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Abstract Carbon dots have stimulated the curiosity of biomedical researchers due to their unique properties, such as less toxicity and high biocompatibility. The synthesis of carbon dots for biomedical application is a core area in research. In the current research, an eco-friendly hydrothermal technique was employed to synthesize high fluorescent, plant-derived carbon dots from Prosopis juliflora leaves extract (PJ-CDs). The synthesized PJ-CDs were investigated by physicochemical evaluation instruments such as fluorescence spectroscopy, SEM, HR-TEM, EDX, XRD, FTIR, and UV-Vis. The UV-Vis absorption peaks obtained at 270 nm due to carbonyl functional groups shifts of n→π*. In addition, a quantum yield of 7.88 % is achieved. The synthesized PJ-CDs showing the presence of carious functional groups O–H, C–H, C=O, O–H, C–N and the obtained particles in spherical shape with an average size of 8 nm. The fluorescence PJ-CDs showed stability against various environmental factors such as a broad range of ionic strength and pH gradient. The antimicrobial activity of PJ-CDs was tested against a Staphylococcus aureus, and a Escherichia coli. The results suggest that the PJ-CDs could substantially inhibit the growth of Staphylococcus aureus. The findings also indicate that PJ-CDs are effective materials for bio-imaging in Caenorhabditis elegans and they can be also used for pharmaceutical applications.

The monomer 1-(isopropylamino)-3-(1-naphthyloxy)-2-propanoacrylate (IANOPA) and monomer 1-(isopropylamino)-3-(1-naphthyloxy)-2-propanomethacrylate (IANOPMA) were synthesized by treating 1-(isopropylamino)-3-(1-naphthyloxy)-2-propanol with acryloylchloride/methacryloyl chloride. The above esterification reactions were carried out in the presence of triethylamine. By employing the free radical polymerization method, the synthesized monomers were converted into polymers by using an initiator 2, 2′-azobisisobutyronitrile in the presence of nitrogen environment at 70±2°C. The monomers and polymers were characterized by various techniques such as FT-IR, UV, 1H NMR, and 13C NMR spectroscopic analyses. Further, differential scanning calorimetry (DSC) was used to estimate the glass transition temperature (Tg). Gel permeation chromatography (GPC) was used to estimate the molecular weight of the polymers. In addition, monomer and polymer surfaces’ morphology was analyzed using SEM analysis. As a primary application, the effectiveness of synthesized monomers and polymers was explored as antibacterial agents against gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Pseudomonas aeruginosa) which were measured from their inhibitory zone diameters. Further, the synthesized polymers, poly-IANOPA and poly-IANOPMA, were utilized for the uptake ability study of heavy metal ions such as Zn2+, Cu2+, Ni2+, and Pb2+ present in water sources by equilibrium method.

IntroductionFungal keratitis (FK) poses a severe threat to vision, potentially leading to blindness if not promptly addressed. Clitoria ternatea flower extracts have a history of use in Ayurvedic and Indian traditional medicines, particularly for treating eye ailments. This study investigates the antifungal and antibiofilm effects of Clitoria ternatea flower extracts on the FK clinical isolate Coniochaeta hoffmannii. Structural details and key compound identification were analysed through FTIR and GC-MS.MethodsThe minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of Clitoria ternatea flower extracts were determined using broth dilution and well plate techniques. Biofilm inhibitory activity was assessed through microscopic evaluation, while anti-irritant and cytotoxic properties were evaluated using CAE-EI and MTT assays. Through GC-MS and FT-IR analysis the compounds dissolved in the extract and their functional group were studied, and their toxicity screening and pharmacokinetic prediction were conducted in silico. Subsequently, compounds with high corneal permeability were further identified, and molecular docking and simulation studies at 150 ns were used to investigate their interactions with fungal virulence factors and human inflammatory proteins.Results and DiscussionAt a concentration of 250 µg/mL, the Clitoria ternatea flower extract displayed effective biofilm inhibition. MIC and MFC values were determined as 500 and 1000 µg/mL, respectively. CAE-EI and MTT assays indicated no significant irritant and cytotoxic effects up to a concentration of 3 mg/mL. Compounds like 9,9-dimethoxybicyclo[3.3.1]nonane-2,4-dione showed high corneal permeability with strong and stable interactions with fungal virulence cellobiose dehydrogenase, endo β 1,4 xylanase, and glucanase, as well as corneal inflammation-associated human TNF-α and Interleukin IL-1b protein targets. The findings indicate that extracts from C. ternatea flowers could be formulated for an effective and safe alternative for developing new topical FK therapeutics.

In this study, we utilized Agaricaceae, or mushrooms, as the carbon source for the hydrothermal production of multifunctional carbon dots (MCDs). The MCDs showed remarkable features such as bright blue fluorescence, exceptional biocompatibility, high quantum yield, and efficient biolabeling ability. Moreover, the MCDs displayed extraordinary specificity towards HOCl, and could detect it in deionized water with a lower detection limit of 3.38 nM. Additionally, the MCDs had potent antioxidant properties, low cytotoxicity, and high cell permeability, as confirmed by DPPH and reducing potential analysis. Furthermore, the MCD probe proved to be highly useful in various biological applications, including the detection of endogenous HOCl in the RAW 264.7 cell line and the assessment of PMA-induced endogenous HOCl formation using confocal imaging. The synthesis of carbon dots (CDs) from a natural resource such as mushrooms is a promising prospect due to their exceptional physicochemical properties and broad range of potential applications.

Abstract The most promising candidates for solar cells and optoelectronic devices are the transition metals dichalcogenides. Here, we employed the well‐known density functional theory to examine the structural, optoelectronic, and elastic characteristics of novel binary chalcogenides. A direct band gap for ZrX2 and an indirect band gap for PtX2 materials were both confirmed by the band structure features. The valence and conduction band regions are formed by the interaction of the A‐d and X‐p bands. Both the formation energy and the cohesive energies are calculated. The phonon dispersion plots confirmed the stability of the structures. Furthermore, the significant optical constants are computed and explained for possible employment in the optoelectronic application. Our computed band gaps and refractive index were found to be inversely associated. The vital elastic properties are also calculated to discuss the mechanical stability of these materials. The greater bulk modulus and Young's modulus for ZrS2 as compared to the studied chalcogenides suggest this material to be harder and more compressible. The B/G values, confirm all the studied dichalcogenides to be ductile. The most ductile of these materials was ZrSe2 with a predicted B/G value of 7.65. The present work could primarily aid in the creation of diverse and potentially useful semiconducting devices and their applications.

In this study, a vertical shaft is coated using silver nanowires (AgNWs) together with reduced graphene oxide (rGO) via the supersonic spray-coating technique to enhance the absorption of solar radiative heat for use in solar air heaters. The rGO/AgNW-coated surface induces multiple light reflections, similar to that in a perfect black body inside a Helmholtz jar, thus enhancing the collection of solar radiation. Air fed into the vertical heated shaft ascends owing to buoyancy. The air temperature difference, ΔT, between the outlet and inlet is measured for various mass flow rates to quantify the heat transferred to the air from the solar-heated vertical shaft. The longitudinal air velocity and temperature distributions inside the shaft are numerically simulated using the fire dynamics simulator. Both two- and three-dimensional simulations are performed, and the results are compared with experimental data for various mass flow rates. The results confirm that the trends observed in both the experiments and simulations agree well for all cases. Multiple metal meshes are installed inside the vertical shaft to induce turbulence, which enhances the heat transfer intensity. This turbulence enhancement is confirmed via smoke visualization and infrared images.

Use of fillers in polymers is to improve thermo-mechanical properties of the resulting material. Fillers are also used in polymeric foam as cell openers. Flexible polyurethane (PU) foams undergo major loss in structural stability when synthetic polyol is replaced with castor oil in the formulation as an alternate polyol. This study probes the effect of various micro and nano-fillers on PU foams prepared using blend polyol containing castor oil and synthetic polyol at a ratio of 1:1. Physical and cellular properties such as foam height, cell diameter, strut thickness and cell number density were evaluated to probe the structural stability of the foam. All foams prepared were found stable while it was found that the densities of the PU foams synthesized were greater than that of the conventional PU foams. Addition of fillers found to enhance thermal and mechanical properties of the foam. Moreover, all foam samples were found to observe thermal stability over and above 258 °C. Minimum glass transition temperature was recorded for 15% HG samples (i.e., −35.5 °C). Highest tensile strength was observed for 15% Si samples whereas, highest elongation was observed for 10% NC.

The cobalt oxide (Co3O4) nanomaterials were prepared by coprecipitation synthesis technique by maintaining the pH of the mother solution at 7, 8, and 9. The prepared nanomaterials were subjected to structural and optical characterizations, and the results were examined. The optical absorption spectral studies reveal that the two absorption bands indicate ligand–metal coordination. The photoluminescence spectra contain emission peak at 488 and 745 nm due to size and shape of the synthesized materials. The magnetic nature of the samples was identified from the hysteresis loop traced by vibrating sample magnetometry (VSM). The Fourier transform infrared (FT-IR) spectrum of Co3O4 nanomaterials reveals two sharp bands absorbed in 584 and 666 cm-1. This ascribes to the Co-O and O-Co-O stretching, respectively. As the pH of the solution varied from 7 to 10, the SEM image authenticates the transformation of Co3O4 nanomaterials morphology from spherical to cubic to agglomerated shape. From the UV-Vis spectra, two absorption bands around 473 nm and 762 nm are observed for the materials prepared at pH 7 and 8. But at pH 9, these two peaks were shifted towards higher wavelengths 515 nm and 777 nm. The observed ferromagnetic nature of Co3O4 nanomaterials clearly show the role of surface spins and surface morphology on the magnetic properties of Co3O4 nanomaterials. The cyclic voltammetry (CV) curves show the rectangular type of voltammogram. This is an indication of good charge propagation with the electrodes. The Nyquist plots of Co3O4 nanomaterials have a semicircle in the high frequency region and a vertical line in the low frequency region. The results suggest that Co3O4 is found to be a promising material for the fabrication of light-emitting diodes, solar cells, and optoelectronic devices.

Substituted pyrazolyl derivatives were synthesized through Suzuki cross coupling of aromatic boronic acid with heterocyclic halide using newly synthesized nano-Pd/chitosan catalyst by the water-mediated green synthesis methodology. The reactivity of the nano-Pd catalyst was highly enhanced by incorporating palladium nanoparticles with a biopolymer chitosan matrix. The synthesized nano-Pd/chitosan catalyst was studied thoroughly for its structure, morphology, and other fundamental aspects such as the size and shape by various techniques including XRD, FESEM, and EDAX analyses. The scope of the catalyst was disclosed by their great stability with remarkable reusability for Suzuki cross-coupling reaction with twelve different boronic acids under the green synthetic methodology.

L-Lactic acid-producing Lactobacillus lactis and L. plantarum were isolated from date wastes. The fermentation process was optimized using a onevariable-at-a-time approach. Dairy wastewater and wastewater from the date industry were utilized as low-cost culture media to produce lactic acid. The selected two bacterial strains were co-cultured in wastewater medium to produce L-lactic acid and D-lactic acid. Lactic acid production was significantly improved by glucose (carbon source), yeast extract (nitrogen source), initial inoculum level, and polysorbate 80. A central composite design and response surface methodology were used to optimize the variables and their levels to improve lactic acid yield. The supplemented yeast extract, glucose, and polysorbate 80 improved lactic acid. The predicted variables and their levels for maximum lactic acid production were glucose (67.5 g/L), yeast extract (10.28 g/L), and polysorbate 80 (0.48 mL/L). The prepared nanocomposites exhibited antibacterial activity against foodborne bacterial pathogens. The structural properties of the silver-polylactic acid nano compost materials were determined. The characterized compost materials exhibited a peak absorption wavelength of 430 nm. The silver and poly(lactic acid) were characterized using X-ray diffraction analysis and were 30 to 50 nm in size. [ABSTRACT FROM AUTHOR]

Using a pulsed laser ablation system, core–shell Au@Se nanoparticles (Au@Se NPs) were efficiently synthesized and incorporated into a polymeric nanofibrous cellulose acetate (CA)/polyvinylidene fluoride (PVDF) solution prior to electrospinning. Highly crystalline Au@Se NPs were formed in a spherical core/shell configuration with core and shell diameters of 10.5 nm and 25 nm, respectively. The networked scaffolds were decorated with micro-distensions with lengths ranging from 2.8 to 4.3 μm at the lowest Au@Se NPs content. Cell viability analysis confirmed the high biocompatibility of the produced scaffolds, with survival ratios around 91.1 ± 3.4% and 88.2 ± 4.3% at the lowest and highest concentrations of Au@Se NPs, respectively. Obviously, the cells spread and proliferated significantly through the nanofibers. Moreover, the cells not only grew on the surface, but also connected through the deeply porous interior of the nanoparticles. The compositions of these nanofibrous scaffolds can be manipulated to realize a new design for the dressing and healing of wounded tissues.

Acetophenone derivatives are eco-friendly corrosion inhibitors to prevent corrosion of mild steel (MS) in acidic medium. In this work, the inhibition effect of 3-nitroacetophenone (3-NA) on the corrosion of MS in acidic medium (1 N HCl) was investigated using weight loss measurements, electrochemical measurements, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and quantum chemistry analysis. The studies were performed using different concentrations of inhibitors and at different temperatures. The results indicated that the inhibition efficiency of 3-NA increases with an increase in inhibitor concentration and reaches to a maximum of 64% at inhibitor concentration of 250 ppm at 30°C. The potentiodynamic polarization measurement indicated that 3-NA acts as mixed category of interdict. The adsorption of 3-NA on MS surface followed the Langmuir adsorption isotherm. The mode of adsorption of 3-NA on MS surface was further studied by quantum chemical calculations based on density functional theory (DFT). The results plainly revealed that 3-NA performs fairly as corrosion interdict for MS in acidic medium.

Abstract The present study reveals the robust and facile methodology for the synthesis of massively selective dispiro-3-phenylpyrrolothiazole hybrids via one-pot 1,3-dipolar cycloaddition reaction by environmentally supported solvents and to evaluate their biological activities. The quaternary ammonium salt eutectic mixture, acetylcholine iodide-ethylene glycol (ACI/EG) medium brings an efficient environment for the synthesis of dispiropyrrolothiazole with excellent yield in shorter reaction time than imidazolium ionic liquids. The eutectic mixture was recovered and reused without any significant drop in their catalytic activity. Among the eight synthesized compounds 4a–h, halogen derivatives are exhibiting significant antimicrobial activities against selected uropathogens pathogens. Interestingly, chloro and bromo derivatives exhibits the minimum inhibitory concentration (MIC) of 12.5 μg/ml and 6.25 μg/ml towards Escherichia coli, Klebsiella pneumonia, and Staphylococcus aureus respectively. In addition, the IC50 values of DPPH radicals with synthesized compounds are interesting, particularly compounds 4a, 4d and 4e shows lower than the control BHA indicating their potent scavenging ability of free radicals.

This work is based on the effect of different gamma doses with pre- and post-alpha-irradiated PM-355 polymer (polycarbonate of allyl diglycol). The phase crystallinity and structural analysis of the reference and irradiated PM-355 polymer were analyzed using an X-ray diffraction (XRD) study. It is revealed that the irradiation and etching reduce the %crystallinity but increase the crystallite size of the PM-355 polymer. The increase in crystallite size of PM-355 polymer after irradiation is supported by the scanning electron microscopic (SEM) analysis. The etching of the samples results in an increase in its track diameter. The optical band gap energy, measured by ultraviolet-visible (UV-VIS) spectroscopy, shows a decrement trend with the increase of gamma and alpha irradiation doses, and etching for all sets of samples under investigation. The number of carbon atoms per conjugation and per cluster has increased after gamma irradiation and etching. However, the increment is more pronounced for etched samples compared to nonetched ones. This indicates that etching results in a bigger size of cluster. Photoluminescence (PL) for both cases before and after etching has a dominant peak around 430 nm before and after irradiation, and change in peak intensity after irradiation confirmed that particle bombardment induced defects and clusters in the PM-355, which serves as nonradiative centers. The polymer can be used as a detector for gamma irradiation.

The aim of this work is to manage the waste product based on polyethylene (PE) films by recycling and reusing it as antistatic material for electronic packaging and electromagnetic interference (EMI) shielding material for protecting electronic equipment from interference of EM radiation. To achieve this, a conductive carbon black has been mixed with the PE waste at different weight percent values by ultrasonication via a solution mixing process. Mixing time for sonication was determined by ultraviolet-visible (UV-VIS) spectra. A differential scanning calorimetry (DSC) study showed that the low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) are immiscible in their blend composition. The tensile properties of PE have reduced substantially after reprocessing. However, the addition of carbon black has improved its strength up to a certain loading. The electrical percolation threshold values, calculated using the classical power law and sigmoidal Boltzmann model, were obtained at 3.5 and 2.8 wt% loading of carbon black, respectively. The conductivity result revealed that 1-2 wt% carbon-loaded composites can be used as antistatic material. The composites, having carbon loading above 4 wt%, can be effective materials for EMI shielding application. The 10 wt% carbon-loaded composite exhibits EMI SE value 33 dB which means there is approximately 99.93% protection of EM radiation at the sample thickness of 1.0 mm. Moreover, FTIR analysis, thermal stability, AC conductivity, dielectric properties, permeability, and current-voltage characteristics are also discussed in detail. There is a substantial increment in thermal stability, and dielectric properties are observed with the addition carbon black loading within the polymer matrix.

Abstract Background Spiropyrrolidine tethered piperidone heterocyclic hybrids were synthesized with complete regio- and stereoselectively in excellent yield via a tandem three-component 1,3-dipolar cycloaddition and subsequent enamine reaction in [bmim]Br. The synthesized compounds were evaluated for their anticancer activity against FaDu hypopharyngeal tumor cells. Findings Interestingly, most compounds displayed cytotoxicities similar to the standard anticancer agent bleomycin, with two of them (5a and 5g) being slightly more active than the reference drug. Conclusion Synthesized compounds have also been evaluated for their apoptosis-inducing properties in a cancer cell model, finding that treatment with compounds 5a–e led to apoptotic cell death.

Herein we report new multiblock chalcone conjugate phthalimide and naphthalimide functionalized copolymers with a topologically novel architecture synthesis using nucleophilic substitution and polycondensation methodology. The structures of the synthesized novolacs were elucidated on the basis of their spectroscopic analysis including FTIR, 1H NMR, and 13C NMR spectroscopy. Further, the number-average and weight-average molecular weights of the novolac polymers were determined by gel permeation chromatography (GPC). We examined the solubility of the synthesized polymers in various organic solvents including CHCl3, CH3CN, THF, H2O, CH3OH, DMSO, and DMF and found they are insoluble in both methanol and water. The novolac polymers were evaluated for their photophysical properties and microbial activities. The investigation of the antimicrobial activities of these polymers reveals significant antimicrobial activity against the pathogens E. coli, S. aureus, C. albicans, and A. niger.

The goal of the present study was to copolymerize 3-(4-acetylphenylcarbamoyl) acrylic acid and styrene using azo-bis-isobutyronitrile (AIBN) as a catalyst. The resulting copolymers exhibited number average molecular weights (Mn) of 3.73–5.23 × 104 g/mol with a variable polydispersity (PDI = 2.3–3.8). The amide group of the PMA/PSA polymer was used for grafting poly (-styrene-maleic acid substituted aromatic 2-aminopyridine) by the Hantzsch reaction using a substituted aromatic aldehyde, malononitrile, and ammonium acetate. The polymer can emit strong blue fluorescence (λ = 510 nm) and its thermal stability and solubility were enhanced by polymer grafting. Moreover, the polymer showed the fluorescence spectra of the copolymer had a strong, broad emission band between 300 to 550 nm (maximum wavelength 538 nm) under excitation at 293 nm. The Hantzsch reaction yields an interesting class of nitrogen-based heterocycles that combine with a synthetic strategy for synthesis of grafted co-polymer pyridine-styrene derivatives. The as-prepared pyridine-based polymer compounds were screened against Gram-positive and Gram-negative bacteria, where a maximum inhibition zone toward all four types of bacteria was observed, including specific antifungal activity. Herein, a series of pyridine compounds were synthesized that showed enhanced fluorescent properties and antimicrobial properties due to their unique structure and ability to form polymer assemblies.

The storage, utilization, and control of the greenhouse (CO2) gas is a topic of interest for researchers in academia and society. The present review article is dedicating to cover the overall role of ionic liquid-modified hybrid materials in cycloaddition reactions. Special emphasis is on the synthesis of various cyclic carbonate using ionic liquid-based modified catalysts. Catalytic activity studies have discussed with respect to process conditions and their effects on conversion and product selectivity for the reaction of cycloaddition of CO2 with styrene oxide. The reaction temperature and the partial pressure of CO2 have found to play a key role in cyclic carbonate formation. The role of other influential parameter (solvent effect) is also discussed for the conversion of cyclic/aromatic oxides to polycarbonate production. Our own research work that deals with ionic liquid-based halide-modified mesoporous catalyst (MCM-41 type) derived from rice husk waste has also been discussed. Finally, the role of carbon dioxide activation and ring-opening mechanisms involved in the cyclic carbonate product formation from CO2 have been discussed.

A facile synthesis of dispirooxindolopyrrolidines has been accomplished via a one-pot three component 1,3-dipolar cycloaddition reaction. The reaction of azomethine ylides generated in situ from L-phenylalanine and substituted isatins with a series of unusual (E)-2-oxoindolino-3-ylidene acetophenone dipolarophiles in the ionic liquid 1-butyl-3-methylimidazolium bromide [bmim]BF4, furnished the cycloadducts in good yields, with the regioisomers 5a–f being obtained with high selectivity. Furthermore, the recyclability of [bmim]BF4, up to five times, was also investigated.

An expedient synthesis of hitherto unexplored novel hybrid heterocycles comprising dispiropyrrolidine, N-styrylpiperidone and indeno[1,2-b]quinoxaline units has been developed via domino multicomponent 1,3-dipolar cycloaddition strategy employing a new class of azomethine ylide in ionic liquid, 1-butyl-3-methylimidazolium bromide. This domino protocol involves, 1,3-dipolar cycloaddition and concomitant enamine reaction affording the dispiropyrrolidine tethered N-styrylpiperidone hybrid heterocycles in moderate to good yield in a single step. These compounds were evaluated for their antimicrobial activity against bacterial and fungal pathogens, therein compounds 8f, 8h, and 8l displayed significant activity against tested microbial pathogens. The synergistic effect revealed that the combination of compound 8h with streptomycin and vancomycin exhibited potent synergistic activity against E. coli ATCC 25922. In addition, molecular docking simulation has also been studied for the most active compound.