JOURNAL OF CHEMICAL THERMODYNAMICS
·
2020
·
IF 2.888
Renren Sun,Haixia He,Yameng Wan,Yueru Wang,Liyuan Li,Jiao Sha,Gaoliang Jiang,Yu Li,Tao Li,Baozeng Ren
For further study on solubility behaviors of melatonin (MT), the solubility of MT in the three mono-solvents {N, N-dimethylformamide (DMF), 2-methoxyethanol, 2-ethoxyethanol} and four binary solvents {(DMF, 2-methoxyethanol, 2-ethoxyethanol and methanol) + ethyl acetate} was measured in a range of 278.15 K–323.15 K by laser monitoring method. The measurement results showed that MT solubility in all tested solvents increased with rising temperature. In binary solvents except methanol + ethyl acetate, the solubility values of MT had a positive relationship with the mass fraction of co-solvents. In methanol + ethyl acetate, the solubility of MT initially increased, followed by a decrease (with the rising mass fraction of methanol) and arrived the highest solubility value at a mass fraction of methanol being 0.4000. The Hansen solubility parameters (HSPs) were applied to study the solubility behaviors of MT in tested solvents. Moreover, in three pure solvents, the measured solubility data of MT was correlated by (NRTL-SAC, NRTL, two-Suffix Margules, UNIQUAC models and modified Apelblat equation). In binary solvents, the solubility data was fitted by (three-Suffix Margules, λh equation, Yaws model equation and modified Apelblat equation). Furthermore, the apparent thermodynamic properties were calculated based on the van’t Hoff equation. The positive values of apparent standard dissolution enthalpy and entropy suggest that the dissolution process of MT in all of chosen solvents is entropy-driven and endothermic. The larger values of ζ H than ζ TS represent that the main contributor of Δ dis G o in all investigated solvents is enthalpy.
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POLYMER
·
2020
·
IF 4.231
Wei-Guang Chen,Nan Hu,Yu Chen,Hong Pan
Multifunctional branched polylactides (BPLAs) with N,N -bis(2-hydroxyethyl)glycine (BHEG) as branching units were prepared. The as-prepared BPLAs had degree of branching in the range of 5.7–9.1%, number-average molecular weight in the range of 7.4 kDa–9.3 kDa, and dispersity in the range of 1.3–1.7. The tertiary amine groups of BHEG units endowed BPLAs intrinsic photoluminescence (PL) nature with quantum yield (QY) in the range of 1.2–2.0% under the maximum excitation wavelength of 360–370 nm and the maximum emission wavelength of 439–445 nm. Oxidized BPLAs showed the maximum excitation wavelength of ca. 473 nm as well as the maximum emission wavelength of ca. 540 nm, and much higher QYs of 9.1–10.5%. The tertiary amine groups of BHEG units also endowed BPLAs guest-encapsulation capacity. The obtained BPLAs were effective multifunctional additives for poly( l -lactide) plastics, embodied with improved crystallization and mechanical properties , PL property and new functions through hosting functional guest molecules.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2020
·
IF 2.369
Quan Lei,Yitong Dai,Panxi Wu,Wenjun Fang,Yongsheng Guo
It has been proven that alcohols can regulate the performance of aviation fuels. In this work, the densities (ρ) and viscosities (η) for the ternary system of isopropylcyclohexane (1) + n-tridecane (2) + n-butanol (3) and the corresponding binary systems have been measured to understand the physical properties of endothermic hydrocarbon fuel with alcohol over the whole composition range at temperatures from 293.15 to 333.15 K under atmospheric pressure (p = 0.1 MPa). The Redlich–Kister equation has been used to fit the excess molar volumes (VmE) and viscosity deviations (Δη) of binary systems, while four semiempirical equations (Singh, Cibulka, Nagata–Tamura, and Redlich–Kister) have been applied to correlate VmE and Δη of the ternary system. For all binary systems, the values of VmE are positive. The values of Δη for binary systems containing n-butanol are all negative. For the ternary system, the values of VmE are all positive and the values of Δη are all negative over the entire concentration range. All results have been interpreted with the perspective of intermolecular interaction and structural effect.
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IRANIAN POLYMER JOURNAL
·
2019
·Vol. 28
·期 11
·957-967
·
IF 1.707
Yang Xiaoli,Wang Kunyan,Yan Lei,Yu QiNing,Xia Hongxia,Liu Yanbo,Yan Chengjun
Multi-stimuli-responsive hydrogels are being increasingly studied due to their sensitive response to small stimuli and wide applications in biosensors and drug delivery. In this study, a multi-stimuli-responsive hydrogel, poly(hydroxyethyl methacrylate- co - N -vinyl pyrrolidone- co -methacrylic acid- co - N -isopropylacryl amide) [poly(HEMA- co -NVP- co -MAA- co -NIPA)], was synthesized by radical polymerization and characterized by Fourier transform infrared (FTIR) and 13 C NMR spectroscopy techniques. With the aids of scanning electron microscopy (SEM) characterization, it was confirmed that the sensitive stimuli-responsive behavior of the hydrogel stemmed from its microstructure variation with those external stimulus. Rheological study showed that the hydrogel had rheological feature of typical elastomer. Compression tests revealed that the poly(hydroxyethyl methacrylate- co - N -vinyl pyrrolidone) [poly(HEMA- co -NVP)] played an important role in enhancing the compressive modulus of such hydrogel. More interestingly, the equilibrium swelling ratio (ESR) studies further confirmed that the composite hydrogel displayed response sensitively to the stimulus of temperature, pH, and ionic strength. Herein, theophylline as a drug model was adopted due to the multi-stimulus properties of hydrogels, which were a potential candidate for drug loading and delivering. Releasing drug continuously in a given period was dependent on the characteristics of solution and loading time. The mechanisms for drug release from the hydrogels were studied by Ritger–Peppas model.
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JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2018
·Vol. 135
·期 6
·3363-3373
·
IF 2.209
Zhang Shijie,Zhang Jiaoqiang,Kou Kaichang,Jia Qian,Xu Yunlong,Zerraza Sofiane,Liu Ning,Hu Rongzu
2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexazisowurtzitane (HNIW)·1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) co-crystal in a 2:1 molar ratio was prepared by a solvent/non-solvent method, and the co-crystal has been characterized by several methods. The enthalpies of dissolution of 2HNIW·HMX co-crystal in N,N -dimethylformamide at different temperatures were measured by a DC08-1 Calvet microcalorimeter under standard atmospheric pressure, and it is indicated that the dissolutions are exothermic process. The empirical formulae for the calculation of the molar enthalpy ( \(\Delta_{\text{diss}} H\) ) of dissolution, relative partial molar enthalpy ( \(\Delta_{\text{diss}} H_{\text{partial}}\) ), relative apparent molar enthalpy ( \(\Delta_{\text{diss}} H_{\text{apparent}}\) ), and enthalpy of dilution ( \(\Delta_{\text{dil}} H_{1,2}\) ) at 298.15 K are obtained. The differential enthalpies ( \(\Delta_{\text{dif}} H\) ) and kinetic equations describing the dissolution process at different temperatures are deduced. Furthermore, the apparent activation energy E = 10.54 ± 0.22 kJ mol -1 and pre-exponential constant A = 0.34 ± 0.03 s −1 of 2HNIW·HMX co-crystal are obtained. The standard molar Gibbs free energy of activation ( \(\Delta G_{ \ne }^{\theta }\) ) at different temperatures is 86.44 ± 0.02 kJ mol −1 (298.15 K), 88.02 ± 0.03 kJ mol −1 (303.15 K), 89.61 ± 0.01 kJ mol −1 (308.15 K), 91.18 ± 0.01 kJ mol −1 (313.15 K), and 92.75 ± 0.02 kJ mol −1 (318.15 K), respectively. The standard molar entropy of activation ( \(\Delta S_{ \ne }^{\theta }\) ) and standard molar enthalpy of activation ( \(\Delta H_{ \ne }^{\theta }\) ) are − 262.55 ± 0.72 J mol −1 K −1 and 7.98 ± 0.22 kJ mol −1 , respectively.
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PLoS One
·
2014
·Vol. 9
·期 10
·e110155
·
IF 3.534
Zhihu Yan,Caili Dai,Haishun Feng,Yifei Liu,Shilu Wang
The viscoelastic properties of worm-like micelles formed by mixing the cationic surfactant N -hexadecyl- N -methylpiperidinium bromide (C 16 MDB) with the anionic surfactant sodium laurate (SL) in aqueous solutions were investigated using rheological measurements. The effects of sodium laurate and temperature on the worm-like micelles and the mechanism of the observed shear thinning phenomenon and pseudoplastic behavior were systematically investigated. Additionally, cryogenic transmission electron microscopy images further ascertained existence of entangled worm-like micelles.
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PubMed
高影响因子
FLUID PHASE EQUILIBRIA
·
2017
·
IF 2.473
Tao Jia,Shengshan Bi,Jiangtao Wu
Compressed liquid densities of n -decane + n -dodecane binary mixtures were measured with a vibrating-tube densimeter at temperatures from (283–363) K and pressures from (0.1–100) MPa over the whole range of composition . The binary mixtures n -decane (1) + n -dodecane (2) were prepared at mole fractions of ( x 1 = 0, 0.2297, 0.4436, 0.6433 0.7841, and 1.0), respectively. The experimental densities of binary mixtures were successfully correlated with the Tait-type equation, and the absolute average percentage deviations of the experimental and calculated values were 0.048%, 0.055%, 0.059%, 0.058%, 0.068%, and 0.052%, respectively. In addition, the excess molar volume was calculated for whole range of temperature, pressure and composition.
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ECOTOXICOLOGY
·
2024
·
IF 2.4
Yang Liu,Liu Kexin,Shi Lina,Chen Ming,Liu Junyan,Dai Shiniu,Xi Yilong,Wen Xinli
N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine (6PPD) and Zn 2+ , extensively used in the tire manufacturing process, are frequently detected in freshwater environments. However, the intergenerational effects of isolated 6PPD exposure and joint 6PPD and Zn 2+ exposure at concentrations approximating environmental levels remain unknown. This study assessed the chronic toxicity and intergenerational effects of 6PPD (0.02–20 μg/L) and a mixture of 6PPD and Zn 2+ (5 μg/L) over three generations in Daphnia magna bioassays. In the F0 generation, a dose-dependent decline in total offspring number was observed with 6PPD exposure alone, while co-exposure with Zn 2+ exacerbated the reproductive toxicity of 6PPD. Across three generations, low-dose (0.02 µg/L) 6PPD alone and combined with Zn 2+ induced a cumulative degenerative maternal effect. Conversely, high-dose (20 µg/L) 6PPD, both independently and in combination with Zn 2+ , exhibited an adaptive maternal effect. Notably, the grandmaternal effect emerged exclusively in the co-exposure group treated with 20 μg/L 6PPD and 5 μg/L Zn 2+ , with no such effect in the group exposed to 20 μg/L 6PPD alone, suggesting that Zn 2+ may enhance the potential toxicity of 6PPD. Overall, this study provides novel insight into the intergenerational impacts of environmentally relevant levels of 6PPD alone and in combination with a heavy metal, elucidating the environmental risks posed by tire-derived chemicals through their synergistic effects on transgenerational toxicity.
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PubMed
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ChemistrySelect
·
2025
·Vol. 10
·期 43
·e04409
·
IF 2
Jialong Yang,Guangqun Zhai
The effect of aerobic dioxygen (O 2 ) residues and hydrogen peroxide (H 2 O 2 ) on dithiobenzoate-mediated reversible addition-fragmentation chain transfer (RAFT) polymerization of methyl methacrylate (MMA) was studied. 2-cyano-2-propyl dithiobenzoate (CPDB) displayed excellent thermally oxidative stability against O 2 in O 2 -rarefied dimethylsulfoxide (DMSO) but was readily oxidized by H 2 O 2 . Azo-initiated CPDB-mediated RAFT polymerization of MMA in DMSO under different media led to multi-component products, consisting of PMMA macro-CTAs, MMA-terminated oligomers and low-MW byproducts, while nitrogen deoxygenating and headspace eliminating gave rise to a comparable CTA efficiency, higher than that headspace limiting. H 2 O 2 -initiated CPDB-mediated headspace-free RAFT polymerization of MMA smoothly proceeded in DMSO even at 50 °C, suggesting the co-initiation by CPDB, and also formed predominant PMMA macro-CTAs, negligible oligomers and some low-MW byproducts. H 2 O 2 -initiated CPDB-mediated headspace-free RAFT polymerization of MMA at 70 °C displayed well-controlled behaviors with 2–5 wt.% byproducts, and the high fidelity of the PMMA macro-CTAs was confirmed by the chain extension via azo-initiated RAFT polymerization and Cu I -catalyzed concurrent ATRP/RAFT polymerization. Graphical AIBN-initiated dithiobenzoate-mediated RAFT polymerization of MMA in O 2 -rarefied DMSO under headspace-free media led to well-controlled behaviors comparable to that under N 2 deoxygenating. H 2 O 2 -initiated RAFT polymerization manifested the unprecedented acceleration by dithiobenzoate; ascribed to its oxidation by H 2 O 2 ; and well-controlled polymerization behaviors.
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INORGANICA CHIMICA ACTA
·
2025
·
IF 3.2
Xingyue Liu,Xuanhao Huang,Yiting Wang,Zhuang Wang,Qiao Yu,Hang Zhou,Rui Li,Songdong Ding
Tri- n -butyl phosphate (TBP), n -octanol and N,N -dihexyloctanamide (DHOA) are often used as phase modifiers to prevent the formation of the third phase during the extraction of trivalent lanthanides and actinides by N,N,N′,N′ -tetraoctyl diglycolamide (TODGA) in spent fuel reprocessing process. In this context, the effects of these three modifiers on the thermodynamic and kinetic behaviors of 0.20 mol·L −1 TODGA in n -dodecane toward Nd 3+ in nitric acid solution were studied and compared together for the first time. A systematic comparison of the effects of the three modifiers on the extraction distribution ratio, stripping percentage, loading capacity, aggregation and extraction kinetics was carried out with the aim of selecting a phase modifier for the TODGA-based process that would work optimally and to elucidate the impact of the modifiers in the TODGA extraction system. It is found that modifier reduces the capacity of TODGA to extract Nd 3+ in the order of DHOA > TBP > n -octanol, slightly hinders the stripping of Nd 3+ , while significantly enhancing the loading capacity of TODGA. With increasing the modifier concentration, the limiting organic phase concentration (LOC) for Nd 3+ increases. At the modifier concentration below 0.30 mol·L −1 , n -octanol has the greatest promotion effect on the LOC value, while at that above 0.50 mol·L −1 , TBP has the best effect. Meanwhile, through the dynamic light scattering analysis for the loaded organic phase, it is also found that the particle size of the aggregates in organic phase decreases significantly upon the addition of modifier. Furthermore, the extraction kinetics studies in a Lewis cell indicate that the addition of modifier can prolong the time to reach extraction equilibrium, and decrease the extraction rate. Although the modifier also exerts some influence on the reaction order and extraction rate constant to some extent, it does not alter the underlying regime of the extraction reaction.
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Neuropsychiatric Disease and Treatment
·
2022
·
IF 2.989
Yuxi Jia,Ping Li,Fei Wu,Fanjie Zeng,Beilin Zhang,Jinpeng Wang
Background: In clinic, valproic acid (VPA) has been widely used in the treatments of epilepsy and is currently under clinical trials for the treatments of multiple diseases. However, gravidas receiving VPA treatment during their early stage of pregnancy were reported to be associated with elevated incidences of autism in their child. In this study, the potential influences of n-3/n-6 polyunsaturated fatty acids (PUFAs) as supplements were investigated in VPA-induced autistic rat model.Materials and Methods: A rat model of autism spectrum disorder (ASD) was established by VPA exposure at the E12.5 day of gestation. Neonatal male Wistar rats (n = 24) were divided into VPA group, A group and B group, while normal neonatal male Wistar rats served as controls. At P21 days, animals in the control and VPA groups were fed with standard chow, while rats in the A group were fed with n-3 PUFA free chow, and those in the B group with n-3/n-6 PUFA (1:5) chow. The duration of the diet was from P21 days to 3 months. All rats were subjected to the examinations of repetitive stereotyped behaviors and changes in social interaction at the end of supplement. The neuroinflammation in the brain and serum was also evaluated. Hematoxylin–eosin (HE) staining and Nissl staining were used to observe the neuronal injury in hippocampus.Results: In the B group, the repetitive stereotyped behaviors reduced, the social communication was improved, the neuronal loss and proinflammatory cytokines in the hippocampus reduced, and the extracellular STAT3 activation was inhibited in the hippocampus, as compared to the B group.Conclusion: Supplements with n-3/n-6 PUFA (1:5) rescues repetitive stereotyped behaviors and social deficits in neonatal rats exposed to VPA, likely due to the improved inflammatory responses through the alteration of STAT3 signaling. This study provides evidence for the use of n-3/n-6 PUF in the treatment of autism in humans.
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TETRAHEDRON
·
2017
·
IF 2.651
Qiujie Tang,Ping Xie,Jin Wang,Jiajun Lin,Chunlai Feng,Charles U. Pittman,Aihua Zhou
Two cascade coupling reactions were developed between N -alkyl(aryl)- N -methacryloyl benzamides and readily available benzyl alcohols or sodium benzenesulfinates . Through a radical cyclization strategy, these one-pot sequential reactions provided two simple and efficient approaches to the synthesis of a variety of isoquinoline-1,3(2H,4H)-dione derivatives in high yields with a broad substrate scope. These compounds are valuable molecules in drug discovery .
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