TITLE:
Surface Modification of NaCl Particles with Metal Films Using the Polygonal Barrel-Sputtering Method
AUTHORS:
Satoshi Akamaru, Mitsuhiro Inoue, Takayuki Abe
KEYWORDS:
Particle Surface Modification; Ionic Crystal; Dry Process; Sputtering Technique; NaCl
JOURNAL NAME:
Materials Sciences and Applications,
Vol.4 No.7B,
July
18,
2013
ABSTRACT: In this study, the surfaces of NaCl particles were modified with metal films using the polygonal barrel-sputtering method. When Pt was sputtered on NaCl particles, the individual particles changed from white to metallic. Characterization of the treated samples indicated that thin Pt metal films were uniformly deposited on the NaCl particles. Immersion of the treated NaCl particles in water revealed that they floated to the surface of the water with the increase in the immersion time, although their original cubic shapes remained unchanged. The floating phenomenon of the Pt-coated NaCl particles, as mentioned above, suggests that NaCl was dissolved by the permeation of water through invisible defects such as grain boundaries in the Pt films, leading to the formation of hollow particle-like materials. It should be noted that uniform film deposition on the NaCl particles could also be achieved by sputtering with Au or Cu. Based on the obtained results, our sputtering method allows uniform surface modification of water-soluble and water-reactive powders that cannot be treated by conventional wet process using water.