内灰化八面体核壳乳剂的制备方法对微晶结构与性能的影响

应用双注仪制备了碘含量1.5%的AgBrI乳剂,在一定温度,pAg和pH下将乳剂成熟到一定程度(D₀>5.0).用此乳剂做为核,采用二次乳化法包壳。本文主要研究了包壳时pH值,壳的组成,厚度对乳剂颗粒大小、形状、显影密度及离子电导的影响。结果表明:(1)当壳的组成为AgBrI时,随氯含量增加(分别为0、2.5、5、10%mol),核壳乳剂表显密度变化不大而内显密度上升;(2)包壳时随pH由低到高(pH为2、4、6、8),乳剂颗粒由小变大。颗粒形状由规整八面体变得棱角模糊,均匀度下降,表显密度由小变大,而内显密度由大变小;(3)在相同pH下包壳,随壳厚度的增加(壳与核卤化银的摩尔数比为:1:0.5,1:1,1:2,1:3)表显密度急剧下降,内显密度变化不大;(4)随包壳时pH增加,卤化银微晶的离子电导增大.

THE INFLUENCES 0F PREPARATION METHOD ONSTRUCTURE AND PROPERTIES OF INTERNALLY FOGGED CORE-SHELL EMULSION

A AgBrI emulsion was prepared by pAg-controlled double jet methods.Reductionsensitization was performed by silver digestion at low pAg values and high pH values(D₀>5.0),them more AgBr was precipitated on to the digested emulsion by the same double-jet procedure at defferent pH values(pH 2,4,6,8).The influence of the method of preparation on the structure and the properties of AgX microcrystals was studied in the PaPer.It was shown that with pH changes during shell-formation grain size increase,thecrystal shape was transformed from regular octahedal to rouned octahedral,and thedensity by surface development and the ionic conductivity increase but density by internal development decrease.At the same pH,the density by surface development was downrapidly with the change of the core-shell ratio of 1:0.5,1:1,1:2,1:3.