Precursor-Less Coating of Nanoparticles in the Gas Phase

Materials

Tobias V. Pfeiffer¹  Puneet Kedia¹  Maria E. Messing²  Mario Valvo³  Andreas Schmidt-Ott¹ 

[1] Faculty of Applied Sciences, Delft University of Technology, Julianalaan 136, Delft 2628 BL, The Netherlands; E-Mail:;Solid State Physics, Lund University, Box 118, Lund 221 00, Sweden; E-Mail:;Department of Chemistry–Ångström Laboratory, Uppsala University, Box 538, Uppsala 751 21 Sweden; E-Mail:

关键词: spark ablation;    nanoparticles;    coating;    gas phase;    continuous process;   

DOI  :  10.3390/ma8031027

来源: mdpi

【 摘 要 】

This article introduces a continuous, gas-phase method for depositing thin metallic coatings onto (nano)particles using a type of physical vapor deposition (PVD) at ambient pressure and temperature. An aerosol of core particles is mixed with a metal vapor cloud formed by spark ablation by passing the aerosol through the spark zone using a hollow electrode configuration. The mixing process rapidly quenches the vapor, which condenses onto the core particles at a timescale of several tens of milliseconds in a manner that can be modeled as bimodal coagulation. Gold was deposited onto core nanoparticles consisting of silver or polystyrene latex, and silver was deposited onto gold nanoparticles. The coating morphology depends on the relative surface energies of the core and coating materials, similar to the growth mechanisms known for thin films: a coating made of a substance having a high surface energy typically results in a patchy coverage, while a coating material with a low surface energy will normally “wet” the surface of a core particle. The coated particles remain gas-borne, allowing further processing.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland