Solid-supported polymeric membranes

Biological membranes count among nature's most remarkable designs. They compartmentalize various cellular functions and serve as portals of entry to and egress from cells and organelles. It is therefore not surprising that they are prominent subjects of extensive fundamental research and serve as an inspiration for the development of novel materials. In an effort to mimic the intricacies that natural membranes display, significant attention has been directed at the development of synthetic membranes. One well-established membrane design is the "solid-supported membrane.'' Lipids, the natural constituents of membranes, have gained a firm footing as building blocks in this field, because the resulting membranes closely mimic natural membranes in both structure and function. However, they are prone to oxidation and membranes composed of lipids suffer the drawbacks of long-term instability and dehydration, thereby limiting their use, especially in applications that require stability in air. Amphiphilic block polymers are currently emerging as novel alternative building blocks for membranes. One great advantage is that they provide a choice of monomers and thus broaden the parameter space for synthetic membrane design. Polymers can therefore be tuned to exhibit diverse chemical, physical, and mechanical membrane properties. Membrane design today benefits markedly from a plethora of available chemistries inherent to polymers. With such options available, a variety of strategies to immobilize membranes on surfaces can be combined advantageously with membrane modifications that include functional groups, thereby generating highly multifunctional platforms. In sum, solid-supported polymeric membranes represent a promising, novel approach to membrane design that calls for the attention we provide them here.