The electric response behavior and microencapsulation of the pigment phthalocyanine green G using interfacial polymerization.

The polyamide microcapsules for the electrophoretic display have been prepared via interfacial polymerization. The core material of the microcapsules is electrophoretic fluid consisted of pigment phthalocyanine green G (CAS No. 1328-53-6) modified with octadecylamine, tetrachloroethylene, and polyoxyethylene octylphenol ether (OP-10). The wall of the polyamide is synthesized from paraphthaloyl chloride and diethylenetriamine. FT-IR indicated that octadecylamine was bonded to pigment phthalocyanine green G with the hydrogen bond. The effect of the amount of octadecylamine on the dispersibility of the pigment suspended in tetrachloroethylene was investigated. Compared to the unmodified pigment, the dispersibility of the modified pigment was improved by 66.7%. The modified pigment migrated to the positive electrode under the direct voltage and the electric response time was about 85 s in 20 V/mm. The average particle size of microcapsules decreased from 834.5 to 258.2 nm as the dosage of OP-10 increased, and the microcapsule yield reached maximum of 83.5% at the OP-10 concentration of 1.5 wt%. With the reduction of the core/wall weight ratio in the range from 1:6 to 1:14, the average particle size improved from 267.4 to 554.4 nm. However, the maximum of the microcapsule yield was 87.6% at the core/wall weight ratio of 1:10. The microcapsule yield reached a peak of 87.6% as the pH value was 12. The average particle size of the microcapsules that obtained at 25 °C was 327.4 nm, which was smaller than those prepared in other temperatures. The formed polyamide microcapsules had a regular spherical shape. [ABSTRACT FROM AUTHOR]