Novel membrane makes filtration cheaper

University of Arkansas researchers have developed a novel membrane that can reduce the cost and improve the efficiency of filtration, a critical process in industries ranging from foods and pharmaceuticals to petrochemicals and paint.

'Not only is this protein-based membrane cheaper to produce than the traditional polymer membranes, it is a 'green' technology,' explained Bob Beitle, associate professor of chemical engineering. 'This is the first membrane of this size created from renewable resources.'

The membrane can be created from whey protein isolates (WPI), a waste product of the food processing industry. It is best suited for microfiltration and ultrafiltration processes, in which all but very tiny particles are filtered out of a liquid.

'A good example of ultrafiltration is milk processing,' said Beitle. 'When milk is processed, an ultrafilter is used to remove all of the particles of butterfat and protein chunks before the milk is pasteurised. Interestingly, it is this whey protein that is used in making the WPI membrane.'

Beitle's colleague, graduate student Juinn Teo, first developed the WPI membrane while working on improving the biocompatibility of membranes.

Biocompatibility is an issue for membranes in medicine because incompatible polymeric membranes can cause blood clots and other serious consequences, according to Teo. He and Beitle are currently working on applications for the membrane.

'This is a novel approach to membrane fabrication and, more importantly, the WPI membrane is highly compatible for a number of biomedical applications,' Teo explained. 'Polymeric membranes have been sued since the beginning, but there is a definite need for more biocompatible membrane materials for biomedical applications and other separations.'

Although medical applications are still some time in the future, other industrial applications are not.

The WPI membrane is reportedly highly resistant to solvents found in the food and pharmaceutical industries. Because of this quality, it can be used to refine vegetable oils and in other solvent-intensive processes.

'This is a classic example of someone asking the right questions and looking at something in a different way,' said Beitle. 'Membranes for filtration and protein whey isolates have been around a long time, but Teo looked at them in a different way and was able to produce a new and very promising membrane.'