<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Porous silica, silica-cobalt, silica-zirconia and zirconia membranes were synthesized by the sol-gel method. Multi-step coating (two, six, and ten steps) was used to reduce the defectiveness of the mesoporous layer. Scanning electron microscopy (SEM) images indicated that an increase in the number of coating steps improved the mesoporous layer quality. The results obtained from gas permeability tests with nitrogen and argon, however, indicated a reduction in the gas permeability with increasing coating steps. The reduction in gas permeability from two to six coating steps was more pronounced than from sixto ten- coating steps. It was found that six-step coating was economically justified in obtaining a uniform mesoporous layer. The results of pore radius calculations by Knudsen flow mechanism revealed that the pores in the silica, silica-cobalt, and zirconia membranes were in the mesoporous range. The sols with a mean particle size more than 100 nm are not recommended for synthesis of mesoporous layer free of defects. Furthermore, the type of acid used as a catalyst is also important in obtaining a layer without defectiveness.</p>
</abstract>

Porous silica, silica-cobalt, silica-zirconia and zirconia membranes were synthesized by the sol-gel method. Multi-step coating (two, six, and ten steps) was used to reduce the defectiveness of the mesoporous layer. Scanning electron microscopy (SEM) images indicated that an increase in the number of coating steps improved the mesoporous layer quality. The results obtained from gas permeability tests with nitrogen and argon, however, indicated a reduction in the gas permeability with increasing coating steps. The reduction in gas permeability from two to six coating steps was more pronounced than from sixto ten- coating steps. It was found that six-step coating was economically justified in obtaining a uniform mesoporous layer. The results of pore radius calculations by Knudsen flow mechanism revealed that the pores in the silica, silica-cobalt, and zirconia membranes were in the mesoporous range. The sols with a mean particle size more than 100 nm are not recommended for synthesis of mesoporous layer free of defects. Furthermore, the type of acid used as a catalyst is also important in obtaining a layer without defectiveness.

Effect of coating steps on uniformity and gas permeability of mesoporous layers in ceramic membranes

Faculty of Chemistry & Chemical Engineering

Materials Science-Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Porous silica, silica-cobalt, silica-zirconia and zirconia membranes were synthesized by the sol-gel method. Multi-step coating (two, six, and ten steps) was...

Effect of coating steps on uniformity and gas permeability of mesoporous layers in ceramic membranes

Published Online: Apr 13, 2021

Page range: 535 - 544

Received: Feb 23, 2018

Accepted: Apr 23, 2019

DOI: https://doi.org/10.2478/msp-2020-0063

Keywords
ceramic membrane, sol-gel, coating steps, defectiveness, gas permeability

© 2020 Shahram G. Pakdehi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Effect of coating steps on uniformity and gas permeability of mesoporous layers in ceramic membranes

Published Online: Apr 13, 2021

Page range: 535 - 544

Received: Feb 23, 2018

Accepted: Apr 23, 2019

DOI: https://doi.org/10.2478/msp-2020-0063

Keywordsceramic membrane, sol-gel, coating steps, defectiveness, gas permeability

© 2020 Shahram G. Pakdehi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
ceramic membrane, sol-gel, coating steps, defectiveness, gas permeability