Y.-H. Na, J. Diep, B. Davis, A. Vora, G. Dubois, R. Al-Rasheed, M. Nassar, G. Geise, B. Freeman
IBM Almaden Research Center, US
desalination, RO, polyamide
We have developed polyamide bi-layer thin film composite membranes to enhance RO-desalination performance. The polyamide bi-lyer membrane consists of conventional non-substituted aromatic polyamide under-layer and HFA-substituted aromatic polyamide top-layer, which can be esaily prepared by a process we call sequential interfacial polymerization. The performance of the bi-layer membrane was intriguing: excellent combination of salt rejection and water flux with efficient arsenic and boron removal was obtained. This new approach to fabricate layered polyamide membranes resulted in the synergy of the characteristic properties of two layers, thus we think it has promise as a new design strategy for improving membrane performance. In the presentation, we will discuss the rational for performance enhancement and the key features of sequential interfacial polymerization which might be critical in the scale-up phase.