Kinds Of Organic Solvents Research Articles

Cholesterol Decorated Diazocine Gelator with Photo‐ and Thermo‐Responsive Properties for Smart Window

Comprehensive SummaryA new gelator (BAzo‐Chol) comprising a diazocine core and two cholesterol units linked via carbamate groups has been designed and synthesized. Its gelation ability in several kinds of organic solvents is identified. Investigations with scanning electron microscopy (SEM), transmission electron microscopy (TEM), rheological measurements, and UV‐vis absorption and 1H NMR spectroscopy reveal that BAzo‐Chol can self‐assemble into elastically interpenetrating one‐dimensional nanostructures in organogels through a cooperative effect of the π‐π interactions, hydrogen‐bonding, and van der Waals forces. Moreover, the unconventional Z/E conformational transitions of these organogels, due to the inclusion of diazocine, endow the BAzo‐Chol gels with excellent photo‐responsive gel‐sol transition and remarkable visible light‐induced chromic properties. Lastly, due to its sensitive response to visible light accompanied by distinct changes in both colour and transparency of the gel‐sol transitions, the potential application of the current gelator in smart windows is signified.

Stereoselective synthesis of (R)-(+)−1-(1-naphthyl)ethylamine by ω-amine transaminase immobilized on amino modified multi-walled carbon nanotubes and biocatalyst recycling

Immobilized enzymes exhibit favorable advantages in biocatalysis, such as high operation stability, feasible reusability, and improved organic solvents tolerance. Herein, an immobilized ω-amine transaminase AtATA@MWCNTs-NH2 is successfully prepared using amino modified multi-walled carbon nanotubes as carrier and glutaraldehyde as crosslinker. Under the optimum immobilization conditions, the activity recovery is 78.7%. Compared with purified enzyme AtATA, AtATA@MWCNTs-NH2 possesses superior stability, even in harsh conditions (e.g., high temperature, acidic or alkali environment, and different kind of organic solvents). To simplify the separation and extraction of products, we choose methanol (10%, v/v) as the cosolvent, replacing DMSO (20%, v/v) in our previous work, for the catalytic reaction of AtATA@MWCNTs-NH2. AtATA@MWCNTs-NH2 can be used for stereoselective synthesis (R)-(+)− 1(1-naphthyl)ethylamine ((R)-NEA) for 15 cycles, with the e.e.p (enantiomeric excess) > 99.5%. The catalytic process of AtATA@MWCNTs-NH2 achieves cycle production of (R)-NEA using methanol as cosolvent.

Versatile Application of TiO2@PDA Modified Filter Paper for Oily Wastewater Treatment

Although membrane separation technology has been widely used in the treatment of oily wastewater, the complexity and high cost of the membrane preparation, as well as its poor stability, limit its further development. In this study, via the vacuum-assisted suction filtration method, polydopamine (PDA)-coated TiO2 nanoparticles were tightly attached and embedded on both sides of laboratory filter paper (FP). The resultant FP possessed the typical wettability of high hydrophilicity in the air with the water contact angle (WCA) of 28°, superoleophilicity with the oil contact angle (OCA) close to 0°, underwater superoleophobicity with the underwater OCA greater than 150°, and superhydrophobicity under the water with the underoil WCA over 150° for five kinds of organic solvents (carbon tetrachloride, toluene, n-hexane, n-octane, and iso-octane). The separation efficiency of immiscible oil/water, oil-in-water, and water-in-oil emulsions using the modified FP is higher than 99%. After 17 cycles of emulsion separation, a high separation efficiency of 99% was still maintained for the FP, along with good chemical and mechanical stability. In addition, successful separation and purification were also realized for the oil-in-water emulsion that contained the methylene blue (MB) dye, along with the complete degradation of MB in an aqueous solution under UV irradiation.

Interaction between Organic Solvents and Three Types of Kerogen Investigated via X-ray Diffraction

In this work, for the first time, a new swelling method was applied to study the chemical structure of kerogen. Structural changes during the swelling process were detected via X-ray diffraction (XRD). Three types of kerogen samples and three organic solvents were selected for this study. It was found that kerogens have a selective absorption of aromatic hydrocarbons compared with saturated hydrocarbons. Type I kerogen demonstrated the strongest ability to sorb hydrocarbons; it can sorb more than half of its own weight at normal temperature and pressure (25 °C and 1.013 × 105 Pa). However, under the same conditions, type III kerogen can sorb around 40% of its own weight. XRD detection revealed that the microcrystalline structure of kerogen was not affected by liquid organic matter during the swelling process. Three kinds of organic solvent are mainly sorbed in the γ band (amorphous carbon) comprising aliphatic carbon, and the γ band swells under the swelling action, causing the value of dγ to increase. This study explored the ability of kerogen to sorb hydrocarbon compounds and discovered the chemical structural units that occur in kerogen during solvent swelling. It is of great significance for the study of the hydrocarbon generation and expulsion in oil shale under geological conditions and the structure of kerogen.

Systematic investigation on the swelling behaviors of acrylonitrile‐butadiene rubber via solubility parameter and Flory‐Huggins interaction parameter

AbstractThree‐dimensional solubility parameters (HSP) of the acrylonitrile‐butadiene rubber (NBR) were determined by combining a software program with equilibrium swelling test. Then, a modified Flory‐Huggins interaction parameter (χHSP) was calculated and compared with the traditional one (χ) in characterizing the swelling behavior of NBR. NBR exhibits quite different swelling responses in the selected seven kinds of organic solvents, which can be differentiated by the energy difference (Ra) and be further correlated with χHSP value between rubber and solvent. The results turn out that the swelling ratio (q) decreases with increasing χHSP value. By mathematical fitting, an exponential relationship between q and χHSP is achieved to predict the swelling behaviors of NBR in the increasing used bio‐fuels, bio‐diesel, and IRM903 being selected for examples. From the prediction model, we can get that there is a high swelling area for bio‐diesel/ethanol system and both a high and low swelling areas for IRM903/ethanol system. Hereby, it is expected that the swelling behavior or oil resistance of NBR based rubber parts can be predicted quantitatively in a concise way now.

Properties of Concrete Prepared with Silane Coupling Agent-Impregnated Coral Aggregate and Coral Concrete.

Silane coupling agent (SCA), a kind of organic solvent, was introduced to improve the performance of coral coarse aggregates and enhance the interfacial adhesion between the inorganic coral aggregate and the cement paste of coral concrete. The crushing indicator and water absorption of the coral aggregates over various dipping times were measured, and the slump, interface microhardness, and compressive strength of coral concrete tested. The microscopic appearances of the coral concrete before and after modification were analyzed based on SEM images. The experimental results indicate that SCA can effectively reduce the crushing indicator and water absorption of coral coarse aggregates, and the modification performance becomes better over time. SCA facilitates the generation of chemical forces between the coral aggregates and cement mortars, improves adhesion between the aggregates and mortars, augments the microhardness of the interface, and increases the compressive strength. According to the microscopic appearance of the treated and untreated coral aggregate interfaces, the aggregates and the mortars are in closer combination after modification.

DIFFUSIVITAS EFEKTIF PADA EKSTRAKSI PADAT-CAIR DITINJAU DARI VARIASI PELARUT

Solvent-extraction is a kind of series mass-transfer. The initial step is solute diffusion to the solid surface, and the next one is solute diffusion from the surface to the solvent-bulk. The mathematical model was proposed to represent the behavior of the solvent-extraction, to determine the effective-diffusivity coefficient. The aim of this research was to compare the effective-diffusivity coefficient of three kinds of organic solvent. This experiment carried out in a batch process, with an erlenmeyer, heater and magnetic stirrer. ft was found that petroleum ether had the largest effective-diffusivity coefficient, compared to acetone and ethanol. The controlling step of diffusion was the solute diffusion from the solid to the surface.

Versatile 3D reduced graphene oxide/poly(amino-phosphonic acid) aerogel derived from waste acrylic fibers as an efficient adsorbent for water purification.

The fabrication of multifunctional materials to remove soluble heavy metal ions and dyes, as well as insoluble oils from waste water is urgently required, yet remains a daunting challenge because of difficulty in controlling their structure and property to satisfy various demands. Herein, for the first time, novel 3D reduced graphene oxide/poly(amino-phosphonic acid) (PAPA) aerogels (rGO/PAPAs) with different PAPA content were developed by solvothermal reduction of the graphene oxide and cross-linking with PAPA chain, and subsequently employed as versatile adsorbent for the removal of complex pollutants such as Cr(III) ion, methylene blue (MB) dye and various kinds of organic solvents from water. Benefiting from the synergistic effect of the reduced graphene oxide (rGO) sheet and PAPA component, as well as its unique 3D structure, the resultant aerogel (rGO/PAPA-2) gained amphiphilic, ultralight, and multifunctional properties. Thus, it showed a fast adsorption rate (within 15min) and high adsorption capacity (up to 327.1mg/g) for Cr(III) ion at an optimal pH of 5.5 due to its unique 3D network structure with abundant amino-phosphonic acid functional groups. The uptake of Cr(III) by rGO/PAPA-2 was fitted well with the Langmuir isotherm and pseudo-second-order kinetic model. The adsorption mechanism of Cr(III) onto rGO/PAPA-2 can be attributed to electrostatic attraction and surface complexation with APA groups. In addition, the rGO/PAPA-2 displayed an excellent adsorption performance for MB (694.5mg/g) and several organic solvents (83.2 to 254.3g/g). Moreover, the rGO/PAPA-2 exhibited a good regeneration (around 99%) and satisfactory recovery abilities for the tested adsorbates. Notably, PAPA chains can be easily prepared from waste acrylic fibers, making it become a cost effective but versatile candidate to prepare new material. Therefore, this work provides a new design strategy to fabricate the rGO/PAPA-2 aerogel with great prospect for sophisticated industrial wastewater cleanup.

Superhydrophobic cellulose acetate/multiwalled carbon nanotube monolith with fiber cluster network for selective oil/water separation

Porous cellulose acetate/carboxylated multiwalled carbon nanotubes (CA/OMWNTs) monolith with superhydrophobicity (155°) and superoleophilicity (∼0°) was first prepared using a facile and green phase separation method. Benefiting from the unique three-dimensional (3D) fiber cluster network structure, the as-prepared CA/OMWNTs monolith reveals a high porosity (93.7 %) and a large specific surface area (85.36 m2/g). As an oil adsorption material, the superhydrophobic porous monolith is able to adsorb the different kinds of organic solvents and oils from water efficiently and selectively with saturated adsorption capacities from 7.39 to 19.84 g g−1. Moreover, the porous monolith exhibits an excellent durability with the highly stable wettability and oil/water separation no matter at different pH (1–14) conditions or extreme temperatures (−20−160 °C). Besides, the CA/OMWNTs monolith also could continuously and rapidly separate oils/organic solvents from oil/water mixtures via a simple and home-made pump-assisted adsorption device, showing potential application in large-area remediation of oily wastewater.

Barbituric acid-based mono/bi-heterocyclic dyes showing distinct spectral behaviors induced by solvents and pH

A series of barbituric acid-based heterocyclic dyes were prepared and fully characterized by ESI-MS, NMR and UV–Vis absorption spectroscopy. UV–Vis spectral comparisons reveal that in contrast to mono-heterocyclic dyes the absorption maxima of barbituric acid-based bi-heterocyclic dyes display significantly bathochromic shifts in wavelength due to the increasing π-conjugated system within the whole molecules. The effects of varying solvent media on the absorption spectra of this group of dyes were investigated, in which bi-heterocyclic dyes are liable to be affected by nature of solvents and present distinct solvatochromism in four kinds of organic solvents. Our results demonstrate that though the equilibrium between the hydrazone and deprotonated azo anion can be driven by pH values for this group of barbituric acid-based heterocyclic dyes, the acid-base effect on their absorption spectra behave differently. In order to further elucidate their different structural and spectral behavior, time-dependent density functional theory (TD-DFT) calculations with the implicit solvent model (SMD) were performed.

A green resin acid ester surfactant from colophony and xylitol: Synthesis, self‐assembly in nonaqueous solvents, and thermodynamics

AbstractAn environmental friendly oil‐soluble surfactant colophony xylitol ester (CXE) is first synthesized from natural colophony and xylitol with the use of hot‐compressed water and subcritical CO2 in a steel autoclave. In this solvent‐free system, the conversion of the reaction was up to 90.30% in 4 h. Thermal gravimetric analysis determine that its thermal stability was as high as 310°C. CXE is effective in reducing the surface tension of six different organic solvents. The greatest effect of surface tension reduction by CXE is in the case of dimethyl sulfoxide, the surface tension of the surfactant solution was as low as 36.26 mN/m at its critical micelle concentration value of 7.49 mM; The greatest effect of interfacial tension reduction by CXE is in the case of turpentine and water, the interfacial tension low to 1.51 mN/m. Furthermore, transmission electron microscope and particle size measurement showed that CXE is successfully self‐assembled into micelles, vesicles, and heteromorphic vesicles in six kinds of organic solvents. Finally, the critical micelle concentration curves at different temperatures provided the thermodynamic parameters of the aggregate formation, found that , , and are negative and increased as the temperature increased.

Flexible and super hydrophobic polymethylsilsesquioxane based silica aerogel for organic solvent adsorption via ambient pressure drying technique

Practical applications of silica aerogels have been restricted due to their hydrophilicity, fragility and high cost of supercritical drying technique. In this work, the successful synthesis of the super hydrophobic polymethylsilsesquioxane (PMSQ) based silica aerogel via the sol-gel technique and ambient pressure drying method is proposed. Dimethoxydimethylsilane (DMDMS) and methyltrimethoxysilane (MTMS) are used as the co-precursors. The MTMS/DMDMS volume ratio is determined at 3/1, and the water contact angle as large as 165°, confirming its super hydrophobicity. The CH3 groups rendering the hydrophobicity gradually disappear after heat treatment at 400 °C. The aerogel is composed of the spherical and smooth secondary particles with diameters at around 3–4 μm, with the most probable pore diameter locating at around 20 μm. The aerogel exhibits excellent elastic property under compression cycling test. Moreover, it displays good adsorption properties over many kinds of organic solvents, as well as excellent cycling adsorption property.

Highly dispersed polypyrrole nanotubes for improving the conductivity of electrically conductive adhesives

It is imperative to fabricate electrically conductive adhesives (ECAs) with excellent electrical performance and mechanical properties. In this article, a kind of polypyrrole nanotubes (PPy nanotubes) having a high aspect ratio and excellent dispersibility in various kinds of organic solvents were prepared and added to conventional Ag-containing adhesives. Stable suspension characteristics of PPy nanotubes in common solvents provided homogeneous dispersion of the PPy nanotubes in the composites. A small amount of PPy nanotubes can remarkably change the structures of the conductive networks of conventional ECAs and significantly improve the ECAs’ conductivity. By only adding 3 wt% PPy nanotubes, the resistivity (5.8 × 10−5 Ω ‧ cm) of the ECAs containing 55 wt% silver decreased to 1/1000 of the comparative ECAs without PPy nanotubes. This resistivity is almost five to one-tenth of the ECAs materials reported by now. Furthermore, the resulted ECAs showed excellent mechanical properties. The electrical resistivity of the new PPy nanotube-containing ECAs remained stable after they were rolled at a 6 mm bending radius for over 5000 cycles or pressed under 1200 kPa. An elastic printed circuit was fabricated using the above-described ECA-containing PPy nanotube, which demonstrates its potential application in the field of flexible electronics.

Marangoni Effect-Driven Transfer and Compression at Three-Phase Interfaces for Highly Reproducible Nanoparticle Monolayers.

Interfacial self-assembly is a powerful technology for preparing large scale nanoparticle monolayers, but fabrication of highly repeatable large scale nanoparticle monolayers remains a challenge. Here we develop an oil/water/oil (O/W/O) three-phase system based on the Marangoni effect to fabricate highly reproducible nanoparticle monolayers. Nanoparticles could be easily transferred and compressed from the lower O/W interface to the upper O/W interface due to the interfacial tension gradient. The O/W/O system can be constructed using different kinds of organic solvents. Through this approach, good uniformity and reproducibility of the nanoparticle monolayers could be guaranteed even using a wide range of nanoparticle concentrations. Furthermore, this strategy is generally applicable to various nanoparticles with different sizes, shapes, components, and surface ligands, which offers a facile and general approach to functional nanodevices.

Purification, characterization and molecular cloning of a dicaffeoylquinic acid-hydrolyzing esterase from human-derived Lactobacillus fermentum LF-12.

Dicaffeoylquinic acids (DiCQAs), the main components of kudingcha made from the leaves of Ilex kudingcha, could be transformed by gut microbiota. However, the information about the related microorganisms and enzymes involved in the biotransformation of DiCQAs in the human gut is limited. Therefore, a strain of bacteria that could hydrolyze DiCQAs, belonging to Lactobacillus fermentum named L. fermentum LF-12, was isolated from human feces in the present study. Furthermore, an esterase for the hydrolysis of DiCQAs was purified from L. fermentum LF-12 and heterogeneously expressed in Escherichia coli. The esterase could be induced to exert superior hydrolytic activity in the presence of lactose as the carbon source. The molecular weight of the purified esterase was determined to be 31.9 kDa, and the isoelectric point, optimal pH and temperature for the esterase were 4.71, 6.5 and 45 °C, respectively. The enzyme activity was improved by Mg2+ and Ca2+, and reduced by Co2+, Cu2+, EDTA and some kinds of organic solvents. The present results provide new insights into the metabolism of DiCQAs by the human gut.

High-Performance Liquid Chromatography Determination of Acrylamide after Its Extraction from Potato Chips

Background: Acrylamide is a known carcinogenic product that has been found among the substances such as potato chips which to be processed under the heat-treatment. In order to extract amounts of acrylamide from fried chips in market, an ultrasound-assisted liquid– liquid extraction (UA-LLE) technique is proposed. The UA-LLE coupled LLE and ultrasonication in a single step. Methods: Chips samples were dissolved in an extracting organic solvent using ultrasonication to prompt transferring of acrylamide into the organic phase. As a result, the extraction time and process efficiency were significantly enhanced through increasing the collision power and mass transfer between grounded chips and organic phase. Results: Important parameters affecting the extraction efficiency such as kind of organic solvent and its volume, re-dissolving solvent and pH were optimized. This newly proposed method has been applied to determine the trace acrylamide in potato chips samples purchased from local market. Conclusion: UA-LLE is a handy, economic and time-saving method, with high extraction yield (over 103% average recovery) and good precision (lower than 15% relative standard deviation, RSD). Most importantly, it seems this method to be an ideal pre-treatment method for the extraction of acrylamide in food matrix in food quality control laboratories.

Structural and Functional Insights Into CmGH1, a Novel GH39 Family β-Glucosidase From Deep-Sea Bacterium.

Glucosidases play key roles in many diseases and are limiting enzymes during cellulose degradation, which is an important part of global carbon cycle. Here, we identified a novel β-glucosidase, CmGH1, isolated from marine bacterium Croceicoccus marinus E4A9T. In spite of its high sequence and structural similarity with β-xylosidase family members, CmGH1 had enzymatic activity toward p-nitrophenyl-β-D-glucopyranoside (p-NPG) and cellobiose. The Km and Kcat values of CmGH1 toward p-NPG were 0.332 ± 0.038 mM and 2.15 ± 0.081 min–1, respectively. CmGH1 was tolerant to high concentration salts, detergents, as well as many kinds of organic solvents. The crystal structure of CmGH1 was resolved with a 1.8 Å resolution, which showed that CmGH1 was composed of a canonical (α/β)8-barrel catalytic domain and an auxiliary β-sandwich domain. Although no canonical catalytic triad residues were found in CmGH1, structural comparison and mutagenesis analysis suggested that residues Gln157 and Tyr264 of CmGH1 were the active sites. Mutant Q157E significantly increased its hydrolase activity up to 15-fold, whereas Y264E totally abolished its enzymatic activity. These results might provide new insights into understanding the different catalytic mechanism during evolution for β-glucosidases and β-xylosidases.

Lanthanide Doped Complexes and Organometallic Clusters: Design Strategies and their Applications in Biology and Photonics

In this review, we discuss the rational design of a new class of lanthanide-doped organometallic nanostructured materials called `molecular minerals`. Molecular minerals are nanostructured materials with a ceramic core made from chalcogenide groups and other heavy metals. Part of the central core atoms is replaced by suitable lanthanide atoms to impart fluorescent spectral properties. The ceramic core is surrounded by various types of organic networks thus making the structure partly ceramic and organic. The central core has superior optical properties and the surrounding organic ligand makes it easy to dissolve several kinds of organic solvents and fluoropolymers to make several kinds of active and passive photonic devices. This chapter starts with elaborate design strategies of lanthanidebased near-infrared emitting materials followed by the experimental results of selected near-infrared emitting lanthanide clusters. Finally, their potential applications in telecommunication, light-emitting diodes and medical imaging are discussed.

3D Graphene-Oil Absorbent Resin Hybrid Gel as High Efficiency Oil Absorbent Material

A new type of high oil absorbent resin (OAR) was synthesized by emulsion polymerization with lauryl methacrylate (LMA) and butyl methacrylate (BMA) as soft monomers, and methyl methacrylate (MMA) as hard monomer. A graphene-oil absorbent resin hybrid aerogel (G-OAR aerogel) was therefore prepared through the hydrothermal reduction of graphene oxide colloidal solution and the oil absorbent resin emulsion. The self-assembly characteristics of graphene oxide in hydrothermal treatment resulted in the formation of 3D porous structure for G-OAR aerogel. The component, morphology and hydrophobicity of G-OAR aerogel were characterized by FTIR, XRD, SEM and contact angle, and its absorption capacities to different kinds of organic solvents and oils were also been investigated. The results indicate that the absorption capacities of G-OAR aerogel reach up to 40-50 g/g for low density organic solvents, like acetone, anhydrous alcohol, cyclohexane, toluene, ethyl acetate and diesel. The absorption capacities are 80-90 g/g for high density and weak polarity organic solvents, like phenixin and castor oil. The good oil absorption property makes it show high potential in the application of wastewater treatment and oil leakage.

The Protective Effects of Graphene Oxide Against the Stress from Organic Solvent by Covering Hela Cells

Background: In recent years, new nanomaterials have received great attention due to their widespread use in agriculture, food safety and pharmacy. Among them, graphene and graphene oxide (GO) are emerging as promising nanomaterials, which may have far-reaching effects on pharmacy and health. </P><P> Objective: In this paper, the living Hela cells were covered by GO (Hela@GO) and the cell viability, reactive oxygen species, membrane integrity and apoptosis of them were compared with the control Hela cells, especially under the stress from four kinds of organic solvent, including dimethyl sulphoxide, ethanol, acetone, and glycerin. </P><P> Results: It was suggested that the GO may protect cells by covering the cells, keeping their membrane integrity, reducing the ROS and decreasing the apoptosis. </P><P> Conclusion: GO has attracted the tremendous attention of their bioapplications. In this research, the GO adhered to Hela cells. It was observed that the Hela@GO grew well. Besides, it was suggested that the GO would play a protective role to Hela cells against four organic solvents, by maintaining the cell membrane integrity, reducing ROS, and inhibiting the apoptosis.