Highly CO2 selective mixed matrix membranes of polysulfone based on hetaryl modified SBA-16 particles

The effect of filler loading and APTES treatment on the performance of PSf/SBA-15 mixed matrix membranes

The fabrication of mixed matrix membranes (MMMs) is of particular importance due to their advantages over neat membranes. The performance of MMMs is a function of the type and fraction of the nanoparticles in the membrane. Moreover, the proper interaction of the polymer and nanoparticles affects the MMMs performance. In this study polysulfone (PSf)/SBA-15 mesoporous silicas MMMs were prepared and their performance was evaluated for CO2/CH4 gas separation. SBA-15 mesoporous silicas were previously synthesized and functionalized with 3-aminopropyltriethoxysilane by post-synthesis treatment. Fourier transform infrared spectroscopy, field emission scanning electron microscopy, N2 adsorption–desorption, and Brunauer–Emmett–Teller analysis was applied to examine the functional groups, morphology, and textural properties of the unmodified and modified mesoporous silica in the prepared membrane, respectively. The effects of modified and unmodified SBA-15 particle loading were investigated for the gas separation performance of PSf/SBA-15 membranes. The experimental results illustrate that a higher modified mesoporous silica loading leads to an increase in gas permeance and gas pair selectivity. The highest increase in permeability and selectivity was related to the incorporation of S2 and AP-S2 into the PSf matrix, respectively.

Immobilized phytases: an overview of different strategies, support material, and their applications in improving food and feed nutrition

Phytases are the most widely used food and feed enzymes, which aid in nutritional improvement by reducing anti-nutritional factor. Despite the benefits, enzymes usage in the industry is restricted by several factors such as their short life-span and poor reusability, which result in high costs for large-scale utilization at commercial scale. Furthermore, under pelleting conditions such as high temperatures, pH, and other factors, the enzyme becomes inactive due to lesser stability. Immobilization of phytases has been suggested as a way to overcome these limitations with improved performance. Matrices used to immobilize phytases include inorganic (Hydroxypatite, zeolite, and silica), organic (Polyacrylamide, epoxy resins, alginate, chitosan, and starch agar), soluble matrix (Polyvinyl alcohol), and nanomaterials including nanoparticles, nanofibers, nanotubes. Several surface analysis methods, including thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and FTIR analysis, have been used to characterize immobilized phytase. Immobilized phytases have been used in a broad range of biotechnological applications such as animal feed, biodegradation of food phytates, preparations of myo-inositol phosphates, and sulfoxidation by vanadate-substituted peroxidase. This article provides information on different matrices used for phytase immobilization from the last two decades, including the process of immobilization and support material, surface analysis techniques, and multifarious biotechnological applications of the immobilized phytases.