title: Highly Porous 3D Fibrous Nanostructured Bioplolymer Films with Stimuli-Responsive Porosity via Phase Separation in Polymer Blend.
abstract: The article describes a novel polymer blend system that yields thin films with unique porous nanoscale morphologies and environmentally responsive properties. The blend consists of sodium alginate and amine end-terminated PEG, which undergoes phase separation during film deposition. The blend films can be readily converted into highly porous membranes using facile treatment with a solution containing divalent ions. The resulting membranes are primarily comprised of alginate hydrogel, whereas the PEG phase is removed from the films during exposure to the saline solution, yielding nanometer-sized pores. The alginate gel phase forms a three-dimensional nanostructure which can be best described as a filament or fibrous network. Because such network geometry is untypical of polymer blends in thin films, possible reasons for the observed phase morphology are discussed. Because of ionizable carboxyl groups, the hydrogel membranes demonstrate responsive behavior, in particular a drastic change in their porosity between a highly porous state and a state with completely closed pores in response to changes in the solution pH. The pore-size tunability can be explored in multiple applications where the regulation of material's permeability is needed.
authors.affiliation: †Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, United States.
authors.forename: Igor
authors.initials: I
authors.lastname: Tokarev
authors.affiliation: †Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, United States.
authors.forename: Venkateshwarlu
authors.initials: V
authors.lastname: Gopishetty
authors.affiliation: †Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, United States.|‡Nanostructured Materials Laboratory, 110 Riverbend Road, The University of Georgia, Athens, Georgia 30602, United States.
authors.forename: Sergiy
authors.initials: S
authors.lastname: Minko
mesh_terms: D000464:Alginates / Q000737:chemistry; D001704:Biopolymers / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry*; D016062:Porosity; D013499:Surface Properties
chemical_list: D000464:Alginates; D001704:Biopolymers; D006603:Hexuronic Acids; D008567:Membranes, Artificial; D020723:Glucuronic Acid
keywords: alginate; membrane; nanostructured thin film; polymer blend; porous material