The importance of angular bending of Gemini surfactants on their encapsulation efficiency

Abstract

The self–assembly of nonionic X-shaped Gemini surfactants is studied here, with the purpose of determining their encapsulation efficiency. Using the coarse-grained simulation method called dissipative particle dynamics, we perform a set of simulations of ternary water/oil/surfactant systems, fixing the oil/surfactant ratio at 1:1. Two surfactant structures are modeled and their efficiency to encapsulate monomeric oil is measured as a function of surfactant concentration. It is found that the encapsulation efficiency is better when the X-shaped surfactant has a more “stretched” structure. Additionally, it is shown that the number of oil/surfactant aggregates formed by surfactants with a relatively “open” structure is less stable as a function of the surfactant concentration. This is in contrast to the surfactants with the stretched structure, which makes the aggregates formed a better alternative as oil trappers. These results should be useful when synthesizing X-shaped Gemini surfactants for their use as thickening agents or drug carriers.