In this work we investigate the potential of a polyethylene glycol-polypropylene glycol-polyethylene glycol, tri-block copolymer as a template for a hybrid carbon/silica membrane for use in the non-osmotic desalination of seawater. Silica samples were loaded with varying amounts of tri-block copolymer and calcined in a vacuum to carbonize the template and trap it within the silica matrix. The resultant xerogels were analyzed with FTIR, Thermogravimetric analysis (TGA) and N2 sorption techniques, wherein it was determined that template loadings of 10 and 20% produced silica networks with enhanced pore volumes and appropriately sized pores for desalination. Membranes were created via two different routes and tested with feed concentrations of 3, 10 and 35 ppk of NaCl at room temperature employing a transmembrane pressure drop of <1 atm. All membranes demonstrated a salt rejection capacity of >85% (in most cases >95%) and fluxes higher than 1.6 kg m−2 h−1. Furthermore, the carbonized templated membranes displayed equal or improved performance compared to similarly prepared non-templated silica membranes, with the best results of a flux of 3.7 kg m−2 h−1 with 98.5% salt rejection capacity, exceeding previous literature reports. In addition, the templated silica membranes exhibited superior hydrostability demonstrating their potential for long-term operation.

Abstract:In this work we investigate the potential of a polyethylene glycol-polypropylene glycol-polyethylene glycol, tri-block copolymer as a template for a hybrid carbon/silica membrane for use in the non-osmotic desalination of seawater. Silica samples were loaded with varying amounts of tri-block copolymer and calcined in a vacuum to carbonize the template and trap it within the silica matrix. The resultant xerogels were analyzed with FTIR, Thermogravimetric analysis (TGA) and N 2 sorption techniques, wherein it was determined that template loadings of 10 and 20% produced silica networks with enhanced pore volumes and appropriately sized pores for desalination. Membranes were created via two different routes and tested with feed concentrations of 3, 10 and 35 ppk of NaCl at room temperature employing a transmembrane pressure drop of <1 atm. All membranes demonstrated a salt rejection capacity of >85% (in most cases >95%) and fluxes higher than 1.6 kg m −2 h −1 . Furthermore, the carbonized templated membranes displayed equal or improved performance compared to similarly prepared non-templated silica membranes,

Herein, this paper perhaps reports for the first time that a series of glass fiber reinforced poly(butylene succinate) composites (GRPBS) using the flameretardant system composed of aluminum hypophosphite (AHP) and melamine cyanurate (MC) are fabricated by melt blending method. When the composite is loaded of 20 wt% AHP/MC with mass ratio about 2:1, it achieves UL-94 V-0 rating with the value of limited oxygen index (LOI) significantly increasing to 30%. Meanwhile, the thermo-gravimetric analysis also well proves that the composite can produce more char residues because of the addition of AHP, however, its thermal stability would slightly decreases. In addition, the results obtained from micro-scale combustion calorimetry testing reveal that total heat release and peak of heat release rate for GRPBS composites combined with AHP and MC both significantly reduce, and the similar results are easily found in cone calorimeter testing. Additionally, the residues after LOI testing are further investigated by Fourier transform infrared spectrometry and scanning electron microscopy, which definitely confirm the formation of the compact char layer with crater-like structure. Mechanism analysis indicates the significant enhancement of flame-retardant efficiency principally benefits from the cooperative work dominated by AHP and MC.