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ID 50508
creator
Inoue, Ryota
Yamamoto, Kazuki
Gunji, Takahiro
subject
Organosilica
Membrane
Gas separation
Pore size
Activation energy
abstract
Bis(triethoxysilyl)propane (BTESP) is a bridged-type organoalkoxysilane with a Si-C3H6-Si bond. It was utilized for membrane fabrication via a sol-gel method to achieve high permselectivity for large molecules. Membrane fabrication parameters such as the acid molar ratio (AR) in the sol and calcination temperature were evaluated for their effect on the network pore size and on gas permeation properties, as evaluated by the molecular size dependence (0.26–0.55 nm) and temperature dependence (50–200 °C) of gas permeance. BTESP membranes with different ARs (10−1, 100, and 10) showed H2/N2 and H2/CF4 selectivities of 20–30 and 640–32,000, respectively. As AR was increased, each gas permeance also increased, but H2 selectivity that corresponds to network pore size was decreased. FT-IR analysis indicated that the density of the Si-OH groups (Si-OH/Si-O-Si) of unfired gels was decreased with a higher AR, so that condensation of the Si-OH groups during the calcination process formed a dense network structure in the case of BTESP membranes with a low AR (10−1). Calcination temperature also affected the network structure of BTESP membranes. BTESP membranes calcined at different temperatures (350, 450, and 600 °C) showed H2/N2 and H2/CF4 selectivities of 10–30 and 410–32,000, respectively. A BTESP membrane calcined at high temperature (600 °C) showed loose networks since the linking units derived from BTESP were decomposed at temperatures above 500 °C, which resulted in the formation of methyl groups. In conclusion, the AR in a sol is suitable for tuning small pore sizes, while calcination temperature as a membrane fabrication parameter offers the advantage of controllability for loose network structures.
journal title
Separation and Purification Technology
volume
Volume 242
start page
116742
date of issued
2020-07-01
publisher
Elsevier
issn
1383-5866
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
author
rights
© 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
This is not the published version. Please cite only the published version. この論文は出版社版ではありません。引用の際には出版社版をご確認、ご利用ください。
relation url
department
Graduate School of Advanced Science and Engineering
note
The full-text file will be made open to the public on 1 July 2022 in accordance with publisher's 'Terms and Conditions for Self-Archiving'