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1.
J Fluoresc ; 32(4): 1263-1277, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35708890

RESUMO

The Schiff-base probe H2VL [6,6'-((1E,1'E)-hydrazine-1,2 diylidenebis(methanylylidene))bis(2-methoxyphenol)] is synthesized and structurally characterized by single crystal X-ray diffraction (SCXRD). H2VL is able to detect selectively acetate ion (OAc-) colorimetrically over other anions with 1:1 co-ordination. The detection limit is found to be 4.93 µM. On the other hand, fluorescence intensity of the receptor is drastically enhanced with Zn2+ and Cd2+ in the presence of acetate as counter anion. N, N-Dimethyl formamide (DMF) or Dimethylsulphoxide (DMSO) and acetate (OAc-) was the best solvent and counter anion for Zn2+/Cd2+ -sensing compared with other solvents and anions, respectively. Detection limit for Zn2+ and Cd2+ are calculated to be 1.94 µM and 1.99 µM, respectively. The strong selective emissive behavior could be attributed to the CHEF (chelation-enhanced fluorescence) process. According to the changes in output emission intensity in DMSO in response to the set of ions (Zn2+, Cd2+ and OAc¯) as input variables, the function of 3-input multifunctional molecular logic circuits has been demonstrated. The molecular docking studies of H2VL with DNA and BSA are also performed to confirm its possible bioactivity.


Assuntos
Cádmio , Zinco , Acetatos , Ânions , Dimetil Sulfóxido , Simulação de Acoplamento Molecular , Espectrometria de Fluorescência , Zinco/química
2.
Mol Divers ; 26(3): 1697-1714, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34482478

RESUMO

In this study, a set of dietary polyphenols was comprehensively studied for the selective identification of the potential inhibitors/modulators for galectin-1. Galectin-1 is a potent prognostic indicator of tumor progression and a highly regarded therapeutic target for various pathological conditions. This indicator is composed of a highly conserved carbohydrate recognition domain (CRD) that accounts for the binding affinity of ß-galactosides. Although some small molecules have been identified as galectin-1 inhibitors/modulators, there are limited studies on the identification of novel compounds against this attractive therapeutic target. The extensive computational techniques include potential drug binding site recognition on galectin-1, binding affinity predictions of ~ 500 polyphenols, molecular docking, and dynamic simulations of galectin-1 with selective dietary polyphenol modulators, followed by the estimation of binding free energy for the identification of dietary polyphenol-based galectin-1 modulators. Initially, a deep neural network-based algorithm was utilized for the prediction of the druggable binding site and binding affinity. Thereafter, the intermolecular interactions of the polyphenol compounds with galectin-1 were critically explored through the extra-precision docking technique. Further, the stability of the interaction was evaluated through the conventional atomistic 100 ns dynamic simulation study. The docking analyses indicated the high interaction affinity of different amino acids at the CRD region of galectin-1 with the proposed five polyphenols. Strong and consistent interaction stability was suggested from the simulation trajectories of the selected dietary polyphenol under the dynamic conditions. Also, the conserved residue (His44, Asn46, Arg48, Val59, Asn61, Trp68, Glu71, and Arg73) associations suggest high affinity and selectivity of polyphenols toward galectin-1 protein.


Assuntos
Galectina 1 , Polifenóis , Sítios de Ligação , Carboidratos/química , Galectina 1/química , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica
3.
Chem Biodivers ; 19(12): e202200540, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36310125

RESUMO

A new series of thieno nucleus embellished trinuclear (19, 20) and tetranuclear (21-24) nitrogen heteroaryl have been synthesized by the Suzuki cross-coupling reaction using bis(triphenylphosphine)palladium(II) dichloride. All the synthesized compounds were characterized by IR, 1 H-NMR, 13 CNMR and Mass spectral properties. In vitro antibacterial studies of the synthesized compound were conducted using broth microdilution assay employing Gram-positive and Gram-negative strains and half-maximal inhibitory concentration (IC50 ) was determined. The result showed that compound 20 possess best antibacterial activity against S. aureus and E. coli with IC50 values of 60 µg mL-1 and 90 µg mL-1 . Further to determine the mode of antibacterial action, compounds 20 and 21 were examined for in vitro bacterial dehydrogenase inhibitory assay. To understand the binding affinity of the synthesized compounds, the docking study was performed in the bacterial dehydrogenase enzyme by AutoDock Vina software and structure was confirmed by Discovery Studio Visualizer. All the synthesized compounds were docked in a good manner within the active sites of the bacterial dehydrogenase enzyme and exhibited good binding energies.


Assuntos
Nitrogênio , Staphylococcus aureus , Escherichia coli , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/química , Bactérias , Modelos Teóricos , Oxirredutases , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Estrutura Molecular
4.
Molecules ; 26(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207072

RESUMO

The aim of the research was to prepare low-cost adsorbents, including raw date pits and chemically treated date pits, and to apply these materials to investigate the adsorption behavior of Cr(III) and Cd(II) ions from wastewater. The prepared materials were characterized using SEM, FT-IR and BET surface analysis techniques for investigating the surface morphology, particle size, pore size and surface functionalities of the materials. A series of adsorption processes was conducted in a batch system and optimized by investigating various parameters such as solution pH, contact time, initial metal concentrations and adsorbent dosage. The optimum pH for achieving maximum adsorption capacity was found to be approximately 7.8. The determination of metal ions was conducted using atomic adsorption spectrometry. The experimental results were fitted using isotherm Langmuir and Freundlich equations, and maximum monolayer adsorption capacities for Cr(III) and Cd(II) at 323 K were 1428.5 and 1302.0 mg/g (treated majdool date pits adsorbent) and 1228.5 and 1182.0 mg/g (treated sagai date pits adsorbent), respectively. It was found that the adsorption capacity of H2O2-treated date pits was higher than that of untreated DP. Recovery studies showed maximal metal elution with 0.1 M HCl for all the adsorbents. An 83.3-88.2% and 81.8-86.8% drop in Cr(III) and Cd(II) adsorption, respectively, were found after the five regeneration cycles. The results showed that the Langmuir model gave slightly better results than the Freundlich model for the untreated and treated date pits. Hence, the results demonstrated that the prepared materials could be a low-cost and eco-friendly choice for the remediation of Cr(III) and Cd(II) contaminants from an aqueous solution.


Assuntos
Cádmio/química , Cromo/química , Metais Pesados/química , Phoeniceae/química , Sementes/química , Água/química , Adsorção , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Íons/química , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Águas Residuárias/química , Poluentes Químicos da Água/química , Purificação da Água/métodos
5.
J Mol Recognit ; 33(7): e2838, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32060998

RESUMO

Dengue infection is the most common arthropod-borne disease caused by dengue viruses, predominantly affecting millions of human beings annually. To find out promising chemical entities for therapeutic application in Dengue, in the current research, a multi-step virtual screening effort was conceived to screen out the entire "screening library" of the Asinex database. Initially, through "Lipinski rule of five" filtration criterion almost 0.6 million compounds were collected and docked with NS3-NS2B protein. Thereby, the chemical space was reduced to about 3500 compounds through the analysis of binding affinity obtained from molecular docking study in AutoDock Vina. Further, the "Virtual Screening Workflow" (VSW) utility of Schrödinger suite was used, which follows a stepwise multiple docking programs such as - high-throughput virtual screening (HTVS), standard precision (SP), and extra precision (XP) docking, and in postprocessing analysis the MM-GBSA based free binding energy calculation. Finally, five potent molecules were proposed as potential inhibitors for the dengue NS3-NS2B protein based on the investigation of molecular interactions map and protein-ligand fingerprint analyses. Different pharmacokinetics and drug-likeness parameters were also checked, which favour the potentiality of selected molecules for being drug-like candidates. The molecular dynamics (MD) simulation analyses of protein-ligand complexes were explained that NS3-NS2B bound with proposed molecules quite stable in dynamic states as observed from the root means square deviation (RMSD) and root means square fluctuation (RMSF) parameters. The binding free energy was calculated using MM-GBSA method from the MD simulation trajectories revealed that all proposed molecules possess such a strong binding affinity towards the dengue NS3-NS2B protein. Therefore, proposed molecules may be potential chemical components for effective inhibition of dengue NS3-NS2B protein subjected to experimental validation.


Assuntos
Dengue/tratamento farmacológico , Inibidores de Proteases/uso terapêutico , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Proteínas não Estruturais Virais/antagonistas & inibidores , Proteínas não Estruturais Virais/metabolismo
6.
J Sep Sci ; 43(11): 2079-2087, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32125088

RESUMO

An ultra high performance liquid chromatography-tandem mass spectrometric method has been developed for the highly sensitive and selective determination of regulated aflatoxins. The extraction of aflatoxins from baby food matrices were performed using liquid-liquid extraction procedure followed by immunoaffinity column cleanup. The higher sensitivity for the determination of target aflatoxins was fulfilled by applying a preconcentration step with immunoaffinity columns after acetonitrile-water extraction. The enhanced selectivity was attained with the triple quadrupole mass analyzer operated in electrospray positive ionization mode. Method validation was tested in five different baby food matrices by recovery experiments. Satisfactory recoveries, between 92 and 103%, with relative standard deviations lower than 8% were achieved in all the tested matrices. The proposed method was found to be specific as no interference peaks were observed for blank samples. The limit of detection of the method was found to be in the range of 0.003-0.008 ng/mL. The validated method was fruitfully applied to the screening of aflatoxins in baby foods and feeds sample retailed in local markets of Riyadh, Saudi Arabia. The obtained levels of all analyzed aflatoxins were below the regulation limits set by European Agency.


Assuntos
Aflatoxinas/análise , Contaminação de Alimentos/análise , Alimentos Infantis/análise , Cromatografia de Afinidade , Cromatografia Líquida de Alta Pressão , Humanos , Lactente , Estrutura Molecular , Espectrometria de Massas em Tandem
7.
Mikrochim Acta ; 187(10): 580, 2020 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-32979097

RESUMO

A 3D flexible domestic waste styrofoam is reported as a surface enhanced Raman scattering (SERS) substrate loaded with BiOCl-BiOBr@Pt/Au semiconductor-plasmonic composites. The hydrothermally prepared BiOCl-BiOBr nanocomposite is thoroughly characterized for its crystal structure using X-Ray diffraction, morphology through scanning electron microscopy, and electronic states of the elements using X-ray photoelectron spectroscopy. The alpha cypermethrin (ACM) is chosen as a model pesticide analyte for SERS investigation. The BiOCl-BiOBr@Pt/Au loaded foam substrate exhibited a high enhancement factor (106) and low limit of detection (10-10 M) upon SERS investigation. The unique architecture of the semiconductor-plasmonic composite enables an efficient charge transfer capability and plasmonic hotspots which aids in the enhancement of target analytes. In order to better demonstrate the versatility towards other pesticides, SERS detection of glyphosate and paraquat pesticides are also performed using the fabricated SERS substrate. The stability of the substrate has been investigated in detail for 30 days and the substrate was highly stable. The BiOCl-BiOBr@Pt/Au-based foam substrate also performed well in rapid real-time sensing of alpha cypermethrin on the kiwi fruit exocarp at lower level concentrations. Graphical abstract.


Assuntos
Nanopartículas Metálicas/química , Praguicidas/química , Poliestirenos/química , Humanos , Prata/química
8.
Molecules ; 25(19)2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33036289

RESUMO

Lower dye concentrations and the presence of several dyes along with other matrices in environmental samples restrict their determination. Herein, a highly sensitive and rapid ultra-performance tandem mass spectrometric method was developed for simultaneous determination of cationic dyes, namely methylene blue (MB), rhodamine B (RB) and crystal violet (CV), in environmental samples. To preconcentrate environmental samples, solid-phase extraction cartridges were developed by using hydrogen peroxide modified pistachio shell biomass (MPSB). The surface morphological and chemical functionalities of MPSB were well characterized. The developed method was validated considering different validation parameters. In terms of accuracy and precision, the %RSD for all three dyes at all four concentration points was found to be between 1.26 and 2.76, while the accuracy reported in terms of the recovery was found to be 98.02%-101.70%. The recovery was found to be in the range of 98.11% to 99.55%. The real sample analysis shows that MB, RB, and CV were found in the ranges of 0.39-5.56, 0.32-1.92 and 0.27-4.36 µg/mL, respectively.


Assuntos
Cromatografia Líquida/métodos , Rodaminas/química , Extração em Fase Sólida/métodos , Violeta Genciana , Azul de Metileno/química
9.
J Environ Manage ; 219: 285-293, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29751259

RESUMO

Herein, Cetyltrimethyl ammonium bromide (CTAB) intercalated and branched polyhydroxystyrene (BPS) functionalized montmorillonite (MMT) nano-composite (BPS-CTAB-MMT) was developed, characterized, and its potential as an adsorbent was tested in sequestering cationic dyes viz. rhodamine B (RB), crystal violet (CV), and methylene blue (MB) from aqueous environment. N2 adsorption/desorption isotherm showed mesoporous BPS-CTAB-MMT surface with a BET surface area of 273.8 m2/g. The appearance of sharp spikes at 2855 and 2925 cm-1 (associated with symmetric and asymmetric tensions of C - H bonds) in infra-red spectrum of BPS-CTAB-MMT indicates successful intercalation of MMT with CTAB and functionalization with BPS. The observed crystallite size of BPS-CTAB-MMT was 66 nm. Comparatively greater weight loss for BPS-CTAB-MMT (11%) than MMT (9%) was observed during thermogravimetric analysis. The adsorption of dyes on BPS-CTAB-MMT was pH dependent with maximum uptake was observed in the pH range: 5-6. For initial dyes concentration (Co) range: 50-150 mg/L, the observed equilibration time for CV was 300 min, whereas for RB and MB the equilibration time varied between 300 and 360 min. Modeling investigations revealed the applicability of Sips isotherm and pseudo-second-order (PSO) kinetic models to dyes adsorption data. Sips maximum adsorption capacity (qs) values for RB, CV, and MB at 55 °C were 476.5, 438.7, and 432.7 mg/g, respectively. The adsorption of dyes on BPS-CTAB-MMT was thermodynamically favorable. Desorption studies showed 42.1% RB and 41.9% CV recovery with 0.1 M NaOH and CH3COCH3, respectively, while only traces of MB were recovered with tested eluents.


Assuntos
Silicatos de Alumínio , Bentonita , Compostos de Cetrimônio , Adsorção , Cetrimônio , Argila , Corantes , Cinética
10.
Molecules ; 23(4)2018 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-29614828

RESUMO

We are reporting a novel azo-azomethine ligand, HL and its complexes with Cu(II) and Fe(III) ions. The ligand and its complexes are characterized by various physico-chemical techniques using C,H,N analyses, FT-IR, ¹H-NMR, ESI-MS and UV-Vis studies. TGA analyses reveal complexes are sufficiently stable and undergo two-step degradation processes. The redox behavior of the complexes was evaluated by cyclic voltammetry. Furthermore, the ligand and its complexes were tested for antimicrobial activity against bacterial and fungal strains by determining inhibition zone, minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The complexes showed moderate antimicrobial activity when tested against Gram +ve and Gram -ve bacterial strains. To obtain insights into the structure of ligand, DFT studies are recorded. The results obtained are quite close to the experimental results. In addition, the energy gap, chemical hardness, softness, electronegativity, electrophilic index and chemical potential were calculated using HOMO, LUMO energy value of ligand.


Assuntos
Anti-Infecciosos/síntese química , Anti-Infecciosos/farmacologia , Compostos Azo/síntese química , Compostos Azo/farmacologia , Cobre/química , Compostos Férricos/síntese química , Compostos Férricos/farmacologia , Tiossemicarbazonas/química , Anti-Infecciosos/química , Compostos Azo/química , Compostos Férricos/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Ligantes , Testes de Sensibilidade Microbiana
11.
J Food Sci Technol ; 55(1): 198-204, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29358811

RESUMO

Quantitative assessment of nitrite (NO2-) anion was performed using a newly developed high throughput ultra performance liquid chromatography-mass spectrometric (UPLC-MS) method. The nitrite determination with the proposed method using micellar mobile phase was unknown. Selected ion reaction mode using negative electrospray ionization was adopted for the identification and quantitative analysis of nitrite. The chromatographic separation was performed using BEH C-18 column and a micellar mobile phase consisted of sodium dodecyl sulphate and acetonitrile in ratio 30:70 was used. The elution of nitrite anion was accomplished in less than 1 min. Under the optimal analysis conditions, the linearity of the developed method was checked in the concentration range of 0.5-20 mg kg-1 NO2- with an excellent correlation coefficient of 0.996. The precisions of the method with relative standard deviation <2% was observed when standard at concentration of 1 mg kg-1 was used. The limit of detection and limit of quantitation of the developed mass spectrometric method was found to be 0.114 and 0.346 mg kg-1, respectively. The developed UPLC/MS method was applied to quantify this anion in processed meats and poultries from various super market of Saudi Arabia (Riyadh region). The recoveries of the nitrite in the various samples were found in the range of 100.03-103.5%.

12.
J Sep Sci ; 38(15): 2597-606, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25989240

RESUMO

An ultra high performance liquid chromatography with mass spectrometry method has been developed for the simultaneous separation, identification and determination of 22 phenolic constituents in honey from various floral sources from Yemen. Solid-phase extraction was used for extraction of the target phenolic constituents from honey samples, while multiwalled carbon nanotubes were used as solid-phase adsorbent. The chromatographic separation of all phenolic constituents was performed on a BEH C18 column using a linear gradient elution with a binary mobile phase mixture of aqueous 0.1% formic acid and methanol. The quantitation was carried out in selected ion reaction monitoring acquisition mode. The total amount of phenolic acids, flavonoids and other phenols in each analyzed honey was found in the range of 338-3312, 122-5482 and 2.4-1342 µg/100 g of honey, respectively. 4-Hydroxybenzoic acid was found to be the major phenolic acid. The main detected flavonoid was chrysin, while cinnamic acid was found to be the major other phenol compound. The regeneration of solid phase adsorbent to be reused and recovery results confirm that the proposed method could be potentially used for the routine analysis of phenolic constituents in honey extract.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Flores/química , Mel/análise , Espectrometria de Massas/métodos , Nanotubos de Carbono , Fenóis/análise , Extração em Fase Sólida
13.
Bioprocess Biosyst Eng ; 38(9): 1803-10, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26104538

RESUMO

Silver nanoparticles have been synthesized and were utilized for the enhanced luminometric estimation of moxifloxacin antibiotic. During the experimental procedure, it was clearly found that the addition of silver nanoparticles intensifies the weak chemiluminescence signal intensity of calcein-KMnO4 system by several folds. It was also obvious that the intensity enhancement was linearly proportional to the moxifloxacin concentration and this phenomenon was further utilized for the quantitative determination of target analyte. Effects of the different chemical variables during the experiment were studied to achieve best chemiluminescence signal. Under the optimized experimental parameters, the linear calibration graph was established over the moxifloxacin concentration range of 6.0 × 10(-8) M to 2.5 × 10(-6) M with coefficient of correlation (r (2)) value 0.9998. The lower detection limit was found to be 5.6 × 10(-9) M. The percentage relative standard deviation calculated from five replicate chemiluminescence measurements was found to be 2.63 %. The developed chemiluminescence technique was successfully applied to the determination of moxifloxacin in tablet formulation and spiked human urine sample.


Assuntos
Análise de Injeção de Fluxo/métodos , Fluoroquinolonas/análise , Medições Luminescentes/métodos , Nanopartículas Metálicas/química , Prata/química , Urinálise/métodos , Antibacterianos/análise , Antibacterianos/urina , Fluoresceínas/química , Fluoroquinolonas/urina , Glucosídeos/química , Humanos , Compostos de Manganês/química , Moxifloxacina , Óxidos/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Comprimidos , Tecnologia Farmacêutica/métodos
14.
RSC Adv ; 14(14): 10120-10130, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38566837

RESUMO

Hybrid supercapacitors can produce extraordinary advances in specific power and energy to display better electrochemical performance and better cyclic stability. Amalgamating metal oxides with metal-organic frameworks endows the prepared composites with unique properties and advantageous possibilities for enhancing the electrochemical capabilities. The present study focused on the synergistic effects of the CuCo(5-NIPA)-Nd2O3 composite. Employing a half-cell configuration, we conducted a comprehensive electrochemical analysis of CuCo(5-NIPA), Nd2O3, and their composite. Owing to the best performance of the composite, the hybrid device prepared from CuCo(5-NIPA)-Nd2O3 and activated carbon demonstrated a specific capacity of 467.5 C g-1 at a scan rate of 3 mV s-1, as well as a phenomenal energy and power density of 109.68 W h kg-1 and 4507 W kg-1, respectively. Afterwards, semi-empirical techniques and models were used to investigate the capacitive and diffusive mechanisms, providing important insights into the unique properties of battery-supercapacitor hybrids. These findings highlight the enhanced performance of the CuCo(5-NIPA)-Nd2O3 composite, establishing it as a unique and intriguing candidate for applications requiring the merging of battery and supercapacitor technologies.

15.
ChemSusChem ; : e202400450, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38660929

RESUMO

For the sluggish reaction kinetics due to a four-electron transfer process, water oxidation is always a major obstacle to solar splitting of water to hydrogen. It remains a tough challenge to develop efficient nonnoble-metal photocatalysts for water oxidation. Herein, we decorate the host photocatalyst of Bi11VO19 nanotubes with the coatalyst of subnanometer MoOx clusters (denoted as Bi11VO19/MoOx hetero-nanotubes) via a one-step cation-exchange solvothermal reaction using Na2V6O16 nanowires as the hard template. It is observed that the morphology and microstructure of Bi11VO19/MoOx hetero-nanotubes vary with the dosage of Mo source and polyvinylpyrrolidone, as well as with the solvent composition. The optimized Bi11VO19/MoOx hetero-nanotubes significantly enhance the photooxidation of water to oxygen with visible light, delivering an oxygen production rate of 790 µmol g-1 h-1, which is 12 times that of bare Bi11VO19 nanotubes. In situ X-ray photoelectron spectroscopy and (photo)electrochemical characterization suggest that the enhanced photoactivity may be caused by the decorated cocatalyst of MoOx clusters, which extracts electrons from Bi11VO19 nanotubes, leaving an abundance of holes for water photooxidation. This work demonstrates a potential strategy to develop photocatalysts for energy conversion by constructing Bi11VO19-based nanostructures.

16.
Heliyon ; 10(3): e25385, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38356584

RESUMO

The aim of this study was to prepare poly-N-isopropylmethacrylamide-co-acrylic acid-acrylamide [p-(NIPMAM-co-AA-AAm)] via precipitation polymerization in an aqueous medium. Rhodium nanoparticles were formed in the microgel network by an in-situ reduction technique with the addition of sodium borohydride as a reducing agent. Pure p-(NIPMAM-co-AA-AAm) and hybrid microgels [Rh-(p-NIPMAM-co-AA-AAm)] microgels were examined by using UV-Visible, FTIR (Fourier Transform Infrared), SEM (Scanning Electron Microscopy), TEM (Transmission Electron Microscopy), DLS (Dynamic Light Scattering) and XRD (X-Ray Diffraction) techniques. The catalytic activities of the hybrid microgel [Rh-(p-NIPMAM-co-AA-AAm)] for the degradation of azo dyes such as alizarin yellow (AY), congo red (CR), and methyl orange (MO) were compared and the mechanism of the catalytic action by this system was examined. Various parameters including the catalyst amount and dye concentration influenced the catalytic decomposition of azo dyes. In order to maximize the reaction conditions for the dye's quick and efficient decomposition, the reaction process was monitored by spectroscopic analysis. The rate constants for reductive degradation of azo dyes were measured under various conditions. When kapp values were compared for dyes, it was found that [Rh-(p-NIPMAM-co-AA-AAm)] hybrid microgels showed superior activity for the degradation of MO dyes compared to the reductive degradation of CR and AY.

17.
RSC Adv ; 14(4): 2205-2213, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38213966

RESUMO

Efficient energy storage and conversion is crucial for a sustainable society. Battery-supercapacitor hybrid energy storage devices offer a promising solution, bridging the gap between traditional batteries and supercapacitors. In this regard, metal-organic frameworks (MOFs) have emerged as the most versatile functional compounds owing to their captivating structural features, unique properties, and extensive diversity of applications in energy storage. MOF properties are governed by the structure and topological characteristics, which are influenced by the types of ligands and metal nodes. Herein, MOFs based on pyridine 3,5-dicarboxylate (PYDC) ligand in combination with copper and cobalt are electrochemically analyzed. Owing to the promising initial characterization of Cu-PYDC-MOF, a battery supercapacitor hybrid device was fabricated, comprising Cu-PYDC-MOF and activated carbon (AC) electrodes. The device showcased energy and power density of 17 W h kg -1 and 2550 W kg -1, respectively. Dunn's model was employed to gain deeper insights into the capacitive and diffusive contributions of the device. With their performance and versatility, the PYDC-based MOFs stand at the forefront of energy technology, ready to power a brighter future for upcoming generations.

18.
Chem Asian J ; : e202400218, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38634303

RESUMO

We have successfully synthesized a new Ni(II)-based coordination polymer (CP) [Ni2(cis-1,4-chdc)2(4,4'-bpy)3(H2O)2] (1); (cis-1,4- H2chdc=cis-1,4-cyclohexanedicarboxylic acid and 4,4'-bpy=4,4'-bipyridine) employing slow diffusion method in a single pot technique. The connectivity of Ni(II) ions and bridging cis-1,4-chdc ligand gives rise to a three-dimensional (3D) framework with 2-fold interpenetrated diamondoid topology. Interestingly, the synthesized CP acts as efficient catalyst for electrocatalytic water splitting. The water oxidation activity of compound 1 exhibits Tafel slope equivalent to 361.48 mV.dec-1 for hydrogen evolution reaction (HER) and 353.53 mV.dec-1 for oxygen evolution reaction (OER) in an alkaline medium while almost similar values of Tafel slope for HER and OER equivalent to 287.33 mV.dec-1 and 289.93 mV.dec-1 respectively in acidic medium. Thus, the compound 1 has excellent efficacy in catalyzing HER and OER in acidic as well as alkaline medium, which is ascribed to its distinctive 3D architecture.

19.
RSC Adv ; 14(9): 5981-5993, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38362074

RESUMO

In the current study, the association and phase separation of cationic tetradecyltrimethylammonium bromide (TTAB) and nonionic Triton X-100 (TX-100) surfactants with promethazine hydrochloride (PMH) were investigated in aqueous ammonium-based solutions. The micellization nature of the TTAB and PMH drug mixture was examined by evaluating critical micelle concentration (CMC) and counterion binding extent (ß) at different salt contents and temperatures (298.15-323.15 K). Micelle formation in the TTAB + PMH mixture was enhanced in the presence of ammonium salts, whereas the process was delayed with an increase in temperature in the respective salt solution. With an increase in salt content, the cloud point (CP) of the TX-100 + PMH mixture decreased, which revealed that the respective progression occurred through the salting out phenomenon. In micellization and clouding processes, the changes in free energies ΔG0m and ΔG0c were found to be negative and positive, respectively, demonstrating that the corresponding processes are spontaneous and non-spontaneous. Standard enthalpies (ΔH0m/ΔH0c) and standard entropies (ΔS0m/ΔS0c) for the association and clouding processes, respectively, were also calculated and discussed. The core forces amid TTAB/TX-100 and PMH in the manifestation of electrolytes are dipole-dipole and hydrophobic forces among the employed components according to the values for ΔH0m/ΔH0c and ΔS0m/ΔS0c, respectively.

20.
Nanomaterials (Basel) ; 13(7)2023 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-37049288

RESUMO

The conversion of worthless municipal solid wastes to valuables is a major step towards environmental conservation and sustainability. This work successfully proposed a technique to utilize the two most commonly available municipal solid wastes viz polythene (PE) and sugarcane bagasse (SB) for water decolorization application. An SBPE composite material was developed and co-pyrolyzed under an inert atmosphere to develop the activated SBPEAC composite. Both SBPE and SBPEAC composites were characterized to analyze their morphological characteristics, specific surface area, chemical functional groups, and elemental composition. The adsorption efficacies of the composites were comparatively tested in the removal of malachite green (MG) from water. The SBPEAC composite had a specific surface area of 284.5 m2/g and a pore size of ~1.33 nm. Batch-scale experiments revealed that the SBPEAC composite performed better toward MG adsorption compared to the SBPE composite. The maximum MG uptakes at 318 K on SBPEAC and SBPE were 926.6 and 375.6 mg/g, respectively. The adsorption of MG on both composites was endothermic. The isotherm and kinetic modeling data for MG adsorption on SBPEAC was fitted to pseudo-second-order kinetic and Langmuir isotherm models, while Elovich kinetic and D-R isotherm models were better fitted for MG adsorption on SBPE. Mechanistically, the MG adsorption on both SBPE and SBPEAC composites involved electrostatic interaction, H-bonding, and π-π/n-π interactions.

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