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Session V54: Membranes, Micelles and Vesicles

2:30 PM–5:30 PM, Thursday, March 8, 2018
LACC Room: 514

Sponsoring Unit: GSOFT
Chair: Radhakrishna Sureshkumar, Syracuse Univ

Abstract: V54.00010 : Interplay between structure and shear flow in micelle-nanoparticle solutions*

4:18 PM–4:30 PM

    Abstract  

Presenter:

Subas Dhakal
(Dapartment of Biomedical and Chemical Engineering, Syracuse Univ)

Authors:

Subas Dhakal
(Dapartment of Biomedical and Chemical Engineering, Syracuse Univ)

Radhakrishna Sureshkumar
(Dapartment of Biomedical and Chemical Engineering, Syracuse Univ)

Abhinanden Sambasivam
(Global Foundries)

Cationic surfactant molecules exhibit rich phase behavior in water. Self-assembly results in spherical, cylindrical and flexible wormlike structures with or without branches. We employ molecular dynamics simulations to study the structure and rheology of self-assembled aggregates of cetyltrimethylammonium chloride surfactants in presence of sodium salicylate counter ions in aqueous solution. Addition of nanoparticles (NPs) to such solutions results in the formation of electrostatically stabilized NP-micelle junctions, leading to a significant increase in the solution viscosity. Distinct rheological properties are observed by changing the surfactant, co-surfactant as well as NP concentrations. Micelle branching causes the solution viscosity to vary as a non-monotonic function of the NP concentration. At higher NP volume fractions and shear rates that exceed the inverse of a characteristic structure relaxation time, flow-alignment of the microstructure causes pronounced shear thinning [Molecular Simulation: http://www.tandfonline.com/doi/abs/10.1080/08927022.2017.1387658]

*We acknowledge the computational resources provided by XSEDE (PHY140044) which is supported by NSF grant number OCI-1053575 and the financial support by National Science Foundation under Grants 1049489 and 1049454