TY - JOUR
T1 - Preparation of microcapsules with narrow-size distribution by complex coacervation
T2 - Effect of sodium dodecyl sulphate concentration and agitation rate
AU - Guo, Huilin
AU - Zhao, Xiaopeng
PY - 2008/6
Y1 - 2008/6
N2 - In this paper, microcapsules with narrow-size distribution, in which the core materials are a kind of suspension containing pigment scarlet powders dispersed in dyed tetrachloroethylene with Span-80 as an emulsifier, are prepared by complex coacervation through controlling sodium dodecyl sulphate (SDS) concentration and agitation rate. The microcapsules, formed in optimized process of 0.01 wt% SDS and 800 rpm, are ∼40 μm in diameter. The phase diagram for the gelatin/SDS/ water system indicates that the concentration of SDS in the experiments is outside of the complex formation zone to form a gelatin-SDS complex. Consequently, SDS preferential adsorbs and enriches on the surface of the core droplets due to its higher surface activity. Then, gelatin deposits with SDS at the core droplet/water interface to form a primary layer of complexation. Subsequently, with the pH lower than the isoelectric point of gelatin, complex coacervate of gelatin and gum arabic grows on the primary layer surface and finally deposits on the droplets to form a secondary layer. On the whole, the research indicates that the existence of SDS not only decreases the droplet diameters and centralizes the droplets size distribution, but also accelerates coacervation of gelatin and gum arabic to reach the core droplet/water interface, forming no aggregating microcapsules.
AB - In this paper, microcapsules with narrow-size distribution, in which the core materials are a kind of suspension containing pigment scarlet powders dispersed in dyed tetrachloroethylene with Span-80 as an emulsifier, are prepared by complex coacervation through controlling sodium dodecyl sulphate (SDS) concentration and agitation rate. The microcapsules, formed in optimized process of 0.01 wt% SDS and 800 rpm, are ∼40 μm in diameter. The phase diagram for the gelatin/SDS/ water system indicates that the concentration of SDS in the experiments is outside of the complex formation zone to form a gelatin-SDS complex. Consequently, SDS preferential adsorbs and enriches on the surface of the core droplets due to its higher surface activity. Then, gelatin deposits with SDS at the core droplet/water interface to form a primary layer of complexation. Subsequently, with the pH lower than the isoelectric point of gelatin, complex coacervate of gelatin and gum arabic grows on the primary layer surface and finally deposits on the droplets to form a secondary layer. On the whole, the research indicates that the existence of SDS not only decreases the droplet diameters and centralizes the droplets size distribution, but also accelerates coacervation of gelatin and gum arabic to reach the core droplet/water interface, forming no aggregating microcapsules.
KW - Agitation rate
KW - Complex coacervation
KW - Microcapsules
KW - Narrow-size distribution
KW - SDS
UR - http://www.scopus.com/inward/record.url?scp=46649113944&partnerID=8YFLogxK
U2 - 10.1080/02652040701861828
DO - 10.1080/02652040701861828
M3 - 文章
C2 - 18465313
AN - SCOPUS:46649113944
SN - 0265-2048
VL - 25
SP - 221
EP - 227
JO - Journal of Microencapsulation
JF - Journal of Microencapsulation
IS - 4
ER -