Colloidal coating for small three dimensional articles, and particularly for fusion targets having glass shells

摘要

Extremely small, three-dimensional articles, such as fusion targets having glass shells (20 to 500 microns in diameter) are coated with alternate layers of colloidal materials. This is accomplished by depositing particles of opposite charge from colloidal suspensions (sols). Articles to be coated are suspended within a drop held in the open end of a closed capillary tube, and colloidal particles are deposited by dipping the capillary into the sols. Alternate monolayers of the particles adhere to the surface of the article. Multilayer coatings are built up by repeated alternate deposition of the monolayers from the sols. Between each deposition, the layers are rinsed with water and the water removed by dipping the capillary tube into a bath of water and then into a bath containing a water displacing agent such as ethanol or dimethyl sulfoxide.