A facile route for fabricating novel polyelectrolyte complex membrane with high pervaporation performance in isopropanol dehydration

STRUCTURE, MORPHOLOGY AND ANTIMICROBIEL PROPERTIES NANOCOMPOSITES BASED ON POLYELECTROLYTE COMPLEXE AND METALIC NANOPARTICLES ARGENTUM AND CUPRUM

Using metods of x-ray diffraction (XRD), transmission electron microscopy (TEM) and antimocrobial properties with test-bacteriums E. coli and S. aureus vere investigated nanocomposites type polymer-metal based on stoichiometric polyelectrolyte complexe (PEC) and metalic nanoparticles argentum and cuprum. Samples PEC with amorphous structure vere formated based on polyelectrolytes natural parentage: Na-carboxymethyl cellulose and β-cyclodextrin that functionalyzed amino grups. Using sorbtion by samples PEC of ions salts AgNO3 and CuSO4 , that losung in water (concentration 0,1 mole/l) vere formated samples of triples polyelectrolyte-metalic coplexes (TPMC). By using method XRD showed existence in volyme TPMC of areas (with amorphous strucrure) of fragmented macromoleculare coils of PEC (macroligande) that co-ordinated as cations Сu2+, so cations Ag+. In result of chemical reduced (using salt NaBH4) this cations transition metalі in volum TPMC, vere formed polymer– metalic nanocomposites with metal nanoparticles argentum and cuprum, what shown using metod XRD. By using metod TEM vere installed, what in nanocomposites metalic nanoparticles cuprum whose middle size 12,4 nm, whereas nanoparticles argentum – 4,3 nm. Antimicrobial tests polymer-metal nanocomposites shown, that antimicrobial properties possess nanoparticles argentum and cuprum.

Recent developments in polymeric nano-based separation membranes

Polymeric nanomaterials, which have tuneable chemical structures, versatile functionalities, and good compatibility with polymeric matrices, have attracted increasing interest from researchers for the construction of polymeric nano-based separation membranes. With their distinctive nanofeatures, polymeric nano-based membranes show great promise in overcoming bottlenecks in polymer membranes, namely, the trade-off between permeability and selectivity, low stability, and fouling issues. Accordingly, recent studies have focused on tuning the structures and tailoring the surface properties of polymeric nano-based membranes via exploitation of membrane fabrication techniques and surface modification strategies, with the objective of pushing the performance of polymeric nano-based membranes to a new level. In this review, first, the approaches for fabricating polymeric nano-based mixed matrix membranes and homogeneous membranes are summarized, such as surface coating, phase inversion, interfacial polymerization, and self-assembly methods. Next, the manipulation strategies of membrane surface properties, namely, the hydrophilicity/hydrophobicity, charge characteristics, and surface roughness, and interior microstructural properties, namely, the pore size and content, channel construction and regulation, are comprehensively discussed. Subsequently, the separation performances of liquid ions/molecules and gas molecules through polymeric nano-based membranes are systematically reported. Finally, we conclude this review with an overview of various unsolved scientific and technical challenges that are associated with new opportunities in the development of advanced polymeric nano-based membranes.

Recent Advances in the Fabrication of Membranes Containing "Ion Pairs" for Nanofiltration Processes

In the face of serious environmental pollution and water scarcity problems, the membrane separation technique, especially high efficiency, low energy consumption, and environmental friendly nanofiltration, has been quickly developed. Separation membranes with high permeability, good selectivity, and strong antifouling properties are critical for water treatment and green chemical processing. In recent years, researchers have paid more and more attention to the development of high performance nanofiltration membranes containing “ion pairs”. In this review, the effects of “ion pairs” characteristics, such as the super-hydrophilicity, controllable charge character, and antifouling property, on nanofiltration performances are discussed. A systematic survey was carried out on the various approaches and multiple regulation factors in the fabrication of polyelectrolyte complex membranes, zwitterionic membranes, and charged mosaic membranes, respectively. The mass transport behavior and antifouling mechanism of the membranes with “ion pairs” are also discussed. Finally, we present a brief perspective on the future development of advanced nanofiltration membranes with “ion pairs”.

Preparation of jujube-cake structure membranes through in situ polymerization of hyperbranched polysiloxane in ethylene-vinyl acetate matrix for separation of ethyl acetate from water

The addition of hyperbranched polysiloxane (HPSiO) could improve the hydrophobic of the membranes which is helpful to recover EA from water.