Researchers develop ultrathin membranes
Video credit: The BP International Centre for Advanced Materials
By Idha Valeur
Researchers from Imperial College London’s Department of Chemical Engineering, UK, in collaboration with BP, have discovered new information about membrane technology in nanofilters. This will lead the way for different research opportunities and industrial applications in future.
Nanofilters have been used in the oil and gas industry to remove salt from seawater, so it can be pumped into reservoirs to extract oil reserves.
Sheetal Handa, Associate Director of the BP-ICAM at BP, said ‘Membranes give us the opportunity to take sea water and to generate the low salinity water that we need to recover more oil and maximise our operational efficiency. Crucially, this requires us to really understand the fundamental composition and workings of polyamide membranes.’
The researchers experimented with the thickness of the polyamide film of a nanofilter and reduced it to the thinnest usable, measuring 6 nanometres. The thin film the researchers found enhanced the speed of which water could pass through. Then the researchers separated the two layers of the nanofilter to study them separately. When they moved on to the second, the supporting layer, the researchers found that, despite previous beliefs, the support layer of the nanofilter acted as a second barrier after the film through which the water had to pass, thus making a noticeable impact on the performance of the filter.
Dr Zhiwei Jiang, Research Associate at the Department of Chemical Engineering and author of the accompanying study Water Transport through Ultrathin Polyamide Nanofilms Used for Reverse Osmosis, published in Advance Materials, Volume 30, Issue 15 (2018) explained that the more porous the support layer, the better the film would perform because the water has to travel a finite distance to find pores through which to escape. He added, ‘The more porous a material, the more opportunities there are for the water to filter through. In future, we hope to optimise the filter performance by ensuring higher porosity support layers are routinely included in the production of filters.’
