【作者】 李媛；

【导师】 魏刚；

【作者基本信息】 北京化工大学 ， 分析化学， 2004， 硕士

【摘要】 本工作是“十五”国家科技攻关项目的一部分,目的是研究利用分子自组装技术在金属表面制备具有防腐蚀功能的纳米膜的可能性。以改性有机硅树脂为原料,采用分子自组装法, 首次在碳钢表面设计、合成了一类新型高度有序自组装体系——有机硅氧烷类自组装单分子膜(SAMs),并探索了该体系在金属腐蚀防护中的使用性能。分子自组装工艺的研究表明,成膜过程中的浸渍温度和浸渍时间对薄膜结构影响不大,而提拉速度、风干时间、稀释剂浓度与种类对薄膜结构与性能有较大影响。提拉速度较大时,制得薄膜的厚度较为均一,耐蚀性较好。汽油作为稀释剂要优于煤油。热处理工艺,尤其是热处理最高温度和升温速度对薄膜结构有较大的影响。热处理最高温度为350℃,升温速度为1℃/min时,所得薄膜保护效果最好。采用X射线能谱仪(EDS)和X光电子能谱(XPS)对薄膜的分析结果指出,所制备的自组装单分子薄膜的化学成分主要是Si、O、C三种元素,Si元素与O元素的平均原子百分比为1:2,且不同区域各元素分布比较均匀。薄膜中Si元素的化学结合方式为SiO2状态。角分辨X光电子能谱(angular-dependent XPS)分析薄膜表层元素的空间分布的结果表明,Si、O交替以Si-O-Si键结合而形成二维空间网络薄膜。扫描电子显微镜(SEM)和原子力显微镜(AFM)分析结果示出,薄膜表面是由椭球形的SiO2颗粒紧密排列而成,平均颗粒度20nm,薄膜形貌为规则的条纹状。采用动电位扫描法对成膜碳钢试样测试的阳极极化曲线显示,碳钢在腐蚀介质中处于钝化状态。浸渍试验结果说明,所制备的薄膜对碳钢基体具有优异的保护性能。更多还原

【Abstract】 The work was supported the China Natinonal Key Technologies R&D Programme ,the objection of this research is the possibility of the anti-corrosion nano-film on carbon steel made by Self-Assembly technology.SAMs ( Self-Assembled monolayers ) nano-structured SiO2 thin films were fabricated for the first time onto the substrate of carbon steel through Molecular Self-Assembly method by dipping into the mixture solution of silicones and gasoline and heat-treating consecutively. The performances of this SAMs in the corrosion and defend fields are studied and explored. A new highly ordered Molecular Self-Assembly systems of silicones on carbon steel was designed and prepared successfully.The influences of processes and factors of the preparation on the thin films were investigated for the Self-Assembly method. The temperature of the dipping and the time of the dipping do not have much influence on the film. The speed of draw-up, the time of air dry and the concentration of the thinner have greatly effect on the film. The film was prepared has excellent protect effect when the temperature of heat treatment is 350℃, and the speed of temperature ascending is 1℃/min. XPS and EDS were proved that the composition of the film was made of by Si, O, C elements. The proportion of Si and O is 1:2.The angular-dependent XPS showed the interspace distribution of different element is relatively uniformity. The mode of the chemistry combination of Si is SiO2. AFM and SEM showed that the film was <WP=5>constituted by contacted particles. The diameters of the particles were 20nm. The anticathode of polarization curve of carbon steel with SAMs by changed- electrical voltage method suggested that carbon steel is passivation state in the rust medium. The result of dipping experiment explained that the nano-structured SiO2 film made by SA method had excellent protection to the substrate for carbon steel.更多还原