FLUID PHASE EQUILIBRIA
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2017
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IF 2.473
Zhiyuan Ma,Anli Xu,Yongqin Du,Jian Wang,Hongkun Zhao,Guowang Diao,Xuedong Zhu,Xuhong Guo
Density, viscosity, refractive index and conductivity of switchable hydrophilicity solvent (SHS) systems ( N,N -dimethylbenzylamine (BDMA), water, and carbon dioxide) were measured as a function of molality of BDMAH-bicarbonate salt for the SHS system at temperatures from (283.15–308.15) K. Three empirical equations were successfully applied to correlate the density, viscosity, refractive index, and electrical conductivity of the SHS systems with temperature and BDMAH-bicarbonate salt concentration. From these experimental results, apparent molar volume , limiting partial molar volume , the relative viscosity and viscosity B -coefficients were calculated. The limiting apparent molar volumes ( V ϕ 0 ) and experimental slopes ( A v ) derived from the Redlich-Mayer type equation have been interpreted in terms of solute-solute and solute-solvent interactions. In terms of Jones-Dole equation, the viscosity B -coefficients with large positive value and dB/dT < 0 were obtained and these facts implied that the BDMAH-bicarbonate salt is water-structure-making.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2012
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IF 1.693
Yabo Hao,Songhong Zhang,Kejian Yao
Vapor–liquid equilibrium (VLE) data for methanol + tert-butylamine + N,N-dimethylformamide (DMF) and constituent binary systems containing tert-butylamine at 101.3 kPa were measured. A maximum boiling point azeotrope was observed at the methanol mole fraction of 0.763, corresponding to the temperature of 340.28 K for the binary system methanol + tert-butylamine. The binary equilibrium data were correlated using Wilson, nonrandom two-liquid (NRTL), and universal quasichemical activity coefficient (UNIQUAC) models, respectively. The VLE data of the ternary system were calculated with the binary interaction parameters of the NRTL model, and the average absolute deviations of the equilibrium temperature and the vapor-phase mole fractions for methanol and tert-butylamine were about 0.87 K, 0.014, and 0.018, respectively. The results show that DMF can break the azeotrope of the methanol + tert-butylamine system as a solvent.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2015
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IF 2.037
Chunlin Li,Qinbo Wang,Binwei Shen,Zhenhua Xiong,Chuxiong Chen
The mole fraction solubilities of 5,10,15,20-tetraphenylporphyrin (TPP) and 5,10,15,20-tetra(p-chlorophenyl)porphyrin (p-ClTPP) in binary system N,N-dimethylformamide (DMF) + water solvent mixtures were measured at atmospheric pressure by using the static method. The temperature and effects of mole fraction of DMF in the solvent mixtures on solubility were studied. The results show that the solubilities of TPP and p-ClTPP increase with the increasing temperature for a certain solvent composition, and the solubilities show a maximum in pure DMF, then the solubilities decrease when the water was added to the system. The experimental data were correlated with modified Apelblat equation. The solubilities calculated by the model were in good agreement with experimental observations. Thermodynamic parameters such as dissolution enthalpy, isobaric heat capacity and Gibbs energy were obtained from the solubility data by using the Clark–Glew equation together with the modified Apelblat equation. The result demonstrated that the dissolving process of TPP and p-ClTPP in DMF + water solvent mixtures is endothermic and not spontaneous.
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Polymer Chemistry
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2016
·Vol. 7
·期 20
·3423-3433
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IF 5.687
Ke Wang,Zefeng Song,Chonggao Liu,Wangqing Zhang
The thermo- and pH/CO2-responsive poly[N-[2-(dialkylamino)ethyl]acrylamide]s containing a polyacrylamide backbone but different N-substitutes of dialkylamine were synthesized and their solution properties were comparatively checked. A controllable RAFT synthesis of poly[N-[2-(dialkylamino)ethyl]acrylamide]s was achieved when a typical trithiocarbonate containing an easily cleavable R group was employed. The RAFT polymerization rate decreases with the increasing C-number in the N-substitutes. The thermo- and pH/CO2-responsive property of poly[N-[2-(dialkylamino)ethyl]acrylamide]s is firmly correlative to the N-substitutes. With the C-number in the R-substitute increasing, the solution properties of poly(N-[2-(dialkylamino)ethyl]acrylamide)s undergo a soluble-to-thermoresponsive-to-insoluble evolution, and the critical pH of poly[N-[2-(dialkylamino)ethyl]acrylamide]s gradually decreases. The dialkylamine moieties in the poly[N-[2-(dialkylamino)ethyl]acrylamide]s lead to a characteristic CO2-response during CO2/N2 bubbling. The present study reveals the structure-dependent solution properties of the thermo- and pH/CO2-responsive poly[N-[2-(dialkylamino)ethyl]acrylamide]s, and these multistimuli-responsive polymers are believed to be very useful due to the controllable RAFT synthesis and tunable solution properties.
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JOURNAL OF MATERIALS RESEARCH
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2014
·Vol. 29
·期 18
·2170-2178
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IF 1.815
Xiaomeng Lü,Jiayu Shen,Ziwei Wu,Jiaxi Wang,Jimin Xie
Plasmonic Ag nanoparticles (AgNPs) with narrow distribution were successfully loaded on graphitic carbon nitride (g-C3N4) sheet by thermal polymerization of melamine precursor and a simple wet-chemical pathway in the presence of polyvinylpyrrolidone (PVP). N,N-dimethylformamide (DMF) was used as an efficient reducing agent as well as a solvent and its presence facilitated homogeneous distribution of AgNPs under mild reaction condition and easy control of its particle growth under different precursor amounts. Ag/g-C3N4 composites of different Ag content were prepared, and the phase, chemical structure, morphologies, electronic and optical properties of Ag/g-C3N4 heterostructures were well characterized, respectively. The photocatalytic activity of Ag/g-C3N4 composites was evaluated by the decolorization of methyl orange (MO), and they exhibited superior photocatalytic activity to bulk g-C3N4 under visible-light irradiation. Influence of Ag content to photocatalytic activity was also discussed and possible mechanism was explored based on the analysis of photoluminescence spectra (PL) and photodecoloration activity.
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JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
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2015
·Vol. 54
·期 8
·1036-1043
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IF 3.113
Xueteng Cao,Daniel Horák,Zesheng An,Zdeněk Plichta
Nonspecific interaction is a key parameter affecting the efficiency of proteins, nucleic acids or cell separation. Currently, many approaches to introduce antifouling properties to materials have been developed. Among these, surface modification with polymer brushes plays a prominent role. The aim of this study was to synthesize new magnetic microspheres grafted with poly( N,N -dimethylacrylamide) (PDMA) that resist nonspecific protein adsorption. Monodisperse macroporous poly(2-hydroxyethyl methacrylate) (PHEMA) microspheres, 4 μm in size, were synthesized by a multiple swelling polymerization method. To render the microspheres magnetic, iron oxide was precipitated inside the microsphere pores. Functional carboxyl groups, introduced by the hydrolysis of the 2-(methacryloyl)oxyethyl acetate (HEMA-Ac) comonomer, were used to react with propargylamine, followed by coupling of a chain transfer agent via an azide-alkyne click reaction. PDMA was grafted from the PHEMA microspheres using reversible addition-fragmentation chain transfer polymerization (RAFT), resulting in surfaces with more than 81 wt % PDMA attached. The successful modification of the microspheres was confirmed by XPS. The magnetic microspheres grafted with PDMA showed excellent antifouling properties as tested in bovine serum protein solutions. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54 , 1036–1043
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International Journal of Nanomedicine
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2013
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IF 3.463
Xiao-juan Hu,Yang Liu,Xiao-feng Zhou,Qiao-ling Zhu,Yong-yan Bei,Ben-gang You,Chun-ge Zhang,Wei-liang Chen,Zhou-li Wang,Ai-jun Zhu,Xue-nong Zhang,Yu-jiang Fan
Novel amphiphilic chitosan derivatives (N-caprinoyl-N-trimethyl chitosan [CA-TMC]) were synthesized by grafting the hydrophobic moiety caprinoyl (CA) and hydrophilic moiety trimethyl chitosan to prepare carriers with good compatibility for poorly soluble drugs. Based on self-assembly, CA-TMC can form micelles with sizes ranging from 136 nm to 212 nm. The critical aggregation concentration increased from 0.6 mg • L −1 to 88 mg • L −1 with decrease in the degree of CA substitution. Osthole (OST) could be easily encapsulated into the CA-TMC micelles. The highest entrapment efficiency and drug loading of OST-loaded CA-TMC micelles(OST/CA-TMC) were 79.1% and 19.1%, respectively. The antitumor efficacy results show that OST/CA-TMC micelles have significant antitumor activity on Hela and MCF-7 cells, with a 50% of cell growth inhibition (IC50) of 35.8 and 46.7 μg. mL −1 , respectively. Cell apoptosis was the main effect on cell death of Hela and MCF-7 cells after OST administration. The blank micelles did not affect apoptosis or cell death of Hela and MCF-7 cells. The fluorescence imaging results indicated that OST/CA-TMC micelles could be easily uptaken by Hela and MCF-7 cells and could localize in the cell nuclei. These findings suggest that CA-TMC micelles are promising carriers for OST delivery in cancer therapy.
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PubMed
高影响因子
JOURNAL OF SEPARATION SCIENCE
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2013
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IF 2.591
Jing Chen,Juan Zhang,Wenpeng Zhang,Zilin Chen
Sarcosine, a potential biomarker of prostate cancer, has drawn great attention in recent years. However, controversial research keeps arising about its role as a biomarker that might come from the two isomers (α-alanine and β-alanine) of sarcosine due to their same molecular weight and similar properties, which could interfere with the accurate detection of sarcosine. In this study, a simple and sensitive method was developed for the detection of sarcosine and the two isomers by LC with ion-trap MS through a novel derivatization reagent N , N ′-dicyclohexylcarbodiimide. N , N ′-Dicyclohexylcarbodiimide is usually considered as a condensation reagent, however, it was directly used as a derivatization reagent through a rearrangement side reaction in this study. The proposed method not only improved the chromatographic retention behavior of sarcosine and its two isomers, which was a benefit to their separation, but also dramatically enhanced the detection sensitivity of sarcosine, which was more favorable for real sample analysis. The factors affecting the productivity of the derivatization reaction, such as reaction time and amount of derivatization reagent, were systematically optimized. The method shows good linearity ( R 2 > 0.99), sensitivity with LODs of sarcosine as low as 1 ng/mL, and repeatability with the RSD < 6.07%. The developed method was applied to the analysis of urine.
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PubMed
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MOLECULAR PHARMACEUTICS
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2014
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IF 4.787
Yanping Li,Yangyang Zhou,Bowen Qi,Tao Gong,Xun Sun,Yao Fu,Zhirong Zhang
Parkinson’s disease (PD) has become one of the most deadly diseases due to a lack of effective treatment. Herein, N-3,4-bis(pivaloyloxy)dopamine-3-(dimethylamino)propanamide (PDDP), a brain-specific derivative of dopamine, was designed and synthesized, which consists of a brain targeted ligand, N,N-dimethyl amino group, and two dipivaloyloxy groups for lipophilic modification. PDDP was investigated both in vitro and in vivo by comparing with L-DOPA and another derivative (BPD) without N,N-dimethyl amino group. PDDP showed a more pronounced accumulation in mouse brain microvascular endothelial cells (bEnd.3) than BPD via an active transport process. The increased cellular uptake of PDDP was proven to be mediated by putative pyrilamine cationic transporters. Following intravenous administration, the concentration of PDDP in the brain was 269.28-fold and 6.41-fold higher than that of L-DOPA and BPD at 5 min, respectively. Additionally, PDDP effectively attenuated the striatum lesion caused by 6-hydroxydopamine (6-OHDA) in rats. More importantly, PDDP presented antioxidant and antiapoptotic effects on 6-OHDA-induced toxicity in human neuroblastoma cells (SH-SY5Y). Thus, N,N-dimethyl amino group-based PDDP represents an effective and safe treatment for PD.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2025
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IF 9.7
Binhang Wang,Libo Sun,Tong Wang,Yujie Cao,Xiang Li,Wenhao Xu,Jie Zhang,Yun Tang
Ordered mesoporous Metal-Organic Frameworks ( meso MOFs), integrating mesopores and micropores, address mass transfer limitations characteristic of microporous materials, thus broadening their application spectrum. However, the synthesis of meso MOFs has been predominantly achievable in aqueous media, rather than in organic solvents, which are more conducive to the growth and stabilization of MOFs. This is primarily attributed to the challenge in forming stable and uniform micelles from block copolymers within organic systems. In this work, meso MOFs are synthesized within N,N-dimethylformamide (DMF) media for the first time, via a micellar microphase separation method facilitating by introducing trace water into the organic solvent DMF. These meso MOFs, featuring non-exposed spherical mesopores and inherent microporosity, demonstrate significantly enhanced performance in the accumulation of reactants, and such characteristics render these materials ideal nanoreactors, endowing them with superior adsorption and degradation capabilities. The adsorptive and degradation removal of tetracycline (TC) by m MIL-101 reached 93.7 %, with its efficiency in both adsorption and degradation of TC being significantly higher than that of traditional MIL-101. This synthetic approach expands the scope of meso MOFs preparation in organic solvents, providing insights for designing a new generation of meso MOFs with diverse compositions and structures, promising applications across various fields and advancing MOF-based technologies.
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PubMed
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APPLIED CATALYSIS B-ENVIRONMENTAL
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2025
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IF 21.1
Xu Liu,Yuheng Zhao,Jun Ma,Yimo Zhang,Hui Zhang,Zhongqing Liu,Yuefeng Liu
The catalytic oxidation of H 2 S into element sulfur using nanocarbon materials is an effective means to solve environmental pollution and realize resource utilization of sulfur. Defect engineering and heteroatom doping are effective strategies for tuning the electronic structure of carbon materials to enhance their catalytic performance. Therefore, rationally exploiting the synergistic effects between defects and heteroatom sites, and elucidating the underlying catalytic mechanisms are essential for the development of high-performance carbon-based catalysts. In this study, we design and synthesize a series of N-doped carbon catalysts containing structural defects, which exhibit significantly enhanced desulfurization performance. Experimental results demonstrate that the NDC-700 catalyst exhibits excellent catalytic activity (95.0% H 2 S conversion and 94.4% S selectivity at 190 °C) and stability (>80 h) while maintaining high performance with high O 2 partial pressures and in the presence of impurity gases such as steam, CO 2 , and CO under mild conditions in continuous mode (≤ 200 °C). XPS analysis, kinetic studies, and oxygen activation experiments reveal that the catalytic performance improves with increasing defect density, despite a decrease in pyridinic N content. DFT calculations further indicate that defect structures substantially alter the local charge distribution around pyridinic N sites, promoting the adsorption and activation of H 2 S and O 2 , ultimately improving catalytic performance. This study elucidates the synergistic interaction between defects and N sites, and further confirms the critical role of defects in enhancing the catalytic function of N-doped carbon materials.
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CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Linsen Li,Zhuwei Yang,Xiao Yang,Hui Xiong,Zhao Jiang,Tao Fang
Liquid organic hydrogen carriers (LOHCs) are considered as promising candidates for large-scale hydrogen storage, which offers significant advantages in terms of hydrogen storage density, ease of storage and transportation. NPhCZ (N-phenylcarbazole)/18H-NPhCZ (perhydro-N-phenylcarbazole) is proposed as a typical system with high hydrogen storage capacity. However, low dehydrogenation activity and selectivity of catalysts restrict the cyclic efficiency of hydrogen storage. In this study, the efficient catalysts are designed by the immobilization of ultrafine, highly dispersed Pd nanoparticles onto Ni, N co-doped carbon materials through wet chemical reduction. The Pd/Ni@NC-10 catalyst exhibits the highest catalytic performance with 100 % conversion, 81.9 % selectivity of NPhCZ and 6.48 wt% hydrogen release amount. Combined with XRD, HRTEM, Raman, XPS, H 2 -TPR, N 2 physisorption characterization methods and DFT calculations, it is found that the doped Ni, N species could synergistically increase the dispersion of loaded Pd nanoparticles, as well as regulate the electronic state around Pd, which in turn accelerates the rate of the rate-limiting step. The evident interaction between Pd nanoparticles and Ni, N co-doped carbon brings the enhancement of dehydrogenation efficiency. Besides, the spent catalysts are measured by XRD, TEM, XPS and evaluated for the dehydrogenation reaction, indicating that Pd/Ni@NC-10 shows good structural stability, durability and recyclability. It provides practical guidance for the design of LOHCs dehydrogenation catalysts.
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