The effect of TBAC on the collective diffusion coefficient and morphology of AOT microemulsion at X = 6.7

2015

Opt. Spectrosc.

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The effect of a triblock oil soluble polymer (PEG-PDMS-PEG) on the properties of water-in-oil (W/O) droplet microemulsion (R ~ 7.5 nm) has been studied as a function of the amount of added polymer. Macroscopically one observes a substantial increase of viscosity with increase of polymer concentration that it is surpassed and effective cross-linking of the droplets takes place. SAXS measurements show that the size of the droplets is not changed by the polymer addition but it induces repulsive interactions ones at high polymer content. One fast (alpha relaxation) and two slow relaxations (beta and gamma relaxations) were observed in mixture system by Quasielastic light scattering (QLS). At high polymer content the network formation leads to slowdown of beta and gamma relaxations in QLS and increase in the motion of alpha. Moreover, the increasing of midblock length of polymer in mixture systems can increasing the different between slow and fast relaxation.

Section: T I T G T I Tmentioning

confidence: 97%

Relaxations of light scattering in mixture of PEG-PDMS-PEG triblock polymer with water in oil nano-droplets

2015

Opt. Spectrosc.

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“…In certain tri-block or end-capped polymers, the polymer-surfactant interaction created the transient network, which affected the dynamic nature of the nanodroplets. [10][11][12] Elsewhere, depletion effect was observed in the mixture of non-interacting of polymers and microemulsions. [9,13] spherical nanodroplets inside.…”

Section: Introductionmentioning

confidence: 92%

Polymer length scale on modification of a reverse microemulsion

Physics and Chemistry of Liquids

Delgosha

2014

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We study water-in-oil microemulsions, in certain the diffusion of water droplets covered with a monolayer of the anionic surfactant docusate sodium in a phase of ndecane mixed with the polyethylene glycol dimethacrylate (PEGD). At constant droplet size we vary the polymer concentration and from structural investigations with small-angle X-ray scattering there was clear evidence for penetration in the droplets. We apply this technique to monitor the size and morphology of the mixture system (docusate sodium microemulsion/PEGD). The structural study of our samples shows spherical-to-cylindrical change in nanodroplets with increase in polymer concentration. The dynamics of system consists of the translation diffusion of the nanodroplets was studied with dynamic light scattering.

“…If the scattering particles of solutions are moving, fluctuations in the scattered intensity with time are directly reflecting the so-called Brownian particle motion of the scattering particles (caused by thermal density fluctuations of the solvent). This is the case because of a change in the interference pattern with changing interparticle position, and correspondingly a change in the detected scattered intensity were measured at a given scattering angle [10][11][12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Quasielastic Light Scattering and Structure of Nanodroplets Mixed with Polycaprolactone

Journal of Spectroscopy

2014

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The interaction of polycaprolactone (PCL) with droplets of a microemulsion is studied with quasielastic light scattering and small angle X-ray scattering At constant droplet size we vary the PCL concentration and there is clear evidence for an increasing attractive interaction of the droplets from structural investigations with small-angle X-ray scattering (SAXS). The collective diffusion coefficient (Dc) of the droplets is monitored with quasielastic light scattering (QELS). We mainly focus on the variation of the dynamic behavior as a function of the PCL concentration and length scale (M.W. = 5000 and 10000) in microemulsion. With increasing PCL concentration and length scale the dynamics of the system slow down. A hard sphere model with depletion potential can fit well the SAXS experiment of microemulsion mixed with PCL. The results show with increase of PCL on microemulsion the size of droplets is constant at 83Å but the size ratio of polymer to droplets is changing.