From channel proteins to industrial biomimetic membrane technology

Abstract

Biomimetic membrane technology, based on the use of nano-scale functional additives in the form of channel proteins or artificially made channel structures, represents an attractive way of optimizing membrane separation technology. However, the nano-scale nature of the additives inherently points to the challenge in up-scaling the membranes to square meter areas. Thus, the ability to up-scale the processes involved in manufacturing will be crucial for translating the protein/nano-science into technology. Here we discuss how highly selective aquaporin proteins can be used to enhance the performance of the classical thin film composite membrane, and how this can be used in relevant membrane elements and module form factors. A particular up-scaling challenge lies in securing large scale membrane protein production. We demonstrate our framework for making batch amounts which are compatible with the large scale production of biomimetic membranes for water purification based on the use of the E. coli expression system.

Improved reverse osmosis thin film composite biomimetic membranes by incorporation of polymersomes

“…Here, the membrane AL is doped with transmembrane proteins facilitating water transport exemplified by the use of the bacterial aquaporin protein isoform Aquaporin Z (AqpZ) [12,13]. However, industrial scale production and incorporation of aquaporins into the AL is not a trivial task due to the need for elaborate protein purification and stabilization steps [14].…”

Increasing the success rate of interfacial polymerization on hollow fibers by the single-step addition of an intermediate layer

“…However, in some applications, nonplanar membrane geometries are preferred. For example, the hollow fiber (or tubular) configuration is needed when feed solutions with either high viscosity and/or high concentration of total suspended solids are being filtered [22]. For such hollow fiber (HF) geometries, the application of a TFC layer at the inner surface of HF supports is even more challenging as the liquid-liquid interface cannot be controlled via gravity.…”

Biomimetic Membranes as a Technology Platform: Challenges and Opportunities

“…The significance of low reverse salt flux is particularly important in applications in which the concentrated FO feed solution is the desired product—such as in up-concentration of beverages/fragrances (e.g., fruit juice and coffee). This was recently demonstrated in the case of coconut milk up-concentration [ 43 ].…”

“…In terms of cost all elements in the aquaporin TFC design—except the proteins—are available in bulk commodities as they already are extensively used in classical dense membrane (e.g., RO) production. The aquaporin protein is not yet a bulk commercial product, but yields as high as 45 g/100 L fermentation has been shown with excellent purifications obtained using cost-effective detergents [ 43 ]. In terms of environmental concerns, the classical TFC membrane design is an accepted technology as exemplified by state-of-the art RO membranes.…”