EUROPEAN POLYMER JOURNAL
·
2017
·
IF 3.531
Dong Liu,Xueyu Li,Hongtao Song,Pucheng Wang,Jie Chen,Qiang Tian,Liangwei Sun,Liang Chen,Bo Chen,Jian Gong,Guangai Sun
Combining neutron and X-ray scattering (SANS, SAXS, and WAXD) as the contrast matching probes, the hierarchical structures of the multi-wall carbon nanotubes/high density polyethylene (MWCNTs/HDPE) composites (0.1–2.0 wt%) have been studied. SANS measurement avoided the correlation peak associated to the semicrystalline nature of HDPE from SAXS, and the passible scattering from the stretch induced voids. Benefitting from SANS data, the power law ( α ) taking the flexible cylinder suggested that whole MWCNTs in the unstretched composites follow a self-avoiding random walk ( α ≈ 1.67). SANS data suggest a hollow flexible cylinder structure with outer and inner diameters (core-shell-like cross section) of the scatterers as ca. 12.6 nm and 4.1 nm, while the Kuhn length is about 43.0 nm. Tensile test displayed improved mechanical properties. Interestingly, the Hermans orientation parameter ( f ) of HDPE crystals ( f c ) in the stretched composites are around a plateau ca. 0.96 initially, while decreased remarkably to 0.776 when the fraction is further increased to 2.0 wt%. f obtained by SANS showed a similar tendency (decreased from 0.756 to 0.572). Combining all the results along with differential scanning calorimetry (DSC) measurement, a mechanism of adhered crystals on the surface of MWCNTs and a reinforcement model are proposed.
研究领域:
高分子材料科学
·
纳米复合材料
·
结构表征
·
中子散射技术
·
X射线散射技术
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2024
·
IF 2.9
Ruiqi Shao,Yingjie Dong,Qingqing Wu,Haiting Shi,Jinxi Bao,Feng Tian,Tianyu Li,Zhiwei Xu
The porous structure of composite nanofibers plays a key role in improving their electrochemical performance. However, the dynamic evolution of pore structures and their action during ion intercalation/extraction processes for negative electrodes are not clear. Herein, porous carbon composite nanofibers (Fe@Fe2O3/PCNFs) were prepared as negative electrode materials for potassium-ion batteries. Electrochemical test findings revealed that the composites had good electrochemical characteristics, and the porous structure endowed composite electrodes with pseudo-capacitive behaviors. After 1500 discharge/charge cycles at a current density of 1000 mA g−1, the specific capacity of the potassium-ion batteries was 144.8 mAh g−1. We innovatively used synchrotron small-angle X-ray scattering (SAXS) technique to systematically investigate the kinetic process of potassium formation in composites and showed that the kinetic process of potassium reaction in composites can be divided into four stages, and the pores with smaller average diameter distribution are more sensitive to changes in the reaction process. This work paves a new way to study the deposition kinetics of potassium in porous materials, which facilitates the design of porous structures and realizes the development of alkali metal ion-anode materials with high energies.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry Letters
·
2023
·
IF 5.7
Zhuanfang Jing,Yongquan Zhou,Toshio Yamaguchi,Koji Yoshida,Kazutaka Ikeda,Koji Ohara,Guangguo Wang
Ion hydration in aqueous solutions plays a paramount role in many fields. Despite many studies on ion hydration, the nature of ion hydration is not consistently understood at the molecular level. Combining neutron scattering (NS), wide-angle X-ray scattering (WAXS), and molecular dynamics (MD), we quantify the ionic hydration degree (hydration ability) systematically for a series of alkali metal and halide ions based on static and dynamic hydration numbers. The former is based on the orientational correlation of water molecules bound to an ion derived from the positional information from NS and WAXS. The latter is defined as the mean number of water molecules remaining in the first coordination shell of an ion over a residence time of bound water molecules around the ion from MD. The static and dynamic hydration numbers distinguish hydration from coordination and quantify the ionic hydration degree, which provides a valuable reference for understanding various phenomena in nature.
研究领域:
物理化学
·
化学物理
·
溶液化学
·
分子模拟
·
材料科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOCHEMISTRY & CELL BIOLOGY
·
2016
·
IF 3.905
Longguang Jiang,Lin Lin,Rui Li,Cai Yuan,Mingming Xu,Joy H. Huang,Mingdong Huang
Platelet endothelial cell adhesion molecule 1 (PECAM-1) is a cell surface receptor widely distributed on endothelium and hematopoietic-derived cells, and maintain the integrity of the blood vessels. PECAM-1 is widely recognized as an endothelial cell marker. The homophilic interaction through its extracellular domain of PECAM-1 (soluble PECAM-1, or sPECAM-1) is important to its functions. However, structural details for such dimerization are not fully understood. Here we report the production of recombinant sPECAM-1 in large quantity by Drosophila expression system and the small-angle X-ray diffraction (SAXS) study. The recombinant sPECAM-1 was found to form one population of dimer, but not oligomer, and was able to bind to heparin immobilized on a chip in surface plasmon resonance imaging (SPRi) binding experiments. The results of SAXS demonstrated that sPECAM-1 formed a symmetric homodimer of Ω-shape in solution, and each protomer adopted an extended conformation. The dimer is mediated through the intermolecular interactions through the first N-terminal domain (D1) of sPECAM-1. This model provides new structural information for its homophilic interaction mechanism.
研究领域:
分子生物学
·
结构生物学
·
免疫学
·
血管生物学
·
生物化学
·
转化医学
✓ 已验证
DOI
高影响因子
Soft Matter
·
2021
·Vol. 17
·期 12
·3494-3502
·
IF 3.679
Wenchang Zhuang,Chunhua Zhao,Yue Pan,Qintang Li
As tailorable solvents, the physiochemical properties of ionic liquids can be tuned by the structure of ions. Herein, we investigate the structural effects of ILs on the self-assembly of surfactants. It has been confirmed that the cationic surfactant 1-hexadecyl-3-methylimidazolium bromide (C16mimBr) can self-assemble into micellar and lamellar lyotropic liquid crystal phases in the aprotic ionic liquid (AIL) 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim]BF4). In this work, we explore the aggregation behaviours in AILs with different alkyl chains on the imidazolium group, i.e., 1-propyl-3-methylimidazolium tetrafluoroborate ([Pmim]BF4), 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4), 1-hexyl-3-methylimidazolium tetrafluoroborate ([Hmim]BF4) and 1-octyl-3-methylimidazolium tetrafluoroborate ([Omim]BF4). With the increase of the cation chain length, AILs have better solubility of the solvophobic part of the surfactants and hence a weaker driving force for self-assembly. Therefore, the critical micellization concentration of C16mimBr in AILs increases as confirmed by the surface tension and small angle X-ray scattering characterizations. More interesting things happen to the phase behaviours. Besides the micellar and lamellar lyotropic liquid crystal phases, a hexagonal lyotropic liquid crystal phase is formed in [Pmim]BF4 while hexagonal and bicontinuous cubic lyotropic liquid crystal phases are formed in [Bmim]BF4, [Hmim]BF4 and [Omim]BF4. It is surprising to observe richer phase behaviours in solvents of lower cohesive energy. The detailed structural information of various aggregates has been obtained by small-angle X-ray scattering. It is demonstrated that AILs work as not only solvents but also co-surfactants.
研究领域:
物理化学
·
胶体与界面化学
·
软物质科学
·
离子液体化学
·
自组装材料
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2024
·
IF 2.8
Keke Chai,Toshio Yamaguchi,Taisen Zuo,Jochi Tseng,Kazutaka Ikeda,Yongquan Zhou
Ethaline, a deep eutectic solvent (DES) composed of choline chloride (ChCl)–ethylene glycol (EG) in a 1:2 molar ratio, is garnering significant interest for its wide potential applications. The nature of liquid formation and the structure of H-bonds within ethaline were investigated by X-ray scattering (XRS), neutron scattering (NS), and MD simulations. The sum of the dissociation energy barriers of Ch-EG (3.31 kJ·mol–1) and EG-Cl (4.28 kJ·mol–1) exceeds that of Ch-Cl (5.97 kJ·mol–1). This results in a more pronounced solvation of ChCl by EG compared to ChCl association, facilitating the solubilization of ChCl crystals by EG to form a DES. A partial radial distribution function (PDF) reveals that Cl– solvation is dominated by the hydroxyl group of EG, while the methylene group dominates Ch+ solvation. The spatial distribution function (SDF) shows that the distribution of EG and Cl– around Ch+ partially overlaps with that of the quaternary ammonium group. However, the center of mass distance of Ch-Cl (4.95 Å) is significantly lower than that of Ch-EG (5.65 Å), suggesting a favorable advantage for Cl– in this competition. Chain and ring structure distributions provide direct evidence of the microheterogeneity of ethaline. Hydroxyl groups on the EG promote the formation of a chain structure in ethaline, while methylene groups favor a ring structure. H-bond, carbon H-bond, and Cl– bridge bond restrict Cl– diffusion. This new understanding is crucial for a deeper comprehension of the microstructure of ethaline and for elucidating its mechanisms in applications.
研究领域:
物理化学
·
材料科学
·
计算化学
✓ 已验证
DOI
PubMed
高影响因子
COLLOID AND POLYMER SCIENCE
·
2023
·Vol. 301
·期 6
·569-576
·
IF 2.4
Ma Mingfang,Wang Tongyu,Liu Renrui,Jiang Wenwen,Niu Zhaocan,Bai Mingjuan,Wu Weiwei,Hao Aiyou,Shang Wenqing
Even though amino acid derivatives are always used as the building blocks to construct gels in supramolecular chemistry, there is still no report about N -alpha-Fmoc- L -valine (Fmoc-V) hydrogel induced by metal ions. Herein, a novel green Fmoc-V hydrogel with stimuli responsiveness was reported. A total of eight metal ions are applied to fabricate gels, but only Zn 2+ and Cu 2+ can induce Fmoc-V hydrogel formation. The formation of Fmoc-V hydrogel is verified by rheometer detection. FT-IR, UV–vis, and SAXS detections are used to study the formation mechanism of Fmoc-V hydrogel, implying hydrogen bond, metal–ligand, and π-π stacking interactions are the driving forces to gel formation. Moreover, this novel green hydrogel with high electrical conductivity performs multiple stimulus responsiveness to temperature, metal ion, and acid, illustrating its great potential applications in various areas.
研究领域:
超分子化学
·
材料科学
·
纳米技术
·
高分子科学
·
物理化学
✓ 已验证
DOI
高影响因子
Soft Matter
·
2024
·Vol. 20
·期 37
·7420-7428
·
IF 2.9
Yue Pan,Chunhua Zhao,Ruirui Wang,Mingjie Zhu,Wenchang Zhuang,Qintang Li
The structure of ionic liquids (ILs) has an influence on their physiochemical properties, determining their performance as self-assembly media. In this study, we focus on the anion effect of aprotic ionic liquids (AILs). The aggregation behaviours of the cationic surfactant 1-hexadecyl-3-methylimidazolium bromide (C16mimBr) have been investigated in the imidazolium AILs with the 1-ethyl-3-methyl imidazolium cation and different anions, including nitrate, ethylsulfate, bis(trifluoromethylsulfonyl) imide and tetrafluoroborate. Surface adsorption parameters of C16mimBr were determined using surface tension measurements, and the critical micellization concentration values in AILs vary for their different cohesive energy. The micellar and lamellar lyotropic liquid crystal phases emerge with the increase of C16mimBr concentrations. The structure and properties of aggregates were determined using small angle X-ray scattering, polarized optical microscopy, rheology and differential scanning calorimetry. The anion effects of AILs on the phase behaviours and structure and properties of aggregates were analysed and discussed. The lamellar lyotropic liquid crystals have shown good conductivity, as confirmed by electrochemical impedance spectroscopy characterization. Our results enhance the understanding of the structure effect of ILs as self-assembly media and contribute to the design of tailorable solvents.
研究领域:
材料科学
·
物理化学
·
胶体与界面科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）