Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (07): 1777 -1782.doi: 10.3866/PKU.WHXB20110725

• PHYSICAL CHEMISTRY OF MATERIALS • Previous Articles    

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).

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