Sat, Nov 1st, 2014 | Polymer chemistry | By BioNews
Thanks to this adjustable pore size, the permeability and selectivity of the membrane can be tuned, for separation purposes or controlled release. The UT scientists see possibilities in analysis and separation of proteins, for example. An extra advantage of the new membranes is the change in colour that takes place. The process of protein detection and analysis becomes visible in an easy way, which may lead to a cheap type of biosensor.
Changing membrane pore size by oxidation and reduction (Image Credit: University of Twente
Another application of the smart membrane is in catalysis. Here, it is possible to kill two birds with one stone. Whilst the pore size and permeabiliteit can be altered using a chemical reaction with silver salt, nanosize particles of silver are deposited on the membrane at the same time. Silver is an important catalyst in many applications.
The membrane research is conducted by the Materials Science and Technology of Polymers group, led by Prof. Julius Vancso. This group is part of the MESA+ Institute for Nanotechnology of the University of Twente.
Scientific Summary from PubMed:
Redox-responsive porous membranes can be readily formed by electrostatic complexation between redox active poly(ferrocenylsilane) PFS-based poly(ionic liquid)s and organic acids. Redox-induced changes on this membrane demonstrated reversible switching between more open and more closed porous structures. By taking advantage of the structure changes in the oxidized and reduced states, the porous membrane exhibits reversible permeability control and shows great potential in gated filtration, catalysis, and controlled release.
Kaihuan Zhang, Xueling Feng, Dr. Xiaofeng Sui, Dr. Mark A. Hempenius and Prof. G. Julius Vancso, Breathing Pores on Command: Redox-Responsive Spongy Membranes from Poly(ferrocenylsilane)s, Angewandte Chemie International Edition, DOI: 10.1002/anie.201408010