物理化学学报 >> 2011, Vol. 27 >> Issue (07): 1777-1782.doi: 10.3866/PKU.WHXB20110725

材料物理化学 上一篇    

具有低表面自由能有机介电薄膜的制备及表征

刘应辉, 康志新   

  1. 华南理工大学机械与汽车工程学院, 国家金属材料近净成形工程技术研究中心, 广州 510640
  • 收稿日期:2011-02-28 修回日期:2011-04-25 发布日期:2011-06-28
  • 通讯作者: 康志新 E-mail:zxkang@scut.edu.cn
  • 基金资助:

    国家自然科学基金(51075151, 50673028)和广东省自然科学基金重点项目(10251064101000001)资助

Preparation and Characterization of a Polymeric Dielectric Film with a Low Surface Free Energy

LIU Ying-Hui, KANG Zhi-Xin   

  1. National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials, School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou 510640, P. R. China
  • Received:2011-02-28 Revised:2011-04-25 Published:2011-06-28
  • Contact: KANG Zhi-Xin E-mail:zxkang@scut.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51075151, 50673028) and Key Program of Guangdong Natural Science Foundation, China (10251064101000001).

摘要:

通过自主开发的有机镀膜技术在Mg-Mn-Ce镁合金表面制备了具有低表面自由能和较高介电常数的有机纳米薄膜. 利用X射线光电子能谱(XPS)分析了表面有机镀膜过程的反应机理, 借助傅里叶变换红外(FT-IR)光谱进一步确认表面有机膜层的存在, 采用接触角测量仪测定了有机薄膜的蒸馏水接触角和表面自由能变化, 使用椭圆偏振光谱仪研究了薄膜的厚度, 并借助精密阻抗分析仪评价了薄膜的介电性能. 有机镀膜后镁合金表面形成了一层纳米级厚度的有机薄膜, 接触角从基体的70.8°上升至150.5°, 表面自由能从基体的37.96 mJ·m-2降低到1.57 mJ·m-2, 镁合金表面从亲水性转变为疏水性; 薄膜的厚度和质量随有机镀膜时间延长先增加后有所减小, 在镀膜20 min时薄膜性能最佳, 此时膜重达到23.5 μg·cm-2, 膜厚最大为147.48 nm, 其相对介电常数也达到最大, 在1 kHz下可达24.922.

关键词: 有机镀膜, 纳米薄膜, 疏水, 表面自由能, 介电薄膜

Abstract:

A polymeric nanofilm with a low surface free energy and high dielectric constant on the surface of a Mg-Mn-Ce magnesium alloy was prepared by a self-developed technique which was designed as polymer plating. The reaction mechanism during polymer plating was analyzed by X-ray photoelectron spectroscopy (XPS). The film formed on the magnesium alloy surface as determined by Fourier transform infrared (FT-IR) spectroscopy. The contact angle of distilled water and the surface free energy of the polymeric film were determined using a contact angle meter. The film thickness was characterized by spectroscopic ellipsometry. The dielectric property of the film was evaluated using a precision impedance analyzer. The experimental results show that the nanoscale polymeric film was successfully formed on the magnesium alloy surface after polymer plating. The contact angle of distilled water for the polymer-plated magnesium alloy increased to 150.5° compared with 70.8° for the substrate and the surface free energy of the polymer-plated magnesium alloy decreased to 1.57 mJ·m-2 from 37.96 mJ·m-2 for the substrate. Therefore, the functional performance changed from hydrophilic to hydrophobic. The film mass and thickness increased with the polymer-plating time before 20 min and then decreased slightly. The film mass and thickness after polymer-plating for 20 min increased to 23.5 μg·cm-2 and 147.48 nm, respectively. The polymer-plated nanofilm at 20 min possesses a high relative dielectric constant of 24.922 at a frequency of 1 kHz.

Key words: Polymer plating, Nanofilm, Hydrophobic, Surface free energy, Dielectric film

MSC2000: 

  • O646