机械化学及其应用

简要介绍了机械化学及其重要分支摩擦化学的基本特征和物理过程，在无机及有机合成化学领域中的典型应用，并强调了摩擦化学在润滑，节能和国民经济建设上的重要作用。     

摩擦化学研究中的类比性分析

作为机械学与化学交叉学科的摩擦化学,它的分析方法和知识体系具有其组成学科的显著特征。借用辩证类比方法尝试分析摩擦化学研究的三则案例,为摩擦化学研究提供方法和知识。     

摩擦化学过程及其模型

本文介绍了与工程技术特别是高技术关系密切的摩擦化学过程.对比了力学激励和热激励所导致的化学反应的差别.介绍了摩擦化学这一学科的形成和定义,研究对象及常用方法.对目前比较流行的“热点”模型和“变形”模型的根据和物理实质及各自的缺点做了阐述和分析.     

仿生干湿摩擦黏附器件的研究进展

生物在自然界的演化过程中进化出了许多独特的干湿摩擦、黏附器官来适应其生存环境.研究人员通过对自然界中典型摩擦与黏附现象的研究、认识和总结,提出了相应的仿生界面摩擦、黏附理论与模型,用于指导人工合成型智能摩擦黏附材料与器件.目前,仿生摩擦、黏附材料体系与器件的设计策略主要以表面微结构、界面物理化学相互作用以及机械形变为基...     

俄歇化学位移及其在表面化学上的应用

从俄歇电子激发过程讨论了化学位移和元素化合价以及电负性的关系, 提供了常用元素在不同化合物中的俄歇电子动能及化学位移数据, 运用俄歇化学位移研究了氧在锌表面的吸附和初始氧化反应, Ti/SiO_2的界面固相反应机理以及摩擦过程中润滑膜的组成和结构.     

过碱烷基酚钙与二烷基二硫代磷酸锌复配形成摩擦膜的表征

利用X射线吸收精细结构光谱(XANES)研究了过碱硫化烷基酚钙与二烷基二硫代磷酸锌(ZDDP)复配使用时对ZDDP形成摩擦膜的表面化学行为的影响, 并提出了其和ZDDP的相互作用机制. 结果表明, 在ZDDP中加入过碱硫化烷基酚钙后完全改变了ZDDP单独使用时形成摩擦膜的结构, 摩擦膜中含有一定数量的钙离子, 其结构以磷酸钙为主; 对较高碱值的过碱硫化烷基酚钙, 在高浓度下使用时, 在摩擦膜形成的同时观测到碳酸钙颗粒的沉积. 此外, ZDDP和过碱硫化烷基酚钙共同使用时形成的摩擦膜厚度减小. 摩擦膜特性的改变是ZDDP和过碱硫化烷基酚钙复配体系抗磨性能变差的主要原因.     

铁铬合金摩擦破损微电偶的形成及作用

本文分析，研究了１Ｃｒ１８合金材料在０．２ｍｏｌ．Ｌ＾１Ｈ２ＳＯ４溶液中的摩擦腐２蚀过程中产生微电偶腐蚀的可能性及原因，并研究了微电偶对摩擦电化学行为的影响，研究结果表明：由于摩擦过程造成材料表面的电化学不均一性是产生微电偶作用的真正原因。未摩擦表面与摩擦表面的面积比显著地影响了摩擦电偶电位和摩擦电偶电流的大小。     

含酯基苯并噻唑衍生物的摩擦膜及热膜化学结构

制备了两种苯并噻唑衍生物2-苯并噻唑基-巯基硫代乙酸正辛酯(MBTT)和2-苯并噻唑基-巯基乙酸正辛酯(MBTA), 并用元素分析和核磁共振谱表征其分子结构. 用X光吸收近边结构谱(X-ray absorption near edge structure, XANES)全面地分析了杂环化合物在矿物油和菜籽油中所形成的摩擦膜和热膜的化学态. 分析结果表明, 在矿物油中, 添加剂MBTT和MBTA摩擦反应生成的摩擦膜主要由FeS2组成, 而菜籽油中, 两种添加剂摩擦反应生成的摩擦膜由FeSO4组成; 在两种基础油中, 两种添加剂生成的热膜都是由FeSO4组成的.     

红外及相关技术在盐湖化学中的应用

在硼酸盐化学、盐湖材料化学及成盐元素化学研究中，由于红外及相关联用技术的应用而取得了很大进展。此文对近年来我国在盐湖化学研究工作中应用红外及相关联用技术的工作进行了综述，对红外新技术在盐湖化学中的应用前景进行了展望。共引用文献65篇。     

X射线光电子能谱技术在高分子材料摩擦化学研究中的应用

X射线光电子能谱技术(XPS)是材料表面分析的重要手段,其近年的快速发展促进了表面化学领域研究的深入.高分子及其复合材料在摩擦学性能方面具有普遍的优势,通过XPS对高分子及其复合材料摩擦表面的分析,可以确定摩擦过程的化学变化,并对改进材料的摩擦学性能起到理论的指导作用.作者主要介绍XPS技术的基本原理,及其在高分子与复合材料摩擦学性能研究中的应用.     

Spectroscopic studies of some novel CuI and CuII complexes derived from the tribochemistry reactions of Kbr, KI and CaI2 with CuII-Girard's T complex [Cu(GT)Cl2(H2O)2(EtOH)]Cl.H2O

Novel CuI and CuII complexes derived from the tribochemistry reactions of [Cu(GT)Cl2(H2O)2(EtOH)Cl.H2O with KBr, KI and CaI2 have been isolated and characterized. The reactions of KI and CaI2 with [Cu(GT)Cl2(H2O)2(EtOH)]Cl.H2O in the solid state are accompanied by colour change, reduction of CuII to CuI and substitution of the chloride by iodide ions. Also, the tribochemistry reaction of KBr with the CuII-GT complex is accompanied by change in colour, substitution of chloride by bromide ions but no reduction has been occurred. All the isolated solid complexes have been characterised by spectral (UV-vis, IR, 1H-NMR), magnetic and thermal measurements. The effect of the variation of the ratio between alkali and/or alkaline earth metal halides (KI, KBr, and CaI2) and the CuII-GT complex has also been investigated.     

Braking Performance of an Organic Brake Pad Based on a Chemically Modified Phenolic Resin Binder

An organic brake pad for railroad passenger-coach braking was prepared using a chemically modified phenolic resin (PF), that was designed and manufactured in our laboratory. The braking performance of the pad was investigated on a full-scale test bench. For comparison, a brake pad based on straight PF was also prepared and investigated. The results showed that the modified PF pad possessed much higher impact strength, and better braking stability and wear resistance than the straight PF pad. It is thought that the better overall properties of the modified PF pad resulted from the changes in chemical structure of the resin during the frictional process and the strong interreaction of the modified resin binder with the hybrid fibers.     

Spectroscopic studies of complex compounds derived from the tribochemistry reactions of KBr and HgX2(Cl, Br, I, CN) with crown ethers (DC18C6 and DB18C6)

Several new K and Hg(II) complexes derived from crown ethers (DC18C6, DB18C6) have been prepared by tribochemistry reactions. The isolated solid complexes have been characterized by I.R. spectral measurements. The isolated solid complexes are compared with the corresponding metal complexes prepared in solution. Also, the IR and NMR spectra of the solid complexes have been used to determine the strength of bond between Hg(II) ion and the crown ether.     

Tribological behavior of the low-concentration boric acid and ZDDP lubricating oil mixtures

Zinc dithiophosphate (ZDDP)-free environmental friendly lubricating oil research studies have gained importance due to the governmental regulations over the last decade. In this study, low concentration boric acid-base oil and ZDDP-base oil mixtures were investigated with a ball on flat reciprocating tribometer to evaluate their tribological performances. The tribological performances of 1, 3, and 5% additive and base oil mixtures were evaluated at boundary lubrication condition in three main contexts including wear rates, surface tribochemistry, and friction. Results showed that there was no significant difference between boric acid and ZDDP friction coefficients. However, boric acid showed poor wear resistance when compared with ZDDP and it cannot be an alternative additive alone to ZDDPs.     

Effects of atomic oxygen irradiation on structural and tribological properties of polyimide/Al2O3 composites

To understand the effects of atomic oxygen (AO) irradiation on the structural and tribological behaviors of polymer composites, polyimide/Al₂O₃ composites were irradiated with AO in a ground‐based simulation facility. The structural changes were characterized by X‐ray photoelectron spectroscopy and attenuated total‐reflection FTIR, whereas the tribological changes were evaluated by friction and wear tests as well as scanning electron microscopy analysis of the worn surfaces. It was found that AO irradiation induced the oxidation and degradation of polyimide molecular chains, which increased the O concentration and decreased the C concentration in the composite surfaces. The destruction action of AO changed the surface chemical structure and morphology of the samples. Friction and wear tests indicated that AO irradiation decreased the friction coefficient but increased the wear rate of both pure and Al₂O₃ filled polyimides. In terms of the tribological properties, appropriate content of Al₂O₃ might be favorable for the improvement of tribological properties in AO environment. Copyright © 2011 John Wiley & Sons, Ltd.     

The effect of interface electrostatic interaction based on acid–base theory on friction behavior

Fluorine‐containing amorphous carbon films [fluoring‐containing diamond‐like carbon (F‐DLC)] were fabricated on Si wafer by direct current plasma enhanced chemical vapor deposition (dc‐PECVD) technique using CF₄ and Ar as gas sources, confirmed by XPS and Raman analyses. The friction tests were carried out on a rotating ball‐on‐disk apparatus in high vacuum atmosphere (≤5.0 × 10^?4 Pa) at the load of 0.5 N selecting glass (mainly containing silicon–oxygen tetrahedron structure) and Al₂O₃ with the same hardness and surface roughness as the counterpart balls. The results indicate that glass/F‐DLC results in lower friction coefficient of 0.14 than that of the Al₂O₃/F‐DLC (0.20). At the same time, no wear was occurred, and the transfer layer was not formed on the counterpart ball for glass/F‐DLC, while the wear of Al₂O₃/F‐DLC is slightly larger than that of glass/F‐DLC. However, just like the glass ball, there is no formation of transfer layer on the Al₂O₃ ball surface. Furthermore, the chemical state of fluorine in the film after friction, which mainly existed in the form of the C–CF and C–F bonds, did not change compared with the F‐DLC film, while the fluorine content has changed significantly. As a result, it is assumed that interface electrostatic interaction based on acid–base theory plays an extremely important role in the process of friction. Copyright © 2017 John Wiley & Sons, Ltd.     

Chemical modification on UHMWPE microparticles to improve the interfacial and tribological properties of UHMWPE/carbon fabric/phenolic laminate in water environment

Carbon fabric (CF)/phenolic laminates filled with pristine and chromic acid treated ultra high molecular weight polyethylene (UHMWPE) microparticles were fabricated. Their interfacial and tribological properties in water environment were comparatively investigated. The interlaminar shear strength (ILSS) of the laminates was tested on a universal testing machine (DY35), and the tribological properties were evaluated by a block‐on‐ring tribo‐tester. The worn surfaces and the interfaces of the laminates were respectively analyzed by scanning electron microscope (SEM) and field emission SEM (FESEM). The change of the chemical composition of UHMWPE microparticles after chromic acid etching was analyzed by Fourier transform infrared spectroscopy (FTIR). The chemical state of carbon fiber surface was examined using X‐ray photoelectron spectroscopy (XPS). The results revealed that the chromic acid treated UHMWPE microparticles had more remarkable effect than the pristine ones on improving not only ILSS and wear resistance of CF/phenolic laminate, but also its immunity to water environment. This should be attributed to the strengthened interfaces in treated UHMWPE/CF/phenolic laminate, which were characterized by the drawn dendritic UHMWPE fibrils firmly clinging on the surfaces of carbon fibers and resin in a Boston ivy‐like manner. Copyright © 2015 John Wiley & Sons, Ltd.     

Influence of carbon content on physicomechanical characteristics of boron carbide

Temperature and amplitude dependences of dynamic shear modulus (SM) and of internal friction (IF) have been measured on boron carbide samples with different carbon content. The samples were investigated at frequencies of torsion oscillations from 0.5 to 5 Hz and at amplitudes of oscillatory deformation from 5×10⁻⁶ to 1×10⁻² at temperatures from 80 to 1000 K. It was shown that absolute values of SM, of critical amplitudes of oscillatory deformation and of shear elastic limit decreased with the decrease of carbon content in the samples. Simultaneously, activation energy of the intensive relaxation-type IF in the vicinity of 450-470 K was also decreased. Cyclic deformation at 1000 K provided additional decrease to physicomechanical characteristics while at annealing in vacuum at the temperatures of 1273 and 1773 K these structure-sensitive properties significantly increased. The observed changes of physicomechanical characteristics were attributed to possible changes of inter-atomic forces in the structure of boron carbide samples.     

Polymers on snow: Toward skiing faster

In this study, small-scale model skis running down a Nordic ski track were used to investigate the tribological properties of polymer ski soles of a wide range of chemical compositions and surface structures on snow at temperatures of −2 to −4 °C. It was found that ski soles consisting of smooth hydrophilic films of an arithmetical mean surface roughness of less than 0.2 μm experience a considerably higher friction with snow than flat hydrophobic films indicating that for such soles, capillary bridging of the lubricating water film between the snow and the ski base is the dominating friction mechanism. An optimum surface roughness of the ski soles was detected —in the range of 0.2–1 μm. At this surface roughness, sliders are always fast, essentially independent of chemical composition of the ski sole and surface topology. At higher surface roughness, it was found that friction between polymer and snow increases again, especially for structured surfaces that are not aligned in the gliding direction. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1543–1551, 2010