Evaluating the Structure and Dynamics of Water in Nanoemulsions Using Rheology, Light Scattering, and Differential Scanning Calorimetry

The goal of this work was to evaluate the microstructure and dynamics of water nanodroplets in isopropyl myristate (IPM)/dioctyl sodium sulfosuccinate (DOSS)/water nanoemulsions (NE) utilized as reactors for nanoparticle synthesis. The characterization of the microstructure and dynamics of selected NE’s was performed using rheology, dynamic light scattering (DLS), and sub-ambient differential scanning calorimetry (SA-DSC). The results obtained from rheological evaluation demonstrated that all the selected IPM/DOSS/water systems exhibited Newtonian behavior. The DLS measurements showed that depending on composition, the water nanodroplets had diameters in the range of 6 to 16 nm. The nanoemulsions did not show droplet aggregation or coalescence over a one-month period of observation, as indicated by the multi-angle DLS study. SA-DSC experiments delineated the states of water within the ternary mixtures. A concentration-related variation in the internal microstructure was identified when water-freezing temperatures were plotted as a function of water content. The ternary mixtures reported in this research were utilized to synthesize silver sulfadiazine and calcium alginate nanoparticles. Insights obtained from this study are being assimilated to design efficient and effective reactors capable of use in nanoparticle synthesis.