Hybrid Zinc Phthalocyanine/PVDF-HFP System for Reducing Biofouling in Water Desalination: DFT Theoretical and MolDock Investigations.

Fouling and biofouling remain significant challenges in seawater desalination plants. One practical approach to address these issues is to develop anti-biofouling membranes. Therefore, novel hybrid zinc phthalocyanine/polyvinylidene fluoride-co-hexafluoropropylene (Zn(4-PPOx)4Pc/PVDF-HFP) membranes were prepared by electrospinning to evaluate their properties against biofouling. The hybrid nanofiber membrane was characterized by atomic force microscopy (AFM), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and contact angle measurements. The theoretical calculations of PVDF-HFP, Zn(4-PPOx)4Pc), and Zn(4-PPOx)4Pc/PVDF-HFP nanofibers were performed using a hybrid functional RB3LYP and the 6-31 G (d,p) basis set, employing Gaussian 09. DFT calculations illustrated that the calculated physical and electronic parameters ensured the feasibility of the interaction of PVDF-HFP with Zn(4-PPOx)4Pc via a halogen-hydrogen bond, resulting in a highly stable and remarkably reactive structure. Moreover, molecular electrostatic potential (MEP) maps were drawn to identify the reactive regions of the Zn(4-PPOx)4Pc and PVDF-HFP/Zn(4-PPOx)4Pc nanofibers. Molecular docking analysis revealed that Zn(4-PPOx)4Pc has highest binding affinity (-8.56 kcal/mol) with protein from S. aureus (1N67) mainly with ten amino acids (ASP405, LYS374, GLU446, ASN406, ALA441, TYR372, LYS371, TYR448, LYS374, and ALA442). These findings highlight the promising potential of Zn(4-PPOx) 4Pc/PVDF-HFP nanocomposite membranes in improving the efficiency of water desalination by reducing biofouling and providing antibacterial properties.

Electrospun Poly (Vinylidene Fluoride-Co-Hexafluoropropylene) Nanofiber Membranes for Brine Treatment via Membrane Distillation.

The major challenge for membrane distillation (MD) is the membrane wetting resistance induced by pollutants in the feed solution. The proposed solution for this issue was to fabricate membranes with hydrophobic properties. Hydrophobic electrospun poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber membranes were produced for brine treatment using the direct-contact membrane distillation (DCMD) technique. These nanofiber membranes were prepared from three different polymeric solution compositions to study the effect of solvent composition on the electrospinning process. Furthermore, the effect of the polymer concentration was investigated by preparing polymeric solutions with three different polymer percentages: 6, 8, and 10%. All of the nanofiber membranes obtained from electrospinning were post-treated at varying temperatures. The effects of thickness, porosity, pore size, and liquid entry pressure (LEP) were studied. The hydrophobicity was determined using contact angle measurements, which were investigated using optical contact angle goniometry. The crystallinity and thermal properties were studied using DSC and XRD, while the functional groups were studied using FTIR. The morphological study was performed with AMF and described the roughness of nanofiber membranes. Finally, all of the nanofiber membranes had enough of a hydrophobic nature to be used in DCMD. A PVDF membrane filter disc and all nanofiber membranes were applied in DCMD to treat brine water. The resulting water flux and permeate water quality were compared, and it was discovered that all of the produced nanofiber membranes showed good behavior with varying water flux, but the salt rejection was greater than 90%. A membrane prepared from DMF/acetone 5-5 with 10% PVDF-HFP provided the perfect performance, with an average water flux of 44 kg.m-2.h-1 and salt rejection of 99.8%.

Influence of hydrogenated diesel/H2O2 blend fuel on diesel engine performance and exhaust emission characterization.

The oxygenated hydro diesel (OHD) is prepared from hydrogen peroxide (H2O2), acetone, and seaweed polysaccharide. A long-term study was carried out on the OHD fuel blend stability for about a year at various temperatures. The long-term stability shows very stable properties, no easy emulsion breaking, and a long storage period. The neat diesel and blend fuel performance test was conducted at various engine speeds, 1700-3100 RPM the diesel blend with 5 wt.% and 10 wt. % of H2O2 revealed the best fraction for reducing smoke and emissions. The blend contains 15 wt.% H2O2, revealing a significant reduction in exhaust temperature without considering the engine's performance. Moreover, the performance of the OHD also revealed an economizing rate, decreasing environmental pollution and prolonging the engine's service life. The diesel engine performance and environmental evaluation leading to exhaust emissions characterization ([Formula: see text], [Formula: see text], and others). Based on the results, the various concentrations of H2O2 are an effective method for reducing the emission of diesel engines. Decreased CO, SO2, unburned hydrocarbons, and NO2 were also observed as percentages of H2O2. Due to increased oxygen content, water content and cetane number, the number of unburned hydrocarbons from diesel fuel decreased with the addition of H2O2. Therefore, the OHD blend can significantly curtail the exhaust emission of conventional diesel fuel, which will help reduce the harmful greenhouse gas emissions from diesel fuel sources.

Carbon Nanoparticles Extracted from Date Palm Fronds for Fluorescence Bioimaging: In Vitro Study.

Numerous studies have been reported on single- and multicolored highly fluorescent carbon nanoparticles (FCNPs) originating from various sources and their potential applications in bioimaging. Herein, multicolored biocompatible carbon nanoparticles (CNPs) unsheathed from date palm fronds were studied. The extracted CNPs were characterized via several microscopic and spectroscopic techniques. The results revealed that the CNPs were crystalline graphitic and hydrophilic in nature with sizes ranging from 4 to 20 nm. The unsheathed CNPs showed exemplary photoluminescent (PL) properties. They also emitted bright blue colors when exposed to ultraviolet (UV) light. Furthermore, in vitro cellular uptake and cell viability in the presence of CNPs were also investigated. The cell viability of human colon cancer (HCT-116) and breast adenocarcinoma (MCF-7) cell lines with aqueous CNPs at different concentrations was assessed by a cell metabolic activity assay (MTT) for 24 and 48 h incubations. The results were combined to generate dose-response curves for the CNPs and evaluate the severity of their toxicity. The CNPs showed adequate fluorescence with high cell viability for in vitro cell imaging. Under the laser-scanning confocal microscope, the CNPs with HCT-116 and MCF-7 cell lines showed multicolor fluorescence emissions, including blue, green, and red colors when excited at 405, 458, and 561 nm, respectively. These results prove that unsheathed CNPs from date palm fronds can be used in diverse biomedical applications because of their low cytotoxicity, adequate fluorescence, eco-friendly nature, and cheap production.

Development of Low Shrinkage Curing Techniques for Unsaturated Polyester and Vinyl Ester Reinforced Composites.

This work investigated low shrinkage curing techniques and characterization of unsaturated polyester (UPE-8340) and vinyl ester (VE-922) reinforced composite. The reinforced polymeric composite was composed using various amounts (0.1 vol.% to 0.5 vol.%) of methyl ethyl ketone peroxide (MEKP) and the proportion of UPE and VE (5 vol.%) was kept fixed throughout the study. The epoxy matrix was formed using a 3D printed acrylonitrile butadiene styrene (ABS) dumbbell shape mold and the specimen was cured in the presence of air and an inner gas (carbon dioxide) using a customized ambient closed chamber system. The influence of MEKP on UPE and VE reinforce composites was studied by investigating curing kinetics, shrinkage, tensile properties, contact angle, and thermal stability. The CO2-cured results show a significant lower shrinkage rate and higher tensile strength and flexural modulus of UPE and VE reinforced composite articles compared with air-cured reinforced composite. These macro-scale results correlate with the air-cured structure, an un-banded smooth surface was observed, and it was found that the lowest amount of MEKP revealed significant improvement in the contact angle of UPET and VE reinforced composites.

Tamisolve® NxG as an Alternative Non-Toxic Solvent for the Preparation of Porous Poly (Vinylidene Fluoride) Membranes.

Tamisolve® NxG, a well-known non-toxic solvent, was used for poly(vinylidene fluoride) (PVDF) membranes preparation via a non-solvent-induced phase separation (NIPS) procedure with water as a coagulation bath. Preliminary investigations, related to the study of the physical/chemical properties of the solvent, the solubility parameters, the gel transition temperature and the viscosity of the polymer-solvent system, confirmed the power of the solvent to solubilize PVDF polymer for membranes preparation. The role of polyvinylpyrrolidone (PVP) and/or poly(ethylene glycol) (PEG), as pore former agents in the dope solution, was studied along with different polymer concentrations (10 wt%, 15 wt% and 18 wt%). The produced membranes were then characterized in terms of morphology, thickness, porosity, contact angle, atomic force microscopy (AFM) and infrared spectroscopy (ATR-FTIR). Pore size measurements, pore size distribution and water permeability (PWP) tests placed the developed membranes in the ultrafiltration (UF) and microfiltration (MF) range. Finally, PVDF membrane performances were investigated in terms of rejection (%) and permeability recovery ratio (PRR) using methylene blue (MB) in water solution to assess their potential application in separation and purification processes.