Evaluating surface smoothness of composite film of well-dispersed silica particles

ABSTRACT

The surface smoothness of a composite film of polyimide and silica particles was evaluated by changing the dielectric constant based on the gap between the film surface and electrode surface. The silica particles were modified by different treatments, then mixed with the polyimide to prepare the particle composite films. The experimental results showed that even in the films with well-dispersed particles, a more suitable dispersion state exists based on the surface roughness. Moreover, an increase in the surface smoothness of the film will increase the dielectric constant of the composite films. The feasibility of this new evaluation method was confirmed after evaluating films with different smoothness and the results of the film surface smoothness scans were compared. This method allows for a fast, large-scale determination of samples and is independent of the film transparency.

KEYWORDS:

• Film
• nanocomposite
• modification
• smoothness
• dielectric constant
• polyimide

Acknowledgements

A part of this research was conducted under the Aichi Research Center for Knowledge Base (Phase III; 2019-2021) ‘Mass production in hollow particles utilizing MI and synchrotron radiation and accelerated development of functional materials’. We also would like to acknowledge Arakawa Chemical Industries, Ltd., (Japan) for providing the low-temperature cured polyimide resin.

Disclosure statement

No potential conflict of interest was reported by the author(s).