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1.
缔合溶液具有与理想溶液显著不同的热力学和谱学性质,对于热力学和谱学的研究,有助于我们理解缔合溶液的特殊行为.谱学技术中核磁共振(NMR)、红外(IR)和拉曼(Raman)光谱是研究分子间相互作用和溶液结构等微观性质的有效方法,谱学已成为分子热力学研究体系"四面体结构"中的第四个顶点.本文对缔合溶液中热力学(汽液平衡和焓)和谱学(NMR,IR和Raman)联系的最新研究进展进行了综述,着重介绍相关的模型,如化学缔合模型、局部组成(LC)、格子流体氢键(LFHB)理论以及统计缔合流体理论(SAFT).  相似文献   

2.
利用有机氟改性环氧树脂是提高环氧树脂综合性能的有效途径。目前含氟环氧树脂已经成为学者研究的重点。文章扼要综述了有机氟对改善环氧树脂的表面性能、耐热性能、介电性能、耐摩擦性能及阻燃性能的最新研究进展。展望了有机氟改性环氧树脂的发展趋势。  相似文献   

3.
纳米晶体材料研究进展   总被引:25,自引:0,他引:25  
综述了目前纳米晶体材料合成、结构、性质和应用的研究和发展现状。通过惰性气体凝结、机械合金、等离子体技术和其他许多方法可以制得纳米晶体材料。尽管早期的研究者认为纳米晶体材料的晶粒边界结构不同于常规材料, 但目前有关纳米晶体材料结构的研究表明其具有与常规晶体材料相同的晶粒边界结构。纳米晶体材料所具有的诸如扩散和烧结、力学、陶瓷和金属间化合物的延展性、电学、热膨胀、光学、磁学、催化和腐蚀行为等性质优于常规多晶材料, 这些性质具有巨大的潜在应用价值。  相似文献   

4.
The incorporation of comonomers during ethylene polymerization can efficiently modulate important material properties of the polyolefins. Utilizing bioresourced comonomers for the generation of high-performance polyolefin materials is attractive from a sustainability point of view. In this contribution, bioresourced eugenol and related comonomers were incorporated into polyolefins through palladium-catalyzed copolymerization and terpolymerization reactions. Importantly, high-molecular-weight catechol-functionalized polyolefins can be generated. The introduction of different metal ions induces efficient interactions with the incorporated catechol groups, leading to enhanced mechanical properties and self-healing properties. Moreover, the catechol functionality can greatly improve other properties such as surface properties, adhesion properties, and compatibilizing properties. The catechol-functionalized polyolefin was demonstrated as a versatile platform polymer for accessing various materials with dramatically different properties.  相似文献   

5.
醛酮类化合物的分子力场参数推导及热力学性质计算   总被引:1,自引:0,他引:1  
王玲  李晓锋  赵立峰  孙淮 《化学学报》2009,67(23):2669-2677
针对醛酮类分子, 基于第一原理的量子化学计算结果开发了准确、可迁移的全原子力场. 利用所得到的力场, 采用分子动力学和蒙特卡罗方法对醛酮类分子的气相分子结构、振动频率、构象能和凝聚相液体性质(密度和蒸发焓), 以及流体的多种热力学性质包括气液相平衡和临界性质, 与涨落相关的等压热容, 传递性质如剪切粘度等进行了计算和预测. 计算结果表明, 该力场可准确地反映气相分子的结构、振动频率、构象能和凝聚相液体密度和蒸发焓等性质, 并准确地预测一系列醛酮类分子的多种热力学性质. 所开发的醛酮类分子力场函数形式简单, 并具有良好的可迁移性和准确性, 在应用范围和计算精度上都有明显的改善和提高.  相似文献   

6.
The incorporation of comonomers during ethylene polymerization can efficiently modulate important material properties of the polyolefins. Utilizing bioresourced comonomers for the generation of high‐performance polyolefin materials is attractive from a sustainability point of view. In this contribution, bioresourced eugenol and related comonomers were incorporated into polyolefins through palladium‐catalyzed copolymerization and terpolymerization reactions. Importantly, high‐molecular‐weight catechol‐functionalized polyolefins can be generated. The introduction of different metal ions induces efficient interactions with the incorporated catechol groups, leading to enhanced mechanical properties and self‐healing properties. Moreover, the catechol functionality can greatly improve other properties such as surface properties, adhesion properties, and compatibilizing properties. The catechol‐functionalized polyolefin was demonstrated as a versatile platform polymer for accessing various materials with dramatically different properties.  相似文献   

7.
8.
The properties of substituents have long been quantified by their effect elsewhere in a molecule. Ideally, intrinsic properties detailing the true properties of a substituent would be used. These properties are ideally transferable between molecules, to be robust and applied in different situations. Through a study on the bond critical point (BCP) properties of 117 substituents and 17 substrates we find that BCP properties from the quantum theory of atoms in molecules are not transferable between different bonded atoms. However, a substituent's changing electronegativity between substrates help quantify the observed variation. The relationship between changing electronegativities and critical point properties enables development of a relationship to predict critical point properties between a substituent and a new substrate, using only the electronegativity of a substituent attached to hydrogen, and the critical point property between the substituent and H.  相似文献   

9.
玻璃微珠填充改性聚合物研究进展   总被引:3,自引:0,他引:3  
玻璃微珠作为一种新型的刚性粒子 ,除了对于聚合物的增强增韧作用 ,在许多方面都已引起聚合物改性工作者的关注。本文从玻璃微珠对聚合物的增韧效果 ,玻璃微珠填充聚合物的拉伸性能、动态力学性能、流变形能、界面以及其他性能等方面综述了近年来玻璃微珠填充改性聚合物的研究进展  相似文献   

10.
In this work we analyze correlations for the maxima of products of some liquid–vapor saturation properties. These points define new characteristic properties of each fluid that are shown to exhibit linear correlations with the critical properties. We also demonstrate that some of these properties are well correlated with the acentric factor. An application is made to predict the properties of two new low global warming potential (GWP) refrigerants.  相似文献   

11.
硒芳香杂环化合物的光谱和电化学性质   总被引:3,自引:0,他引:3  
用紫外光谱,荧光光谱和循环伏安法研究了含硒芳香杂环化合物(苤硒脑)在不同溶剂中的谱学和电化学性质,对不同分子结构或取代基的苤硒脑化合物的性质进行了比较,并初步探讨了溶剂对苤硒脑化合物谱学性质的影响规律。  相似文献   

12.
含氟聚酰亚胺的研究进展   总被引:8,自引:1,他引:7  
综述了含氟聚酰亚胺研究的新进展,介绍了含氟单体,聚合物合成方法及主要性质。着重介绍了含氟聚酰亚胺的物理化学性质,光学和电学性能以及气体选择透过性。同时简述全氟代聚酰亚胺的合成,性能及应用前景。  相似文献   

13.
The ionic strength has significant effects on the thermodynamic properties of ionic species and on the transformed thermodynamic properties of biochemical reactants at specified pH values. These effects are discussed for species, reactants, and enzyme-catalyzed reactions. This has led to three new thermodynamic properties: (z(j)(2) - NH(j)), (z(2) - N(H))(i), and Delta(r)(z((2)-N(H)), which are referred to as ionic strength coefficients. The first of these is a property of a species, the second is a property of a reactant, and the third is the property of an enzyme-catalyzed reaction. The effects of ionic strength on standard thermodynamic properties of species, standard transformed thermodynamic properties of reactants, and standard transformed thermodynamic properties of enzyme-catalyzed reactions are proportional to these new thermodynamic properties.  相似文献   

14.
In additive manufacturing, polymer composites are used for setting tailored properties. Short glass fibers can be used as fillers for polyamide 12 for enhancing stiffness or tensile strength as well as for reducing shrinkage. In this paper, the effects of short glass fibers on polyamide 12 concerning powder properties, process behavior and part properties in laser beam melting of polymers (SLS) are investigated. It could be shown that by increasing the short glass fiber content powder properties as well as part properties are immensely affected. By adding glass fibers, powder properties, like flowability and diffuse reflection decrease. The isothermal crystallization changes resulting in a narrower processing window. Concerning mechanical properties, short glass fibers allow for a higher stiffness until a critical limit of filler concentration within this study is reached, after which the tensile strength decreases. The elongation of break decreases by rising the filler content.  相似文献   

15.
共聚酯PEIT-PEG结晶性能的研究   总被引:3,自引:0,他引:3  
通过偏光显微镜、广角X衍射与FTIR三种测试手段对共聚酯PEIT-PEG的结晶性能进行了系统的研究,重点分析了间苯二甲酸(IPA)、聚乙二醇(PEG)分子量和含量对共聚酯结晶性的影响。研究表明,PEIT与PEG之间发生了共聚反应,IPA的引入使PET结晶性能下降,晶粒尺寸减少,结晶度降低。引入PEG后,当PEG分子量和含量较低时,共聚酯结晶性能提高;当PEG含量较高时,在PEG分子量不变的情况下,随着PEG含量的增加,结晶性能下降;若PEG重量含量相同,PEG分子量越高,结晶性能越好。  相似文献   

16.
Transition metal oxide clusters with unsaturated carboxylate ligands bonded to their surface were polymerized in the presence of organic co-monomers by various polymerization techniques to form cluster-reinforced polymers. The properties of the cluster-crosslinked hybrid polymers are distinctly different to those of the parent polymers and originate from both crosslinking and filler effects. Variation of the cluster proportion, the kind of employed cluster, the ratio of functional and non-functional capping ligands and the polymerization conditions allows modifying the materials properties of the hybrid materials. The most important changes in materials properties compared with the cluster-free polymers relate to the swelling behavior, thermal stability and mechanical properties. Furthermore, cluster-specific properties can be introduced into the polymers, such as magnetic properties.  相似文献   

17.
As a result of environmental concern, there is an increasing interest in the development of biodegradable polymers for packaging with suitable properties, as an alternative to the synthetic petroleum‐based polymers. However, such biodegradable polymers are prevented for use in wide industrial and commercial packaging because of their limited gas and vapor barrier properties. This obstacle urges innovative strategies to achieve enhanced gas barrier properties using “bio‐layering” technologies. Whey protein isolate (WPI), a by‐product of the cheese industry, has quite promising properties for packaging purposes. It possesses good oxygen, aroma, and oil barrier properties; however, its permeability to water vapor is high. In this study, several WPI coatings were obtained, adding polyvinyl alcohol and pectin to improve the coated film properties; in addition, nanoclays were used to improve water vapor barrier properties. Comparison of neat poly (lactic acid) film versus poly (lactic acid) coated with WPI presented advantage of the later: improvement of about 90% in the oxygen barrier properties and about 27% in the water vapor barrier properties. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

18.
研究了带有不同取代基的显影促进基团对DAR成色剂照相性能的影响.通过比较3个母体及吸附基团相同而显影促进基团不同的DAR成色剂的照相性能,发现不同酰基取代的显影促进基团对DAR成色剂的照相性能有较大的影响,其中带三氟乙酰基取代的显影促进基团的DAR成色剂的照相性能最佳.  相似文献   

19.
偶联剂对TATB造型粉表面性质及力学性能的影响   总被引:2,自引:0,他引:2  
采用偶联技术制备TATB造型粉,研究了偶联剂加入前后TATB造型粉的表面行为及其力学性能。结果表明采用偶联技术能够改善TATB造型粉的力学性能和氟橡胶对TATB的粘附。其中,KH550是一种较为理想的改善TATB造型粉性能的偶联剂。  相似文献   

20.
Insects represent a rich source of protein and a more sustainable alternative to conventional animal sources. Insect proteins are diverse in amino acid composition, structure, and physicochemical and functional properties. Processing treatments cause changes in properties of insect proteins and protein-enriched fractions of varying purity, affecting their techno-functional properties and the possible application range. This review discusses recent findings on the effect of processing techniques on the techno-functionality of insect protein fractions including solubility, foaming, emulsifying, and gelling properties. It is demonstrated that a treatment type and its intensity alter physicochemical and functional properties to different degrees. The review also shows the potential for the production of insect-derived food ingredients with tailored functional properties using the diversity of available processing methods.  相似文献   

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