Room Temperature In Solvents Research Articles

User-Friendly and Responsive Electrochemical Detection Approach for Triclosan by Nano-Metal-Organic Framework.

Antimicrobial resistance poses a significant challenge to public health, and is worsened by the widespread misuse of antimicrobial agents such as triclosan (TCS) in personal care and household products. Leveraging the electrochemical reactivity of TCS's phenolic hydroxyl group, this study investigates the electrochemical behavior of TCS on a Cu-based nano-metal-organic framework (Cu-BTC) surface. The synthesis of Cu-BTC via a room temperature solvent method, with triethylamine as a regulator, ensures uniform nanoparticle formation. The electrochemical properties of Cu-BTC and the signal enhancement mechanism are comprehensively examined. Utilizing the signal amplification effect of Cu-BTC, an electrochemical sensor for TCS detection is developed and optimized using response surface methodology. The resulting method offers a simple, rapid, and highly sensitive detection of TCS, with a linear range of 25-10,000 nM and a detection limit of 25 nM. This research highlights the potential of Cu-BTC as a promising material for electrochemical sensing applications, contributing to advancements in environmental monitoring and public health protection.

Undesired films with brilliant whiteness produced from a transparent amorphous polymer solution during room temperature evaporation or water washing

AbstractDuring the use, storage, or cleaning of polyetherimide (PEI) solutions, undesired white films often appear. In this study, equivalent experiments of PEI solutions involving room temperature evaporation and solvent exchange with water are conducted to simulate their air exposure and water washing processes, respectively. Specifically, we focus on investigating the phenomenon and mechanism of white appearance in their films from room temperature evaporation with a cellular‐like porous structure and solvent exchange films that exhibit a finger‐like porous structure. Results obtained from FE‐SEM, UV–Vis spectroscopy, and Datacolor reflectance spectrophotometer indicate that both types of porous structures exhibit long‐range disorderliness, leading to multiple scattering of incident light and high reflectance across the visible light spectrum resulting in a white appearance. Furthermore, due to different structures caused by phase separation, mechanical properties of solvent exchange films are significantly inferior compared with those of films from room temperature evaporation. Finally, we verify the universality of these mechanisms for white film formation in PEI through experiments using PS and PMMA. This study provides insights into efficient utilization of polymer solutions and offers new strategies for biomimetic preparation of white films.Highlights White cellular‐like porous films were prepared by solvent evaporation method. White finger‐like porous films were produced through solvent exchange by water. Multiple scattering caused by above porous structures led to white appearance. Finger‐like porous films with nanosphere as the basic scatter unit had a luster. Universality of both white formation mechanisms was verified by PMMA and PS.

Decoration of MnFe2O4@cys with Pd as a highly efficient nanocatalyst in C-C coupling reaction at ambient temperature

An environmentally friendly nano-catalyst was prepared by the functionalization of MnFe2O4 with cysteine (MnFe2O4@cys) and decoration with Pd(0) (MnFe2O4@cys/Pd) and fully characterized with physicochemical techniques. As-prepared MnFe2O4@cys/Pd was applied as a catalyst in the carbon-carbon (C-C) Suzuki-Miyaura coupling reaction using various aryl halides and phenylboronic acid with electron withdrawing and electron donating groups. The MnFe2O4@cys/Pd catalyst showed high efficiency, achieving significant reaction conversions and yields even with small amounts used in mild conditions such as room temperature and green solvents. The new nanocatalyst was stable, easily isolated by an external magnet, and was used at least 5 times without any noticeable decrease in its catalytic efficiency.

Patchable Transparent Standalone Piezoelectric P(VDF-TrFE) Film for Radial Artery Pulse Detection

Wearable or patchable biosensors have attracted tremendous attention due to their continuous health-monitoring capabilities. In particular, self-powered passive biosensors based on a piezoelectric nanogenerator (PENG) have demonstrated measurements of physiological signals from which cardiovascular information can be analyzed such as heart rate and blood pressure. However, challenges still remain with regard to both material and device aspects. For the effective and accurate measurement of extremely weak physiological signals, various methods have been introduced, including employment of inorganic lead-based piezoelectric materials and design of a complex material or device structure. In spite of their effectiveness in enhancing the piezoelectric output response, the introduced methods brought concomitant issues, such as toxicity and complexity. We present unique methods to produce a transparent standalone piezoelectric polymer film which can be directly transferred to any surface such as the human skin. Through a room temperature solvent vapor annealing process, we further enhance the crystallinity and a portion of the ferroelectric β-phase of the transparent standalone polymer film, resulting in an improved piezoelectric output response. Based on these two new methods introduced, we demonstrate a simple sandwich-structured, transparent, and patchable biosensor based on PENG for radial artery detection with significantly reduced complex manufacturing processes, providing great practical value.

Morphology regulation of isomeric covalent organic frameworks for high selective light scattering detection of lead

Isomerism is an essential and ubiquitous phenomenon in organic chemistry, yet it is rarely observed in covalent organic frameworks (COFs). Herein, we synthesized two framework-isomeric COFs (BATD-Dma-COF-K and BATD-Dma-COF-R) and found for the first time that the light scattering signal of the COFs can be used for the analytical detection of lead ion. By using solvothermal and room temperature solvent synthesis methods, controlling different synthesis conditions, and introducing regulators to increase the energy difference between different products, the product with the lowest energy could be synthesized under specific conditions. This method could control the morphology of the synthesized COF and realize the precise synthesis of framework-isomeric COF by changing the experimental conditions. The structures of the two framework-isomeric COFs were characterized and confirmed by a series of analytical methods. Based on the principle that lead ions coordinate with N and O on the surface of two skeletal isomers BATD-Dma-COFs to enhance the light scattering signal of the COFs, a light scattering probe was developed by BATD-Dma-COF for the detection of metal lead ion in water samples. Lead ion concentration in the range from 2.0 to 250.0 μM had a good linear relationship with the light scattering intensity increase of the COFs with detection limit as low as 0.8397 μM by BATD-Dma-COF-K and 0.9207 μM by BATD-Dma-COF-R.

In-situ construction of Bi2WO6/Bi5O7I heterojunctions by room-temperature solvent method for efficient photocatalytic degradation

In the present work, the flower spherical Bi2WO6/Bi5O7I S-scheme heterojunction was constructed by solution precipitation under room-temperature for photocatalytic degradation of organic pollutants and the working mechanism was investigated. As a special feature, 0.05 BWBOI performed the best photocatalytic capacity under visible light irradiation and was significantly able to degrade 98% of rhodamine B and 92% of bisphenol A in 90 min, whereas ciprofloxacin was degraded to 67% in 120 min. The composite structure was determined by XRD, FT-IR, XPS, and BET characterization, while the electron migration direction and heterojunction scheme were determined by electrochemical and ESR characterization. Eventually, addition of Bi2WO6 not only broadened the light absorption range of the composites, but also achieved the successful construction with Bi2WO6/Bi5O7I of S-scheme heterojunctions to accelerate the transport rate of photogenerated carriers. Finally, the current work presents a novel bismuth-based photocatalyst and offers new ideas for the facile preparation of semiconductor heterojunctions.

Room-Temperature Solvent Evaporation Induced Crystallization: A General Strategy for Growth of Halide Perovskite Single Crystals by Applying the Le Chatelier's Principle.

The growth of high-quality halide perovskite single crystals is imperative to study their intrinsic physical properties and to realize high-performance optoelectronic devices. Here, a room-temperature solvent evaporation-induced crystallization (RTSEIC) method is reported based on Le Chatelier's principle, which provides a general strategy to grow halide perovskite single crystals including 3D, 2D, 1D, and 0D, and either hybrid or all-inorganic halide perovskites. Taking 2D n-BA2 PbBr4 (n-BA = butylammonium) as an example, the room-temperature crystallization kinetics is demonstrated. The centimeter-sized n-BA2 PbBr4 single crystals exhibit an extremely small full width at half maximum (FWHM) of 0.024° in (0 0 2) plane rocking curve and a small trap density of 2.74× 1010 cm-3 . The superior crystalline quality endows the n-BA2 PbBr4 single crystal ultraviolet photodetectors with recorded performance among reported n-BA2 PbBr4 ultraviolet photodetectors, demonstrating a detectivity reaching 1.8× 1013 Jones, a fast response time of 55 µs and a high on-off ratio of 104 . The low-cost, simple, general, and efficient RTSEIC method is anticipated to promote the blossoming of halide perovskites single crystals.

Bio-efficacy of Solvent Extracts of Botanicals against Brinjal Shoot and Fruit Borer, Leucinodes orbonalis (Guenee) under in vitro Condition

This study evaluated the effectiveness of solvent extracts of A. indica, C. inerme, and O. sanctum against Leucinodes orbonalis, a borer of brinjal shoots and fruit. The room temperature solvent extraction method was used to get the acetone, petroleum ether, and methanol extracts of the botanicals, A. indica 100% (76.54%) methanol extract had the highest antifeedant efficacy. The acetone and petroleum ether extracts of A. indica 100% (65.45%; 60.42%) and C. inerme 100% (57.25%; 51.78%) were also effective antifeedants. The per cent larval mortality of L. orbonalis was highest in the methanol, acetone and petroleum ether extracts of A. indica 100% (89.33%; 80%; 71.33%), A. indica 75% (76.67%; 70%; 67%) and A. indica 50% (68.67%; 63.67%;58.67%), respectively.

Nature of Linear Spectral Properties and Fast Relaxations in the Excited States and Two-Photon Absorption Efficiency of 3-Thiazolyl and 3-Phenyltiazolyl Coumarin Derivatives.

Coumarin-based fluorescent agents play an important role in the manifold fundamental scientific and technological areas and need to be carefully studied. In this research, linear photophysics, photochemistry, fast vibronic relaxations, and two-photon absorption (2PA) of the coumarin derivatives, methyl 4-[2-(7-methoxy-2-oxo-chromen-3-yl)thiazol-4-yl]butanoate (1) and methyl 4-[4-[2-(7-methoxy-2-oxo-chromen-3-yl)thiazol-4-yl]phenoxy]butanoate (2), were comprehensively analyzed using stationary and time-resolved spectroscopic techniques, along with quantum-chemical calculations. The steady-state one-photon absorption, fluorescence emission, and excitation anisotropy spectra, as well as 3D fluorescence maps of 3-hetarylcoumarins 1 and 2 were obtained at room temperature in solvents of different polarities. The nature of relatively large Stokes shifts (∼4000-6000 cm-1), specific solvatochromic behavior, weak electronic π → π* transitions, and adherence to Kasha's rule were revealed. The photochemical stability of 1 and 2 was explored quantitatively, and values of photodecomposition quantum yields, on the order of ∼10-4, were determined. A femtosecond transient absorption pump-probe technique was used for the investigation of fast vibronic relaxation and excited-state absorption processes in 1 and 2, while the possibility of efficient optical gain was shown for 1 in acetonitrile. The degenerate 2PA spectra of 1 and 2 were measured by an open aperture z-scan method, and the maximum 2PA cross-sections of ∼300 GM were obtained. The electronic nature of the hetaryl coumarins was analyzed by quantum-chemical calculations using DFT/TD-DFT level of theory and was found to be in good agreement with experimental data.

Facile Cellulase Immobilisation on Bioinspired Silica.

Cellulases are enzymes with great potential for converting biomass to biofuels for sustainable energy. However, their commercial use is limited by their costs and low reusability. Therefore, the scientific and industrial sectors are focusing on finding better strategies to reuse enzymes and improve their performance. In this work, cellulase from Aspergillus niger was immobilised through in situ entrapment and adsorption on bio-inspired silica (BIS) supports. To the best of our knowledge, this green effect strategy has never been applied for cellulase into BIS. In situ entrapment was performed during support synthesis, applying a one-pot approach at mild conditions (room temperature, pH 7, and water solvent), while adsorption was performed after support formation. The loading efficiency was investigated on different immobilisation systems by Bradford assay and FTIR. Bovine serum albumin (BSA) was chosen as a control to optimize cellulase loading. The residual activity of cellulase was analysed by the dinitro salicylic acid (DNS) method. Activity of 90% was observed for the entrapped enzyme, while activity of ~55% was observed for the adsorbed enzyme. Moreover, the supported enzyme systems were recycled five times to evaluate their reuse potential. The thermal and pH stability tests suggested that both entrapment and adsorption strategies can increase enzyme activity. The results highlight that the entrapment in BIS is a potentially useful strategy to easily immobilise enzymes, while preserving their stability and recycle potential.

A new insight into the ZIF-67 based triboelectric nanogenerator for self-powered robot object recognition

The ZIF-67 based additively manufactured triboelectric nanogenerator to shed light upon the room temperature solvent assisted synthesis, physiochemical properties and self-powered robot object detection.

Room temperature and non-halogenated solvent processed terpolymers for high-efficient polymer solar cells

Most of polymer solar cells (PSCs) are currently processed using halogenated solvents and require high temperature manufacturing. However, the realization of non-halogenated environmental-friendly solvents processing and room temperature treatment are the basis for future commercialization of batteries. In this work, two terpolymers PffBT4T-4T2FC-9/1 and PffBT4T-4T2FC-4/1 were synthesized by introducing a self-assembly third unit, bis(2-hexyldecyl)5,5‴-dibromo-3″,4′-difluoro-[2,2’:5′,2’’:5″,2‴-quaterthiophene]-3,3‴-dicarboxylate (4T2FC) into the poly [(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3‴-di (2-octyldodecyl)-2,2’; 5′,2’’; 5″,2‴-quaterthiophen-5,5‴-diyl)] (PffBT4T-2OD) polymer matrix via random copolymerization. The obtained terpolymers have relatively weaker self-aggregation properties and enable the spin-coating process at room temperature compared with the pristine copolymer PffBT4T-2OD. More importantly, the ester group of the 4T2FC unit can improve the solubility of the conjugated polymers in halogen-free solvent. Ultimately, a superior power conversion efficiency (PCE) of 9.11% was obtained from the optoelectronic device based on PffBT4T-4T2FC-9/1, which is one of the highest values of PSCs based on fullerene system treated with non-halogenated solvents at room temperature. These results demonstrate that these new terpolymers with ester group are promising candidates for high performance environmental-friendly solvent processed solar cells.

Room temperature solvent extraction for simple and fast determination of total concentration of Ca, Cu, Fe, Mg, Mn, and Zn in bee pollen by FAAS along with assessment of the bioaccessible fraction of these elements using in vitro gastrointestinal digestion

Background and aimBee pollen is recognized to be a source of different nutrients, including minerals. As a food supplement, its quality and safety due to concentrations of essential macro- and microelements, and harmful trace elements has to be verified. Fast and simple element analysis of bee-collected pollen can be regarded as an important part of its quality assurance and control. The present study aimed at developping a new method for determination of selected elements (Ca, Cu, Fe, Mg, Mn, Zn) of bee pollen based on solvent extraction and completely avoiding a high temperature treatment with concentrated reagents. In addition, in vitro gastrointestinal digestion was used to assess bioavailability of elements from this food supplement. MethodsBee pollen samples were dried and pulverized. Total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn were determined by flame atomic absorption spectrometry (FAAS) in sample solutions obtained by wet digestion (WD) in concentrated HNO3 or alternatively by solvent extraction (SE) with diluted solutions of HNO3. Gastrointestinal digestion was mimicked using simulated solutions of gastric and intestinal juices followed by determination of Ca, Cu, Fe, Mg, Mn and Zn concentrations in the bioaccessible fraction by FAAS. ResultsA new simple and fast method for determination of total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn in bee pollen was developed and validated. The method combined room temperature, two-hour SE with 0.5 mol L−1 HNO3 with FAAS measurements versus simple standard solutions. It provided precision within 1–5 % and trueness better than 8%, and was shown to be suitable for fast analysis of different polyfloral bee pollens. In vitro gastrointestinal digestion revealed that elements were well (70–85 % for Ca, Mg) and fairly (27–43 % for Cu, Fe, Mn, and Zn) bioaccessible from bee pollen. By pouring with water and swelling overnight, bioaccessibility of studied elements from such prepared bee pollen was increased on average by less than 15 % (Mn), 20 % (Ca, Cu, Fe, Zn) or 30 % (Mn). ConclusionsAvoiding long-lasting, high-temperature wet digestion with concentrated reagents, the proposed sample treatment along with FAAS provided precise and true results of total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn in bee pollen. The method was simple and fast, and enabled to analyze a higher number of samples. Simulated gastrointestinal digestion of bee pollen have shown for the first time that Ca and Mg are the most bioaccessible from this bee product. Bioaccessibility of Cu, Fe, Mg, and Zn from bee pollen are close to or lower than 40 %.

Investigation on structural, optical, dielectric, mechanical and thermal properties of 4-methoxyaniline hydroquinone cocrystal: A promising optical power limiting material

A new non proton transfer compound, Bis(4-methoxyanline) hydroquinone (4MAHQ) has been produced and crystal obtained by the room temperature solvent evaporation technique. The corresponding crystal structure and influence of intra-molecular hydrogen bonding interactions have been reported. SCXRD study exposes that 4MAHQ crystallizes in triclinic system. The crystals were subjected to thermal, mechanical, dielectric and optical and NLO studies. The thermal stability was studied by TG/DTA and the crystal is found to have been stable up to 185 °C. The mechanical properties were obtained from Vickers’s hardness studies. The dielectric responses of the crystal were studied for different frequencies versus variable temperature between 303 and 373 K. The transparency of the crystal in the range 330–1100 nm was confirmed by Ultraviolet–visible spectral studies. The Z-scan study confirmed the existence of high third order nonlinear optical susceptibility in 4MAHQ.

Novel Features of 9‐Methylene‐9H‐thioxanthene (MTAE) in Living Anionic Polymerization

AbstractFor this study, a new epithio‐1,1‐diphenylethylene (DPE) derivative, namely, 9‐Methylene‐9H‐thioxanthene (MTAE), is synthesized, and its copolymerization reactions are investigated, showing distinctive features in living anionic copolymerization. At room temperature and hydrocarbon solvents, MTAE cannot be copolymerized with styrene (St) but can be copolymerized with 1,4‐divinylbenzene (DVB), forming a linear alternating copolymer. Based on this finding, ter‐polymerization of MTAE, DVB and St is conducted to generate a special alternating structure. Additionally, MTAE is found to exhibit fairly high reactivity in copolymerization with Isoprene (Ip) under the same conditions. An alternating sequence of alt‐MTAE/Ip containing high trans‐geometric Ip content (76% of trans‐1,4) and a di‐block sequence of alt‐MTAE/Ip‐b‐Ip are easily obtained. Its experimental reactivity ratio with Ip is investigated via the in situ 1H NMR method (rIp = 0.28), and the corresponding kinetic behaviors and sequence structure are elucidated. Finally, the origin of the effect of MTAE on the isomerism of Ip during chain propagation is investigated by density functional theory (DFT) calculations, and it is found that the bridge sulfur atom in MTAE interacts strongly with living species. This special finding provides a novel approach for the sequence regulation, precise functionalization, and stereo‐structure control in living anionic polymerization originating from monomer structure design.

Non-Ionic Deep Eutectic Liquids: Acetamide-Urea Derived Room Temperature Solvents.

A family of non-ionic deep eutectic liquids has been developed based upon mixtures of solid N-alkyl derivatives of urea and acetamide that in some cases have melting points below room temperature. The eutectic behaviour and physical characteristics of a series of eleven eutectic mixtures are presented, along with a molecular dynamics study-supported hypothesis for the origin of the non-ideal mixing of these substances. Their use as solvents in applications ranging from natural product extraction to organic and polymer synthesis are demonstrated.

Extraction Methods and Inhibition Studies of Ten Plant Extracts on Nine Yam Rot Pathogenic Microorganisms

Nine microorganisms, comprising of four bacteria, Erwinia carotovora, Pseudomonas aeruginosa, Serratia marcescens, Klebsiella oxytoca and five fungi, Rhizopus stolonifera, Aspergillus niger, Aspergillus flavus, Fusarium oxysporum and Penicillium marneffei, isolated from rotten yam tubers of 2016 harvest year, were treated with ten plants extracts (Passiflora edulis, Daniella oliveri, Ceiba pentandra, Jatropha tanjorensis, Azadrichta indica, Carica papaya, Moringa oleifera, Mangifera indica, Terminalia catapa and Senna alata), singly and synergistically by incorporation of extract in media for inhibition test. Two plant extracts singly and completely inhibited the growth of three organisms: Terminalia catapa at 100% and 10-1 showed complete inhibition (a) of Erwinia carotovora. Passiflora edulis at undiluted (100%) concentration completely inhibited Rhizopus stolonifer and Penicillium marneffei, respectively. Synergistic plant extract recorded complete inhibition (a) of all the four bacteria isolates at 2 mL extract incorporation; ten (10) mL extract incorporation in media recorded complete inhibition (a) of three out of the five fungi isolates: Rhizopus stolonifer, Fusarium oxysporum and Penicillium marneffei, respectively; the other two fungi recorded high inhibition (b) of Aspergillus niger and Aspergillus flavus, respectively. Hot aqueous synergistic plants extract recorded poor inhibition of the isolates as compared to the cold. Soxhlet solvent extracted synergistic plants extract, however, recorded lower inhibition as compared to hot aqueous synergistic plants extract and cold aqueous synergistic plants extracts. Room temperature solvent extracted synergistic plants extracts recorded inhibition that was same as that obtained with cold aqueous synergistic plants extract. This research indicates that heat employed extractions recorded less inhibition activity.

In-situ facile deposition of TiO2 hole blocking layers for efficient hole-conductor-free perovskite solar cells

A compact hole blocking layer is necessary for high efficient perovskite solar cell, which was usually fabricated by spin coating or spray pyrolysis with the followed annealing process, or vacuum deposition. Here, we deposited TiO2 compact layers by an in-situ room-temperature solvent method, which were applied as an effective hole blocking layer for hole-conductor-free perovskite solar cells with carbon electrodes. The thickness of the TiO2 compact layer can be easily regulated by the depositing time. By optimizing the TiO2 depositing time, the power conversion efficiency of hole-conductor-free perovskite solar cells was up to 10.66%.

Polymer immobilized [Mg@PS-anthra] complex: An efficient recyclable heterogeneous catalyst for the incorporation of carbon dioxide into oxiranes at atmospheric pressure and Knoevenagel condensation reaction under solvent free condition

Chemical fixation of CO2 into the organic molecules is very challenging from the perspective of greenhouse gas consumption and manufacturing of chemicals with C1 backbone. The process was developed with the synthesis of an efficient polystyrene functionalized Magnesium-anthranilic acid complex (Mg@PS-anthra). The catalytic system was successfully explored as a heterogeneous catalyst for the synthesis of cyclic carbonates by CO2 fixation at atmospheric pressure and Knoevenagel condensation reaction under room temperature solvent free condition. The material was thoroughly characterized by diffuse reflectance UV-vis, FTIR spectroscopy, thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and powder X-ray diffraction (PXRD) techniques. The catalytic pathway has been investigated for the cyclo-addition reaction of epoxides using atmospheric CO2 accompanied by the Knoevenagel condensation reaction with a variety of different aldehydes over cost effective environmental friendly Mg-catalyst. This is attributed to its high catalytic activity, recovery simplicity and excellent five times recycling efficiency; without any substantial decrease in catalytic performance.

Counterion Effect of Amine Salts on Ring‐Opening Polymerization of 1,3‐Benzoxazines

AbstractThe effect of nucleophilicity of counterions of amine HX salts as catalysts on the ring‐opening polymerization (ROP) of 1,3‐benzoxazines is investigated. The significant reduction observed for the ROP temperature is related to the nucleophilicity of counterions and found to show a general trend as I− > Br− > Cl−, as studied by differential scanning calorimetry and Fourier transform infrared spectroscopy. Moreover, the latent character of the amine salts is also demonstrated by tracking the benzoxazine–amine salt mixtures using 1H NMR spectroscopy. The spectral analysis gives evidences for the dormant nature of the amine HX salts toward benzoxazine at room temperature in solvent. Besides, thermal stabilities of the cured benzoxazine monomers with and without catalysts are investigated by thermogravimetric analysis.