d) Understanding the Effects of Synthesis and Treatment On Network Stability and Surface Chemistry of Silica
AIChE Annual Meeting
2012
2012 AIChE Annual Meeting
Engineering Sciences and Fundamentals
Particle Synthesis and Stabilization
Monday, October 29, 2012 - 4:20pm to 4:40pm
The present
study investigated the effects of synthesis, pretreatment and hydrothermal
treatment on the porosity and surface chemistry of the silica nanoparticles with
the overall goal of controlling these material properties. Silica nanoparticles were synthesized
over a wide size range (6 – 500nm) and characterized via BET, TEM, and
surface silanol quantification via probe molecule titration and UV-Vis
spectroscopy. Calcination in air at 500 °C increased structural stability, making
the silica resistant to etching in water as reflected in constant
surface areas through
multiple cycles of calcination and hydrothermal treatment. An interesting
correlation between surface silanol concentration and apparent surface area, measured
by both nitrogen and argon physisorption, was observed. Dehydroxylation of the sample resulted
in a decrease of measured surface area, proportional
to the reduction of surface silanol concentration. The effect of surface silanols on gas adsorption is
currently being investigated via Monte Carlo computational studies.
See more of this Group/Topical: Engineering Sciences and Fundamentals