冠醚化合物做为晶体生长的物理成熟剂

THE CROWN COMPOUNDS AS PHYSICAL RIPENERS FOR AgBr CRYSTAL GROWTH

本文在制备AgBr八面体乳剂初液中,加入一系列不同量的1,7,10,16-四氧-4,13-二硫代杂环十八烷(2S-18-C-6),结果由于(2S-18-C-6)与银离子产生了络合,降低了乳剂成核的过饱和度,所得乳剂的颗粒大小与加入2S-18-C-6的量成正比。由于所得乳剂颗粒大小分布产生了变化,而使乳剂的光化学性质以及介电损耗也产生了规律性的变化。同时还发现,在乳剂成熟过程中,加入含杂质原子不同的冠醚化合物1,4,7,10,13,16-六氧环十八烷(18-C-6),1,7,10,16-四氧-4,13-二氮代杂环十八烷(2N-18-C-6),N-对甲苯磺酰基-7-氮杂-1,4,10,13-四氧硫杂环十六烷(NTsTTH)对晶体的物理成熟作用有很大差异,2S-18-C-6是很好的物理成熟剂,2N-18-C-6、NTsTTH是AgBr的溶剂,18-C-6的成熟作用很弱,说明冠醚化合物对AgBr的溶解成熟作用与其环上所含杂原子有关。

It was found that the AgBr grain size increased with the increasing concentration of l,7,10,16-tetraoxa-4,13-dithia-cyclooctadencan (2S-18-C-6) in the emulsion due to the latter's complexation with Ag+, and subsequently the decrease of the supersaturation of the AgBr nucleation, and the photochemistry and dielectric loss of the prepared AgBr emulsion changed with the grain size in a regular pattern. The addition of the crown ether to the deionized bone-gelatin solution made small crystals dissolved, thus, well-distributed emulsion with high contrast could be got. Emulsion ripening was quite concerned with the heteroatoms in the crown ethers,2S -18 - C - 6 could act as a strong physical ripener while l,7,10,16-tetraoxa-4,13-diazacyclooctadecan (2N-18-C-6)and N-toluensulfonyl -7-aza-l,4,10,13-tetrathiacyclohexadecan (NTsTTH) could only act as the solvents of AgBr, and 1,4,7,10,13,16-hexaoxacyclooctadecan (18-C-6) has merely ripening effect on the emulsion.