The Study On Thermochromism Of Bromocresolpurple Materials

A series of thermochromism materials were prepared, choosing bromocresolpurple as chromophoric reagent, some kings of phenols, carboxylic acid or boric acid as delomorphic reagent. This paper studied the infection of the dosage of delomorphic reagent and fillings to the thermochromism property.The results of research indicate that, when phenols and carboxylic acid as delomorphic reagent, the fillings must be filled, if we want to get the good materials of low temperature and reversible thermochromic. The thermochromism property of the materials was the best when the mass ratio of bromocresolpurple, delomorphic reagent and hexadecane was 1∶1∶10～1∶4∶40. The color of materials was red in different degrees under the low temperature and yellow when the temperature is 43~52℃. The materials had the bright colors, short recovering time and high stability of color changing, but the lightfastness and high temperature resistance are not very good.When boric acid act as delomorphic reagent, the materials can change colors without fillings at different temperatures. When the mass ratio of bromocresolpurple and borac acid was 1∶100~1∶200, the materials have better performance, it's color was yellow under the low temperature and hyacinth under the high when the temperature is 85℃～100℃. The materials had short recovering time, good at reversibility and high stability of color changing, but bad in high temperature resistance. The color of the materials would be brighter, and high temperature resistance would be greatly improved when chromatography silica gel or Al2O3 act as the fillings . There was no fusion during the color changing, and the materials had bright color and luster, short recovering time, high stability of color changing, good light fastness, it's a perfect thermochromism materials.