Smart Science Vol. 3, No. 2, pp. 74-79(2015)
http://dx.doi.org/10.6493/SmartSci.2015.333
Electrophoretic ink display prepared by jelly fig pectin/gelatin microspheres Wing-Ming Chou, Li-Lun Wang, and Hsin Her Yu* Department of Biotechnology, National Formosa University, 64 Wenhua Road, Huwei, Yunlin, 63208 Taiwan. * Corresponding Author / E-mail:
[email protected] , TEL: +886-5-6315490, FAX: +886-5-6315502 KEYWORDS : Jelly fig pectin, microcapsules, coacervation, electrophoretic display.
A brand new Bio-Electronic ink (Bio-E ink) display device was prepared and characterized in this study. Semiconductor material, copper phthalocyanine (CuPc) was modified by cationic surfactants, cetylpyridinium chloride (CPC), as the core material, and the shell of capsule was prepared by jelly fig pectin, gelatin and sodium dodecyl sulphate (SDS). Here, jelly fig pectin was provided as the shell material for the first time. Chemical structure of the modified CuPc was characterized by Fourier Transform Infrared Spectrometer (FTIR). The core-shell microcapsules were achieved by coacervation method in an oil/water (O/W) emulsion system. The particle size and morphology of microcapsules were affected by the concentrations of SDS and pH values of the O/W emulsion system. A new microcapsule-based electrophoretic display device was presented. Its image display ability of the microcapsules electrophoretic device was presented as appropriated electric power was applied, and the response time was 0.06 sec under 0.1 V/µm of electric field. Moreover, we found that its image contrast ratio of display device was influenced by the particle sizes of the microcapsules. Manuscript received: February 9, 2015 / Accepted: March 18, 2015
[4]-[6]. In our study, the method of complex coacervation was provided, using jelly fig pectin/gelatin and CuPc as the shell and core material, respectively. During coacervation, the encapsulability of a core material by shell material is upon the amount of polyelectrolytic components that can be absorbed on the micro-droplet surfaces. pH, agitation rate and surfactant concentration were also reported to be a crucial factors for the quality and optimal yield of microcapsules [7], [8]. In a complex coacervation process the wall surrounding the core material is constituted of at least two oppositely charged high molecular weight colloids. One of best studied systems for complex coacervation was using gelatin/ gum arabic as the shell material [7]-[9]. Gelatin obtained by a hydrolysis of collagen is a polyampholyte; while gum arabic composed of β-(1-3)-linked D-galactopyranosyl units as backbone is a natural branched complex polysaccharide. Pectin found in the cell walls of most plants is a naturally occurring heterogeneous polysaccharide and is mainly composed of long sequences of partially methyl-esterified α-(1-4)-linked Dgalacturonic residues [10]. Low-methoxy (with a degree of esterification
