Plasma-enhanced modification of the pore size of ceramic membranes

• Published in: Desalination Vol. 184; no. 1; pp. 99 - 104
• Main Authors: Alvarez, S., García, A., Manolache, S., Denes, F., Riera, F.A., Álvarez, R.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2005; Elsevier
• Subjects: Applied sciences; Chemical engineering; Cold-plasma techniques; Exact sciences and technology; Inorganic membranes; Membrane modification; Membrane separation (reverse osmosis, dialysis...); Pollution; Pore size; Reactors; Cold-plasma techniques; Pore size; Inorganic membranes; Membrane modification; Water treatment; Plasma gas; Gas mixture; Plasma reactor; Retention; Water permeability; Design; Membrane separation; Tubular membrane; Cold plasma; Ultrafiltration; Titanium oxide; Ceramic materials; Inorganic membrane
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2005.03.065

The aim of this work was to reduce the pore size of inorganic ultrafiltration membranes using cold-plasma techniques. Kerasep tubular multi-channel ceramic membranes (Orelis S.A., France) with a TiO 2-ZrO 2 selective layer on an Al 2O 3-TiO 2 support and molecular weight cut-offs (MWCO) of 15,000 g/mol were used. Experiments were performed using an originally designed RF-twin chamber plasma reactor, where the tubular membrane is an integrated part of the reaction chamber. It was equipped with a 40 kHz power supply. Membrane surfaces were first cleaned and activated by exposing them to O 2 plasmas. To carry out the membrane modification a mixture of TiCl 4-O 2 was used as plasma-gas. This step was performed under a RF-power of 50 w and for 30 min. Different pressures (50, 100, 150 and 200 mTorr) were considered for the gas-mixture, while the percentage of TiCl 4 in the mixture was of 10%. The cold-plasma treatment was able to create TiO 2-type structures on the membrane surface. After the treatment water permeability through the membrane decreased, while PEG retention increased. These observations can be related to a decrease of the membrane pore size.