UV-blocking and photocatalytic properties of Ag-coated cotton fabrics with Si binders for photo-degradation of recalcitrant dyes in aqueous solutions under sunlight.

Textile wastewater laden with dyes has emerged as a source of water pollution. This possesses a challenge in its effective treatment using a single functional material. In respond to this technological constraint, this work presents multifunctional cotton fabrics (CFs) within a single, streamlined preparation process. This approach utilizes the adherence of Ag NPs (nanoparticles) using Si binder on the surface of CFs, resulting in Ag-coated CFs through a pad dry method. The prepared samples were characterized using scanning electron microscope-energy dispersive X-ray electroscopy (SEM-EDS), thermal gravimetric analysis (TGA), Fourier transformation infrared (FT-IR). It was found that the FT-IR spectra of Ag NPs-coated CFs had peaks appear at 3400, 2900, and 1200 cm-1, implying the stretching vibrations of O-H, C-H, and C-O, respectively. Based on the EDX analysis, the presence of C, O, and Ag related to the coated CFs were detected. After coating the CFs with varying concentrations of Ag NPs (1%, 2% and 3% (w/w)), they were used to remove dyes. Under the same concentration of 10 mg/L and optimized pH 7.5 and 2 h of reaction time, 3% (w/w) Ag-coated CFs exhibited a substantial MB degradation of 98 %, while removing 95% of methyl orange, 85% of rhodamine B, and 96% of Congo red, respectively, following 2 h of Vis exposure. Ag NPs had a strong absorption at 420 nm with 2.51 eV of energy band gap. Under UV irradiation, electrons excited and produced free radicals that promoted dyes photodegradation. The oxidation by-products included p-dihydroxybenzene and succinic acid. Spent Ag-coated CFs attained 98% of regeneration efficiency. The utilization of Ag-coated CFs as a photocatalyst facilitated treated effluents to meet the required discharge standard of lower than 1 mg/L mandated by national legislation. The integration of multifunctional CFs in the treatment system presents a new option for tackling water pollution due to dyes.

SAR, Molecular Docking and Molecular Dynamic Simulation of Natural Inhibitors against SARS-CoV-2 Mpro Spike Protein.

The SARS-CoV-2 virus and its mutations have affected human health globally and created significant danger for the health of people all around the world. To cure this virus, the human Angiotensin Converting Enzyme-2 (ACE2) receptor, the SARS-CoV-2 main protease (Mpro), and spike proteins were found to be likely candidates for the synthesis of novel therapeutic drug. In the past, proteins were capable of engaging in interaction with a wide variety of ligands, including both manmade and plant-derived small molecules. Pyrus communis L., Ginko bibola, Carica papaya, Syrian rue, and Pimenta dioica were some of the plant species that were studied for their tendency to interact with SARS-CoV-2 main protease (Mpro) in this research project (6LU7). This scenario investigates the geometry, electronic, and thermodynamic properties computationally. Assessing the intermolecular forces of phytochemicals with the targets of the SARS-CoV-2 Mpro spike protein (SP) resulted in the recognition of a compound, kaempferol, as the most potent binding ligand, -7.7 kcal mol-1. Kaempferol interacted with ASP-187, CYS-145, SER-144, LEU 141, MET-165, and GLU-166 residues. Through additional molecular dynamic simulations, the stability of ligand-protein interactions was assessed for 100 ns. GLU-166 remained intact with 33% contact strength with phenolic OH group. We noted a change in torsional conformation, and the molecular dynamics simulation showed a potential variation in the range from 3.36 to 7.44 against a 45-50-degree angle rotation. SAR, pharmacokinetics, and drug-likeness characteristic investigations showed that kaempferol may be the suitable candidate to serve as a model for designing and developing new anti-COVID-19 medicines.

Design and Exploration of Benzene Like Azobis Triazoles for Long-range Push-Pull Photo-Switching Attributes.

This research paper presents a comprehensive study on the design and photovoltaic parameters of azobenzene type 24 photo switches (PSs) of triazole by density functional theory (DFT). The focus was on investigating how to create a long-range push-pull effect of different substituents on the PS properties for their application in photovoltaics by further substituent decoration. Their range of values for the maximum wavelength (λmax) ranged 315-556 nm while their HOMO-LUMO energies (Egaps) were 0.57-6.35eV. The stability of the PS was evaluated by measuring hardness (η) and softness (σ) values. Additionally, photovoltaic parameters such as open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), and maximum power (Pmax) were calculated to assess the performance of the PS as photovoltaic materials. The results revealed that PSs 6 exhibited promising photovoltaic parameters to include Voc values ranging from 0.4-1.63eV, FF values ranging from 0.5438-0.929, Jsc values ranging from 19.27-50.75 mA/cm2, and Pmax values ranging from 14.72-75.91W. This indicates its potential as an efficient light-harvesting material for photovoltaic applications. Moreover, this study presents a pioneering investigation on the correlation between rotational velocity (R) and Mayer bond index (MBI) for the first time. The findings revealed a significant correlation between R and MBI, providing valuable insights into the structural dynamics of the PS. This novel finding opens up new avenues for understanding the structural dynamics of PS and their potential applications in various fields, including photovoltaics. The study provides valuable insights into the structure-property relationships of azobenzene-based PS and their suitability for photovoltaic devices. Further investigations are warranted to optimize the design of the PS, enhance their photovoltaic performance, and explore the underlying mechanisms of the correlation between R and MBIs.

Fabrication, characterization, and application of light weight thermal insulation material from combined buffing dust and plaster of paris for construction industry.

Buffing dust, generated from tannery industries, is a source of air pollution in Pakistan. Valorization of the waste into another useful material is important to deal with the environmental pollution, while reducing waste disposal costs in landfills. To demonstrate its technological strength, this work fabricates a thermal insulation material made of plaster of Paris and the buffing dust (from tanning waste) in the form of a composite with superior mechanical properties and low thermal conductivity. Buffing dust with concentrations ranging from 5 to 20% (w/w) were loaded in the composite. The samples synthesized were made slurry of plaster of Paris, buffing dust, and water at ambient temperature. The physico-mechanical properties of composite were analyzed. It was found that the composite had better thermal insulation properties than the panels of the plaster of Paris. Its thermal conductivity was reduced to 15% after adding buffing dust (20% w/w). All the materials had physico-chemical properties like tensile strength (0.02 MPa and 0.06 MPa), density (700-400 kg/m3), water absorption (5.2-8.6%) and thermal conductivity (0.17000-0.09218 W/m-K). Thermogravimetric analysis showed that the material was thermally stable at temperatures ranging from 145 to 177 °C, while FT-IR results revealed that the composite contained O-H, N-H, and CO functional groups. SEM analysis displayed that the composite's homogeneity was reduced with low voids due to buffing dust addition, while EDX analysis showed that the composite contained 23.62% of S, 26.76% of Ca, 49.2% of O and 0.42% of C. This implies that buffing dust could be recycled to manufacture heat insulation materials for construction sector to reduce air pollution, while minimizing energy consumption. By integrating the buffing dust from tanning waste and the plaster of Paris as a composite for construction sector, this work promotes the recycling of unused waste, while saving public funds. Instead of paying landfill fees and polluting soil, the waste may be recycled at lower cost, while reducing environmental damage.

Tackling microplastics pollution in global environment through integration of applied technology, policy instruments, and legislation.

Microplastic pollution is a serious environmental problem that affects both aquatic and terrestrial ecosystems. Small particles with size of less than 5 mm, known as microplastics (MPs), persist in the environment and pose serious threats to various species from micro-organisms to humans. However, terrestrial environment has received less attention than the aquatic environment, despite being a major source of MPs that eventually reaches water body. To reflect its novelty, this work aims at providing a comprehensive overview of the current state of MPs pollution in the global environment and various solutions to address MP pollution by integrating applied technology, policy instruments, and legislation. This review critically evaluates and compares the existing technologies for MPs detection, removal, and degradation, and a variety of policy instruments and legislation that can support the prevention and management of MPs pollution scientifically. Furthermore, this review identifies the gaps and challenges in addressing the complex and diverse nature of MPs and calls for joint actions and collaboration from stakeholders to contain MPs. As water pollution by MPs is complex, managing it effectively requires their responses through the utilization of technology, policy instruments, and legislation. It is evident from a literature survey of 228 published articles (1961-2023) that existing water technologies are promising to remove MPs pollution. Membrane bioreactors and ultrafiltration achieved 90% of MPs removal, while magnetic separation was effective at extracting 88% of target MPs from wastewater. In biological process, one kg of wax worms could consume about 80 g of plastic/day. This means that 100 kg of wax worms can eat about 8 kg of plastic daily, or about 2.9 tons of plastic annually. Overall, the integration of technology, policy instrument, and legislation is crucial to deal with the MPs issues.

Structural and Electronic (Absorption and Fluorescence) Properties of a Stable Triplet Diphenylcarbene: A DFT Study.

A triplet diphenylcarbene, bis[3-bromo-5-(trifluoromethyl)[1,1'-biphenyl]-4-yl]methylidene (B3B), with exceptional stability was discovered by chemists from Japan's Mie University. To investigate its different quantum chemical features, a theoretical analysis was predicated on Density Functional Theory (DFT) and Time Dependent-DFT (TD-DFT) based technique. According to the findings, the singlet-triplet energy gap (ES-T), as well as HOMO-LUMO energy bandgap (EH-L), was found to be diminished when nucleophilicity (N) rose. We looked at the geometrical dimensions, molecular orbitals (MOs), electronic spectra, electrostatic potential, molecular surfaces, reactivity characteristics, and thermodynamics features of the title carbene (B3B). Its electronic spectra in different solvents were calculated using TD-DFT and Polarizable Continuum Model (PCM) framework. The estimated absorption maxima of B3B were seen between 327 and 340 nm, relying on the solvents, and were attributed to the S0 → S1 transition. Estimated fluorescence spectral peaks were found around 389 and 407 nm with the S1 and S0 transitions being identified. Its fluorescence/absorption intensities revealed a blue shift change when the solvent polarity was increased. The least exciting state has been discovered to be the π → π* charge-transfer (CT) phase. According to the Natural Bonding Orbital (NBO) exploration, ICT offers a significant role in chemical system destabilization. Furthermore, several hybrid features were used to determine the NLO (nonlinear optical) features (polarizability, first-order hyperpolarizability, and dipole moment). The calculated values suggest that B3B is a promising candidate for further research into nonlinear optical properties.

Synthesis, spectral analysis and biological evaluation of Nalkyl/aralkyl/aryl-4-chlorobenzenesulfonamide derivatives.

New potent organic compounds were synthesized with an aim of good biological activities such as antibacterial and anti-enzymatic. Three series of sulfonamide derivatives were synthesized by treating N-alkyl/aryl substituted amines (2a-f) with 4-chlorobenzensulfonyl chloride (1) to yield N-alkyl/aryl-4-chlorobenzenesulfonamide(3af) that was then derivatized by gearing up with ethyl iodide (4), benzyl chloride (5) and 4-chlorobenzyl chloride (6) using sodium hydride as base to initialize the reaction in a polar aprotic solvent (DMF) to synthesize the derivatives, 7a-f, 8af and 9a-f respectively. Structure elucidation was brought about by IR, 1H-NMR and EIMS spectra for all the synthesized molecules which were evaluated for their antibacterial activities and inhibitory potentials for certain enzymes.

Realizing the effect of s-block metals on a charge transfer crystal of indol-2-one for enhanced NLO responses with efficient energetic offsets.

CONTEXT: Due to their unique photophysical properties, organic charge transfer crystals are becoming promising materials for next-generation optoelectronic devices. This research paper explores the impact of s-block metals on a charge transfer crystal of indol-2-one for enhanced nonlinear optical (NLO) responses with efficient energetic offsets. The study reveals that alkali metals can enhance NLO performance due to their free electrons. METHOD: The Perdew-Burke-Ernzerhof functional of DFT with dispersion correction (D3) was used, and the λmax values ranged between 596 and 669 nm, with the highest value for dichloromethane (DCM). Leveraging the unique properties of metals allowed for the development of nonlinear optical materials with improved performance and versatility. Softness (σ) values provide insight into electron density changes, with higher values indicating a greater tendency for changes and lower values indicating the opposite. The NLO results for the chromophores MMI1-MMI6 show varying linear polarizability (< α0 >) along with their first (ß0) and second (γ0) hyperpolarizabilities. Chromophore MMI4 stands out with the highest NLO performance, having two potassium (K) atoms. Its < α0 > , ß0, and γ0 values of 4.19, 7.09, and 17.43 (× 10-24 e.s.u), respectively, indicate a significant enhancement in NLO response compared to the other chromophores. The transitions involving (O20)LP → (C3-N5)π* and (O19)LP → (N12-C13)π* exhibit the highest level of stabilization, followed by (O23)π → (C10-C11)π*, while (C6-N12)π → (C6-C7)π* shows the lowest level of stabilization for chromophore MMI4. The present research work is facile in its nature, and it can be helpful for synthetic scientist to design the new materials for uniting crystal properties with metal doping for efficient NLO devices.

Beyond surface: Unveiling ecological and economic ramifications of microplastic pollution in the oceans.

Every year, the global production of plastic waste reaches a staggering 400 million metric tons (Mt), precipitating adverse consequences for the environment, food safety, and biodiversity as it degrades into microplastics (MPs). The multifaceted nature of MP pollution, coupled with its intricate physiological impacts, underscores the pressing need for comprehensive policies and legislative frameworks. Such measures, alongside advancements in technology, hold promise in averting ecological catastrophe in the oceans. Mandated legislation represents a pivotal step towards restoring oceanic health and securing the well-being of the planet. This work offers an overview of the policy hurdles, legislative initiatives, and prospective strategies for addressing global pollution due to MP. Additionally, this work explores innovative approaches that yield fresh insights into combating plastic pollution across various sectors. Emphasizing the importance of a global plastics treaty, the article underscores its potential to galvanize collaborative efforts in mitigating MP pollution's deleterious effects on marine ecosystems. Successful implementation of such a treaty could revolutionize the plastics economy, steering it towards a circular, less polluting model operating within planetary boundaries. Failure to act decisively risks exacerbating the scourge of MP pollution and its attendant repercussions on both humanity and the environment. Central to this endeavor are the formulation, content, and execution of the treaty itself, which demand careful consideration. While recognizing that a global plastics treaty is not a panacea, it serves as a mechanism for enhancing plastics governance and elevating global ambitions towards achieving zero plastic pollution by 2040. Adopting a life cycle approach to plastic management allows for a nuanced understanding of possible trade-offs between environmental impact and economic growth, guiding the selection of optimal solutions with socio-economic implications in mind. By embracing a comprehensive strategy that integrates legislative measures and technological innovations, we can substantially reduce the influx of marine plastic litter at its sources, safeguarding the oceans for future generations.

DFT-guided structural modeling of end-group acceptors at Y123 core for sensitizers as high-performance organic solar dyes and NLO responses.

CONTEXT: The organic solar cells (OSCs) are being developed with the goal of improving their photovoltaic capabilities. Here, utilizing computational methods, six new nonfullerene acceptors (NFA) comprising dyes (A1-A6) have been created by end-group alterations of the Y123 framework as a standard (R). METHODS: The DFT-based investigations at B3LYP/6-31G + (d,p) level were applied to evaluate their properties. The planar geometries associated with these structures, which lead to improved conjugation, were validated by the estimation of molecular geometries. Dyes A1-A6 have shorter Egap than R, according to a frontier molecular orbital (FMO) investigation, which encourages charge transfer in them. The dyes with their maximum absorption range were shown by optical properties to be 692-711 nm, which is significantly better than R with its 684 nm range. Their electrostatic and Mulliken charge patterns provided additional evidence of the significant separation of charges within these structures. All the dyes A1-A6 had improved light harvesting efficiency (LHE) values as compared to Y123, highlighting their improved capacity to generate charge carriers by light absorption. With the exception of dye A4, all newly developed dyes might have a superior rate of charge carrier mobility than R, according to reorganization energies λre. Dyes A3 and A4 had the greatest open-circuit voltage (Voc). Dye A3 exhibited improvement in all of its examined properties, making it a promising choice in DSSC applications.

Source, occurrence, distribution, fate, and implications of microplastic pollutants in freshwater on environment: A critical review and way forward.

The generation of microplastics (MPs) has increased recently and become an emerging issue globally. Due to their long-term durability and capability of traveling between different habitats in air, water, and soil, MPs presence in freshwater ecosystem threatens the environment with respect to its quality, biotic life, and sustainability. Although many previous works have been undertaken on the MPs pollution in the marine system recently, none of the study has covered the scope of MPs pollution in the freshwater. To consolidate scattered knowledge in the literature body into one place, this work identifies the sources, fate, occurrence, transport pathways, and distribution of MPs pollution in the aquatic system with respect to their impacts on biotic life, degradation, and detection techniques. This article also discusses the environmental implications of MPs pollution in the freshwater ecosystems. Certain techniques for identifying MPs and their limitations in applications are presented. Through a literature survey of over 276 published articles (2000-2023), this study presents an overview of solutions to the MP pollution, while identifying research gaps in the body of knowledge for further work. It is conclusive from this review that the MPs exist in the freshwater due to an improper littering of plastic waste and its degradation into smaller particles. Approximately 15-51 trillion MP particles have accumulated in the oceans with their weight ranging between 93,000 and 236,000 metric ton (Mt), while about 19-23 Mt of plastic waste was released into rivers in 2016, which was projected to increase up to 53 Mt by 2030. A subsequent degradation of MPs in the aquatic environment results in the generation of NPs with size ranging from 1 to 1000 nm. It is expected that this work facilitates stakeholders to understand the multi-aspects of MPs pollution in the freshwater and recommends policy actions to implement sustainable solutions to this environmental problem.

Controlled preparation of grafted starch modified with Ni nanoparticles for biodegradable polymer nanocomposites and its application in food packaging.

Grafting of starch with methyl methacrylate was carried out using a free radical mechanism. Free radicals were generated by the thermal disintegration of potassium persulphate at the temperature of 60°C. A variety of experimental methods were investigated to check the effect of different parameters such as (temperature, amount of starch, quantity of monomer) for efficient grafting. The optimum temperature found for good grafting was 60°C. The initial amount of starch was taken as 0.75 g. Keeping the amount of starch constant, the quantity of monomer was reduced gradually from 10 to 2 ml in portions of 5 and 3 ml. The controlled biodegradability of the grafted product was obtained by using a 3 ml monomer in 0.75 g starch. This grafted polymer showed 31.45% biodegradability in 60 days. The nanocomposite of starch grafted methyl methacrylate was prepared by incorporating 0.02 g Ni nanoparticles in the reaction flask 15 min before the completion of reaction time. The starch grafted polymer and nanocomposite of this were fully characterized by SEM, FTIR, TGA, and DSC techniques. The soil burial method was applied to estimate the biodegradability of samples. The polymer containing Ni nanoparticles was less biodegradable than without nanoparticles. Such polymers can be efficiently used as packaging material for food items. RESEARCH HIGHLIGHTS: Through a free radical method, methyl methacrylate was grafted onto the backbone of starch in this study. During the process, nickel nanoparticles were added to achieve the nickel nanocomposite of the starch grafted polymer. The breakdown of starch grafted polymer after 60 days in a soil burial experiment was 31.45%, whereas the degradation of nanocomposites was 20.07%. Our synthesized nanocomposite polymers can be effectively employed as packaging material for food items.

Efficacy of Various Types of Berries Extract for the Synthesis of ZnO Nanocomposites and Exploring Their Antimicrobial Potential for Use in Herbal Medicines.

Nanoscience has developed various greener approaches as an alternate method for the synthesis of nanoparticles and nanocomposites. The present study discusses the efficacy of berries extract for the synthesis of ZnO nanocomposites. Characterization of synthesized nanocomposite were done by SEM, UV/VIS spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, and XRD techniques. The crystalline nature of the synthesized nanoparticles was verified by XRD pattern in the range of 10-80 nm. The UV absorption peak of Elaeagnus umbellata (ZnO-EU) nanocomposite at 340 nm, Rubus idaeus (ZnO-Ri) nanocomposite at 360 nm, and Rubus fruticosus (ZnO-Rf) nanocomposite at 360 nm was observed. The nanocomposites were analyzed for their antimicrobial activity and found to be effective against three phytopathogens. The antimicrobial activity of ZnO nanocomposites showed good results against Escherichia coli (341), Staphylococcus aureus (345B), and Pseudomonas aeruginosa (5994 NLF). This study presents a simple and inexpensive approach for synthesizing zinc oxide nanocomposites with effective antibacterial activity.

Construction of a binary S-scheme S-g-C3N4/Co-ZF heterojunction with enhanced spatial charge separation for sunlight-driven photocatalytic performance.

A step-scheme (S-scheme) photocatalyst made of sulfurized graphitic carbon nitride/cobalt doped zinc ferrite (S-g-C3N4/Co-ZF) was constructed using a hydrothermal process because the building of S-scheme systems might increase the lifespan of highly reactive charge carriers. Utilizing cutting-edge methods, the hybrid photocatalyst was evaluated by employing TEM, XPS, XRD, BET, FTIR, transient photo-response, UV-vis, EIS and ESR signals. In order to create a variety of binary nanocomposites (NCs), nanoparticles (NPs) of 6% cobalt doped zinc ferrite (Co-ZF) were mixed with S-g-C3N4 at various concentrations, ranging from 10 to 80 wt%. For photocatalytic dye removal, a particular binary NC constructed between S-g-C3N4 and Co-ZF produces a huge amount of catalytic active sites. The findings showed that loading of S-g-C3N4 on 6% Co-ZF NPs serves as a good heterointerface for e-/h+ separation and transportation through the S-scheme S-g-C3N4/Co-ZF heterojunction. By boosting the hybrid system's BET surface area for the photocatalytic process, the addition of 6% Co-ZF improves the system's ability to absorb more sunlight and boosts its photocatalytic activity. The highest photo-removal effectiveness (98%), which is around 2.45 times higher than that of its competitors, was achieved by the hybrid photocatalyst system with an ideal loading of 48% Co-ZF. Furthermore, the trapping studies showed that the primary species involved in the MB aqueous photo-degradation were ˙OH- and h+.

Fabrication of Guided Tissue Regeneration Membrane Using Lignin-Mediated ZnO Nanoparticles in Biopolymer Matrix for Antimicrobial Activity.

Periodontal disease is a common complication, and conventional periodontal surgery can lead to severe bleeding. Different membranes have been used for periodontal treatment with limitations, such as improper biodegradation, poor mechanical property, and no effective hemostatic property. Guided tissue regeneration (GTR) membranes favoring periodontal regeneration were prepared to overcome these shortcomings. The mucilage of the chia seed was extracted and utilized to prepare the guided tissue regeneration (GTR) membrane. Lignin having antibacterial properties was used to synthesize lignin-mediated ZnO nanoparticles (∼Lignin@ZnO) followed by characterization with analytical techniques like Fourier-transform infrared spectroscopy (FTIR), UV-visible spectroscopy, and scanning electron microscope (SEM). To fabricate the GTR membrane, extracted mucilage, Lignin@ZnO, and polyvinyl alcohol (PVA) were mixed in different ratios to obtain a thin film. The fabricated GTR membrane was evaluated using a dynamic fatigue analyzer for mechanical properties. Appropriate degradation rates were approved by degradability analysis in water for different intervals of time. The fabricated GTR membrane showed excellent antibacterial properties against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacterial species.