Wail Falath

Chlorine resistance of reverse osmosis membranes is usually reported as the fraction of salt rejection retained after chlorination, a metric that depends on the initial rejection. This secondary reanalysis quantifies the dependence for published data on substrate-free poly(vinyl alcohol) (PVA) membranes containing multi-walled carbon nanotubes (MWCNT), Gum Arabic (GA) or graphene oxide (GO). Within the solution–diffusion model, the change in salt passage was expressed as an observed ratio, k_R, which also includes any change in flux or swelling and is not a direct measure of chemical degradation. Judged by rejection retention, all three fillers reduced the relative rejection loss about tenfold at their best-performing loadings. Relative to each study’s control, however, GO produced no consistent reduction in k_R across loadings (3.11 ± 0.48 versus 3.20); MWCNT produced a moderate reduction (1.16–1.49 versus 1.76) and GA a reduction only at 0.1–0.5 wt%; these differences persisted, marginally for MWCNT, at rejection uncertainties of two percentage points. For GO and GA, most or all of the apparent improvement (97–111% in the more robust decomposition order) reflected the higher initial rejection. Rejection retention therefore overstates the benefit of fillers that raise selectivity; the salt-passage ratio offers a simple correction when post-exposure flux is unavailable.

Polypropylene-reinforced composites exhibit a trade-off between stiffness and toughness. In this study, the impact of incorporating Polyolefin Elastomers (POE) and Polyvinyl Alcohol (PVA) fibers as individual and hybrid reinforcement to Talc-reinforced polypropylene composites in the presence of a compatibilizer was explored. The main focus of this study was on achieving an optimal stiffness/toughness balance. Several ternary and quaternary hybrid composite systems were developed and analyzed. All components were melt blended using a twin-screw extruder, then injection molded for subsequent mechanical and morphological analysis. The predominant energy-absorbing mechanism for PVA fibers was found to be fiber pull-out. For Talc particles, the dominating micromechanical deformation process was debonding due to poor adhesion. A large stiffness of approximately 1.4 - 1.65 GPa Young's modulus and notched Izod impact strength ranges between 170 and 200 J/m were attained with the quaternary hybrid system, PP/POE/Talc/PVA fibers. These values represent a notable increase, with Young's modulus being 45% higher and the izod impact strength surpassing that of the control sample by over 500%. In addition to imparting strength and toughness to PP, PVA fibers have a lower density than other conventional reinforcements, like Carbon/Glass fibers and Talc. This makes this hybrid composite suitable for automotive applications.

The recent development of fabricating thin film nanocomposite (TFN) membranes by utilizing two-dimensional (2D) metal–organic frameworks (MOFs) nanosheets has drawn significant attention due to their potential to enhance membrane performance. The current work focuses on synthesizing 2D nickel-based MOF nanosheets by exfoliating their 3D pillared layered MOF counterpart and then decorating the polyamide (PA) layer of the TFN membranes with different concentrations of the nanosheets. All modified TFN membranes exhibited improved pure water flux (> 50% for the TFN membrane with the highest nanosheet concentration, N-3 with 0.015% 2D-Ni MOF nanosheet) while retaining excellent salt rejection for both monovalent (NaCl) and divalent salts (> 95% for the TFN membrane with the highest nanosheet concentration) compared to the pristine MPD/TMC membrane. Remarkable anti-fouling properties against a 200 ppm bovine serum albumin (BSA) protein foulant, evidenced by its substantial water flux recovery ratio of 91.7% were observed by the modified TFN membranes. Therefore, this current approach of modifying the active PA layer of TFN membranes with 2D MOF nanosheets is quite effective and efficient for fabricating efficient desalination membranes.

Polypropylene‐reinforced composites mostly exhibit a trade‐off between stiffness and toughness. In this study, the impact of incorporating polyolefin elastomer (POE) and Polyvinyl Alcohol (PVA) fibers as individual and hybrid reinforcement to glass fiber‐reinforced polypropylene composite in the presence of a compatibilizer was explored. The main focus was on achieving an optimal stiffness/toughness balance. Several ternary and quaternary hybrid composite systems were developed and analyzed. All components were melt‐blended using a twin‐screw extruder and then injection molded for subsequent mechanical and morphological analysis. A significant stiffness of approximately 2.4 GPa Young's modulus, and notched izod impact strength ranges between 250 and 400 J/m can be attained with the quaternary hybrid system, PP/GF/POE/PVA fibers. Its performance can be controlled by altering the POE/PVA fibers ratio to achieve the targeted stiffness/toughness balance. These values represent a remarkable increase, with Young's modulus being 120% higher and the izod impact strength surpassing that of the control sample by over 800%. The achieved results aligned with the requirements of the automotive industry, so the developed composites could have a high potential for automotive parts.Highlights: Ternary and quaternary hybrid systems were fabricated by a twin‐screw extruder. An improvement of 120% in stiffness and 800% in toughness was observed. Distinct micromechanical deformation mechanisms were identified. Remarkable stiffness‐toughness balance was achieved. Reduction in weight makes the system suitable for automotive applications.