Polyvinyl alcohol and aminated cellulose nanocrystal membranes with improved interfacial compatibility for environmental applications.

Biogas up-gradation is a useful method to control CO2 emission and enhance the green process. The demand for renewable sources is increasing due to the depletion of fossil fuels. Thin-film nanocomposites functionalized with tunable molecular-sieving nanomaterials have been employed to tailor membranes with enhanced permeability and selectivity. In this work, the cellulose nanocrystals as a filler in the polyvinyl alcohol matrix are prepared to achieve high-performance facilitated transport membranes for CO2 capture. Considering the mechanical stability, interfacial compatibility and high moisture uptake of the filler, the main objective of this work was to develop a novel aminated CNC (Am-CNC)/polyvinyl alcohol nanocomposite membrane for biogas upgrading. The hydroxyl groups (O-H) on the reducing end of the cellulose nanocrystals were replaced by amino groups (N-H2). It was discovered through Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) that adding Am-CNCs in PVA membranes shows an increment in the CO2 removal and effectively upgrades the biogas. The effect of change in concentration of Am-CNC and feed pressure was investigated. The results showed that with increasing Am-CNC concentration up to 1.5 wt%, the thickness of the selective membrane layer increased from 0.95 to 1.9 µm with a decrease in the moisture uptake from 85.04 to 58.84%. However, the best CO2 permeance and selectivity were achieved at 0.306 m3/m2.bar.h (STP) and 33.55, respectively. Furthermore, there was a more than two-fold decrease in CO2 permeance and a 27% decrease in the CO2/CH4 selectivity when the feed pressure increased from 5 to 15 bar. It was revealed that PVA/Am-CNC membrane is high performing for the biogas upgradation.

A multifunctional vanillin-infused chitosan-PVA hydrogel reinforced by nanocellulose and CuO-Ag nanoparticles as antibacterial wound dressing.

Wound healing is an intricate and ever-evolving phenomenon that involves a series of biological processes and multiple stages. Despite the growing utilization of nanoparticles to enhance wound healing, these approaches often overlook properties like mechanical stability, toxicity, and efficacy. Hence, a multifunctional wound dressing is fabricated using Chitosan-PVA membrane crosslinked with vanillin and reinforced with nano-cellulose and CuO-Ag nanoparticles in this study. FTIR, SEM, and XRD were employed to study the morphology and structural properties of the membrane. Biomedical tests including biodegradability, antimicrobial study, cytotoxicity, and animal models were conducted to evaluate the membrane's performance as a wound healing material. The membrane displayed impressive mechanical strength, measuring as high as 49.985 ± 2.31 MPa, and had a hydrophilic nature, with moisture retention values up to 98.84 % and swelling percentages as high as 191.67 %. It also demonstrated biodegradable properties and high cell viability of up to 92.30 %. Additionally, the fabricated membranes exhibited excellent antimicrobial activity against both gram-positive and gram-negative bacteria, with maximum zone of inhibition measuring 16.8 ± 0.7 mm and 9.2 ± 0.1 mm, respectively. Moreover, the membranes also demonstrated superior wound healing properties. These results suggested great potential of fabricated membranes as an effective wound dressing material.

Graphene-grafted bimetallic MOF membranes for hazardous & toxic contaminants treatment.

Development of membrane with improved carbon dioxide (CO2) gas separation capability is a significant challenge. However, the fabrication of membrane that efficiently separate and purification CO2-containing gases has been the focus of global attention. Cellulose Acetate (CA) has robust reinforcing characteristics when incorporated within a suitable polymer matrix. This work focus on the synthesis of novel mixed matrix membranes (MMMs) by introducing Graphene-grafted bimetallic MOFs in Cellulose Acetate polymer. The graphene-grafted bimetallic MOF (GG-BM MOFs) was prepared by a hydrothermal technique. Whereas, the solution casting approach used to fabricate membranes. The 1-5 wt% of GG-BM MOFs incorporated into the CA matrix. The mechanical, hydrophilicity and adsorption characteristics of fabricated MMMs were investigated. The crystallinity of MMM enhanced after the addition of GG-BM MOFs. In addition, the mechanical characteristics of MMMs were improved with the incorporation of GG-BM MOFs inside the polymer matrix. Maximum stress and strain was obtained for 2 wt% MMM (36.4 N/mm2 and 11% respectively). The CO2 adsorption performance was evaluated at 10 bar and 45 °C. The FTIR results represent insignificant bond shifting with the addition GG-BM MOFs at these conditions. The overall results showed that MMMs containing 2 wt% GG-BM MOFs have good adsorption properties for CO2 i.e 3.15 wt% of CO2. The MMMs have shown a decrease in the mechanical properties and CO2 adsorption at the higher GG-BM MOFs loading due to the presence of agglomeration which was confirmed through SEM. Thus, the addition of GG-BM MOFs in the CA matrix positively altered the physicochemical characteristics of the resulting MMMs, which could assist them in achieving remarkable CO2 adsorption at 2 wt%.

Wood as a green and sustainable alternative for environmentally friendly & flexible electronic devices.

Electronic are usually constructed from non-renewable, non-biodegradable, and hazardous materials. Due to the frequent upgrading or discarding of electronic devices, which contributes significantly to environmental pollution, there is a high demand for electronics made from renewable and biodegradable materials with less harmful components. To this end, due to their flexibility, strong mechanical, and optical properties, wood-based electronics have become very appealing as substrates especially for flexible electronics and optoelectronics. However, incorporating numerous features including high conductivity and transparency, flexibility, and mechanical robustness into an environmentally friendly electronic device remains very challenging. Herein, authors have provided the techniques used to fabricate sustainable wood based flexible electronics coupled with their chemical, mechanical, optical, thermal, thermomechanical, and surface properties for various applications. Additionally, the synthesis of a conductive ink based on lignin and the development of translucent wood as a substrate are covered. Future developments and broader applications of wood-based flexible materials are discussed in the final section of the study, with an emphasis on their potential in fields including wearable electronics, renewable energy, and biomedical devices. This research improves upon prior efforts by demonstrating new ways to simultaneously attain better mechanical and optical qualities and environmental sustainability.

Development of ZnO-GO-NiO membrane for removal of lead and cadmium heavy metal ions from wastewater.

The presence of heavy metal (HM) ions, such as lead, cadmium, and chromium in industrial wastewater discharge are major contaminants that pose a risk to human health. These HMs should separate from the wastewater to ensure the reuse of the discharged water in the process and mitigate their environmental impacts. The distinctive mechanical properties of 2D graphene oxide (GO), and the antifouling characteristics of metal oxides (ZnO/NiO) nanoparticles combined to produce composites supporting special features for wastewater treatment. This study employed solution casting and phase inversion methods to synthesize PSF-based GO, ZnO-GO, and ZnO-GO-NiO mixed matrix membranes and the effects of variation in composition on the removal of lead (Pb2+) and cadmium (Cd2+) ion was examined. Several characterization techniques including X-ray diffraction analysis, scanning electron microscopy, energy dispersive X-ray, and Fourier transform infrared spectroscopy were applied to analyze the synthesized NPs and MMMs. The composite membranes were also analyzed in terms of their porosity, permeability, hydrophilicity, surface roughness, zeta potential, thermal stability, mechanical strength, and flux regeneration at various transmembrane pressures (2-3 kgcm-2), and pH value (5.5). The highest adsorption capacities were measured to be 308.16 mg g-1 and 354.80 mg g-1 for Pb (II) and Cd (II), respectively, for membrane (M4_A) having 0.3 wt% of ZnO-GO-NiO nanocomposite, at 200 mg L-1 of feed concentration and 1.60 mL min-1 of permeate flux. The Pb (II) and Cd (II) adsorption breakthrough curves were created, and the results of the experiment were compared with the data of the Thomas model.

Anticancer Properties of Ru and Os Half-Sandwich Complexes of N,S Bidentate Schiff Base Ligands Derived from Phenylthiocarbamide.

The versatile coordinating nature of N,S bidentate ligands is of great importance in medicinal chemistry imparting stability and enhancing biological properties of the metal complexes. Phenylthiocarbamide-based N,S donor Schiff bases converted into RuII /OsII (cymene) complexes and characterized by spectroscopic techniques and elemental analysis. The hydrolytic stability of metal complexes to undergo metal-halide ligand exchange reaction was confirmed both by the DFT and NMR experimentation. The ONIOM (QM/MM) study confirmed the histone protein targeting nature of aqua/hydroxido complex 2 aH with an excellent binding energy of -103.19 kcal/mol. The antiproliferative activity against a panel of cancer cells A549, MCF-7, PC-3, and HepG2 revealed that ruthenium complexes 1 a-3 a were more cytotoxic than osmium complexes and their respective ligands 1-3 as well. Among these ruthenium cymene complex bearing sulfonamide moiety 2 a proved a strong cytotoxic agent and showed excellent correlation of cellular accumulation, lipophilicity, and drug-likeness to the anticancer activity. Moreover, the favorable physiochemical properties such as bioavailability and gastrointestinal absorption of ligand 2 also supported the development of Ru complex 2 a as an orally active anticancer metallodrug.

Hydroxypyrone derivatives in drug discovery: from chelation therapy to rational design of metalloenzyme inhibitors.

The versatile structural motif of hydroxypyrone is found in natural products and can be easily converted into hydroxypyridone and hydroxythiopyridone analogues. The favourable toxicity profile and ease of functionalization to access a vast library of compounds make them an ideal structural scaffold for drug design and discovery. This versatile scaffold possesses excellent metal chelating properties that can be exploited for chelation therapy in clinics. Deferiprone [1,2-dimethyl-3-hydroxy-4(1H)-one] was the first orally active chelator to treat iron overload in thalassemia major. Metal complexes of hydroxy-(thio)pyr(id)ones have been investigated as magnetic resonance imaging contrast agents, and anticancer and antidiabetic agents. In recent years, this compound class has demonstrated potential in discovering and developing metalloenzyme inhibitors. This review article summarizes recent literature on hydroxy-(thio)pyr(id)ones as inhibitors for metalloenzymes such as histone deacetylases, tyrosinase and metallo-ß-lactamase. Different approaches to the design of hydroxy-(thio)pyr(id)ones and their biological properties against selected metalloenzymes are discussed.

Facile coating of micronutrient zinc for slow release urea and its agronomic effects on field grown wheat (Triticum aestivum L.).

Slow release urea has been widely tested in recent past as an effective method to enhance the crop productivity with fewer environmental concerns. However, very few research studies have been performed using micronutrients as a source of slow release of urea nitrogen. A laboratory and field study were carried out to check the agronomic effects of zinc oxide nanoparticles and its bulk salt coatings on urea prills on wheat (Triticum aestivum L.). Different concentrations of zinc oxide nanoparticles (0.25, 0.5 and 4% elemental zinc) were coated on urea prills to slow down the release rate. Bulk zinc oxide salt (ZnO) with similar concentrations was also used in parallel to make a comparison between nano and bulk salt. The SEM of zinc oxide nanoparticles clearly depicted zinc oxide nanoparticles size within a range of 50-90 nm. The XRD and FTIR spectrums also showed its characteristics peak at designated positions. Field study revealed than 0.5% zinc oxide nanoparticles coated urea boosted the crop growth and yield in comparison to the bulk zinc oxide coated urea having similar zinc concentrations, i.e., 0.25%, 0.5% and 4% elemental zinc. The plant parameters like plant height, root length, root volume, grain yield and dry matter weight were significantly increased due to application of zinc oxide nanoparticles.

Cellulose acetate based sustainable nanostructured membranes for environmental remediation.

Membrane-based gas separation has a great potential for reducing environmentally hazardous carbon dioxide (CO2) gas. The polymeric membranes developed for CO2 capturing have some limitations in their selectivity and permeability. There is a need to overcome these issues and developed such membranes having high-performance CO2 capture with cost-effectiveness. The present study aimed to synthesize mixed matrix membranes (MMMs) having improved properties CO2 adsorption performance and stability than that of pure polymer. Further, the effect on CO2 adsorption by increasing the filler concentration in MMMs was investigated. The MMMs were synthesized by incorporating (1-5 wt%) Cu-MOF-GO composites as filler into cellulose-acetate (CA) polymer matrix by adopting the solution casting method. The performance of MMMs was studied by changing the Cu-MOF-GO composite concentration (1-5 wt%) in the polymer matrix at 45 °C up to 15 bar. Morphological analysis by using SEM confirms that by increasing the concentration of Cu-MOF-GO more than 3% will result in their agglomeration in MMM. The successful incorporation of MOF within the polymer matrix of MMMs was confirmed through the presence of functional groups using FTIR and Raman spectroscopy. XRD analysis revealed that pure CA changes its semi-crystalline behaviour into crystalline by the addition of Cu-MOF-GO. The maximum tensile stress and strain rate of MMMs was 45.1 N/mm2 and 12.8%. In addition, with an increase in (4-5 wt%) Cu-MOF-GO concentration the hydrophilicity of MMMs decreases. The maximum uptake rate of CO2 was 1.79 mmol/g and 7.98 wt% at 15 bar. The adsorption results conclude that Cu-MOF-GO composite and CA-based MMM can be effective for CO2 capture.

Development and testing of zinc sulfate and zinc oxide nanoparticle-coated urea fertilizer to improve N and Zn use efficiency.

Nitrogen (N) losses from conventional fertilizers in agricultural systems are very high, which can lead to serious environmental pollution with economic loss. In this study, innovative slow-release fertilizers were prepared using zinc (Zn) [nanoparticles (NPs) or in bulk], using molasses as an environmentally friendly coating. Several treatments were prepared using Zn in different concentrations (i.e., 0.25%, 0.5%, and 4% elemental Zn). The zinc oxide nanoparticles (ZnO-NPs) were prepared from zinc sulfate heptahydrate (ZnSO4·7H2O), and were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Furthermore, the Zn-loaded urea samples were tested for urea N release rate, leaching of water from soil, and crushing strength to assess the impact of coating on the final finished product. Pot experiments were conducted simultaneously to check the agronomic effects of Zn-coated slow-release urea on the growth and development of wheat (Triticum aestivum L.). The laboratory and pot results confirmed that the ZnO-NP treatments boost wheat growth and yield as a result of reduced N and Zn release. UZnNPs2 (urea coated with 0.5% ZnO-NPs and 5% molasses) demonstrated the best results among all the treatments in terms of slow nutrient release, N and Zn uptake, and grain yield. The UZnNPs2 treatment increased plant yield by 34% (i.e., 4,515 vs. 3,345 kg ha-1) relative to the uncoated prill-treated crop because of the slower release of Zn and N.

Challenges and recent trends with the development of hydrogel fiber for biomedical applications.

Hydrogel is the most emblematic soft material which possesses significantly tunable and programmable characteristics. Polymer hydrogels possess significant advantages including, biocompatible, simple, reliable and low cost. Therefore, research on the development of hydrogel for biomedical applications has been grown intensely. However, hydrogel development is challenging and required significant effort before the application at an industrial scale. Therefore, the current work focused on evaluating recent trends and issues with hydrogel development for biomedical applications. In addition, the hydrogel's development methodology, physicochemical properties, and biomedical applications are evaluated and benchmarked against the reported literature. Later, biomedical applications of the nano-cellulose-based hydrogel are considered and critically discussed. Based on a detailed review, it has been found that the surface energy, intermolecular interactions, and interactions of hydrogel adhesion forces are major challenges that contribute to the development of hydrogel. In addition, compared to other hydrogels, nanocellulose hydrogels demonstrated higher potential for drug delivery, 3D cell culture, diagnostics, tissue engineering, tissue therapies and gene therapies. Overall, nanocellulose hydrogel has the potential for commercialization for different biomedical applications.

Cellulose acetate-polyvinyl alcohol blend hemodialysis membranes integrated with dialysis performance and high biocompatibility.

Hemodialysis considered as therapy of end-stage renal disease (ESRD) for the separation of protein and uremic toxins based on their molecular weights using semi-permeable membranes. Cellulose Acetate (CA) hemodialysis membrane has been widely used in the biomedical field particularly for hemodialysis applications. The main issue of CA membrane is less selectivity and hemocompatibility. In this study, to enhance the filtration capability and biocompatibility of CA hemodialysis membrane modified by using Polyvinyl Alcohol (PVA) and Polyethylene Glycol (PEG) as additives. CA-PVA flat sheet membranes were cast by phase inversion method, and separation was done by dead-end filtration cell. The synthesized membranes were described in terms of chemical structure using Fourier Transform Infrared Spectroscopy (FTIR) and morphology by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), pure water flux, solute permeation, and protein retention. Biocompatibility of the membranes was tested by the platelet adherence, hemolysis ratio, thrombus formation, and plasma recalcification time. SEM images exposed that the CA-PVA membrane has a uniform porous structure. 42.484 L/m2 h is the maximum pure water flux obtained. The CA-PVA rejected up to 95% of bovine serum albumin (BSA). A similar membrane separated 93% of urea and 89% of creatinine. Platelet adhesion and hemolysis ratio of casted membranes were less than the pure CA membrane. Increased clotting time and less thrombus formation on the membrane's surface showed that the fabricated membrane is biocompatible. CA-PVA hemodialysis membranes are more efficient than conventional reported hemodialysis membranes. It revealed that CA-PVA is high performing biocompatible hemodialysis membrane.

Nano architectured cues as sustainable membranes for ultrafiltration in blood hemodialysis.

Membranes with zeolites are encouraging for performing blood dialysis because zeolites can eliminate uremic toxins through molecular sieving. Although the addition of various pore-gen and adsorbent in the membrane can certainly impact the membrane production along with creatinine adsorption, however, it is not directed which pore-gen along with zeolite leads to better performance. The research was aimed at reducing the adsorption of protein-bound and uremic toxins by using mordenite zeolite as an adsorbent while polyethylene glycol and cellulose acetate as a pore generating agent. Membranes were cast by a phase-inversion technique which is cheap and easy to handle as compared to the electro-spinning technique. Through this strategy, the ability to adsorb creatinine and solute rejection percentage were measured and compared against the pristine PSU, when only PEG was used as a pore-modifier and when PEG along with CA was used as a pore-modifier along with a different concentration of zeolite. The experiments revealed that PEG membranes can give a better solute rejection percentage (93%) but with a low creatinine adsorption capacity that is 7654 µg/g and low bio-compatibility (PRT 392 s, HR 0.46%). However, PEG/CA membranes give maximum creatinine adsorption that is 9643 µg/g and also better bio-compatibility (PRT 490 s, HR 0.37%) but with a low BSA rejection (72%) as compared to the pristine PSU and PEG membranes. The present study finds that the concentration of mordenite zeolite affects the membrane performance because its entrapment and large pore size of the membrane decreases solute rejection but increases creatinine uptake level along with the better bio-compatibility.

Metal Organic Frameworks Derived Sustainable Polyvinyl Alcohol/Starch Nanocomposite Films as Robust Materials for Packaging Applications.

Bio-nanocomposites-based packaging materials have gained significance due to their prospective application in rising areas of packaged food. This research aims to fabricate biodegradable packaging films based upon polyvinyl alcohol (PVA) and starch integrated with metal-organic frameworks (MOFs) or organic additives. MOFs offer unique features in terms of surface area, mechanical strength, and chemical stability, which make them favourable for supporting materials used in fabricating polymer-based packaging materials. zeolitic imidazolate frameworks (ZIFs) are one of the potential candidates for this application due to their highly conductive network with a large surface area and high porosity. Present research illustrates a model system based on ZIF-67 (C8H10N4Co) bearing 2-10 wt.% loading in a matrix of PVA/starch blend with or without pyrolysis to probe the function of intermolecular interaction in molecular packing, tensile properties, and glass transition process. ZIF-67 nanoparticles were doped in a PVA/starch mixture, and films were fabricated using the solution casting method. It was discovered through scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR) that addition of ZIF-67 and pyrolyzed ZIF-67 changed and enhanced the thermal stability of the membrane. Moreover, 2-10 wt.% loading of ZIF-67 effected the thermal stability, owing to an interlayer aggregation of ZIF-67. The membranes containing pyrolyzed ZIF-67 showed mechanical strength in the order of 25 MPa in a moderate loading of pyrolyzed ZIF-67 (i.e., at 4 wt.%). The crystallinity enhanced by an increment in ZIF-67 loading. On the other hand, pyrolyzed ZIF-67 carbon became amorphous because of the inert environment and elevated temperature. The surface area also increased after the pyrolysis, which helped to increase the strength of the composite films.

Biodegradable Polymer Coated Granular Urea Slows Down N Release Kinetics and Improves Spinach Productivity.

Low nitrogen (N) utilization efficiency due to environmental N losses from fertilizers results in high-cost on-farm production. Urea coating with biodegradable polymers can prevent these losses by controlling the N release of fertilizers. We calculated N release kinetics of coated granular with various biodegradable polymeric materials and its impact on spinach yield and N uptake. Different formulations were used, (i) G-1: 10% starch + 5% polyvinyl alcohol (PVA) + 5% molasses; (ii) G-2: 10% starch + 5% PVA + 5% paraffin wax (PW); (iii) G-3: 5% gelatin + 10% gum arabic + 5% PW; (iv) G-4: 5% molasses + 5% gelatin + 10% gum arabic, to coat urea using a fluidized bed coater. The morphological and X-ray diffraction (XRD) analyses indicated that a uniform coating layer with no new phase formation occurred. In the G-2 treatment, maximum crushing strength (72.9 N) was achieved with a slowed-down N release rate and increased efficiency of 31%. This resulted in increased spinach dry foliage yield (47%), N uptake (60%) and apparent N recovery (ANR: 130%) from G-2 compared to uncoated urea (G-0). Therefore, coating granular urea with biodegradable polymers is a good choice to slower down the N release rate and enhances the crop yield and N utilization efficiency from urea.

Preparation and characterization of PVA/nanocellulose/Ag nanocomposite films for antimicrobial food packaging.

Antimicrobial packaging is an area of emerging interest and is rapidly expanding with application of nanotechnology. The present work investigates the effect of nanocellulose (NC) and Ag NPs on the physical, mechanical and thermal properties of PVA nanocomposite films. The tensile strength of PVA was improved from 5.52 ±â€¯0.27 MPa to 12.32 ±â€¯0.61 MPa when filled with 8 wt% of NC. Nanocomposite films exhibited strong antibacterial activity against both Staphylococcus aureus (MRSA) and Escherichia coli (DH5-alpha). The maximum inhibition zone at 0.5 g Ag NPs with 12 wt% NC against DH5-alpha was 14 ±â€¯0.70 mm. While, the maximum inhibition zone at 0.3 g Ag NPs for 16 wt% NC was 13.6 ±â€¯0.68 mm against MRSA. Moreover, nanocomposites films have no cytotoxicity effect on HepG2 and cell viability was more than 90%. Based on mechanical properties and antibacterial potential of the developed nanocomposite films, it can be envisaged to use these films for packaging applications.

Mechanical, thermal and swelling properties of phosphorylated nanocellulose fibrils/PVA nanocomposite membranes.

Cellulose nanofibrils (CNF) have strong reinforcing properties when incorporated in a compatible polymer matrix. This work reports the effect of the addition of phosphorylated nanocellulose (PCNF) on the mechanical, thermal and swelling properties of poly(vinyl alcohol) (PVA) nanocomposite membranes. The incorporation of nanocellulose in PVA reduced the crystallinity at 0%RH. However, when the films were exposed to higher humidities the crystallinity increased. No apparent trend is observed for mechanical properties for dry membranes (0% RH). However, at 93% RH the elastic modulus increased strongly from 0.12MPa to 0.82MPa when adding 6% PCNF. At higher humidities, the moisture uptake has large influence on storage modulus, tan δ and tensile properties. Membranes containing 1% PCNF absorbed most moisture. Swelling, thermal and mechanical properties indicate a good potential for applying of PVA/phosphorylated nanocellulose composite membranes for CO2 separation.