Manuscript Ultrasonic assisted dispersal of Cu Nanopowder For repository.pdf (1.57 MB)
Download file

Ultrasound assisted dispersal of a copper nanopowder for electroless copper activation

Download (1.57 MB)
journal contribution
posted on 24.03.2016, 13:15 by John E. Graves, Mark Sugden, Robert E. Litchfield, David HuttDavid Hutt, Timothy J. Mason, Andrew J. Cobley
This paper describes the ultrasound assisted dispersal of a low wt./vol.% copper nanopowder mixture and determines the optimum conditions for de-agglomeration. A commercially available powder was added to propan-2-ol and dispersed using a magnetic stirrer, a high frequency 850 kHz ultrasonic cell, a standard 40 kHz bath and a 20 kHz ultrasonic probe. The particle size of the powder was characterized using dynamic light scattering (DLS). Z-Average diameters (mean cluster size based on the intensity of scattered light) and intensity, volume and number size distributions were monitored as a function of time and energy input. Low frequency ultrasound was found to be more effective than high frequency ultrasound at de-agglomerating the powder and dispersion with a 20 kHz ultrasonic probe was found to be very effective at breaking apart large agglomerates containing weakly bound clusters of nanoparticles. In general, the breakage of nanoclusters was found to be a factor of ultrasonic intensity, the higher the intensity the greater the de-agglomeration and typically micron sized clusters were reduced to sub 100 nm particles in less than 30 min using optimum conditions. However, there came a point at which the forces generated by ultrasonic cavitation were either insufficient to overcome the cohesive bonds between smaller aggregates or at very high intensities decoupling between the tip and solution occurred. Absorption spectroscopy indicated a copper core structure with a thin oxide shell and the catalytic performance of this dispersion was demonstrated by drop coating onto substrates and subsequent electroless copper metallization. This relatively inexpensive catalytic suspension has the potential to replace precious metal based colloids used in electronics manufacturing.

Funding

The authors would like to thank the EPSRC for funding this research through the Innovative Electronics Manufacturing Research Centre (IeMRC), Grant Number EP/H03014X/1. In addition, the authors are grateful to the industrial collaborators, Chestech Ltd, Printed Electronics Ltd and Graphic Plc for technical support and provision of materials.

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Published in

ULTRASONICS SONOCHEMISTRY

Volume

29

Pages

428 - 438 (11)

Citation

GRAVES, J.E. ... et al, 2016. Ultrasound assisted dispersal of a copper nanopowder for electroless copper activation. Ultrasonics Sonochemistry, 29, pp. 428 - 438.

Publisher

© Elsevier

Version

AM (Accepted Manuscript)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Acceptance date

23/10/2015

Publication date

2015-10-24

Copyright date

2016

Notes

This paper was accepted for publication in the journal Ultrasonics Sonochemistry and the definitive published version is available at http://dx.doi.org/10.1016/j.ultsonch.2015.10.016

ISSN

1350-4177

Language

en