JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2020
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IF 2.369
Yang Li,Yang Zhang,Xue Zhong Wang
The solubility of dimethyl 2,2′-azobis(2-methylpropionate) (AIBME) was determined in 15 pure solvents, including cyclohexane, dichloromethane, diethyl ether, acetone, tetrahydrofuran, ethyl acetate, tetrachloromethane, acetonitrile, methylbenzene, methanol, ethanol, n-propyl alcohol, isopropanol, n-butyl alcohol, and iso-butyl alcohol, and in a binary solvent system (methanol + water) at the temperature range from 253.15 to 293.15 K at atmospheric pressure. Between 278.15 and 293.15 K, the solubility of AIBME is more sensitive to temperature in alcohol solvents than in other solvents. However, the solubility of AIBME in nonalcoholic solvents decreased more rapidly than in alcohol solvents below 278.15 K. The AIBME solubility in the binary solvent system (methanol + water) is positive to temperature and the initial mole fraction of methanol. The measured solubility data of AIBME in pure solvents were correlated by the modified Apelblat equation, the λh equation, the nonrandom two-liquid (NRTL) model, and the Wilson model. The measured solubility data of AIBME in binary solvent systems were correlated by the modified Apelblat equation, the nonrandom two-liquid (NRTL) model, and the Wilson model. Among the four models, the NRTL model is the best model to fit the solubility of AIBME, especially in alcohol solvents. In addition, the mixing properties of AIBME in 15 pure solvents, including standard mixing Gibbs energy, mixing enthalpy, and mixing entropy, were calculated and discussed. The results provide useful information for practical optimization of AIBME crystallization processes.
研究领域:
化学工程
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物理化学
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DOI
高影响因子
CHROMATOGRAPHIA
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2019
·Vol. 82
·期 10
·1579-1583
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IF 1.552
Lou Chunli,Zheng Mengmeng,Xu Yao,Shen Yuting,Kang Jingwu
A sensitive method was developed for detecting 2,2′-azobis(2-amidinopropane) dihydrochloride in polyvinylpyrrolidone by capillary electrophoresis with indirect UV detection. The detection sensitivity was improved significantly using the field-amplified sample injection technique. The background electrolyte was composed of 25 mM imidazole-HCl solution (pH 4.0), in which imidazole acted as the cation probe for the indirect detection at UV 214 nm. Effects of the experimental parameters including pH, the concentration of imidazole as well as the sample injection time on sample preconcentration were investigated and optimized. Under the optimized conditions, baseline separation of 2,2′-azobis(2-amidinopropane) ion with other ions in the polyvinylpyrrolidone samples was achieved within 8 min. The RSD% for the repeatability of the migration time and the peak area were determined as 0.95% and 3.47%, respectively. The limit of detection (LOD, S / N = 3) and the limit of quantitation (LOQ, S / N = 10) were determined as 1.11 × 10 −5 M and 2.77 × 10 −5 M, respectively. The measured recovery at three concentration levels was in the range of 101–104%. This method was successfully applied to detect 2,2′-azobis(2-amidinopropane) in the commercial polyvinylpyrrolidone samples.
研究领域:
分析化学
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制药工程
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DOI
高影响因子
E-POLYMERS
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2015
·Vol. 15
·期 4
·263-270
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IF 0.569
Kai Liang,Qingquan Liu,Meixuan Peng
Cross-linked cationic polystyrene (CCPS) nanospheres with monodispersity were successfully generated by soap-free miniemulsion polymerization of styrene and divinylbenzene with 2,2′-azobis (2-amidinopropane) dihydrochloride as a water-soluble initiator. The effects of output power of the homogenizer and the concentration of the initiator and cross-linking agent on the particle size and coefficient of variation of CCPS nanospheres were systematically investigated and discussed. The weight percent of N element on the particle surface and the ζ potential were determined as different initiator concentrations were employed for the preparation of CCPS nanospheres. Furthermore, the technique of nitrogen adsorption/desorption was applied to characterize the specific surface area and the total pore volume of the CCPS nanospheres, which were generated from different amounts of divinylbenzene. Overall, the present study provides a simple route for producing cross-linked polymer nanospheres with monodispersity.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2018
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IF 2.829
Baijun Liu,Zhongyu Fu,Wenting Meng,Ming Chen,Guangfeng Wu,Mingyao Zhang,Huixuan Zhang
Macroemulsion polymerization is the most widely used approach for the fabrication of the monodisperse polymer particles. During the polymerization process, particle nucleation plays a critical role in determining particle size distribution of the ultimate particles. In general, the repulsion between ionic oligomeric radicals and micelles enhances particle nucleation, resulting in smaller particle sizes. In this study, methacryloxyethyltrimethyl ammoniumchloride (MATMAC) and 2′azobis (2methylpropionamidine) dihydrochloride (AIBA) were used as the cationic species to shield the negative charges of sodium dodecyl sulfate micelle, inducing in situ charge neutralization in the nucleation period, and further decreasing the particle number, enlarging the particle size of the ultimate latex particles. The ultimate particle size of MATMAC or AIBA system reached ～ 200 nm, which is the 2 times bigger than that without any cationic species. Moreover, a narrow particle size distribution was obtained for these systems. The in situ charge neutralization between the cationic species and surfactant molecules enhanced the oligomeric radical capture rate of micelles, further narrowing the particle nucleation time and inducing primary particle coagulation.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
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2024
·Vol. 59
·期 45
·20929-20943
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IF 3.5
Ye Cai,Li Xiaohong,Chen Jianjun,Hafsa
Crosslinking is a crucial step to keep fibrous morphology and improve ceramic yield in the fabrication process of SiC fibers. Comparing with the oxygen crosslinking, thermal crosslinking can reduce the introduction of oxygen within fibers. In this study, a novel method for preparing the SiC fibers was proposed by combining dry spinning and thermal crosslinking. The spinning solution was prepared by blending a low-molecular-weight (~ 1000 Da) polycarbosilane (PCS) with polyisobutene (PIB) as spinning additive, acrylic acid (AA) as crosslinking agent, and 2,2'-Azobis (2,4-dimethyl) valeronitrile (ABVN) as initiator. The crosslinking mechanism, morphology, composition and microstructure, and mechanical properties of fibers were investigated. The results showed that the morphology of AA-containing PCS fibers was well preserved at 300 ℃ with a low heating rate (0.5 ℃/min), while PCS fibers without AA exhibited the melting or deformation. The crosslinking reaction between C = C groups in AA-containing PCS and Si–H bonds in PCS was triggered by ABVN. Furthermore, AA-containing PCS green fibers experienced pyrolysis at 1100 ℃ and then were annealed at 1500 ℃ (denoted as SiC-1500). SiC-1500 fibers, with an average diameter of 10.47 ± 0.50 μm and average tensile strength of 1.35 ± 0.65 GPa, have a smooth surface and relative dense structure. But SiC-1500 fibers were still an amorphous structure due to the suppression of graphite phase for the growth of β-SiC grains. This work not only breaks through the limitations that only uses high-molecular-weight PCS for dry spinning, but also successfully combines dry spinning and thermal crosslinking technology to obtain SiC fibers. Graphical abstract
研究领域:
材料科学
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陶瓷学
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纤维科学
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DOI
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
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2024
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IF 3.3
Yulin Zhang,Xusheng Li,Ruijing Liu,Xin Huang,Yiting Yang,Jingquan Yuan,Ying Zhang,Jianxia Sun,Weibin Bai
BACKGROUND Diminished ovarian reserve has a serious impact on female reproduction with an increasing incidence every year. An important cause of this is oxidative stress. Rubi fructus , a traditional medicinal and edible plant, has shown therapeutic effects against gynecological diseases. Vanillic acid, isoquercitrin, kaempferol-3- O -rutinoside, kaempferol-3- O -sophoroside, oleanolic acid, tormentic acid, tiliroside, and ellagic acid are the major bioactive components in R. fructus . However, studies involved in the effectiveness and mechanism of these components in oxidative stress-induced ovarian dysfunction are scarce. RESULTS In this study, the protective mechanisms of the bioactive components were evaluated in human ovarian granulosa cells. Isoquercitrin was significantly superior to other bioactive components in relieving damage in human ovarian granulosa cells induced by 2,2-azobis (2-methylpropionamidine) dihydrochloride, considering enhanced cell viability, reduced reactive oxygen species accumulation, and improved mitochondrial membrane potential level. Isoquercitrin protected human ovarian granulosa cells from oxidative stress by regulating the enzyme activity of glutathione peroxidase, inhibiting cell apoptosis, improving the expression of genes related to oxidative stress, and ameliorating heme oxygenase 1 protein expression. CONCLUSION Isoquercitrin, a bioactive component in R. fructus , has a significant protective effect on oxidative damage induced by 2,2-azobis (2-methylpropionamidine) dihydrochloride in human ovarian granulosa cells, providing evidence for its potential application in protecting ovarian function. © 2024 Society of Chemical Industry.
研究领域:
药理学
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生殖生物学
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氧化应激
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细胞生物学
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DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2022
·
IF 9.965
Yang Wang,Yafei Wen,Yun Qu,Zhichao Pei,Yuxin Pei
Nitric oxide (NO)-mediated gas therapy (GT) and alkyl radical (R•) therapy (ART) are emerging cancer therapy modes, and multi-mode therapy has been recognized as an attractive strategy for enhancing anti-cancer efficacy. In this work, a thermal-responsive R• initiator 2,2′-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (AIBI)-loaded glycol-targeting NO nanogenerator was constructed by first the covalent conjugation of thermal-responsive NO donor of S-nitrosothiols (RSNO) on the surface of mesoporous silica-coated gold nanorods ( [email protected] ), then the coating of a supramolecular complex of amino pillar[5]arene (NP5) and galactose derivative (G), and finally the loading of AIBI. The glycol-targeting NO nanogenerator demonstrated specific targeting ability to HepG2 cells owing to the recognition between galactose residues and asialoglycoprotein receptors (ASGPR). Specially, upon 808 nm near-infrared (NIR) irradiation, the AIBI-loaded NO nanogenerator generated hyperthermia to achieve photothermal therapy (PTT), and further GT and ART resulted from the thermal responsiveness of RSNO and AIBI, respectively. In vitro experiments revealed that the AIBI-loaded glyco-targeting NO nanogenerator had good biocompatibility and exhibited effective inhibition to the proliferation of HepG2 cells. This work provides a novel way to supramolecular hybrid drug delivery systems for triple-mode targeting therapy of PTT/GT/ART.
研究领域:
癌症治疗
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纳米技术
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药学
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材料科学
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
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2020
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IF 4.469
Chen Hua,Kaimin Chen,Zun Wang,Xuhong Guo
Cationic latexes have received wide attention due to their special properties and potential applications in wood coatings, fabric treatment, etc. However, the practical application of cationic latexes was hindered due to their poor stability, especially the alkali resistance stability. In this work, various stable cationic polyacrylate latexes were prepared by an efficient route. Three cationic comonomers, i.e., methacrylatoethyl trimethyl ammonium chloride (DMC), 2-(dimethylamino)ethyl methacrylate (DMAEMA), and 2-aminoethyl methacrylate hydrochloride (AEMH), were used in the aqueous semi-continuous seeded emulsion polymerization of methyl methacrylate (MMA) and butyl acrylate (BA) using cetyl trimethyl ammonium bromide (CTAB) and 2,2′-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (AIBI) as the cationic emulsifier and initiator, respectively. The alkali resistance of the latex could be significantly improved by the addition of cationic monomer DMC and be simply tuned by adjusting DMC dosage. The improved stability of the latex might originate from the higher charge density on the surface of the latex by the introduction of DMC. Moreover, the effects of initiator dosage, emulsifier dosage and different cationic comonomers on the latex preparation and the film properties were also systematically investigated. This work not only introduces an efficient route to prepare cationic latexes with superior stability, but also paves the way for latexes to be used in applications such as textile finishing, paper industry, and biomedical field, etc.
研究领域:
材料科学
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化学工程
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高分子化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）