Electroless plating of copper layer on surfaces of urea–formaldehyde microcapsule particles containing paraffin for low infrared emissivity--颗粒学报PARTICUOLOGY

Zhou, X., Mao, J., & Qiao, Z. (2016). Electroless plating of copper layer on surfaces of urea–formaldehyde microcapsule particles containing paraffin for low infrared emissivity. Particuology, 24, 159-163. https://doi.org/10.1016/j.partic.2014.12.006

Electroless plating of copper layer on surfaces of urea–formaldehyde microcapsule particles containing paraffin for low infrared emissivity

Xi Zhou, Jian Mao ^*, Zhen Qiao

College of Materials Science and Engineering, Sichuan University, No. 24, South Section 1, Yihuan Road, Chengdu 610064, Sichuan, China

10.1016/j.partic.2014.12.006

Volume 24, February 2016, Pages 159-163

Received 17 July 2014, Revised 30 November 2014, Accepted 3 December 2014, Available online 7 April 2015, Version of Record 21 January 2016.

E-mail: maojian@scu.edu.cn

Highlights

• UFP microcapsules with paraffin core and urea–formaldehyde shell were electroless-plated by copper.

• The lowest infrared emissivity achieved by electroless copper plating was 0.68.

• UFP with copper mass increase of 300% had balanced infrared emissivity and phase-change enthalpy.

Abstract

A copper coating was deposited by electroless plating on the surfaces of urea–formaldehyde microcapsules containing paraffin (UFP) particles. This composite microcapsule structure had low infrared (IR) emissivity and maintained a constant temperature, and could be used in IR stealth applications. The electroless copper layer formation and its micro-appearance, and the effect of the copper layer on the IR emissivity and thermal properties of the composite microcapsules were investigated. The IR emissivity of the composite microcapsules at wavelengths of 1–14 μm gradually decreased with increasing copper mass on the surface. After formation of an integrated copper layer, the rate of IR emissivity decrease was lower. This is because the copper coating improves the surface conductivity of the UFP; a high conductivity results in high reflectivity, which leads to a decrease in IR emissivity. The lowest IR emissivity achieved was 0.68. The phase-change enthalpy of the composite microcapsules decreased with increasing amount of copper coated on the surface because of the high density of copper. When the mass increase of the UFP after electroless copper plating was about 300%, the composite microcapsules had low IR emissivity (about 0.8) and a high phase-change enthalpy (80 J/g).

Graphical abstract

Keywords

Phase-change material; Urea–formaldehyde microcapsules containing paraffin particle; Electroless copper plating; Low infrared emissivity; Enthalpy

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