10.1021/acsomega.8b00632.s001
Hiroki Inde
Hiroki
Inde
Masakoto Kanezashi
Masakoto
Kanezashi
Hiroki Nagasawa
Hiroki
Nagasawa
Toshimi Nakaya
Toshimi
Nakaya
Toshinori Tsuru
Toshinori
Tsuru
Tailoring a Thermally Stable Amorphous SiOC Structure
for the Separation of Large Molecules: The Effect of Calcination Temperature
on SiOC Structures and Gas Permeation Properties
American Chemical Society
2018
Gas Permeation Properties
Thermally Stable Amorphous SiOC Structure
N 2 atmosphere
oxidative stability
network pore size
CF
Amorphous SiOC networks
SF
gas permeation properties
N 2 adsorption
SiOC membrane calcined
2018-06-13 13:57:58
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Tailoring_a_Thermally_Stable_Amorphous_SiOC_Structure_for_the_Separation_of_Large_Molecules_The_Effect_of_Calcination_Temperature_on_SiOC_Structures_and_Gas_Permeation_Properties/6509681
A SiOC
membrane with high oxidative stability for gas separation
was tailored by utilizing vinyltrimethoxysilane, triethoxysilane,
and 1,1,3,3-tetramethyldisiloxane as Si precursors. Amorphous SiOC
networks were formed via the condensation of Si–OH groups,
the hydrosilylation of Si–H and Si–CHCH<sub>2</sub> groups, and a crosslinking reaction of Si–CH<sub>3</sub> groups, respectively. The crosslinking of Si–CH<sub>3</sub> groups at temperatures ranging from 600 to 700 °C under a N<sub>2</sub> atmosphere was quite effective in constructing a Si–CH<sub>2</sub>–Si unit without the formation of mesopores, which
was confirmed by the results of N<sub>2</sub> adsorption and by the
gas permeation properties. The network pore size of the SiOC membrane
calcined at 700 °C under N<sub>2</sub> showed high oxidative
stability at 500 °C and was appropriate for the separation of
large molecules (H<sub>2</sub>/CF<sub>4</sub> selectivity: 640, H<sub>2</sub>/SF<sub>6</sub>: 2900, N<sub>2</sub>/CF<sub>4</sub>: 98).
A SiOC membrane calcined at 800 °C showed H<sub>2</sub>/N<sub>2</sub> selectivity of 62, which was approximately 10 times higher
than that calcined at 700 °C because the SiOC networks were densified
by the cleavage and redistribution reactions of Si–C and Si–O
groups.