有机小分子染料和聚阳离子分子超薄膜的制备及其摩擦学性能研究

制备了以有机小分子染料酸性红 1 8为阴离子、以聚烯丙基氯化铵和聚乙烯亚胺为聚阳离子的分子沉积膜 ,用紫外可见分光光度计、接触角测定仪和椭圆偏振光测厚仪对所制备的超薄膜进行了表征 .用DF PM型动 静摩擦系数精密测定装置考察了超薄膜的摩擦学性能 ,采用扫描电子显微镜对薄膜的磨痕表面进行了观察 .结果表明 ,所制备的超薄复合沉积膜具有良好的减摩和耐磨性能     

静电自组装铁电超薄膜及其性能研究

利用静电自组装方法在石英玻璃表面交替沉积聚二烯丙基二甲基氯化铵(PDDA)和聚偏氟乙烯(PVDF)超薄膜,制得PDDA/PVDF铁电复合超薄膜.通过石英晶体微天平实时监测超薄膜的沉积,研究了超薄膜的表面形貌、结构及电性能.结果表明,自组装每层PVDF超薄膜的厚度为7.5 nm;PDDA/PVDF铁电复合超薄膜的表面平整、均匀,其中C1s的光电子能谱与极化处理后充负电荷的PVDF铁电聚合物一致,但F1s由于溶解再组装过程而降低了0.3 eV;静电自组装材料纳米级的薄膜厚度和聚合物的络合作用导致了铁电复合超薄膜的非晶结构和高的表面电阻率.     

硅表面复合自组装膜的制备及其摩擦性能

采用自组装技术在单晶硅表面制备了3-氨基丙基三乙氧基硅烷(APTES)-SiO2-APTES复合膜,并对其表面的组成、结构及摩擦性能进行了表征.结果表明:复合膜表面对水的接触角约为63°,且表面平整、致密,其平均粗糙度(Ra)约为0.963nm.通过原子力显微镜(AFM)和透射电子显微镜(TEM)观察到夹层中SiO2颗粒的粒径约为20-50nm,较均匀地分布在第一层APTES膜的表面.与APTES自组装单层膜(SAMs)相比,APTES-SiO2-APTES复合膜由于纳米SiO2颗粒的引入而表现出更低的摩擦系数和更长的耐磨寿命.     

一种新型锂离子电池用聚合物电解质复合膜的制备和性能表征

阐述了一种新型锂离子电池用PVDF-HFP(聚偏氟乙烯-六氟丙烯聚合物树脂)基聚合物电解质复合膜的制备过程. 对复合膜中使用的无机TiO2纳米颗粒进行固体超强酸化处理, 并进行颗粒表面酸强度H0测试、XRD晶体结构分析以及复合膜的电解液吸附率测试和电化学阻抗谱测试. 采用PE无纺布支撑体作为增强材料, 以浸涂方法制备复合膜,并进一步组装为锂离子电池, 性能测试表明该电池具有良好的电化学性能.     

烧结型NdFeB永磁体表面有机纳米复合膜的制备及性能

采用自组装分子膜技术在烧结型NdFeB永磁体表面制备了三嗪硫醇三乙基硅烷(TES)自组装分子膜(TES-SAMs), 在TES-SAMs的基础上利用自主开发的有机镀膜技术制备了具有含氟官能团的三嗪硫醇(ATP)有机纳米复合薄膜(TES-ATP). 通过X射线光电子能谱仪(XPS)、傅里叶变换红外(FTIR)光谱仪、椭圆偏振光谱仪、原子力显微镜(AFM)和接触角测量仪对薄膜的表面状况进行评价, 使用UMT-2型摩擦磨损试验机研究TES-SAMs和TES-ATP的微摩擦学性能. 研究结果表明: TES-SAMs和TES-ATP的膜厚分别是5.08和29.78nm; 表面自由能从基体的73.13 mJ·m^-2下降到TES-SAMs的63.69 mJ·m^-2和TES-ATP复合膜的10.19 mJ·m^-2, 且TES-ATP复合膜对蒸馏水的接触角为123.5°, 成功实现了NdFeB表面由亲水到疏水的转换.TES-SAMs和TES-ATP均能有效降低摩擦系数, TES-SAMs的摩擦系数为0.22, TES-ATP的摩擦系数为0.12, 而基体的摩擦系数为0.71; 同时, TES-ATP还表现出良好的抗磨性能. TES-ATP复合膜为微机电系统中的摩擦磨损问题的解决提供了一种新思路.     

可修复纤维损伤的防霜和防雾聚合物复合膜

聚合物材料内部具有的微/纳米尺度的结构赋予了它们独特的功能.然而，聚合物材料在使用时不可避免地会遭受机械损伤，这会使得聚合物材料的微/纳米结构受到破坏，导致聚合物材料自身功能的丧失.为了解决上述问题，我们利用聚丙烯酸(PAA)与聚丙烯酰胺(PAAm)的嵌段共聚物(PAA-b-PAAm)和聚二烯丙基二甲基氯化铵(PDDA)形成的复合物溶液，通过提拉成膜，然后在25℃、相对湿度为～100%的环境中退火处理，制备了可修复纳米纤维损伤的防霜和防雾聚合物复合膜(PAA-b-PAAm/PDDA).亲水的PAA-b-PAAm/PDDA膜的纳米纤维结构可以增加水滴和膜表面的接触面积并促进膜对水分子的快速吸收，从而赋予了该膜优异的防雾防霜性能.得益于聚合物链间静电与氢键作用的动态性，PAA-b-PAAm/PDDA膜具有优异的自修复性能，不仅能修复宽度为几十微米的划痕，还能使断裂的纤维重新连接并恢复其原有的纳米纤维结构.     

表面修饰Ag_2S纳米微粒的合成及摩擦学行为研究

在水醇混合介质中,采用同阳离子共沉淀法合成了有机化合物表面修饰的Ａｇ２Ｓ纳米微粒,在高速钢基底上制备成膜,研究了它的摩擦学特性。结果表明：修饰后的Ａｇ２Ｓ纳米微粒粒径小,性能稳定,在有机介质中分散成透明溶液。ＡｇＤＤＰ膜和Ａｇ２Ｓ ＤＤＰ膜均可显著降低钢基底的摩擦系数。研究证实表面修饰Ａｇ２Ｓ纳米微粒的摩擦作用机制是在较低负荷下表面修饰层起主要作用,在较高负荷下Ａｇ２Ｓ纳米核起主要的承载和减摩抗磨作用。     

含氟聚合物修饰碳纳米管及其聚氨酯复合疏水膜的研究

利用羟基碳纳米管上的羟基与2-溴异丁基酰溴之间的简单反应, 在碳纳米管上引入了含溴ATRP引发剂, 并进一步引发含氟丙烯酸酯的ATRP聚合, 从而在碳纳米管表面接枝上了低表面能的含氟聚合物. 红外光谱(FT-IR)、热重分析(TGA)和透射电镜(TEM)的研究结果表明碳纳米管与含氟聚合物之间为化学键连接. 以此低表面能聚合物包裹的碳纳米管作为填充粒子, 采用溶液浇铸方法制备了聚氨酯/碳纳米管复合膜, 并利用溶剂四氢呋喃(THF)刻蚀表面获得了不同碳纳米管裸露程度的复合膜材料. 静态接触角测试结果表明, 无论是羟基碳纳米管还是低表面能修饰的碳纳米管均可提高其复合膜的疏水性能, 且其疏水性能随碳纳米管含量的增加而增加; 相同含量时, 含氟聚合物接枝后的碳纳米管使复合膜具有更佳的疏水性能, 膜表面经溶剂刻蚀后可显著提高其疏水性能. 采用扫描电子显微镜(SEM)研究了加入碳纳米管和溶剂刻蚀对聚合物表面微观结构以及材料表面疏水性能的影响. 上述结果表明: 利用接枝聚合物可改变碳纳米管本身的疏水性能, 并可进一步制备新型的具有表面疏水性能的聚合物纳米复合材料.     

铂钯修饰聚N-乙酰苯胺膜电极对甲酸的电催化氧化

由电化学方法在石墨电极表面制备了规整多孔的纳米结构聚N-乙酰苯胺(PAANI)膜,并以其为载体制备了Pt-Pd/PAANI/C二元金属微粒修饰的聚合物复合膜电极.SEM和XRD研究结果表明,Pt、Pd微粒在PAANI膜中均匀分散,有效地改善了催化剂中贵金属的分散度和电极的结构.在0.5mol/L H2SO4+0.5mol/LHCOOH溶液中的循环伏安结果表明,Pt-Pd/PAANI/C电极在酸性溶液中电催化氧化甲酸的性能明显优于直接电沉积的Pt-Pd/C电极,且表现出较高的稳定性.     

具有抗菌性能的载药复合微纳米纤维的制备及其结构和性能表征

利用静电纺丝技术制备了一种具有抗菌性能的氧化锌(ZnO)/聚乳酸(PLA)/聚己内酯(PCL)载药微纳米纤维膜,并通过扫描电子显微镜(SEM)、X射线衍射(XRD)和傅里叶变换红外光谱(FTIR)分别对复合膜的表面形态、元素组成和化学结构进行表征。通过抗菌实验评价了复合膜的抗菌性能,用紫外分光光度计测试复合膜在体外的药物释放行为。结果显示,以物理共混的方式将ZnO和氢溴酸高乌甲素(LAH)成功载入复合微纳米纤维;与PLA/PCL复合微纳米纤维膜相比,ZnO/PLA/PCL复合微纳米纤维膜表现出更好的抗菌效率。当ZnO含量为10%(wt)时,复合微纳米纤维膜具有最佳的抗菌性能;药物释放性能结果表明,ZnO/PLA/PCL复合微纳米纤维膜具有良好的药物缓释性能。     

TiO2/聚丙烯酸丁酯纳米复合膜的制备及摩擦性能

二氧化钛;TiO2/聚丙烯酸丁酯纳米复合膜的制备及摩擦性能     

仿贝壳结构的自组装纳米复合薄膜的制备、表征及摩擦学性能研究

利用超分子自组装方法在普通玻璃表面制备了仿贝壳有机-无机复合纳米薄膜 。采用X射线衍射仪、傅立叶红外光谱仪、X射线光电子能谱仪及透射电子显微镜等 对薄膜结构进行了表征。用动-静摩擦系数测定仪初步考察了其摩擦行为。结果表 明,这种薄膜具有机-无机有序交替的层状纳米复合结构,其聚合前的层间距为4. 20 nm, 聚合后的层间距为3.91 nm。聚合后的仿贝壳自组装纳米复合薄膜具有良好 的减摩性能。     

纳米Au-TiO2复合薄膜的溶胶-凝胶法制备、表征和性能

用溶胶-凝胶法制备了纳米Au-TiO₂复合薄膜.X射线衍射、X射线光电子能谱、原子力显微镜、紫外-可见光谱及摩擦磨损实验研究表明,复合薄膜均匀致密,Au以纳米晶粒形式均匀、不连续分散镶嵌于TiO₂基体中,纳米Au粒径为14～25nm;复合薄膜在可见光区有较强的吸收,吸收峰位置和强度与烧结温度和金的添加量有关;复合薄膜具有良好的抗磨减摩性能,在1N负荷下,摩尔分数为5%的Au-TiO₂薄膜的摩擦系数仅为0.09～0.10,耐磨寿命多于2000滑动周次.     

Characterization and tribological investigation of self-assembled trimethoxysilyl-functionalized poly(phthalazinone ether ketone)thin films on glass substrates

<正>Trimethoxysilyl-functionalized PPEK(PKGS) films had been designed to serve as wear resistant coatings for silicon surfaces. These surface films were formed by a dip-coating technique applied to self-assembled monolayers(SAMs).The formation and wetting behavior of PKGS films were characterized by means of contact angle measurement.The friction coefficient of the film prepared is very low(about 0.1),and the anti-wear behavior is good,with a lack of failure after sliding over 1800 s.     

Investigation of tribological properties of Al2O3-polyimide nanocomposites

Polyimide (PI) nanocomposites with different proportions of nanoparticle Al₂O₃ were made by compression molding at elevated temperature. The mechanical and tribological properties of the resulting PI-based nanocomposites were investigated. The bending strength and microhardness of the nanocomposite specimens were determined, and the tribological behavior of the nanocomposite blocks in dry sliding against a plain carbon steel ring was evaluated on an M-2000 friction and wear tester. The morphologies of the worn nanocomposite surfaces and transfer films on the counterpart steel ring were observed on a scanning electron microscope. Results indicated that the PI-based nanocomposites with appropriate proportions of nanometer Al₂O₃ exhibited lower friction coefficient and wear volume loss than PI under the same testing conditions. The nanocomposite containing 3.0wt.%–4.0wt.% nanometer Al₂O₃ registered the lowest wear volume loss under a relatively high load. The differences in the friction and wear behaviors of PI and PI–Al₂O₃ nanocomposites were attributed to the differences in their worn surface morphologies, transfer film characteristics, and wear debris features. The agglomerated abrasives on the worn composite and transfer film surfaces contributed to increase the wear volume loss of the nanocomposites of higher mass fractions of nanometer Al₂O₃.     

Assessment of surface damage characteristics of polymeric optical sheets of LCD backlight unit

The backlight unit of a liquid crystal display (LCD) consists of a set of vertically stacked polymeric optical sheets that may experience sliding motion when subjected to vibration. In this work, the surface damage characteristics of the optical sheets were assessed by conducting sliding tests between specimens sampled from the sheets. Surface morphology and hardness of the sheets were also measured using surface characterization tools. It was found that friction coefficient between the polarization film of the LCD panel and dual brightness enhanced film (DBEF) was the highest with a value of ∼0.35. Also, DBEF and diffusion plate suffered the most amount of surface damage. Based on the results of the wear tests, wear maps were constructed from which the relative degree of surface damage could be identified. It was determined that the friction and wear behavior of the polymeric sheets were influenced significantly by their surface morphology and hardness.     

Investigation of transfer film of PTFE/bronze composites on 2024Al surface

Polytetrafluoroethylene (PTFE) composites filled with 10–30% volume content of bronze powder were prepared through molding and sintering process. Transfer films of these composites were prepared on surface of 2024 Al bar through friction method under certain condition. Roughness, morphology, andelement of these transfer films were investigated using scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) methods. Tribological propertiesof these transfer films sliding against GCr15 steel ball were tested using a DFPM reciprocating tribometer. Worn surfaces were observed and analyzed using SEM and EDS methods. It was found that uniformity and continuity of the transfer films were obviously improved by the increase of bronze content of the composites. Transfer films with better uniformity and continuity holds longer wear life. Considerably lower friction coefficient and longer wear life of these transfer films indicate that the transfer films prepared in the experiment could effectively prevent direct contact of metal friction pair and thus protect them from heavy wear. SEM and EDS analyses of the worn surfaces indicate that adhesion wear and fatigue wear were main wear modes of the transfer film. Copyright © 2009 John Wiley & Sons, Ltd.     

Functionalized imidazolium wear‐resistant ionic liquid ultrathin films for MEMS/NEMS applications

As a kind of new material, ionic liquids (ILs) are considered a new type of lubricant for micro/nanoelectromechanical system (M/NEMS) due to their excellent thermal and electrical conductivity. However, so far, only a few reports have investigated the friction and wear of thin films of these materials at the micro scale. Evaluating the nanoscale tribological performance of ILs when applied as films of a few nanometers thickness on a substrate is a critical step for their application in M/NEMS devices. To achieve this purpose, IL thin films with four kinds of anions were synthesized and prepared on single‐crystal silicon wafers by the dip‐coating method. Film thickness was determined by the ellipsometric method. Their surface morphologies were observed by means of atomic force microscopy (AFM). The nano and micro tribological properties of the IL films were investigated by a friction force microscope (FFM)with a spherical probe and a UMT‐2MT tribotester, respectively. The corresponding morphologies of the wear tracks of the IL films were examined using a three‐dimensional non‐contact interferometric microscope. The impact of temperature on the adhesion behavior was studied, as well as the effect of sliding frequency and load on the friction coefficient, load bearing capacity and anti‐wear durability. It was found that friction, adhesion and durability of IL films were strongly dependent on their anionic molecular structures, wettability and ambient environment. Copyright © 2010 John Wiley & Sons, Ltd.     

Tribological properties of multilayer nanostructure TiO2 thin film doped by SiO2

Multilayer of TiO₂ and TiO₂:SiO₂ thin films were grown on a glass substrate by sol?Cgel processes, followed by high temperature treatment at 500?°C. The fine grained TiO₂ films controlled by SiO₂ dopant showed very good wear resistance and endurance life. Energy dispersive X-ray spectroscopy was used to indicate the elements in the films. X-ray diffraction analyses indicated that TiO₂ and TiO₂:SiO₂ film contain only anatase phase. The morphologies of the original and worn surfaces of the samples were analyzed by means of scanning tunneling microscope and scanning electron microscopy. The tribological properties of TiO₂ and TiO₂:SiO₂ thin films sliding against AISI52100 steel pin were evaluated on a pin on disk friction and wear tester. The results showed that 25-layer TiO₂:SiO₂ films are superior in reducing friction and resisting wear compared with the glass substrate.