Abstract: The properties and ionic conductivities of internal sensitive emulsions,the core of which were chemically sensitized with sulfur-plus-gold,were studied.If the amount of Na₂S₂O₃ and AuCl₃ increased at a constant ratio when internally sensitized,the internal sensitivity and the ionic conductivity increased whereas the surface sensitivity decreased.With increasing the amount of AuCl₃,added with a fixed amount of Na₂S₂O₃,the internal sensitivity increased with almost the same surface sensitivity and decrease of ionic conductivity.The addition of the stabilizer 583 at the core surface can cause decrease of internal fog and ionic conductivity.Both the surface sensitivity and ionic conductivity decrease with the increase of the mole ratio of the core to the shell. When iodide was introduced at the grain shell surface,the ionic conductivity increased rapidly.

Key words: internal sensitive emulsion, core-shell emulsion, Chemical sensitization.photographic property, ionic conductivity