The dynamic immiscibility between vegetable oil and organic silica precursors during sol-gel synthesis was used to tailor the microstructure of gels made with tetraethoxysilane (TEOS) or tetraethoxysilane+methyltrimethoxysilane (MTMS). Vegetable oil was investigated as an environmentally friendly and cheaper alternative to many other porogens. Oil concentrations of 9.09 v/v% and 33.33 v/v% were studied. For both TEOS and TEOS+MTMS gels, the miscibility of the oil and precursor decreases as the silica gel network forms, leading to oil-rich regions within the silica matrix. Gels containing MTMS maintained partial miscibility with the oil during gel formation due to the non-hydrolysable methyl groups on the MTMS. The pore structure of MTMS gels appeared more interconnected compared to the isolated pores observed in gels made with only TEOS. To create membranes with hierarchical pore structures, solvent exchanges were performed on gels or dried gels (i.e., xerogels) were calcined. The effect of the methyl group was also observed in the results of the time sweep rheology, as the addition of oil to the TEOS+MTMS gels caused an increase in the time to form the spanning gel. The trend was the opposite for oil additions to TEOS gels, which only contained polar groups. Xerogel membranes made with TEOS+MTMS had higher specific surface areas (SSAs) than those made with TEOS. For oil concentrations of 33.33 v/v%, xerogels made from TEOS+MTMS had an average SSA of 1068 + 113 m2 g-1, an order of magnitude higher than the average SSA of 103 + 6 m2 g-1 for xerogels made with TEOS.
Baskaran, Karthikeyan, et al. "Membrane synthesis via in-situ pore formation in silica gels through dynamic miscibility with soybean oil." Colloids and Surfaces. A, Physicochemical and Engineering Aspects, vol. 636, Mar. 2022. https://doi.org/10.1016/j.colsurfa.2021.128183
Baskaran, Karthikeyan, Ali, Muhammad, Riley, Brian J., Bates, Jeffrey, Zharov, Ilya, & Carlson, Krista (2022). Membrane synthesis via in-situ pore formation in silica gels through dynamic miscibility with soybean oil. Colloids and Surfaces. A, Physicochemical and Engineering Aspects, 636. https://doi.org/10.1016/j.colsurfa.2021.128183
Baskaran, Karthikeyan, Ali, Muhammad, Riley, Brian J., et al., "Membrane synthesis via in-situ pore formation in silica gels through dynamic miscibility with soybean oil," Colloids and Surfaces. A, Physicochemical and Engineering Aspects 636 (2022), https://doi.org/10.1016/j.colsurfa.2021.128183
@article{osti_1872428,
author = {Baskaran, Karthikeyan and Ali, Muhammad and Riley, Brian J. and Bates, Jeffrey and Zharov, Ilya and Carlson, Krista},
title = {Membrane synthesis via in-situ pore formation in silica gels through dynamic miscibility with soybean oil},
annote = {The dynamic immiscibility between vegetable oil and organic silica precursors during sol-gel synthesis was used to tailor the microstructure of gels made with tetraethoxysilane (TEOS) or tetraethoxysilane+methyltrimethoxysilane (MTMS). Vegetable oil was investigated as an environmentally friendly and cheaper alternative to many other porogens. Oil concentrations of 9.09 v/v% and 33.33 v/v% were studied. For both TEOS and TEOS+MTMS gels, the miscibility of the oil and precursor decreases as the silica gel network forms, leading to oil-rich regions within the silica matrix. Gels containing MTMS maintained partial miscibility with the oil during gel formation due to the non-hydrolysable methyl groups on the MTMS. The pore structure of MTMS gels appeared more interconnected compared to the isolated pores observed in gels made with only TEOS. To create membranes with hierarchical pore structures, solvent exchanges were performed on gels or dried gels (i.e., xerogels) were calcined. The effect of the methyl group was also observed in the results of the time sweep rheology, as the addition of oil to the TEOS+MTMS gels caused an increase in the time to form the spanning gel. The trend was the opposite for oil additions to TEOS gels, which only contained polar groups. Xerogel membranes made with TEOS+MTMS had higher specific surface areas (SSAs) than those made with TEOS. For oil concentrations of 33.33 v/v%, xerogels made from TEOS+MTMS had an average SSA of 1068 + 113 m2 g-1, an order of magnitude higher than the average SSA of 103 + 6 m2 g-1 for xerogels made with TEOS.},
doi = {10.1016/j.colsurfa.2021.128183},
url = {https://www.osti.gov/biblio/1872428},
journal = {Colloids and Surfaces. A, Physicochemical and Engineering Aspects},
volume = {636},
place = {United States},
year = {2022},
month = {03}}
Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC05-76RL01830
OSTI ID:
1872428
Report Number(s):
PNNL-SA-165506
Journal Information:
Colloids and Surfaces. A, Physicochemical and Engineering Aspects, Journal Name: Colloids and Surfaces. A, Physicochemical and Engineering Aspects Vol. 636
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 623, Issue 1https://doi.org/10.1016/j.nima.2010.02.241