Influence of the oleic phase and co-surfactant addition in non-ionic microemulsified systems

Fabiola Dias Da Silva Curbelo,Giovanna Lais Rodrigues Leal,Tarsila Melo Tertuliano,Beatriz Sales Cavalcanti Nascimento,Alfredo Ismael Curbelo Garnica,Raphael Ribeiro Da Silva

doi:10.33448/rsd-v10i2.12902

Fabiola Dias Da Silva Curbelo, Giovanna Lais Rodrigues Leal + Show 4 more

Open Access

https://doi.org/10.33448/rsd-v10i2.12902

Copy DOI

Abstract

Microemulsion is a thermodynamically stable dispersion consisting of an aqueous and an organic phases, both stabilized by surfactant molecules and when in need, co-active surfactant. The nature and structure of these components are essential in the formulation of microemulsified systems. For this, the construction of phase diagrams can be a fundamental tool to characterize the ideal experimental conditions for the existence and operation of microemulsions. Thus, the present work had as objective to obtain a comparison between microemulsions with different compositions through the construction of ternary diagrams, aiming to achieve the most stable system. To produce microemulsified systems, a non-ionic surfactant (Ultranex NP 60), a co-surfactant (Isopropyl Alcohol), two organic phases (pine oil and castor oil) and an aqueous phase (glycerin solution) were used. Also complementing the study, rheological tests of the oleic phases were accomplished, as well as their thermogravimetric analysis. The focus of the reached ternary diagrams was to find the system with the largest Winsor type IV region (microemulsion). It was verified this region had a significant increase by the addition of the co-surfactant in the medium and using a vegetable oil, such as pine oil, since it promotes strong surfactant-oil interactions on the interface.

Highlights

Microemulsions (ME) can be defined as fine dispersions, thermodynamically stable, consisting of an aqueous phase and an organic phase, both stabilized by surfactant molecules and more, when necessary, co-surfactants (Winsor, 1948; Daltin, 2011; Pietrangeli, & Quintero, 2013; Garnica et al, 2020)
These diagrams presented two regions according to Winsor's classification: a single-phase microemulsion region (WIV), and another with two phases, microemulsion and excess aqueous phase (WII)
The test results suggest that the addition of the Isopropyl alcohol co-surfactant to the NP 60 ethoxylated noniphenol surfactant was positive for obtaining larger microemulsion regions, regardless of the other components

Summary

Introduction

Microemulsions (ME) can be defined as fine dispersions, thermodynamically stable, consisting of an aqueous phase and an organic phase (usually oleic), both stabilized by surfactant molecules and more, when necessary, co-surfactants (Winsor, 1948; Daltin, 2011; Pietrangeli, & Quintero, 2013; Garnica et al, 2020). For the spontaneous formation of microemulsified systems, the interfacial tension must be close to zero This system has some advantages such as transparency, high stability, easy preparation, and the ability to minimize the interfacial differences between water and oil (Thomas, 2004). This work consists of a comparative study of the composition of microemulsions, differentiated by the organic and surfactant components of their structure, with the objective of finding a more suitable microemulsified system through the incorporation of a co-active agent in the system

Methodology

Results and Discussion

Conclusion