Influence of the Surfactant Concentration on the Rose Oil Filled Urea-Formaldehyde Microcapsules

The microencapsulation process proceeds much more efficiently, with a higher yield and quality of the resulting microcapsules in the presence of an emulsifier. Its influence is due, on the one hand, to the reduction in the diameter of the microcapsules and on the other hand - to an increase in the thickness, density and quality of the capsule wall. However, the type and amount of emulsifier must be precisely selected to obtain satisfactory results, while avoiding the adverse effect of capsule agglomeration and increasing the cost of the process. In the presented work, SDS was used in different concentrations: 0 %, 0.5 %, 1 %, 2 %, 3 %, 4 %, 5 % for encapsulation of rose oil by in situ polymerization between urea and formaldehyde. Experimental results showed that the efficiency of the microencapsulation process increased with raising surfactant concentration. Nevertheless, the presence of a large amount of surfactant (over 3 %) was undesirable, due to an increase in the viscosity of the reaction medium, followed by an increase in the size of the microcapsules because of their sticking together. In addition, the presence of a large amount of surfactant is economically unprofitable, which is the reason for realizing these studies with the aim of selecting the optimal amount of emulsifier.