Porous Polyelectrolytes: The Interplay of Charge and Pores for New Functionalities

Abstract

The past decade has witnessed rapid advances in porous polyelectrolytes and there is tremendous interest in their synthesis as well as their applications in environmental, energy, biomedicine, and catalysis technologies. Research on porous polyelectrolytes is motivated by the flexible choice of functional organic groups and processing technologies as well as the synergy of the charge and pores spanning length scales from individual polyelectrolyte backbones to their nano‐/micro‐superstructures. This Review surveys recent progress in porous polyelectrolytes including membranes, particles, scaffolds, and high surface area powders/resins as well as their derivatives. The focus is the interplay between surface chemistry, Columbic interaction, and pore confinement that defines new chemistry and physics in such materials for applications in energy conversion, molecular separation, water purification, sensing/actuation, catalysis, tissue engineering, and nanomedicine.

Controlling Structural Transformation of Polyelectrolyte Films for Spatially Encapsulating Functional Species

“…The formation of microporous structures within a film can provide considerable internal volume to load guest species for further applications . For a microporous (PEI/PAA‐N 3 ) 8 film, guest species can be dissolved in solvents and loaded into the film through wicking method.…”

“…Incorporating various functional species into polyelectrolyte films can be attractive for many applications, including but not limited to detection, catalysis, drug delivery, and tissue engineering . Although many encapsulation approaches have been developed, most of them tend to incorporate guest species into polyelectrolyte films uniformly in the direction parallel to the surface of substrates .…”

“…In the past decades, the dynamic features of polyelectrolyte films have aroused considerable interests in a variety of fields, including separation, electronics, energy, and optics . We recently demonstrated that the structural transformation of microporous polyelectrolyte films can be enabled at saturated humidity, under the condition that the interchain interactions can be highly weakened and the mobility of polyelectrolyte chains can be activated .…”

Surface characterization of polysaccharide scaffolds by inverse gas chromatography regarding application in tissue engineering

“…In recent years, scaffolds produced by freeze‐drying polyelectrolyte complexes (PECs), formed by electrostatic interactions established between oppositely charged polysaccharides, have been reported in literature . Produced by a straightforward method that does not require toxic chemicals or organic solvents, this type of scaffolds has the potential to be used in many tissue engineering applications .…”

“…In recent years, scaffolds produced by freeze‐drying polyelectrolyte complexes (PECs), formed by electrostatic interactions established between oppositely charged polysaccharides, have been reported in literature . Produced by a straightforward method that does not require toxic chemicals or organic solvents, this type of scaffolds has the potential to be used in many tissue engineering applications . Chitosan, being the only common polysaccharide of cationic nature and being extensively used as biomaterial, with well‐established favourable biological properties, has been used as the cationic component, while a variety of polysaccharides, such as alginate, pectin, hyaluronic acid, carboxymethyl cellulose, and carrageenan, have been used as the anionic counterpart …”