An emulsion prepared so as to minimize the effect of any chemical action on the grains was in its "primitive" state, i.e., that no chemical sensitizing had occurred during the formation of the emulsion grains in "inert" gelatin. Another emulsion was made so as to maximize the effect of any chemical action on the grains by chemical sensitizing methods. This emulsion was also prepared in "inert" gelatin. Sodium Borohydride was added at various levels of concentration to chemically fog both emulsions. The developable density was measured. Also, an attempt was made to measure the amount of reduction sensitization occurring if any. The loss of sodium borohydride in a 1.0 N sodium hydroxide solution was minimum for the time used. An appreciable difference in the photographic effect produced by the use of sodium borohydride was measured and observed. Density is proportional to concentration of sodium borohydride added for the primitive emulsion. Some reduction sensitization was measurable on the primitive emulsion.
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Department, Program, or Center
School of Photographic Arts and Sciences (CIAS)
Laufer, S. and Golembe, R., "Use of borohydride to determine the difference in the developable density for a chemically sensitized and non-sensitized emulsion." (1965). Thesis. Rochester Institute of Technology. Accessed from
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