No abstract

Pervaporation (PV) has shown great promise in water desalination technology. In this work, laponite XLG-Poly (vinyl alcohol) (PVA-Lap) mixed matrix membranes (MMMs) were fabricated to investigate the elaboration of desalination of high-salinity water by pervaporation. The influence of laponite content on the morphology, chemical structure and hydrophilicity of the membranes was investigated. In addition, salt transport properties in the membranes were observed. Moreover, the effect of different laponite content in the PVA matrix on the desalination performance was observed at temperatures from 40°C to 70 °C and feed solutions with up to 10 wt% NaCl. The prepared MMMs showed higher hydrophilicity and roughness of the surface and higher mechanical stability. The higher water flux of 58.6 kg/m 2 .h with a salt rejection over 99.9 % was achieved using 2 wt% laponite XLG MMMs desalinating 3 wt% aqueous NaCl solution at 70 °C. The salt permeability in the membrane was lower by two orders of magnitude than that of water. The water/salt selectivity increased, while the water permeability decreased, with increasing of laponite content in the membrane.

Lignin has attracted particular interest for the preparation of functional polymers, and the dispersion and compatibility of lignin in a polymer are key parameters determining properties. In this work, the Pickering emulsion template method was used to introduce lignin nanoparticles into poly(lactic acid) (PLA) with improved dispersion. The effect of lignin as the stabilizer of Pickering emulsions was studied in the paper as well as its influence on the thermal, rheological and mechanical properties of the blends prepared. The obtained PLA/lignin films had reduced light transmission in the UV light region, and Young's modulus of PLA/lignin blends increased, while their tensile strength and elongation-at-break decreased as compared to neat PLA film. The introduction of lignin improved crystallinity of PLA from 7.5% to over 15%, and increased its decomposition temperature by about 10 °C. The lignin in the blends prepared by the Pickering emulsion template approach had much larger load bearing capacity than the dispersed lignin particles in the usual melt blended material, because of better dispersion and smaller particles. All the results indicated that the Pickering emulsion template method improves the dispersion of lignin (over 5.0 wt%) in PLA and improve UV protection, crystallinity, decomposition temperature and Young's modulus of PLA, which had an advantage in industrial applications.