The effect of TiO₂ morphology on the surface modification of poly (ethylene terephthalate) for electroless plating

Abstract

In this study, a surface modification of the poly (ethylene terephthalate) (PET) film using TiO₂ photocatalytic treatment was investigated. In order to enhance the adhesion strength between the PET film and the electroless copper film, the effects of TiO₂ crystal forms, TiO₂ particle sizes, and TiO₂ content, as well as treatment condition, upon the surface contact angle, surface characterization, and adhesion strength were investigated. Anatase TiO₂ with a particle size of 5 nm had a high catalytic activity and dispersibility in aqueous solution. After the optimal photocatalytic treatment, the surface contact angle of the PET film decreased from 84.4° to 19.8°, and the surface roughness of the PET film increased from 36 to 117 nm. The adhesion strength between the PET film and the electroless copper film reached 0.89 KN m⁻¹. X-ray photoelectron spectroscopy analyses indicated the carbonyl group was formed on the PET surface after photocatalytic treatment, and the surface hydrophilicity was improved. Consequently, TiO₂ photocatalytic treatment is an environmentally friendly and effective method for the surface modification of the PET film.

Keywords:

• PET surface modification
• metallization
• photocatalytic treatment
• electroless Cu plating
• adhesion strength

Acknowledgments

The authors would like to thank Research Fund for the National Natural Science Foundation of China (grant number 21273144) and Doctoral Program of Higher Education of China (grant number 20110202110004).