Membrane-based separation technologies have drawn significant interest because of their compactness, low energy consumption, and ability to be easily integrated with existing processes. There has been significant interest in the utilization of natural materials derived from sustainable and renewable resources for membrane fabrication. Cellulose is one of the promising polymers which has been extensively studied in membrane fabrication and modification due to its abundant availability, non-toxicity and biodegradability.
View Article and Find Full Text PDFThermoelectric membrane distillation has shown promise as a new membrane distillation technique capable of improving energy consumption metrics. This study features an experimental design approach to investigating the performance of a thermoelectric membrane distillation system. Screening and full factorial designs were implemented in Minitab 16 to determine the optimal process conditions for minimizing the specific energy consumption of the system.
View Article and Find Full Text PDFThis paper proposes the use of monovalent selective electrodialysis technology to concentrate the valuable sodium chloride (NaCl) component present in seawater reverse osmosis (SWRO) brine for direct utilization in the chlor-alkali industry. To enhance monovalent selectivity, a polyamide selective layer was fabricated on commercial ion exchange membranes (IEMs) through interfacial polymerization (IP) of piperazine (PIP) and 1,3,5-Benzenetricarbonyl chloride (TMC). The IP-modified IEMs were characterized using various techniques to investigate changes in chemical structure, morphology, and surface charge.
View Article and Find Full Text PDFThin-film composite (TFC) structure has been widely employed in polymeric membrane fabrication to achieve superior performance for desalination and water treatment. In particular, TFC membranes with a thin active polyamide (PA) selective layer are proven to offer improved permeability without compromising salt rejection. Several modifications to TFCs have been proposed over the years to enhance their performance by altering the selective, intermediate, or support layer.
View Article and Find Full Text PDFElectrically-conductive membranes became the center of attention owing to their enhanced ion selectivity and self-cleaning properties. Carbon nanostructures (CNS) attain high electrical conductivity, and fast water transport. Herein, we adopt a water-based, simple method to entrap CNS within Alginate network to fabricate self-cleaning nanofiltration membranes.
View Article and Find Full Text PDFHigh optical transparency combined with high optical haze are essential requirements for optoelectronic substrates. Light scattering caused by haze is responsible for increasing light harvesting in photon-absorbing active materials, hence increasing efficiencies. A trade-off between transparency and haze is common in solar substrates with high transparency (~90%) and low optical haze (~20%), or vice versa.
View Article and Find Full Text PDFLight-management films made entirely from natural polymers with tunable haze properties are developed via a facile approach. A novel green method based simply on the blending of network cellulose (NC)/water suspension with alginate (CaAlg) aqueous solution is proposed. The unique NC suspension created by a controlled hydrolysis of microcrystalline cellulose acts as the scatterer media while alginate serves as the transparent host matrix.
View Article and Find Full Text PDFNanosized zeolite Y is used in various applications from catalysis in petroleum refining to nanofillers in water treatment membranes. Ball milling is a potential and fast technique to decrease the particle size of zeolite Y to the nano range. However, this technique is associated with a significant loss of crystallinity.
View Article and Find Full Text PDFHydrolysis is the heart of the lignocellulose-to-bioethanol conversion process. Using enzymes to catalyze the hydrolysis represents a more environmentally friendly pathway compared to other techniques. However, for the process to be economically feasible, solving the product inhibition problem and enhancing enzyme reusability are essential.
View Article and Find Full Text PDFThis work describes the development of sulfated cellulose (SC) polymer and explores its potential as an electrolyte-membrane for direct methanol fuel cells (DMFC). The fabrication of our membranes was initiated by the preparation of the novel sulfated cellulose solution via controlled acid hydrolysis of microcrystalline cellulose (MCC). Ion-conductive crosslinked SC membranes were prepared following a chemical crosslinking reaction.
View Article and Find Full Text PDFAlthough free-standing sheets of multiwalled carbon nanotubes (MWCNT) can provide interesting electrochemical and physical properties as electrodes for redox flow batteries, the full potential of this class of materials has not been accessible as of yet. The conventional fabrication methods produce sheets with micro-porous and meso-porous structures, which significantly resist mass transport of the electrolyte during high-current flow-cell operation. Herein, we developed a method to fabricate high performance macro-porous carbon nano-foam free standing sheets (Puffy Fibers, PF), by implementing a freeze-drying step into our low cost and scalable surface-engineered tape-casting (SETC) fabrication method, and we show the improvement in the performance attained as compared with a MWCNT sheet lacking any macro pores (Tape-cast, TC).
View Article and Find Full Text PDFIn this work, a hydrocracking catalyst, nano zeolite Y-NiO-WO is reshaped into nanofibrous form. This novel composite fiber show good mechanical strength together with a uniform elemental distribution for both the acidic and hydrogenation components as confirmed through scanning transmission electron microscopy. The catalyst is tested for -heptane hydrocracking in a continuous flow fixed-bed reactor at reaction temperatures of 350 °C and 400 °C with a time on stream of 180 minutes.
View Article and Find Full Text PDFHydrophobic PVDF-HFP nanowebs were fabricated by a facile electrospinning method and proposed for harvesting fog from the atmosphere. A strong adhesive force between the surface and a water droplet has been observed, which resists the water being shed from the surface. The water droplets on the inhomogeneous nanomats showed high contact angle hysteresis.
View Article and Find Full Text PDFCellulose consists of amorphous and crystalline regions. It is the crystalline regions which may be exploited to produce nanocrystalline cellulose (NCC). In order to extract nanocrystalline cellulose from native cellulose, sulfuric acid hydrolysis is typically used.
View Article and Find Full Text PDFThe complex, multi-level super molecular architecture of cellulose has been the subject of interest for several decades. The mechanical, physical, and environmental properties of cellulose depend on the molecular, supramolecular and morphological structure of the cellulose. This paper gives a brief overview to micro structural analysis of cellulose, as studied using transmission electron microscopy and scanning electron microscopy.
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