Poly membranes block copolymer

Recently, a new class of inhibitors (nonionic polymer surfactants) was identified as promising agents for drug formulations. These compounds are two- or three-block copolymers arranged in a linear ABA or AB structure. The A block is a hydrophilic polyethylene oxide) chain. The B block can be a hydrophobic lipid (in copolymers BRIJs, MYRJs, Tritons, Tweens, and Chremophor) or a poly(propylene oxide) chain (in copolymers Pluronics [BASF Corp., N.J., USA] and CRL-1606). Pluronic block copolymers with various numbers of hydrophilic EO (,n) and hydrophobic PO (in) units are characterized by distinct hydrophilic-lipophilic balance (HLB). Due to their amphiphilic character these copolymers display surfactant properties including ability to interact with hydrophobic surfaces and biological membranes. In aqueous solutions with concentrations above the CMC, these copolymers self-assemble into micelles. 

The membrane used depends on the nature of the organics. Poly(vinyl alcohol) and cellulose acetate [14] have been used to separate alcohols from ethers. Polyurethane-polyimide block copolymers have been used for aromatic/aliphatic separations [17]... 

In contrast, organophilic PV membranes are used for removal of (volatile) organic compounds from aqueous solutions. They are typically made of rubbery polymers (elastomers). Cross-linked silicone rubber (PDMS) is the state-of-the-art for the selective barrier [1, 43, 44]. Nevertheless, glassy polymers (e.g., substituted polyacetylene or poly(l-(trimethylsilyl)-l-propyne, PTMSP) were also observed to be preferentially permeable for organics from water. Polyether-polyamide block-copolymers, combining permeable hydrophilic and stabilizing hydrophobic domains within one material, are also successfully used as a selective barrier. 

Yang DJ et al (2007) Fabrication and characterization of hydrophilic electrospun membranes made from the block copolymer of poly(ethylene glycol-co-lactide). J Biomed Mater Res A 82(3) 680-688... 

A system with interesting properties is the poly(ethylene oxide)-Wock-poly[2-(diethylamino) ethyl methacrylalc -.sfa -[3-(trimclhoxysilyl)propyl methacrylate] (PEO-b-P(DEA-sfaf-TMSPMA)) block copolymer. This self-crosslinkable copolymer formed vesicles which demonstrated pH-tunable membrane permeability [223],... 

Keywords Block copolymers, Coarse-grained models, Collective phenomena. Computer simulation, Fusion, Lipid membranes, Monte Carlo techniques, Poly-mersome, Pore formation, Self-assembly, Self consistent field theory, Vesicle... 

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