Values Of Rate Constants Research Articles

Shelf-life Estimation of Dried Chili in Vacuum Packaging

This research aimed to build a model for estimating the shelf life of dried chilies in vacuum packaging stored at any storage temperature. The shelf-life estimation of dried red chilies was carried out based on the change rate of dried chilies quality parameters using the ASLT (Accelerated Shelf-Life Testing) method with the Arrhenius approach. The shelf-life estimation using the ASLT method was carried out by conditioning the storage room, which could accelerate the degradation reaction, stored at temperatures above room temperature. Prior to storage, red chilies were dried until their moisture content reaches 10%. Then it was packaged in vacuum packaging made of PE (polyethylene) plastic and stored at 35°C. During the storage period, the observation was conducted on some quality parameters, namely moisture content, color, and vitamin C content. The same experiments were also carried out at 40°C, 45°C, and 50°C to obtain different rate constant values. The shelf-life estimation results from the Arrhenius equation model were selected based on the critical parameter, in this study the critical parameter was the decrease of vitamin C content. The shelf life of dried red chilies that were packed in vacuum stored at room temperature (25°C) could maintain its quality up to 365 days. Keywords: Arrhenius, ASLT, Red chili, Vacuum packaging, Shelf life,

Biosynthesis of CoCr2O4/ZnO nanocomposites using Basella alba L. leaves extracts with enhanced photocatalytic degradation of malachite green in aqueous media

The use of chemical materials to tackle environmental concerns has undergone significant evolution, particularly in the pursuit of strategies for removing pollutants from wastewater as part of environmental remediation an increasingly crucial research topic. Employing green photocatalysts stands out as an efficient and cost-effective approach, playing a key role in promoting sustainable environmental remediation. This study introduces the modification of zinc oxide with cobalt chromite (CoCr2O4/ZnO) through a green synthesis method employing Basella alba L. leaves extract (BALE). Utilizing various characterization techniques, including FT–IR, UV–Vis DRS, XRD, SEM-EDS, and TEM, key features of ZnO, CoCr2O4, and CoCr2O4/ZnO nanocomposites were identified. The optical band gaps for ZnO, CoCr2O4, and CoCr2O4/ZnO nanocomposites were determined as 3.16, 1.71, and 2.80 eV, respectively, where it was shown that the band gap of the ZnO was reduced significantly. CoCr2O4/ZnO nanocomposites displayed a cubic shape of CoCr2O4 on the surface of ZnO, with a particle size of 23.84 ± 8.08 nm. The photocatalytic activity was assessed through the degradation of malachite green under visible light irradiation, where the CoCr2O4/ZnO nanocomposites exhibited superior photodegradation efficiency at 90.91%, surpassing ZnO alone (57.09%). This improvement in photocatalytic activity is attributed to a reduced band gap energy and a high rate constant value of 9.57 × 10−3 min−1, demonstrating pseudo-first-order reaction kinetics. In summary, this research presents the development of a ZnO-based photocatalyst with exceptional performance, especially in the visible light spectrum, making it a promising candidate for applications in wastewater removal.

Sustainable phycoremediation of mushroom farm wastewater using novel isolated microalga (Chlamydomonas asymmetrica SAG70.72): Experimental and kinetic studies

This study aimed to assess the mushroom farm wastewater (MFW) treatment potential using novel isolated microalga Chlamydomonas asymmetrica strain SAG70.72. Microalga was isolated from the Ganga River located in Haridwar, India, and identified using an 18S rRNA-based sequencing technique. For phycoremediation experiments, different concentrations of MFW (i.e., 0 % as control, 50, and 100 %) were used to cultivate isolated C. asymmetrica under laboratory conditions. The results showed that the maximum significant (p < 0.05) reduction in total dissolved solids (TDS: 87 %), biochemical oxygen demand (BOD: 93 %), chemical oxygen demand (COD: 92 %), total Kjeldahl's nitrogen (TKN: 87 %), and total phosphorus (TP: 97 %) were observed in 50 % MFW treatment. Moreover, proximate, biochemical, and fatty acids methyl esters (FAMEs) composition of C. asymmetrica were also found highest in 50 % MFW treatment. The first-order reaction-based kinetic model also depicted the highest value of rate constant (k) in the same treatment. Moreover, the growth of C. asymmetrica was best simulated using the logistic model as compared to the modified Gompertz models. The findings of this study suggested that the implementation of isolated C. asymmetrica in MFW treatment systems could contribute to the mitigation of environmental impacts associated with mushroom cultivation.

A new BiOCl–ZnFe2O4/CNTs ternary composite for remarkable photocatalytic degradation studies of a herbicide and a diazo dye

Fabrication of binary or ternary nanocomposite of different semiconducting materials has received considerable attention for the development of an efficient, novel and realistic photocatalyst. Herein, we report the synthesis of BiOCl, spinel ZnFe2O4, BiOCl–ZnFe2O4 hybrid, and BiOCl–ZnFe2O4/CNTs ternary composite. Pure BiOCl and spinel ZnFe2O4 were synthesized by co-precipitation method while BiOCl–ZnFe2O4 hybrid and BiOCl–ZnFe2O4/CNTs ternary composite by an ultra-sonication approach. The prepared photocatalytic samples were scrutinized by X-ray diffraction (XRD) technique, Fourier transform infra-red (FTIR) spectroscopy, and UV–Visible (UV–Vis) spectroscopy. The calculated optical energy gaps of BiOCl and spinel ZnFe2O4 using Tauc equation were 3.21 eV and 2.19 eV respectively. The photocatalytic efficiency of all prepared photocatalysts was tested against a herbicide (Pendimethalin), and an anionic diazo dye (Congo red). The obtained results revealed that carbon nanotubes based ternary composite of BiOCl–ZnFe2O4 hybrid has high rate and percentage degradation for both pendimethalin and congo red among all synthesized materials. For pendimethalin removal, the value of rate constant of BiOCl–ZnFe2O4/CNTs is 0.01 min−1 and % degradation is 88.6 %. Moreover, BiOCl–ZnFe2O4/CNTs ternary composite exhibits 95.27 % degradation and rate constant of 0.02 min−1 for congo red dye. The higher photocatalytic removal activity of ternary composite (BiOCl–ZnFe2O4/CNTs) as compared to other fabricated photocatalysts is due to its high surface area, greater adsorption capability, high charge transfer rate and low e−/h+ pair recombination. Hence, BiOCl–ZnFe2O4/CNTs composite could be an efficient photocatalyst for the mineralization of various organic industrial effluents.

Plant axillary stem gall extract mediated bioengineered CuO nanoprisms as robust and reusable catalyst for photocatalytic and catalytic degradation of water pollutants

The current work explains the synthesis of bioengineered CuO nanoprisms using axillary stem gall extract of the Ziziphus mauritiana plant. The photocatalytic and catalytic reduction potential of bioengineered CuO nanoprisms was analyzed for the photo-mineralization of methylene blue (MB) organic dye under exposure to visible light and catalytic reduction of 4-nitrophenol (4-NP) in the presence of NaBH4 solution. The biogenic CuO nanoprisms were characterized using XRD, FTIR, FESEM, EDS, and UV–Vis. spectroscopic techniques. The mean crystallite size of CuO nanoprisms was estimated to be 34.24 nm while the band gap energy value was found to be 1.47 eV. 99.21 % of MB dye was photo-mineralized within 70 min of visible light illumination at pH=5 and 30 mg of catalyst whereas 4-NP was almost completely reduced to 4-AP within 5 min in the presence of bioengineered CuO (NPs). The data of photo-mineralization of MB dye and catalytic reduction of 4-NP well agreed to the pseudo-first-order kinetics with the rate constant values of 63.86 × 10−3 and 0.8439 min−1, respectively. The reactive species entrapping studies revealed that •OH radicals were the key active species affianced in the photo-mineralization of MB dye. Photostability and reusability tests established that only a 9 % decline in the dye degradation efficiency of bioengineered CuO was observed after the fifth cycle of reuse under visible light irradiation.

Spectroscopic and in silico evaluation on the interactive behavior between substituted β-2,3-dihydrofuran naphthoquinones and human serum albumin

The interactive profile between human serum albumin (HSA, the main carrier of endogenous and exogenous compounds in the human bloodstream) and five potential anticandidal agents, namely 2,3-dihydro-2-phenyl-naphtho[1,2-b]furan-4,5‑dione (1) and its derivatives 2–5 was studied by biophysical techniques, i.e., UV–vis, circular dichroism, steady-state and time-resolved fluorescence, combined with in silico calculations. The Stern-Volmer quenching constant (KSV) trend in three different temperatures and the bimolecular quenching rate constant (kq ≈ 1012 M−1s−1) values indicated a ground-state association HSA:1–5 which was confirmed by time-resolved fluorescence decays. Both KSV and modified Stern-Volmer binding constant (Ka) values are in the order of 104 M−1, indicating a moderate binding affinity, following the same reported trend for 1,4-naphthoquinones (the isomeric form of the naphthoquinones under study). There is only one main binding site for HSA:1–5, probably the subdomain IIA where the Trp-214 residue can be found. The association is driven both enthalpically and entropically, perturbing both the microenvironment around Trp-214 residue and weakly the α-helix content of albumin. Overall, the β-2,3-dihydrofuran naphthoquinones 1–5 showed favorable binding affinity to HSA to achieve their therapeutical potential and control of effective dosages.

Magnetically separable rare earth metal incorporated CdFe2O4 photocatalyst for degradation of cationic and azo dyes

Herein, the present study illustrates hydrothermal synthesis of pristine and Gd doped CdFe2O4 nanoparticles. The synthesized nanoparticles were analysed by various analytical methods to investigate the structural, vibrational, optical and morphological information about the photocatalysts. The surface area of the 2 % Gd-CdFe2O4was achieved to have greater value. The pristine and Gd (1 % and 2 %) – CdFe2O4 was investigated for its photocatalytic activity on reducing cationic and azo dyes. The photocatalyst showed efficiency of 90 % and 98 % for both cationic and azo dyes. The greater rate constant values of the photocatalysts revealed the better activity of hydroxyl radicals which took part majorly in photocatalysis. The stability of the sample was analysed and the stableness was same for about four cycles. The greater efficiency and better stability were attributed to the optimum dopant level of Gd ions into CdFe2O4 photocatalyst. The better recombination rate and hydroxyl radicals activity made the enthusiastic candidate for water remediation process.

Biochemical Properties and Antithrombotic Effect of a Serine Protease Isolated from the Medicinal Mushroom Pycnoporus coccineus (Agaricomycetes).

The purification of a fibrinolytic enzyme from the fruiting bodies of wild-growing medicinal mushroom, Pycnoporus coccineus was achieved through a two-step procedure, resulting in its homogeneity. This purification process yielded a significant 4.13-fold increase in specific activity and an 8.0% recovery rate. The molecular weight of P. coccineus fibrinolytic enzyme (PCFE) was estimated to be 23 kDa using sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. PCFE demonstrated its optimal activity at a temperature of 40 °C and pH 8. Notably, the enzymatic activity was inhibited by the presence of zinc or copper metal ions, as well as serine protease inhibitors, such as phenylmethylsulfonyl fluoride and 4-amidinophenylmethanesulfonyl fluoride. PCFE exhibited remarkable specificity towards a synthetic chromogenic substrate for thrombin. The enzyme demonstrated the Michaelis-Menten constant (Km), maximal velocity (V ), and catalytic rate constant (Kcat) values of 3.01 mM, 0.33 mM min-1 μg-1, and 764.1 s-1, respectively. In vitro assays showed PCFE's ability to effectively degrade fibrin and blood clots. The enzyme induced alterations in the density and structural characteristics of fibrin clots. PCFE exhibited significant effects on various clotting parameters, including recalcification time, activated partial thromboplastin time, prothrombin time, serotonin secretion from thrombin-activated platelets, and thrombin-induced acute thromboembolism. These findings suggest that P. coccineus holds potential as an antithrombotic biomaterials and resources for cardiovascular research.

Green route synthesis of transition metal doped V2O5 nanoparticles, with emerging biomedical applications

In this proposed work we synthesized the pristine V2O5 nanoparticles and Ag (3.2 % (SV-1), 14.5 %, (SV-5) 23.4 % (SV-9), Cd (5.8 % (CV-1), 23.5 % (CV-5), 35.7 % (CV-9)) and Ru doped (4.9 % (RV-1), 20.7 % (RV-5), 32 % (RV-9)) V2O5 nanoparticles using vigna radiata extract. The nanoparticles were characterized by various techniques like UV-DRS, FT-IR, XRD, FE-SEM and HR-TEM. The antibacterial activities of nanoparticles were studied using bacterial strains such as Staphylococcus aures (S.aureus), Streptococcus pneumoniea (S. pneumoniea), Pseudomonas aeruginosae (P. aeruginosae), Klebsiella pneumoniea (K. pneumoniea) and Escherichia coli (E.coli). Among the nanoparticles the potential bacterium growth inhibition of 99 % for S.aureus was observed for CV-5. The binding efficiency of the nanoparticles with the biomolecule BSA was studied by using UV–visible absorption and emission spectral techniques. It was found that there is a binding interaction between them and the binding constant values are in the range from 104 to 105 M−1. The quenching rate constant (kq) value is bigger than the maximum diffusion constant of biomolecules 2.0 x 1010M−1s−1 suggesting that the interaction is static quenching type. In glucose oxidation studies lower potential with a high current density of 440 mA/cm2 occurred for pristine V2O5 NPs.

Fast synthesis of nanoporous Cu/Ag bimetallic triangular nanoprisms via galvanic replacement for efficient 4-nitrophenol reduction.

We report the synthesis of nanoporous Cu/Ag bimetallic triangular nanoprisms (BTNPs) using a galvanic replacement method. Based on ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), X-ray diffraction (XRD), energy dispersive spectrometry (EDS), selected area electron diffraction (SAED) and X-ray photoelectron spectroscopy (XPS) analyses, the structure of Cu/Ag BTNPs was characterized. The prepared Cu/Ag BTNPs exhibited excellent catalytic activity and good cycling stability for the reduction of 4-nitrophenol (4-NP) due to the synergistic effect between Cu and Ag elements. The kinetic rate constant (k) and turnover frequency (TOF) values reached 331 × 10-3 s-1 and 500 × 10-3 s-1, respectively, which were higher than those of previously reported Cu, Ag, Au, Cu/Ag or Cu/Au-based catalysts. We hope that the development of promising routes for high-quality BTNPs can broaden their applications in catalysis and environmental sustainability.

The effect of gold nanostructure morphology on label-free electrochemical immunosensor design

In this research, various electrodeposition techniques were used to form gold nanostructures (AuNSs) on the surface of graphite rod electrode (GE). Three distinct AuNS morphologies on GE have been achieved based on the composition of electrodeposition solution. The use of H2SO4 as a supporting electrolyte resulted in the formation of smaller but more numerous AuNSI with a modified electrode’s electroactive surface area (EASA) of 0.213 cm2. Exchanging the supporting electrolyte to KNO3 and increasing HAuCl4 concentration facilitated the formation of bigger AuNSII particles with electrode EASA of 0.116 cm2. Finally, a partial coverage of GE by branched gold nanostructures (AuNSIII) was achieved with an estimated EASA of 0.110 cm2, when the HAuCl4 and KNO3 concentrations were increased. Estimated values of heterogeneous electron transfer rate constant did not depend on AuNS morphology. Electrode modified with AuNSI exhibited the highest bovine serum albumin (BSA) immobilization efficiency and the highest relative response for the detection of specific polyclonal antibodies against BSA (p-anti-BSA) compared to other modified electrodes. The limit of p-anti-BSA detection in PBS buffer was calculated as 0.63 nM, while in blood serum it was 0.71 nM. Linear ranges were from 1 to 7 nM and from 1 to 5 nM, respectively.

Kinetic study of the hydrolysis of ester with mineral acid by spectrophotometer at different temperature

To determine the kinetic parameters and activation energy of the hydrolysis of ethyl acetate with hydrochloric acid monitored by spectrophotometry. The first order fits were automatically drawn and the values of the first order rate constants (k) were calculated using standard equations as part of the program. Acidic hydrolysis of ethyl acetate is essentially an irreversible and first order reaction whereas alkaline hydrolysis is an irreversible and second order reaction. Rate of reaction is the change in the number of molecules of reacting species per unit volume per unit time. In this hydrolysis of ethyl acetate with hydrochloric acid to accelerate the reaction mixture. A simple and sensitive kinetic spectrophotometric method presented for the determination of rate constant, order of reaction and activation energy. This method based on a kinetic investigation of ethyl acetate and hydrochloric acid at 35°C and 45°C temperature. The reaction followed spectrophotometrically by measuring the absorbance at 500 nm as a function of time. The initial rate and fixed time methods utilized for construction of calibration graphs successfully for the determination of rate constant, order of reaction and activation energy. The rate constant after calculation from the graphs was approximately k1 ≈ 0.00260 Sec-1 k2 ≈ 0.00322 Sec-1 by titration and spectrophotometric method respectively, order of reaction found to be first order and the activation energy for this reaction is 17.44 kJ/mol. One factor that influences the absorbance of a sample is the concentration (c). As the concentration increases, more radiation is absorbed and the absorbance increase. Therefore, the absorbance is directly proportional to the concentration.

Fe(VI) oxidation of synthetic phenolic antioxidants: Kinetics, influencing factors, transformation mechanism and toxicity

Synthetic phenolic antioxidants (SPAs) have been commonly used in industrial and domestic products to prevent the adverse effects of oxidants such as oxygen. However, attention to the removal of SPAs is scarcely attracted. In this paper, the removal kinetics, influencing factors, transformation mechanisms and toxicity in Fe(VI) oxidation of 18 SPA congeners were investigated in detail. Results showed that propyl gallate (PG), butylated hydroxyanisole (BHA), and tert-butylhydroquinone (TBHQ) had the highest reactivities with Fe(VI), while the reaction rate constant (kapp) value of 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate (UV120) was the lowest (221.3 M−1 s−1). A robust quantitative structure–activity relationship (QSAR) model between kapp and molecular structural descriptors of SPAs was established. The energy gap between the lowest unoccupied molecular orbital (ELUMO) and the highest occupied molecular orbital (EHOMO) was a vital parameter to determine the removal efficiencies of the SPA congeners. Furthermore, the numbers of oxygen atoms and alkyl groups in SPA structures also determined their reactivities with Fe(VI) to some extent. In addition, aqueous 2,6-di-tert-butyl-4-methylphenol (BHT, a representative of SPAs) could be efficiently removed with the increased amount of oxidant, and decreased substrate concentration and slightly alkaline conditions. Seventeen intermediates were identified, and oxidation routes including H-abstraction, single- and double-oxygen(s) transfer, and coupling were deduced. However, H-abstraction inevitably led to the generation of BHT-Q with higher toxicity than parent. These findings provide novel insights into the production and removal of SPA analogs.

Impact of anaerobic zone on biodegradation of micropollutants: Comparison of micropollutants’ removal efficiencies in lab-scale anaerobic bioreactor and in full-scale anaerobic zone

To predict the fate of micropollutants (MPs) in the anaerobic zone at the lab and full-scale levels, anaerobically biological removal (adsorption and biodegradation) of 40 MPs was performed. Among the 40 MPs in the full-scale anaerobic tank, estriol and acetaminophen showed the highest total removal efficiencies in the anaerobic zone (∼100 %). In batch tests, five MPs belonging to estrogens (estriol and 17b-estradiol), parabens (ethyl paraben and propyl paraben), and iopromide were completely removed within 12 h. Meanwhile, MPs belonging to perfluorinated compounds and nitrosamines were infrequently removed (<20 %) within 12 h. The obtained solid-water distribution coefficient (Kd) and biodegradation rate constants (Kbiol) values were used for predictive modeling of residual MPs’ concentrations in the full-scale anaerobic zone and were compared with Kbiol obtained from the oxic zone. Most MPs had similar Kbiol values regardless of redox conditions (oxic or anaerobic); however, caffeine, ibuprofen, naproxen, trimethoprim, and iopromide showed different values depending on the redox conditions. Differences in the efficiencies of total MP’ removal were noted between that predicted via modeling and actually observed (-37 % [iopromide] to 49 % [caffeine]) under altered conditions such as levels of dissolved oxygen (DO) and introduction of the primary or returned sludge. This implies that strictly anaerobic conditions are required for the degradation of specific MPs. The Kd and Kbiol values obtained in this study could help predict changes in the concentration of MPs in the anaerobic zone.

A comparative and comprehensive study on robust silver-immobilized chitosan/carboxy methyl chitosan macromolecules for elimination of dyes

This study explores the potential of modified chitosan (CH) resulting from carboxy methyl (CM) group substitution in the chitosan skeleton, producing carboxy methyl chitosan (CMCH). Silver (Ag) was loaded to chitosan and modified chitosan (carboxy methyl substituted chitosan) supported on cellulose filter paper (FP) to tailor organic–inorganic macromolecule composites “Ag-Chi/CFP and Ag-CMCH/CFP” further applied as substantial composite for the reductive removal of methyl orange (MO) and rhodamine B (RB) dyes from wastewater. The synthesized catalyst was characterized via FTIR, 1H NMR, XRD, and SEM analysis. The degree of substitution was also measured, which was approximately 0.85. The reductive elimination efficiency of Ag-CMCH/CFP and Ag-Chi/CFP for MO dye was 95.31% and 88.85 %. In comparison, the elimination of RB was 98.28 and 94.04 %, respectively, in 16 min time, 0.6 mM Ag concentration, 40 mg/L, dye concentration and 0.3 M NaBH4 concentration. The synthesized catalysts were recycled three times. The degradation of MO and RB dyes using Ag-CMCH/CFP and Ag-Chi/CFP catalysts can be described by the first-order kinetic model. The determination coefficients (R2) and rate constants (k) values for MO degradation were found to be 0.9934 and 0.1736 s−1 for Ag-CMCH/CFP, and 0.9242 and 0.1001 s−1 for Ag-Chi/CFP, respectively. Similarly, for RB degradation, the R2 values were 0.9866 for Ag-CMCH/CFP and 0.9803 for Ag-Chi/CFP, with corresponding k values of 0.219 s−1 and 0.1548 s−1, respectively. The degradation process was optimized using response surface methodology (RSM) to determine the optimal conditions for maximum dye removal efficiency. The RSM models were statistically significant, as validated by ANOVA and correlation coefficient values. The F values of MO and RB models are significant as they have 2450.15 and 21999.37, respectively. The P value for both was <0.0001.

Quantitative structure-biotransformation relationships of organic micropollutants in aerobic and anaerobic wastewater treatments

Biotransformation is one of the dominant processes to remove organic micropollutants (OMPs) in wastewater treatment. However, studies on the role of molecular structure in determining the biotransformation rates of OMPs are limited. We evaluated the biotransformation of 14 OMPs belonging to different chemical classes under aerobic and anaerobic conditions, and then explored the quantitative structure-biotransformation relationships (QSBRs) of the OMPs based on biotransformation rates using valid molecular structure descriptors (electrical and physicochemical parameters). Pseudo-first-order kinetic modeling was used to fit the biotransformation rate, and only 2 of the 14 OMPs showed that the biotransformation rate constant (kbio) values were higher under anaerobic conditions than aerobic conditions, indicating that aerobic conditions were more favorable for biotransformation of most OMPs. QSBRs infer that the electrophilicity index (ω) is a reliable predictor for OMPs biotransformation under aerobic conditions. ω corresponds to the interaction between OMPs and microbial enzyme active sites, this process is the rate-limiting step of biotransformation. However, under anaerobic conditions the QSBR based on ω was not significant, indicating that specific functional groups may be more critical than electrophilicity. In conclusion, QSBRs can serve as alternative tools for the prediction of the biotransformation of OMPs and provide further insights into the factors that influence biotransformation.

Development of an Efficient Thionolactone for Radical Ring-Opening Polymerization by a Combined Theoretical/Experimental Approach.

The environmental impact of plastic waste has been a real problem for the past decades. The incorporation of cleavable bonds in the polymer backbone is a solution to making a commodity polymer degradable. When radical polymerization is used, this approach is made possible by radical ring-opening polymerization (rROP) of a cyclic monomer that allows for the introduction of a weak bond into the polymer backbone. Among the various cyclic monomers that could be used in rROP, thionolactones are promising structures due to the efficiency of the C═S bond to act as a radical acceptor. Nevertheless, only a few structures were reported to be efficient. In this work, we used DFT calculations to gain a better understanding of the radical reactivity of thionolactones, and in particular, we focused on the transfer rate constant ktr value and its ratio with the propagation rate constant kp of the vinyl monomer. The closer to 1, the better is the statistical incorporation of the two comonomers into the backbone. These theoretical results were in good agreement with all of the experimental data reported in the literature. We thus used this approach to understand the key parameters to tune the reactivity of thionolactone to prepare random copolymers. We identified and prepared the 7-phenyloxepane-2-thione (POT) thionolactone that led to statistical copolymers with styrene and acrylate derivatives that were efficiently degraded under accelerated conditions (KOH in THF/MeOH, TBD in THF, or mCPBA in THF), confirming the theoretical approach. The compatibility with RAFT polymerization as well as the homopolymerization behavior of POT was established. This theoretical approach paves the way for the in-silico design of new efficient thionolactones for rROP.

Lead integrated two-dimensional (MXene/PbCrO4) nanocomposite designed for energy storage and photocatalytic degradation applications

Supercapacitors (SCs), among other electrochemical device applications, require materials with maximal energy storage capacity, and the stacked two-dimensional titanium carbide MXene (Ti3C2) sparked the development of these materials. This paper embellished to present smoothed MXene/PbCrO4 nanocomposite via co-precipitation method along with modified sol–gel achieved lead chromate (PbCrO4) nano-crystalline for energy storage and photocatalytic applications using ethylene glycol as connecting agent to restrict nano-particle growth. It is evident from photoluminescence spectra that peak intensity has decreased, whilst Raman spectra show the presence of MXene and lead peaks in the nanocomposite, whereas FTIR has revealed the presence of functional groups in synthesized material. According to calculations made using EIS spectra, the charge transfer resistance is 1.4 Ω, with the electron shift rate constant Kapp value 6.98 10−9 cm s−1. Additionally, the electrochemical performance of the designed material in supercapacitors at 0.3Ag−1 of current density indicates elevated capacitance of 5408 Fg−1 with scan rate of 10 mV s−1 using 1MKOH aqueous electrolyte, resulting in power and energy densities of 2991.8 W kg−1 and 110.1 Wh K−1 g−1, respectively. UV–vis spectra shows the nanocomposite has a 1.86 eV band gap that, in the presence of direct sunlight, might cause the destruction of MB dye at a rate of 92.79%. These findings suggested that the newly created MXene/PbCrO4 nanocomposite demonstrates evidence of substantial features as compared to single materials has potential as an electrode material for supercapacitors as well as best photocatalyst for the degradation of organic pollutants regarding water purification.

Broccoli Leaves (Brassica oleracea var. Italica) as a Source of Bioactive Compounds and Chemical Building Blocks: Optimal Extraction Using Dynamic Maceration and Life Cycle Assessment

Bioactive compounds (BACs) and chemical building blocks (CBBs) play a pivotal role in driving economic growth. These compounds, known for their diverse applications in pharmaceuticals, agriculture, and manufacturing, have become integral to meeting the increasing demand for sustainable and innovative products. In this research, we used and characterized dynamic maceration to extract BACs and CBBs from broccoli leaves (BLs). A central composite design (CCD) was selected to evaluate the effect of temperature (from 4 °C to 70 °C), ethanol concentration (from 30% to 70% (v/v)), and exposition time (15 to 60 min) on total phenolic content (TPC) (mg of gallic acid equivalents (GAEs) per 100 g of dry biomass (db)). A confirmation experiment (CE) was performed to reproduce the optimal conditions (50 °C, 36.92 min, and 30% (v/v)) for BAC extraction. Results indicated a GAE concentration of 112.95 ± 0.92 mg/100 g db, while the statistical model predicted a value of 111.87 mg of GAEs/100 g db (error of 0.95%) with a rate constant (k) value of 0.0154 mg/g·min (R2 of 0.9894). BACs and CBBs were identified with gas chromatography–electron impact mass spectrometry detecting l-isoleucine, l-leucine, malonic acid, and succinic acid, among others. Finally, a life cycle inventory (LCI) was developed to determine global warming (GW) and water consumption (WC), among others, for 10 g of BL extract. Findings reported herein prove the sustainability of eco-friendly extraction of BACs and CBBs for the effective use of agricultural by-products.

Facile green synthesis of Phyllanthus emblica extract based Ag-NPs for antimicrobial and response surface methodology based catalytic reduction applications

Silver nanostructures were synthesized by utilizing facile and simple green methodology based on the usage of biogenic Phyllanthus emblica fruit extract. The Fourier transform infrared spectroscopy revealed that the numerous phytochemicals were found to be present in the extract that were responsible for reducing the precursor salt into nanoparticles. After 10 min, the silver nanoparticles were formed in the system while the further nucleation for 30 min resulted in the generation of the silver nanostructures with dual morphology (spherical & rod-like morphology). The reaction time/nucleation time was found to be the major factor responsible for the modulation of the morphology of the biogenic nanomaterials. The crystalline nature with the cubic crystal system was observed in the case of the silver nanostructure via X-ray diffraction analysis. The antimicrobial efficacy investigated for these nanostructures revealed that the silver nanostructures possess comparable or greater efficacy than the selected control. The excellent efficacy is attributed to the smaller size and the peculiar morphological characteristics of the silver nanostructures. The catalytic reduction of 4-nitrophenol via silver nanostructures was also investigated by using the response surface methodology as an optimization tool. An extremely high percentage reduction value of 96.491 % with the rate constant value of 0.277 min−1 was documented in the case of Ag-NSs. The prepared silver nanostructures were found to be extremely stable till six reuse cycles. Our findings affirm that the efficient synthesis of nanostructures is achieved by using P. emblica fruit extract and the synthesized material further presents excellent viability for antimicrobial and catalytic applications.