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Polymers Jul 2023A novel thiol-functionalized polysilsesqioxane containing hydroxyl and methyl groups was synthesized using a simple acid-catalyzed sol-gel method to develop an epoxy...
A novel thiol-functionalized polysilsesqioxane containing hydroxyl and methyl groups was synthesized using a simple acid-catalyzed sol-gel method to develop an epoxy hardener with low odor, low volatile organic compound (VOC) emissions, and fast curing at low temperatures. The synthesized thiol-based hardeners were characterized using Fourier transform infrared spectroscopy, nuclear magnetic resonance, thermogravimetric analysis (TGA), and gel permeation chromatography and compared with commercially available hardeners in terms of odor intensity and VOC emissions using the air dilution olfaction method and VOC analysis. The curing behavior and thermal and mechanical properties of the epoxy compounds prepared with the synthesized thiol-based hardeners were also evaluated. The results showed that synthetic thiol-based hardeners containing methyl and hydroxyl groups initiated the curing reaction of epoxy compounds at 53 °C and 45 °C, respectively. In contrast, commercial thiol-based hardeners initiated the curing reaction at 67 °C. Additionally, epoxy compounds with methyl-containing synthetic thiol-based hardeners exhibited higher TGA at a 5% weight loss temperature (>50 °C) and lap shear strength (20%) than those of the epoxy compounds with commercial thiol-based hardeners.
PubMed: 37447592
DOI: 10.3390/polym15132947 -
Biochimica Et Biophysica Acta.... Apr 2024Mitochondrial membrane potential (Δψ) and morphology are considered key readouts of mitochondrial functional state. This morphofunction can be studied using...
Mitochondrial membrane potential (Δψ) and morphology are considered key readouts of mitochondrial functional state. This morphofunction can be studied using fluorescent dyes ("probes") like tetramethylrhodamine methyl ester (TMRM) and Mitotrackers (MTs). Although these dyes are broadly used, information comparing their performance in mitochondrial morphology quantification and Δψ-sensitivity in the same cell model is still scarce. Here we applied epifluorescence microscopy of primary human skin fibroblasts to evaluate TMRM, Mitotracker Red CMXros (CMXros), Mitotracker Red CMHXros (CMH2Xros), Mitotracker Green FM (MG) and Mitotracker Deep Red FM (MDR). All probes were suited for automated quantification of mitochondrial morphology parameters when Δψ was normal, although they did not deliver quantitatively identical results. The mitochondrial localization of TMRM and MTs was differentially sensitive to carbonyl cyanide-4-phenylhydrazone (FCCP)-induced Δψ depolarization, decreasing in the order: TMRM ≫ CHM2Xros = CMXros = MDR > MG. To study the effect of reversible Δψ changes, the impact of photo-induced Δψ "flickering" was studied in cells co-stained with TMRM and MG. During a flickering event, individual mitochondria displayed subsequent TMRM release and uptake, whereas this phenomenon was not observed for MG. Spatiotemporal and computational analysis of the flickering event provided evidence that TMRM redistributes between adjacent mitochondria by a mechanism dependent on Δψ and TMRM concentration. In summary, this study demonstrates that: (1) TMRM and MTs are suited for automated mitochondrial morphology quantification, (2) numerical data obtained with different probes is not identical, and (3) all probes are sensitive to FCCP-induced Δψ depolarization, with TMRM and MG displaying the highest and lowest sensitivity, respectively. We conclude that TMRM is better suited for integrated analysis of Δψ and mitochondrial morphology than the tested MTs under conditions that Δψ is not substantially depolarized.
Topics: Humans; Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; Mitochondria; Aldehydes; Fibroblasts; Organic Chemicals
PubMed: 38109971
DOI: 10.1016/j.bbabio.2023.149027 -
Saudi Journal of Biological Sciences Nov 2023Textile dyes and heavy metals like hexavalent chromium [Cr(VI)] are considered major water pollutants. In addition, microbial contamination also seriously threatens...
Textile dyes and heavy metals like hexavalent chromium [Cr(VI)] are considered major water pollutants. In addition, microbial contamination also seriously threatens potable water availability. The present study used seed aqueous extract to synthesize copper nanoparticles (MOS-CuNPs). MOS-CuNPs were characterized by various spectroscopy and microscopic techniques. MOS-CuNPs were shown to be effectual at removal of Cr(VI). The initial concentration of Cr(VI), contact time, pH, and temperature all impacted the removal of Cr(VI) by different concentrations of MOS-CuNPs. At low concentrations of MOS-CuNPs (0.3 mg/ml) pseudo-first order and high concentrations of MOS-CuNPs (0.4 and 0.5 mg/ml), pseudo-second order kinetics were obeyed. Thermodynamic analysis revealed that Cr(VI) was removed spontaneously, and the reaction was exothermic. In adsorption isotherm, equilibrium data followed Langmuir equation for Cr(VI) adsorption by MOS-CuNPs and maximum uptake capacity calculated was 38.6 mg/g. MOS-CuNPs efficiently removed cationic (rhodamine B, malachite green and methylene blue and) and anionic (congo red, titan yellow and methyl orange) dyes within 10 min of contact time. Further MOS-CuNPs showed antimicrobial activity against human pathogenic bacteria and fungi. Altogether, MOS-CuNPs could be used for environmental (water treatment) and biological applications.
PubMed: 37841667
DOI: 10.1016/j.sjbs.2023.103820 -
Frontiers in Chemistry 2023oil and are rich sources of bioactive compounds and have been utilized to formulate various herbal formulations, however, due to certain environmental conditions, pure...
oil and are rich sources of bioactive compounds and have been utilized to formulate various herbal formulations, however, due to certain environmental conditions, pure extract form is prone to degradation. Therefore, in this, study, a green hydrodistillation technology was used to extract and root for the further application in development of pectin crosslinked carboxymethyl cellulose/guar-gum nano hydrogel. Both oil and extract revealed the presence of spirojatamol and hexadecanoic acid methyl ester. Varied concentrations (w/w) of cross-linker and gelling agent were used to formulate oil emulsion extract gel (OEEG1, OEG1, OEEG2, OEG2, OEEG3, OEG3, OEEG4, OEG4, OEEG5, OEG5), in which OEEG2 and OEG2 were found to be stable. The hydrogel displayed an average droplet size of 186.7 nm and a zeta potential of -20.5 mV. Endo and exothermic peaks and the key functional groups including hydroxyl, amide II, and amide III groups confirmed thermal stability and molecular structure. The smooth surface confirmed structural uniformity. Bactericidal activity against both Gram-positive (25.41 ± 0.09 mm) and Gram-negative (27.25 ± 0.01 mm) bacteria and anti-inflammatory activity (49.25%-83.47%) makes nanohydrogel a potential option for treating various infections caused by pathogenic microorganisms. In conclusion, the use of green hydrodistillation technology can be used to extract the bioactive compounds that can be used in formulation of biocompatible and hydrophobic nanohydrogels. Their ability to absorb target-specific drugs makes them a potential option for treating various infections caused by pathogenic microorganisms.
PubMed: 37780989
DOI: 10.3389/fchem.2023.1260165 -
Biomimetics (Basel, Switzerland) Jan 2024Radiative cooling is a promising strategy to address energy challenges arising from global warming. Nevertheless, integrating optimal cooling performance with commercial...
Radiative cooling is a promising strategy to address energy challenges arising from global warming. Nevertheless, integrating optimal cooling performance with commercial applications is a considerable challenge. Here, we demonstrate a scalable and straightforward approach for fabricating green radiative cooling coating consisting of methyl cellulose matrix-random diatomites with water as a solvent. Because of the efficient scattering of the porous morphology of diatomite and the inherent absorption properties of both diatomite and cellulose, the aqueous coating exhibits an excellent solar reflectance of 94% in the range of 0.25-2.5 μm and a thermal emissivity of 0.9 in the range of 8-14 µm. During exposure to direct sunlight at noon, the obtained coating achieved a maximum subambient temperature drop of 6.1 °C on sunny days and 2.5 °C on cloudy days. Furthermore, diatomite is a naturally sourced material that requires minimal pre-processing, and our coatings can be prepared free from harmful organic compounds. Combined with cost-effectiveness and environmental friendliness, it offers a viable path for the commercial application of radiative cooling.
PubMed: 38248624
DOI: 10.3390/biomimetics9010050 -
Molecules (Basel, Switzerland) Jan 2024In this paper, the green synthesis of isoeugenol methyl ether (IEME) from eugenol by -methylation and isomerization is completed using a one-step green process. In the...
In this paper, the green synthesis of isoeugenol methyl ether (IEME) from eugenol by -methylation and isomerization is completed using a one-step green process. In the methylation reaction, dimethyl carbonate (DMC) was used as a green chemistry reagent instead of the traditional harmful methylation reagents, in accordance with the current concept of green chemistry. The phase transfer catalyst (PTC) polyethylene glycol 800 (PEG-800) was introduced into the isomerization reaction to break the barrier of difficult contact between solid and liquid phases and drastically reduce the reaction conditions by shortening the reaction time and reducing the alkalinity of the reaction system. The catalytic systems for the one-step green synthesis of IEME were screened, and it was shown that the catalytic system "KCO + PEG-800" was the most effective. The effects of reaction temperature, n(DMC):n(eugenol) ratio, n(PEG-800):n(eugenol) ratio, and n(KCO):n(eugenol) ratio on eugenol conversion, IEME yield, and IEME selectivity were investigated. The results showed that the best reaction was achieved at a reaction temperature of 140 °C, a reaction time of 3 h, a DMC drip rate of 0.09 mL/min, and n(eugenol):n(DMC):n(KCO):n(PEG-800) = 1:3:0.09:0.08. As a result of the conversion of 93.1% of eugenol to IEME, a yield of 86.1% IEME as well as 91.6% IEME selectivity were obtained.
PubMed: 38276627
DOI: 10.3390/molecules29020551 -
Inorganic Chemistry Jul 2023Replacement of the chloride ligand of PtCl{κ-,,-[py-CHR-py]} (R = H (), Me ()) and PtCl{κ-,,-[py-O-CH-O-py]} () by hydroxido gives Pt(OH){κ-,,-[py-CHR-py]} (R = H (),...
Replacement of the chloride ligand of PtCl{κ-,,-[py-CHR-py]} (R = H (), Me ()) and PtCl{κ-,,-[py-O-CH-O-py]} () by hydroxido gives Pt(OH){κ-,,-[py-CHR-py]} (R = H (), Me ()) and Pt(OH){κ-,,-[py-O-CH-O-py]} (). These compounds promote deprotonation of 3-(2-pyridyl)pyrazole, 3-(2-pyridyl)-5-methylpyrazole, 3-(2-pyridyl)-5-trifluoromethylpyrazole, and 2-(2-pyridyl)-3,5-bis(trifluoromethyl)pyrrole. The coordination of the anions generates square-planar derivatives, which in solution exist as a unique species or equilibria between isomers. Reactions of and with 3-(2-pyridyl)pyrazole and 3-(2-pyridyl)-5-methylpyrazole provide Pt{κ-,,-[py-CHR-py]}{κ--[R'pz-py]} (R = H; R' = H (), Me (). R = Me; R' = H (), Me ()), displaying κ--pyridylpyrazolate coordination. A 5-trifluoromethyl substituent causes N-to-N slide. Thus, 3-(2-pyridyl)-5-trifluoromethylpyrazole affords equilibria between Pt{κ-,,-[py-CHR-py]}{κ--[CFpz-py]} (R = H (), Me ()) and Pt{κ-,,-[py-CHR-py]}{κ--[CFpz-py]} (R = H (), Me ()). 1,3-Bis(2-pyridyloxy)phenyl allows the chelating coordination of the incoming anions. Deprotonations of 3-(2-pyridyl)pyrazole and its substituted 5-methyl counterpart promoted by lead to equilibria between Pt{κ-,,-[pyO-CH-Opy]}{κ--[R'pz-py]} (R' = H (), Me ()) with a κ--pyridylpyrazolate anion, keeping the pincer coordination of the di(pyridyloxy)aryl ligand, and Pt{κ-,-[pyO-CH(Opy)]}{κ--[R'pz-py]} (R' = H (), Me ()) with two chelates. Under the same conditions, 3-(2-pyridyl)-5-trifluoromethylpyrazole generates the three possible isomers: Pt{κ-,,-[pyO-CH-Opy]}{κ--[CFpz-py]} (), Pt{κ-,,-[pyO-CH-Opy]}{κ--[CFpz-py]} (), and Pt{κ-,-[pyO-CH(Opy)]}{κ-,-[CFpz-py]} (). The N-pyrazolate atom produces a remote stabilizing effect on the chelating form, pyridylpyrazolates being better chelate ligands than pyridylpyrrolates. Accordingly, reactions of - with 2-(2-pyridyl)-3,5-bis(trifluoromethyl)pyrrole yield Pt{κ-,,-[py-CHR-py]}{κ--[(CF)C(py)HN]} (R = H (), Me ()) or Pt{κ-,,-[pyO-CH-Opy]}{κ--[(CF)C(py)HN]} (), displaying κ--pyrrolate coordination. Complexes - are efficient green phosphorescent emitters (488-576 nm). In poly(methyl methacrylate) (PMMA) films and in dichloromethane, they experience self-quenching, due to molecular stacking. Aggregation occurs through aromatic π-π interactions, reinforced by weak platinum-platinum interactions.
PubMed: 37343120
DOI: 10.1021/acs.inorgchem.3c00694 -
RSC Advances Mar 2024In this study, we have delved into various reactions conducted using green solvents or under solvent-free conditions, employing hydrogen bonding organocatalysis to...
In this study, we have delved into various reactions conducted using green solvents or under solvent-free conditions, employing hydrogen bonding organocatalysis to advance more sustainable practices in chemical synthesis. The outcomes suggest that cyclopentyl methyl ether could potentially replace non-polar organic solvents such as hexane and toluene with comparable enantioselectivity and yields. The non-polar nature of liquefied or supercritical CO restricts its application to reactions that require non-polar solvents. Furthermore, pursuing solvent-free conditions, even without liquid substrates, might result in similar conversion rates with reduced catalyst loading. These findings highlight the potential of exploring solvent-free conditions when enantioselectivity is not of concern. Based on the results, solvent-free conditions and bio-based solvents can serve as viable alternatives to conventional organic solvents without compromising performance. This is expected to influence the way chemists approach reaction optimisation within method development in the field, fostering a broader adoption of environmentally friendly approaches.
PubMed: 38454950
DOI: 10.1039/d4ra00679h -
Ecotoxicology and Environmental Safety Nov 2023In this study, a green approach was used to synthesize SmMnO magnetic nanoparticles via the auto combustion method, where pomegranate juice was utilized as a natural...
In this study, a green approach was used to synthesize SmMnO magnetic nanoparticles via the auto combustion method, where pomegranate juice was utilized as a natural fuel. The concentration of fuel was varied to investigate its effect on the purity and morphology of SmMnO nanoparticles. The physiochemical properties of the synthesized nanoparticles, including crystal structures, morphology, optical, and magnetic properties, were investigated using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier-Transform Infrared Spectroscopy (FTIR), Vibrating Sample Magnetometer (VSM), Diffuse Reflectance Spectroscopy (DRS), X-ray fluorescence (XRF) and Brunauer-Emmett-Teller (BET). The band gap of the as-synthesized nanoparticles was determined to be 1.8 eV, indicating their potential as a photocatalyst. The photocatalytic activity of SmMnO nanoparticles was evaluated against Methyl violet and Erythrosine, and the mechanism of photocatalyst was determined using EDTA, benzoic acid, and benzoquinone as scavengers. Photocatalytic activity was studied in both UV and visible light, and it was found that the maximum degradation (94%) was related to the degradation of Erythrosine (10 ppm) in the presence of visible light. The stability test of SmMnO performed and confirmed the stability of nanoparticles after 5 cycles. The results suggest that SmMnO nanoparticles synthesized via the green auto combustion method using pomegranate juice as a natural fuel can serve as a promising photocatalyst for the degradation of organic pollutants in the environment. Further studies can be conducted to investigate their potential in other applications.
Topics: Samarium; Water Pollutants; Erythrosine; Light; Nanoparticles; Environmental Pollutants; Water; Catalysis
PubMed: 37856984
DOI: 10.1016/j.ecoenv.2023.115578 -
Ultrasonics Sonochemistry Oct 2023In this study, the effects of organic acid-soaking (malic, citric, tartaric, and succinic acid) and sonication on the formation of flavor and α-dicarbonyl compounds in...
In this study, the effects of organic acid-soaking (malic, citric, tartaric, and succinic acid) and sonication on the formation of flavor and α-dicarbonyl compounds in Robusta (C. canephora syn. Coffea robusta) green beans were investigated. A total of 20 volatile compounds were identified in Robusta coffee. Furfural and 5-methyl furfural, two dominant volatile compounds in Arabica coffee, increased after organic acid pretreatment. In Robusta coffee processed from 3% malic acid-soaked coffee beans, furfural and 5-methyl furfural increased by 90.99% and 24.92%, respectively, compared to the control. In Robusta coffee processed from 3% malic acid-sonicated (280 W, 1 h) coffee beans, furfural and 5-methyl furfural increased by 236.03% and 114.77%, respectively. α-Dicarbonyls (glyoxal, methylglyoxal, and diacetyl) were significantly (p < 0.05) decreased in all Robusta coffees after organic acid pretreatment. In Robusta coffee processed from coffee beans soaked and sonicated in tartaric acid solution, the α-dicarbonyls decreased by up to 44% and 58%, respectively, compared to the control. This study suggested the pretreatment methods to enhance the flavor substances and reduce the α-DCs in Robusta coffee.
Topics: Coffea; Sonication; Furaldehyde; Malates; Organic Chemicals
PubMed: 37673014
DOI: 10.1016/j.ultsonch.2023.106580