Length scale of polyisopirene and dynamic light scattering and structure of sodium-2-diethylhexyl sulfosuccinate/water/decane

The mixture of polyisopirene (PI) and sodium-2-diethylhexyl sulfosuccinate /decane/water microemulsion (ME) at AOT to water molar ratio (X = 30) and droplet mass fraction (m_f,drop = 0.08) was studied with dynamic light scattering and small-angle X-ray scattering (SAXS). The light scattering was used to obtain the diffusion coefficient of Brownian motion of the nano-droplets at different polymer concentrations and molecular weights (1000 and 4700) in the ME. The dynamics of the nano-droplets decreased with the increase of molecular weight (from 1000 to 4700) and concentration (from 0.01 to 0.09) of PI. The study of the structure by SAXS showed that with increase of PI (MW = 1000) mass fraction from 0.01 to 0.09 at ME, the size of the droplets changes from 4.5 to 4.3 nm and with increase of PI (MW = 4700) concentration at ME, the size of droplets changes from 4.8 to 4.4 nm. The size ratio of droplets to polymer decreased with increase of concentration and molecular weight of polymer and also the interaction between the droplets increased with increase of polymer concentration.     

Light scattering and SAXS of spherical to cylindrical transition of AOT/H2O/cyclohexane/PI

The mixture of polyisoprene with sodium-2-diethylhexyl sulfosuccinate (AOT)/H₂O/cyclohexane microemulsion is studied with the photon correlation spectroscopy (PCS) and small angel X-ray scattering (SAXS). The water with AOT induces nano-droplets inside the cyclohexane and addition of concentration and length scale of polyisoprene (PI) can change diffusion of nano-droplets. The collective diffusion coefficient (D_c) of nano-droplets decreased with increase in concentration of PI. From SAXS experiment, a spherical–cylindrical transition of nano-droplets by increase in polyisoprene concentrations observed that it can describe behaviour of diffusion.