H. Saijo et al., NUCLEATION AND GROWTH OF CYANINE DYE J-AGGREGATES ON AGBR EMULSION CRYSTALS STUDIED BY ANALYTICAL COLOR FLUORESCENCE ELECTRON-MICROSCOPY, Journal of imaging science and technology, 39(6), 1995, pp. 539-546
Cathodoluminescence images of lfopropyl-5,6,5',6'-dibenz-9-ethyl-oxaca
rbocyanine J-aggregates adsorbed on (100) surfaces of practical emulsi
on AgBr microcrystals were used to study nucleation, preferential adso
rption, and growth. Nucleation of J-aggregates occurred when dye molec
ules were added to gelatin sols of AgBr microcrystals and the aggregat
e nuclei adsorbed to the surface of AgBr. Residual dyes in the solutio
n worked to increase the size of existing aggregate nuclei on the surf
ace and did not contribute nucleation of new aggregates. The temperatu
re rise of solutions during aging led to normal size distribution of J
-aggregates, suggesting that there is a most stable size of J-aggregat
es for given growing conditions. The surface selectivity of J-aggregat
es on adsorption was checked by comparing J-aggregation on AgBr cubes,
octahedra, and cuboctahedra.