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101.
The halogen-bonded complexes between H2Te/Me2Te and the dihalogen molecules XY (XY = F2, Cl2, Br2, I2, ClF, ClBr, BrF, BrCl, BrI, IF, ICl, IBr) have been studied to investigate the dependence of its strength and nature on the halogen donor X and its adjoining atom Y, as well as the methyl groups in the electron donor. The interaction energy varies between −1.7 and − 43.5 kcal/mol, indicating that the Te atom in H2Te/Me2Te has a strong affinity for the dihalogen molecules. For the H2Te-XY complex, the halogen bond is stronger for the heavier halogen donor X atom and the strong electron-withdrawing group Y. However, for Me2Te-XY, the halogen bond is stronger for the lighter halogen donor X atom. The H2Te/Me2Te-F2 complex has the largest interaction energy, although the σ-hole on F2 is the smallest in magnitude. In most of the complexes, the electrostatic and polarization contributions to the binding strength are similar in magnitude. However, for H2Te/Me2Te-F2, the polarization contribution is much larger than the electrostatic contribution, with a significant contribution from charge transfer. 相似文献
102.
Temperature‐dependent phase‐segregation behavior and antifouling performance of UV‐curable methacrylated PDMS/PEG coatings 下载免费PDF全文
Yunjiao Gu Shuxue Zhou Huali Luo Limin Wu Wei Gao Jinlong Yang 《Journal of Polymer Science.Polymer Physics》2016,54(16):1612-1623
Controllable phase segregation adjustment for immiscible polymer blends has always been tough, which hinders the development of amphiphilic antifouling coatings from more accessible blends. Herein, methacrylated poly(dimethylsiloxane) (PDMS‐MA) was synthesized and mixed with poly(ethylene glycol)methylether methacrylate (PEG‐MA). It was interestingly discovered that these PDMS‐MA/PEG‐MA blends displayed upper critical solution temperatures (UCST) due to thermo‐induced conformational change of PEG‐MA and the UCST changed with PDMS‐MA/PEG‐MA mass ratios. Micro‐/nano‐phase segregation, nanophase segregation, or homogenous morphology were therefore achieved. These PDMS‐MA/PEG‐MA blends with different mass ratios were UV‐cured under varying temperatures to fabricate coatings. Their surface morphology and wettability are readily adjusted by phase segregation. For the first time, highly hydrophilic surface was achieved for coatings with microphase segregation because of the exposure of PEG‐rich domains, which exhibited an enhanced protein resistance against bovine serum albumin (BSA). Anti‐bacterial performance (Shewanella loihica) was also observed for these PDMS/PEG coatings. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1612–1623 相似文献
103.
介绍了一个综合化学实验--功能聚合物表面的制备和化学修饰,及其教学思路。通过相分离法制备功能聚合物表面,探究不同溶剂组分对聚合物表面功能的影响,同时通过点击化学的方法对亲水表面进行修饰制备疏水表面,用静滴法测量表面接触角大小,并借助扫描电子显微镜对修饰前后的功能聚合物进行表征。结果显示,随着溶剂配方中1-癸醇的减少和环己醇的增加,亲水表面的接触角增大,疏水表面接触角减小,修饰过后的亲水表面表现出良好的疏水性能。该综合实验整合了大学化学基础知识、化学学术前沿以及实验基本技能,有利于培养学生的创新思维,提高综合能力。 相似文献
104.
Heba Shaaban 《液相色谱法及相关技术杂志》2018,41(4):180-187
In this work, a fast analytical method based on hydrophilic interaction liquid chromatographic-Ultraviolet detection (HILIC-UV) using a short narrow bore cyano-bonded silica column packed with fully porous sub-2?µm particles has been developed for simultaneous determination of eight pharmaceuticals in wastewater. The method involved pre-concentration and clean-up by solid phase extraction using Oasis HLB extraction cartridges. The analytes were separated using a mobile phase consisted of acetonitrile and 5?mM ammonium acetate buffer (95:5?v/v) with a flow rate of 0.6?mL/min. The chromatographic separation was optimized in order to achieve short analysis time and good resolution for all analytes in a single run. Each analyte was detected at its maximum wavelength for higher sensitivity. All analytes could be separated in 5.7?min with resolution ≥2.7. The optimized method was validated based on linearity, precision, detection and quantification limits, selectivity and accuracy. The detection limits of the studied pharmaceuticals ranged from 0.6 to 3?µg/L, while limits of quantification were in the range from 2 to 10?µg/L with UV detection. The developed method is fast, reliable, cost-effective and could be used for the analysis of the studied analytes in other matrices such as food, pharmaceutical preparations and biological fluids. 相似文献
105.
Seven series of polyimides have been analyzed and compared with regard to the correlation between their conformational rigidity parameters, such as the Kuhn segment, the characteristic ratio, the Van der Waals volume and free volume, and some physical properties, such as glass transition temperature, dielectric permittivity, and permeability to different gases. This review concentrates on the author's own work, placed in the context of the broader field. The conformational rigidity parameters were calculated by using the Monte Carlo method, while the values of physical properties were taken from published articles. 相似文献
106.
Dual‐responsive micrometer‐sized core‐shell composite polymer particles were prepared by dispersion polymerization followed by seeded copolymerization. Polystyrene (PS) particles prepared by dispersion polymerization were used as core particles. N‐isopropyl acrylamide (NIPAM) and methacrylic acid (MAA) were used to induce dual‐responsive that is thermo‐ and pH‐responsive properties in the shell layer of composite polymer particles, prepared by seeded copolymerization with PS core particles. Temperature‐ and pH‐dependent adsorption behaviors of some macromolecules on composite polymer particles indicate that produced composite polymer particles exhibit dual‐responsive surface properties. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
107.
E. B. Melnikova M. M. Elchaninov A. A. Milov B. S. Lukyanov 《Chemistry of Heterocyclic Compounds》2008,44(9):1070-1076
The electrophilic reactions (nitration, bromination, hydroxymethylation, formylation, acylation) and radical substitution
reactions (nitration, arylation) of 2-(2-furyl)benzothiazole have been studied. It was found that all of the reactions occur
at position 5 of the furan ring. Only nitration in PPA gave the 5',6-dinitro derivative. Quantum-chemical calculation data
for the electron density distribution in the neutral and protonated 2-(2-furyl)benzothiazole molecules are given.
Dedicated to Boris Aleksandrovich Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1331–1338, September, 2008. 相似文献
108.
采用分步悬浮聚合法制备了由大孔聚二乙烯基苯和聚丙烯酸甲酯组成的聚合物互贯网络(Interpenetrating polymer networks IPN),经过乙二胺氨解,得到由疏水性的大孔聚二乙烯基苯和亲水性的聚丙烯酰乙二胺组成的聚合物互贯网络(polydivinylbenzene/polyacrylethylenediamine IPN即PDVB/PAEM IPN),测定了合成的IPN的物理和化学结构,研究了PDVB/PAEM IPN对pH 6.5的水溶液中双酚A (Bisphenol A即BPA)的吸附性能.结果表明,合成的PDVB/PAEM IPN是含有氨基和酰胺基的多孔性IPN;树脂对水溶液申双酚A的等量吸附焓在20kJ/mol~50kJ/mol之间;动态吸附及脱附实验表明,湿态PDVB/PAEM IPN树脂对水溶液中双酚A的饱和吸附量达到约30mg/mL.树脂可以通过乙醇再生. 相似文献
109.
Bing-Chang Tan Qian Wang Long-Long Jiang Ying Song Prof. Xin-Tao Wu Prof. Tian-Lu Sheng 《欧洲无机化学杂志》2023,26(12):e202300003
To investigate the effect of ligand remote (>10 Å) substituents on the bridging metal center on the metal-to-metal charge transfer (MMCT) properties in cyanidometa-bridged complexes, a series of new cyanidometal-bridged complexes and their one-electron and two-electron oxidation products have been synthesized and well characterized (namely, trans-[Cp(dppe)Fe−NC−(L)Ru(PPh3)−CN−Fe(dppe)Cp][PF6]n (n=2, 3, 4) (L=dmptpy, 1[PF6]n ; L=meoptpy, 2[PF6]n ; L=t-Buptpy, 3[PF6]n ) (Cp=1,3-cyclopentadiene, dppe=1,2-bis(diphenylphosphino)ethane, PPh3=triphenylphosphine, dmptpy=4′-(4-dimethylaminophenyl)-2,2′,6′,2′′-terpyridine, meoptpy=4′-(4-methoxyphenyl)-2,2′,6′,2′′-terpyridine, t-Buptpy=4′-(4-tertbutylphenyl)-2,2′,6′,2′′-terpyridine)). The investigations suggest that the cyanido-stretching (νCN) vibration energy for the complexes is unsensitive to the electron-donating ability change of the remote substituents of the cyanidometal bridging auxiliary ligand from tertbutyl, methoxy to dimethylamino group. However, the MMCT energies of the one- and two-electron oxidation complexes are still sensitive to the remote substituents of the ligand on the bridging metal center, and decreases with the increase of the electron-donating ability of the remote substituents from tertbutyl, methoxy to dimethylamino group. All one-electron and two-electron oxidation products belong to Class II mixed valence compounds according to the classification of Robin and Day. 相似文献
110.
Quantification of a mixture of peptides in solution was achieved by disposable patterned hydrophilic chip based matrix-assisted laser desorption/ionization mass spectrometric imaging(MALDI MSI).Compared with other quantitative methods for peptides in solution, this method is label-free and does not require separation of the multiple components of the solution before analysis. Uniform hydrophilic spots and high mass accuracy measurements provided confident identification and quantitative analysis of imaged compounds. The linear correlation between concentration and grayscale of image in the range of 5 fmol/μ L to 1 pmol/μ L was obtained for all four peptides. Good sensitivity and excellent reproducibility were also achieved. The method expands the application of MALDI MSI from tissues to solutions. 相似文献