JOURNAL OF PHYSICAL CHEMISTRY B
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2023
·
IF 3.3
Zhuanfang Jing,Yongquan Zhou,Toshio Yamaguchi,Koji Ohara,Jianming Pan,Guangguo Wang,Fayan Zhu,Hongyan Liu
The underlying recognition mechanisms of alkali metal ions by crown ethers in aqueous solutions are yet to be fully understood at the molecular level. We report direct experimental and theoretical evidence for the structure and recognition sequence of alkali metal ions (Li+, Na+, K+, Rb+, and Cs+) by 18-crown-6 in aqueous solutions by wide-angle X-ray scattering combined with an empirical potential structure refinement modeling and ab initio molecular dynamics simulation. Li+, Na+, and K+ are located in the negative potential cavity of 18-crown-6, with Li+ and Na+ deviating from the centroid of 18-crown-6 by 0.95 and 0.35 Å, respectively. Rb+ and Cs+ lie outside the 18-crown-6 ring and deviate from the centroid of 18-crown-6 by 0.05 and 1.35 Å, respectively. The formation of the 18-crown-6/alkali metal ion complexes is dominated by electrostatic attraction between the cations and the oxygen atoms (Oc) of 18-crown-6. Li+, Na+, K+, and Rb+ form the H2O···18-crown-6/cation···H2O “sandwich” hydrates, while water molecules only hydrate with Cs+ of the 18-crown-6/Cs+ complex on the same side of Cs+. Based on the local structure, the recognition sequence of 18-crown-6 for alkali metal ions in an aqueous solution follows K+ > Rb+ >Na+ >Li+, which is completely different from that (Li+ > Na+ > K+ > Rb+ > Cs+) in the gas phase, confirming that the solvation medium seriously affects the cation recognition of crown ethers. This work provides atomic insights into understanding the host–guest recognition and solvation behavior of crown ether/cation complexes.
研究领域:
化学
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物理化学
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DOI
PubMed
高影响因子
CHEMICAL PHYSICS LETTERS
·
2021
·
IF 2.328
Chenrui Jiang,Zhaorui Song,Meriem Fizir,Ping Yang,Meiru Liu,Pierre Dramou,Hua He
The interaction between cucurbit[6]uril and chain amino acids was studied via fluorescence probe method, molecular simulation, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. The experimental results of this work show that the cucurbit[6]uril host possesses a strong binding force with the chain amino acids leucine and methionine, and can form a host–guest inclusion complex. At the same time, the side chain alkyl moieties of the guests leucine, methionine and valine are contained in the hydrophobic cavity of cucurbit[6]uril, but the host–guest interaction between cucurbit[6]uril and valine molecule is weak.
研究领域:
化学
·
生物化学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2015
·Vol. 133
·期 6
·
IF 1.768
Maolin Li,Yuhua Zhong,Zheng Wang,Andreas Fischer,Florian Ranft,Dietmar Drummer,Wei Wu
A novel flame-retardant composite was prepared by introducing a phosphorus-nitrogen flame retardant and DOPO-SiO 2 into PA6. DOPO-SiO 2 was synthesized successfully in a one-step process. PA6/OP1314/DOPO-SiO 2 achieved a UL 94 V-0 rating with an LOI value of 31%. The maximum mass loss rate of decomposition decreased significantly and char residue increased to 11.6 wt % compared with that of pure PA6. The compacted and dense char was formed due to the combination of the P-N flame retardant and DOPO-SiO 2 . The complex viscosity of PA6/OP1314/DOPO-SiO 2 increased considerably which tend to prevent the dripping phenomenon. The flame-retardant mechanism of PA6/OP1314/DOPO-SiO 2 was also investigated by Fourier transform infrared spectroscopy FTIR at different temperatures and the pyrolysis products were investigated by pyrolysis gas chromatography/ mass spectrum (Py-GC/MS). It was assumed that DOPO-SiO 2 and the hypophosphite of OP1314 possess excellent flame retardancy during the gaseous phase. Meanwhile, melamine and phosphate reacted with the pyrolytic products of PA6 to protect the matrix during the condensed phase. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 42932.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2022
·Vol. 24
·期 22
·13773-13783
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IF 3.945
Xian-Yi Jin,Xin Dai,Jie Zhao,Qingmei Ge,Mao Liu,Zhu Tao,Hang Cong
A supramolecular polymer was developed through the encapsulation of polypyrrole by cucurbit[6]uril (PPy@Q[6]), which was employed as the electrode material to improve the capacitor ability of conductive polypyrrole. In the optimized ratio of 2 : 1 (CPPy : CQ[6]), the capacitor properties of the supramolecular material were evaluated, and a high specific capacitance of 414 F g−1 at 10 mV s−1 was obtained, which was 3.1 times higher than that of pure polypyrrole (132 F g−1). A comprehensive analysis suggested that the capacitance performances should be relevant to the component, surface area, and pore volume of the materials. The addition of 0.4 M Fe2(SO4)3 into the electrolyte provided a surprising specific capacitance of 3530 F g−1 on the cucurbituril-encapsulated polypyrrole electrode material, with a high energy density of 707 W h kg−1 at a power density of 32 000 W kg−1 and a current density of 8 A g−1. The 81.6% capacitance retention maintained after 1000 cycles revealed the acceptable cycling capacity of the proposed supramolecular supercapacitor system, which demonstrated good performance even at a low temperature of −20 °C.
研究领域:
材料科学
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电化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
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2019
·Vol. 54
·期 13
·9456-9465
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IF 3.442
Yang Yu-ting,Yi Chun-wang
In this study, a novel surface modification approach for preparation of nanoscale titanium dioxide using aluminate coupling agent was developed. By optimizing the adding content of aluminate coupling agent and the reaction temperature, modified titanium dioxide (A-TiO 2 ) particles with a minimum Z -average size of 32 nm and a narrow PDI of 0.214 were obtained. Further tests revealed that A-TiO 2 was super-hydrophobic with water contact angle of 151.39°. Moreover, the dispersion behaviors and morphologies of TiO 2 and A-TiO 2 particles in different solvents were further investigated. The results indicated that A-TiO 2 could be well dispersed in hot liquid caprolactam, making it suitable for preparing full-dull polyamide-6 polymers.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
Frontiers in Pharmacology
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2023
·
IF 5.6
Zhang Hua,Yan Shu,Zhan Yan,Ma Sheng,Bian Yicong,Li Shaorong,Tian Junjun,Li Guangze,Zhong Dafang,Diao Xingxing,Miao Liyan
SHR6390 (dalpiciclib) is a selective and effective cyclin-dependent kinase (CDK) 4/6 inhibitor and an effective cancer therapeutic agent. On 31 December 2021, the new drug application was approved by National Medical Product Administration (NMPA). The metabolism, mass balance, and pharmacokinetics of SHR6390 in 6 healthy Chinese male subjects after a single oral dose of 150 mg [14C]SHR6390 (150 µCi) in this research. The Tmax of SHR6390 was 3.00 h. In plasma, the t1/2 of SHR6390 and its relative components was approximately 17.50 h. The radioactivity B/P (blood-to-plasma) AUC0-t ratio was 1.81, indicating the preferential distribution of drug-related substances in blood cells. At 312 h after administration, the average cumulative excretion of radioactivity was 94.63% of the dose, including 22.69% in urine and 71.93% in stool. Thirteen metabolites were identified. In plasma, because of the low level of radioactivity, only SHR6390 was detected in pooled AUC0-24 h plasma. Stool SHR6390 was the main component in urine and stool. Five metabolites were identified in urine, and 12 metabolites were identified in stool. Overall, faecal clearance is the main method of excretion.
研究领域:
药理学
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药物代谢动力学
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肿瘤学
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产品关联
DOI
PubMed
高影响因子
Polymers
·
2023
·Vol. 15
·期 8
·1887
·
IF 5
Hui Fang,Guifeng Li,Kai Wang,Fangjuan Wu
This study investigates the effect of adding stearic acid (SA) on the thermal conductivity of polyamide 6 (PA6)/boron nitride (BN) composites. The composites were prepared by melt blending, and the mass ratio of PA6 to BN was fixed at 50:50. The results show that when the SA content is less than 5 phr, some SA is distributed at the interface between BN sheets and PA6, which improves the interface adhesion of the two phases. This improves the force transfer from the matrix to BN sheets, promoting the exfoliation and dispersion of BN sheets. However, when the SA content was greater than 5 phr, SA tends to aggregate and form separate domains rather than being dispersed at the interface between PA6 and BN. Additionally, the well-dispersed BN sheets act as a heterogeneous nucleation agent, significantly improving the crystallinity of the PA6 matrix. The combination of good interface adhesion, excellent orientation, and high crystallinity of the matrix leads to efficient phonon propagation, resulting in a significant improvement in the thermal conductivity of the composite. The highest thermal conductivity of the composite is achieved when the SA content is 5 phr, which is 3.59 W m−1K−1. The utilization of a composite material consisting of 5phr SA as the thermal interface material displays the highest thermal conductivity, and the composite also demonstrates satisfactory mechanical properties. This study proposes a promising strategy for the preparation of composites with high thermal conductivity.Keywords:thermal conductivity;polyamide;boron nitride;stearic acid
研究领域:
材料科学
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热管理技术
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DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Yufen Gu,Bobo Guo,Zao Yi,Xianwen Wu,Jiao Zhang,Hua Yang
One decisive factor for the photocatalytic performance of ZnSn(OH) 6 (ZSO) is nanoparticle morphology. However, the mechanism of the well-defined morphology preparation remains unknown, which leads to the systematic investigation of various parameters in the hydrothermal method . Here, shell-like hollow Archimedean ZSO nanocubes were prepared by a hydrothermal method under suitable conditions, with a uniform particle size distribution and superior dispersion. The effects of hydrothermal time, temperature, pH and surfactant on the microscopic morphology and photocatalytic degradation of methylene blue (MB) dye were investigated. The enhanced photodegradation efficiencies ( η ) of MB were 97.7%, 96.3%, 89.6%, and 96.2% for 8 h-ZSO, 120 ℃-ZSO, 2.85-ZSO, and Hexadecyl trimethyl ammonium Bromide-ZSO (CTAB-ZSO), respectively, which strongly depended on the morphology, leading to differences in physicochemical properties, such as bandgap and charge transfer resistance. The results suggested that a single change in hydrothermal time, temperature, pH, or surfactant can effectively improve the microscopic morphology and photocatalytic performance of ZSO, which may pave the way for the ingenious design of other high-performance photocatalysts . A growth mechanism was proposed for shell-like hollow ZSO prepared in an alkaline environment.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2017
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IF 5.951
Yan Gao,Lu Ye,Shuyan Cao,Hu Chen,Yanan Yao,Jian Jiang,Licheng Sun
Perovskite hydroxide CoSn(OH)6 nanoparticles were synthesized and used for the first time in the photocatalytic reduction of CO2 to CO. Under mild reaction conditions and using [Ru(bpy)3](PF6)2 as the photosensitizer, a high photocatalytic efficiency of 19.3 μmol for CO evolution with a high selectivity of 86.46% was obtained. The photocatalytic activity and CO selectivity were further improved by adding weak Brönsted acids, as proton sources, to the system.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 15
·5095
·
IF 3.748
Yonghuan Zhao,Yang Meng,Feichao Zhu,Juanjuan Su,Jian Han
The emergence of graphene-based polymer composite fibers provides a new opportunity to study the high-performance and functional chemical fibers. In this work, we have developed an efficient and convenient method with polydopamine (PDA) to functionalize and reduce graphene oxide (GO) simultaneously, and the modified graphene nanosheets can obtain uniform dispersion and strong interfacial bonding in nylon 6 (PA6). Furthermore, the reinforced PA6 composite fibers were prepared through mixing PDA-rGO into the PA6 polymer matrix and then melt spinning. The functional modification was characterized by surface analysis and structural testing including SEM, TEM, FTIR, and Raman. When the addition amount of the modified GO was 0.15 wt%, the tensile strength and Young’s modulus of the composite fiber reached 310.4 MPa and 462.3 MPa, respectively. The results showed a meaningful reinforcement with an effect compared to the pure nylon 6 fiber. Moreover, the composite fiber also exhibited an improved crystallinity and thermal stability, as measured by DSC and TGA.Keywords:graphene oxide;polydopamine;PA6;composite fiber;reinforce;Young’s modulus
研究领域:
材料科学
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高分子化学
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产品关联
DOI
PubMed
高影响因子
SN Applied Sciences
·
2019
·Vol. 1
·期 11
·1-8
·
IF 0
Zhang Xue,Sun Lei,Chen Yingbo,Yin Cuiyu,Liu Dongqing,Ding Ermin
Flame retardant polyamide 6 (PA6) composites (PA6/PTCDA) were prepared by in situ polymerization of caprolactam with adding 0.01–2.5 wt% perylene-3,4,9,10-tetracar-boxylic dianhydride (PTCDA). The structure and properties of PA6/PTCDA composites were studied by Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, thermal conductivity, and limiting oxygen index (LOI) measurements. The results indicated that the crystallization of the PA6 chains was suppressed with 2.5 wt% PTCDA, and the LOI of the composite was 29.5. At the same time, the addition of PTCDA made the composites form a coke layer in the process of combustion, protecting the flammable components from volatilization and enhanced the flame retardant performance of the composites. This indicated that the PA6/PTCDA composite prepared by in situ polymerization possessed good flame retardant properties.
研究领域:
材料科学
·
高分子化学
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DOI
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2015
·
IF 2.587
Yijian Wu,Hui Zhang,Baoqing Shentu,Zhixue Weng
Organo-montmorillonite (OMMT) was introduced into SEBS-g-MA toughened poly(phenylene oxide)/polyamide-6 (PPO/PA6) blends simply by melt extrusion. The effects of OMMT on morphology, rheology, and mechanical behaviors of toughened PPO/PA6 nanocomposites were studied by scanning electron microscope, transmission electron microscope, capillary rheometer and mechanical tests. The addition of OMMT could decrease the size of dispersed PPO domains in PA6 matrix and melt viscosity of the toughened PPO/PA6 nanocomposites. Besides, exfoliated OMMT also brought significant improvement of tensile properties and heat deflection temperature (HDT), simultaneously. For nanocomposites with exfoliated OMMT, OMMT induced more core–shell toughening particles with the optimized size, and thus, elastomer-OMMT synergistic toughening was achieved in the PPO/PA6 nanocomposites. Consequently, PPO/PA6 nanocomposites with high tensile strength, excellent impact performance, improved HDT, and good processability were obtained.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）