Preparation and Characterization of Oil Containing Microcapsules Obtained by an Interaction Induced Coacervation

Abstract

A novel method for microencapsulation of oil by coacervation is presented. The method employs segregative phase separation between sodium carboxymethyl cellulose (NaCMC) and a complex of hydroxypropylmethyl cellulose (HPMC) and sodium dodecylsulfate (SDS), which results in coacervate formation. Microstructural properties of the coacervate can be varied by tuning NaCMC-HPMC/SDS interaction, which is achieved by changing SDS concentration. Microcapsules preparation route is presented. Encapsulation efficiency and dispersion properties of microcapsules with coacervate shell of different properties and different oil content were tested. Microcapsules with smallest droplet size, the narrowest droplet size distribution, and with lowest extractability of encapsulated oil were obtained when NaCMC-HPMC/SDS interaction results in formation of the most compact coacervate shell, no matter of the encapsulated oil.

Keywords:

• Coacervation
• complex formation
• microencapsulation
• polymer-surfactant interaction
• segregative phase separation

This work was supported by Ministry of Science of the Republic of Serbia (Grant Number 20022). The authors are thankful to Colorcon Ltd. (England) for their generous gift of the HPMC sample.