Surface Enhanced Raman Spectroscopic Studies of Silver-Filled Epoxies.
01 January 1986
Recently it has been postulated that certain silver-filled epoxies stored for extended periods at room temperature before curing develop a high bulk resistivity due to the formation of a thin insulating layer on the silver flake. Surface enhanced Raman experiments were undertaken to confirm the existence of the postulated layer and determine its composition. The Raman spectrum showed the presence of amorphous, three-coordinate carbon. The intensity of this Raman signal is significantly greater in samples that show increased resistivity as a result of extended room temperature storage before cure. It is argued that the amount of amorphous carbon increases with room temperature storage and causes the increased resistivity.