硅烷化金属表面处理的研究进展及展望

金属表面硅烷化处理被认为是一种新型环保型的金属表面处理技术,使金属具有较好的耐腐蚀性,有望取代传统的磷化和铬酸盐钝化.本文综述了金属表面硅烷化处理的研究进展,并对目前研究中存在的问题进行了分析,展望了今后重点的研究方向.     

金属表面用硅烷处理液的制备工艺及表征

研究了一种金属表面硅烷化处理液制备工艺,并对该处理液以及经过处理后钢表面薄膜进行了分析和评价。结果表明:此工艺所得硅烷处理液的性能优良,能够在长时间内具有较好的稳定性及防腐效果。这一结果对开展金属表面硅烷化处理以及相应处理液研究均具有参考价值。     

金属表面硅烷化防护处理及其研究现状

综述了一种新型的金属表面防护处理技术--硅烷化处理的研究现状.对硅烷膜的制备工艺、表征及膜覆盖电极的性能进行了详细介绍.文中也同时探讨了硅烷溶液的水解与失效问题,这两个基础问题的研究有助于了解金属表面硅烷膜的形成,并对制备工艺的优化起到决定性作用.最后还介绍了更具发展潜力的电沉积制备硅烷膜技术并提出了展望.     

冷轧钢表面磷化膜和硅烷膜的制备与性能

通过在冷轧钢表面进行磷化处理和硅烷化处理,应用极化曲线、硫酸铜点滴和盐水全浸泡测试其耐蚀性能,并对其与有机涂层间的结合力进行评价。结果表明,经硅烷化处理形成的硅烷膜耐蚀性能及与有机涂层间的结合力明显优于未处理的磷化膜。扫描电子显微镜(SEM)显示磷化膜的结构较为疏松,而γ-(甲基丙烯酰氧)丙基三甲氧基硅烷膜表面致密均匀。     

硅烷增强镁合金防腐有机涂层的研究

为了提高镁合金的耐腐蚀性能,结合硅烷处理和胶粘涂层技术在AZ31镁合金表面制备了环氧防腐涂层。通过扫描电镜对涂层表面形貌进行观察,采用划格法、浸泡法及盐雾试验等分析镁合金表面硅烷处理对有机涂层的附着力及耐蚀性的影响。研究结果表明：采用KH-550型硅烷进行处理后,镁合金基体与有机涂层之间形成化学键,涂层与基体结合牢固,附着力为1级,耐饱和盐水23d不起泡。硅烷处理明显提高了有机涂层对基体的附着力和耐蚀性,因此,硅烷＋胶粘涂层的方法可用于镁舍金的表面防腐。     

乙烯基三乙氧基硅烷(VS)水解关键工艺

采用硅烷偶联剂对金属进行预处理是一种新型、环保的表面处理工艺,可以显著提高涂层的结合力及金属耐蚀性能,有望替代传统的磷化和钝化处理,而水解过程是决定金属表面硅烷化预处理好坏的关键。采用反射吸收红外光谱法研究了温度、pH、醇水比及硅烷体积分数等关键因素对乙烯基三乙氧基硅烷水解的影响,确定了水解液中获得最多硅醇单体时的水解工艺参数;在一定温度范围内,硅烷溶液水解程度随着水解温度的升高而增大;通过比较si-O-Fe与si-O-si峰强的变化,确定Si-O-Fe与si-O-si在金属表面存在竞争协同作用。     

金属涂装预处理新技术与涂层性能研究方法进展

评述了近年发展起来的硅烷化和原位磷化两种金属涂装预处理新技术和有机涂层金属体系腐蚀降解行为的现代研究方法(红外照相法、红外技术)的最新进展.此两种金属表面处理方法能够显著增强有机涂层与金属基体的结合力,有望取代对环境具有危害的传统磷化和铬酸盐转化技术.红外照相技术可更直观地了解涂层下金属的腐蚀发展过程及腐蚀类型;结合SKP和SAM 两种技术能够更深入认识涂层金属发生腐蚀过程中腐蚀电位及腐蚀区域的发展变化.     

金属表面硅烷防护膜层的研究进展

硅烷处理技术工艺简单,无毒,无污染,所得膜层与金属基体具有良好的结合力,且防腐蚀性能与铬酸盐转化膜相当。因此,在众多铬酸盐替代技术中显示出巨大的潜力。全面综述了硅烷膜层的防护机制、硅烷处理工艺以及不同金属基体表面硅烷膜层的研究进展。由综述分析可知：硅烷与金属表面的结合主要为化学键结合;文献中多采用浸渍的方法直接在金属表面形成硅炕膜层,而对于电沉积方法的研究还处于初步阶段;硅烷膜层的自愈性能主要是通过添加稀土实现的。根据综述分析的结果,指出了当前硅烷研究存在的问题及主要研究方向。     

金属表面无铬替代处理技术的研究进展

金属表面铬酸盐转化膜不仅具有优异的耐腐蚀性能,还具有自我修复功能,但是环保的需要使得铬酸盐钝化工艺将逐渐被各种无铬钝化无毒技术所替代。介绍了硅酸盐、钼酸盐、稀土复合转化膜、有机硅烷等各种无铬钝化工艺的优缺点和发展现状。并指出了今后金属表面处理无铬无毒钝化的方向。     

OTS自组装单分子膜在玻璃表面功能化的研究

采用分子自组装技术在羟基化的玻璃基片表面成功制备了十八烷基三氯硅烷单层膜 (OTS-SAMs).运用接触角测试仪测定了水在自组装薄膜表面的接触角;用原子力显微镜(AFM)分析了OTS-SAMs的表面形貌,并对经过紫外线照射改性的OTS-SAMs薄膜表面进行分析.结果表明:该组装膜具有很好的疏水性,其对水的接触角高达105°;在组装初期2 min内,十八烷基三氯硅烷水解产物主要是与基体表面的羟基发生聚合反应,表现为岛状物结构团簇,随着组装时间的增加,基体表面的有机硅烷分子之间发生聚合反应,当组装15 min后,成膜过程趋于稳定,可以在基体表面形成平整致密的自组装薄膜;经过紫外线照射改性后的薄膜表面亲水性明显提高,在2 h时达到了很好的羟基化效果.     

Depositing nanolayers of volatile organic compounds on metals for higher resistance to atmospheric corrosion

Atmospheric corrosion stability of metals can be achieved by coating their surfaces with superthin nanoscale layers. The scientific principles of inhibiting metal corrosion have been under development for many years, but a new direction of progress has emerged recently. The main achievement of research in this new direction is the possibility of covering metals in nanoscale films that, despite their extreme thinness, ensure high corrosion resistance of the metals under various atmospheric conditions. To this end, methods are suggested for producing such coatings from volatile organic compounds that can adsorb on metal surfaces from the gaseous phase. Increasing the irreversibility of adsorption of volatile corrosion inhibitors is necessary to strengthen the protective effect of the nanolayers they form on the surface. Nanolayer-coating protection has a number of fundamental advantages, including retention of article dimensions, a lack of a need for special utilization and degreasing methods, and affordability.     

A corrosion study of hot-dip galvanized steel sheet pre-treated with γ-mercaptopropyltrimethoxysilane

In the present work an organofunctional silane, γ-mercaptopropyltrimethoxysilane (γ-MPS), has been deposited on hot-dip galvanized cold rolled steel from different silane solution concentrations. Painted and unpainted silane treated samples were corrosion tested and painted samples were adhesion tested. The surface chemistry of the unpainted silane treated samples was investigated with AES, ToF-SIMS and EDS and the surface morphology was studied with SEM.The results show that the silane film thickness is dependent on the silane concentration in the silane solution and a higher silane concentration gives a thicker film. Moreover, thicker films tend to give films with a pronounced crack pattern and even detachment of film debris. Corrosion tests of unpainted samples show that γ-MPS can not work as a passivation treatment but gives a very good adhesion to the paint.     

白炭黑偶联处理对硅橡胶性能影响研究

采用不同偶联剂对M-5气相白炭黑进行了表面改性,以增强白炭黑与硅橡胶的相容性.对处理前后的白炭黑进行了FT-IR分析,对比分析了偶联剂的类型和用量对气相白炭黑表面性能的影响,测试了室温硫化硅橡胶添加白炭黑后的力学性能.红外测试结果表明:偶联剂分子接枝到了白炭黑表面.表面改性效果最好的是乙烯基三甲氧基硅烷(Al71),白炭黑用量15%时硅橡胶拉伸强度最大可达到1.5MPa,由其配制的胶粘剂对铝-硅橡胶板的粘接强度达到1.3MPa.     

Improved corrosion protection of aluminum alloys by electrodeposited silanes

Organofunctional silanes recently have emerged as outstanding, environmentally friendly corrosion protectors for metal substrates, compared with conventional chromate treatments. A simple immersion technique is typically used to coat the metal surface with silane films. However, the thickness and uniformity of the films are uncontrolled in this process. This paper proposes a new deposition technique for the silane films on the metal surface, i.e., by electrodeposition. Hydrolyzed silanes are water-soluble, ionized molecules, so they can be deposited on metals by electrodeposition. Various combinations of silane mixtures were tested at different voltages, pH values, bath concentrations, and exposure times on panels of alloy aluminum and mirror-polished ferro-plate. The surface structure was characterized by scanning electron microscopy (SEM) and ellipsometry. The resistance of the film to corrosion was investigated by direct current (DC) polarization and electrochemical impedance spectroscopy (EIS) techniques. Electrodeposition results in a more organized and uniform film with fewer pores, compared with immersed or dipped films. This paper was presented at the 2nd International Surface Engineering Congress sponsored by ASM International, on September 15–17, 2003, in Indianapolis, Indiana, and appears on pp. 320–26 of the Proceedings.     

表面微结构对冰粘附强度的影响

目的研究试片表面粗糙度及分形维数对冰粘附强度的影响。方法通过对裸铝表面进行化学刻蚀及氟硅烷修饰,制备不同表面试片,测试试片表面的粗糙度和分形维数,应用冰粘附强度实验装置测试不同试片表面的冰粘附强度。结果粗糙度(x)与粘附强度(y)的关联式为:y=1.0966x+51.816(亲水表面),y=-0.67x+74.98(疏水表面)。分形维数(z)与粘附强度(y)的关联式为:y=-146.6z+493.5(亲水表面),y=95.45z-209.9(疏水表面)。结论亲水表面试片冰粘附强度随粗糙度的增加而增加,随分形维数的增加而减小,疏水表面试片的变化趋势则相反。冰粘附强度与粗糙度及分形维数之间存在较强的线性关系。表面粗糙度相同的试片经氟硅烷修饰后,冰粘附强度降低,且表面粗糙度越大,冰粘附强度下降越多。     

Adhesion hysteresis of silane coated microcantilevers

We have developed a new experimental approach for measuring hysteresis in the adhesion between a free standing thin film and a substrate. By accurately measuring and modeling the deformations in micromachined cantilever beams that are subject to combined interfacial adhesive and applied electrostatic forces, we determine adhesion energies for advancing and receding contacts. We examined adhesion hysteresis for silane coated cantilevers and found no hysteresis at low relative humidity (RH) conditions. The dominant contribution to interfacial energy at low RH is van der Waals attraction between portions of the surfaces that are separated by nanometer asperities. In contrast, significant hysteresis was observed for surfaces that were exposed to high RH conditions. Atomic force microscopy studies of these surfaces showed spontaneous formation of silane mounds that have irreversibly transformed from initially uniform hydrophobic surface layers. Contact mechanics considerations show that the compliance of the mounds can reasonably allow microcapillaries in surrounding hydrophilic areas to bridge at high RH as the surfaces are forced into contact by an externally applied load, leading to the adhesion hysteresis.