NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 43
·期 1
·103-110
·
IF 3.201
Funian Mo,Jianfeng Ban,Lulu Pan,Bo Shi,Shaorong Lu
In this study, a novel series of supramolecular liquid crystalline (LC) polyurethane composites, named SMPU–#HOBA (# represents the molar ratio of HOBA/BINA), were successfully prepared by incorporating hexadecyloxybenzoic acid (HOBA) into pyridine-containing polyurethane (PU). The effect of HOBA on the structure, morphology, and properties has been carefully investigated. The results demonstrate that the obtained SMPU–#HOBA composites not only maintained the LC property of the HOBA mesogen, but also enhanced the intrinsic crystallization of the soft segment phase. Thus, the composites showed an excellent multi-shape memory property with two crystalline temperatures. Moreover, self-gripping was demonstrated revealing reversible bidirectional shape memory by virtue of molecular flipping and movement of the hard segment domain. These composites display a rare combination of LC properties, multi-shape memory properties, and reversible bidirectional shape memory properties, which makes them ideal for many potential applications in smart temperature sensitive devices.
研究领域:
高分子科学
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材料科学
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智能材料
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软物质物理
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功能高分子
✓ 已验证
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2018
·
IF 3.485
Xiong Xu,Jianying Yu,Lihui Xue,Bianyang He,Wei Du,Huang Zhang,Ying Li
The excellent comprehensive performance of SBS modified bitumen (SMB), during a long-term thermo- and photo-oxidative exposure, will fail to satisfy the pavement requirement. In this paper, the synergistic effect of 4,4′-diphenylmethane diisocyanate (MDI) and 1,4-butanediol diglycidyl ether (BUDGE) on the molecular weight of aged SBS was firstly studied, through a simulation, to confirm whether a new polymer structure can be obtained. Then, the reactive rejuvenating system containing MDI, BUDGE and bituminous composition returning agent (MDI-BUDGEs) was applied in the rejuvenation of aged SMB. The results show that the rebuilt molecular structure of aged SBS can be obtained with the combination of MDI and BUDGE. Meanwhile, MDI-BUDGEs can improve the low-temperature ductility and inhibit the sharp fall of the softening point of aged SMB, while decrease the viscosity-temperature response at 120–165 °C. Also, MDI-BUDGEs can contribute for increasing the viscous component, improving the fatigue resistance and remaining the high-temperature performance grade of aged SMB, and moreover, decrease the limited elastic modulus and the elastic-plasticity transition rate to avoid the occurrence of the brittle failure within a small strain range.
研究领域:
道路工程材料
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高分子材料老化与修复
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沥青化学
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流变学
·
建筑材料耐久性
✓ 已验证
DOI
高影响因子
JOURNAL OF THE CHINESE CHEMICAL SOCIETY
·
2017
·Vol. 64
·期 4
·412-419
·
IF 0.935
Xiu-Yan Dong,Sunday Folaranmi Akogun,Wei-Min Zhou,Wen-Kui Dong
A new tetranuclear Zn(II) complex, [{Zn(L)(μ-OAc)Zn(H 2 O)} 2 ], based on an asymmetrical salamo-type bisoxime chelating ligand H 3 L (6-hydroxy-4′-chloro-2,2′-[ethylenediyldioxybis(nitrilomethylidyne)]diphenol) was synthesized and characterized by elemental analyses, differential thermal methods, single-crystal X-ray crystallography, and IR, UV–vis, and fluorescence spectra. The Zn(II) complex crystallizes in the triclinic system, space group P -1 with cell parameters a = 9.0742(6) Å, b = 11.8225(5) Å, c = 12.4182(8) Å, Z = 2, V = 1212.56(12) Å 3 , R 1 = 0.0572, and wR 2 = 0.1734. The environment of the tetranuclear Zn(II) complex is penta-coordinated having a slightly distorted trigonal bipyramidal geometry. Moreover, a 1D chain supramolecular structure is formed along the c -axis by the intermolecular C1–H1B⋯O14 hydrogen bonds; in the same manner, C2–H2C⋯Cg2 functions in the formation of supramolecular structures along the a -axis of the 1D chain. A 2D supramolecular structure along the ac plane extends infinitely under the force of intermolecular hydrogen bonds. Differential scanning calorimetry-thermogravimetry thermal analysis provides evidence of the coordination of Zn(II) atoms to the ligand H 3 L. The Zn(II) complex shows intense photoluminescence with a maximum emission at ~453 nm upon excitation at 360 nm.
研究领域:
无机化学
·
配位化学
·
超分子化学
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材料化学
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分析化学
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物理化学
·
晶体学
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2015
·
IF 4.494
Xuliang Lin,Xueqing Qiu,Duming Zhu,Zihao Li,Ningxin Zhan,Jieyi Zheng,Hongming Lou,Mingsong Zhou,Dongjie Yang
Effect of the molecular structure of lignin-based polyoxyethylene ether (EHL–PEG) on enzymatic hydrolysis of Avicel and corn stover was investigated. With the increase of PEG contents and molecular weight of EHL–PEG, glucose yield of corn stover increased. EHL–PEG enhanced enzymatic hydrolysis of corn stover significantly at buffer pH 4.8–5.5. Glucose yield of corn stover at 20% solid content increased from 32.8% to 63.8% by adding EHL–PEG, while that with PEG4600 was 54.2%. Effect of EHL–PEG on enzymatic hydrolysis kinetics of cellulose film was studied by quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM). An enhancing mechanism of EHL–PEG on enzymatic hydrolysis kinetics of cellulose was proposed. Cellulase aggregates dispersed by EHL–PEG excavated extensive cavities into the surface of cellulose film, making the film become more loose and exposed. After the maximum enzymatic hydrolysis rate, the film was mainly peeled off layer by layer until equilibrium.
研究领域:
生物质转化
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酶工程
·
高分子化学
·
表面科学
·
可再生能源
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY A
·
2011
·
IF 2.732
Min Xie,Yajing Qi,Yongjun Hu
2-Phenylethylamine (PEA) is the simplest aromatic amine neurotransmitter, as well as one of the most important. In this work, the conformational equilibrium and hydrogen bonding in liquid PEA were studied by means of Raman spectroscopy and theoretical calculations (DFT/MP2). By changing the orientation of the ethyl and the NH2 group, nine possible conformers of PEA were found, including four degenerate conformers. Comparison of the experimental Raman spectra of liquid PEA and the calculated Raman spectra of the five typical conformers in selected regions (550−800 and 1250−1500 cm−1) revealed that the five conformers can coexist in conformational equilibrium in the liquid. The NH2 stretching mode of the liquid is red-shifted by ca. 30 cm−1 relative to that of an isolated PEA molecule (measured previously), implying that intermolecular N−H···N hydrogen bonds play an important role in liquid PEA. The relative intensity of the Raman band at 762 cm−1 was found to increase with increasing temperature, indicating that the anti conformer might be favorable in liquid PEA at room temperature. The blue shift of the band for the bonded N−H stretch with increasing temperature also provides evidence of the existence of intermolecular N−H···N hydrogen bonds.
研究领域:
物理化学
·
光谱学
·
计算化学
·
分子结构
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）