Paper Number
FE27 

Session
Foams, Emulsions, Surfactants, and Micelles

Title
Developing a scattering model for semiflexible chains in flow to assess flow-enhanced scission of wormlike micelles

Presentation Date and Time
October 12, 2021 (Tuesday) 5:00

Track / Room
Track 3 / Meeting Room A-B

Authors (Click on name to view author profile)

  1. Zhang, Jiamin (University of California, Santa Barbara, Department of Chemical Engineering)
  2. Smith, Gregory S. (Oak Ridge National Laboratory, retired)
  3. Corona, Patrick T. (University of California, Santa Barbara, Department of Chemical Engineering)
  4. Leal, L. Gary (University of California, Santa Barbara, Department of Chemical Engineering)
  5. Helgeson, Matthew E. (University of California, Santa Barbara, Department of Chemical Engineering)

Author and Affiliation Lines (in printed abstract book)
Jiamin Zhang1, Gregory S. Smith2, Patrick T. Corona1, L. Gary Leal1 and Matthew E. Helgeson1
1Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106; 2Oak Ridge National Laboratory, retired, Oak Ridge, TN 37831

Speaker / Presenter 
Zhang, Jiamin

Keywords
experimental methods; theoretical methods; computational methods; micelles; polymer solutions; surfactants

Text of Abstract
Understanding changes in microstructural dynamics under nonlinear deformations is critical for designing flow processing of semiflexible chains, such as wormlike micelles, bottlebrush polymers, and DNA. Although flow-small angle neutron scattering (flow-SANS) is suitable for studying how the material deforms in flow, scattering models for semiflexible chains in flow haven’t been developed previously due to the challenge of describing the combined effect of the overall chain conformation and the segmental orientation. To address this challenge, we develop a detailed scattering model for semiflexible chains in flow by using connected rods to represent the chains and incorporating an orientation distribution for the segments that is self-consistent with the overall stretch and orientation of the chain. We apply this new modeling framework to study wormlike micelles to deconvolute the contributions to the scattering from changes in micelle orientation, stretching, and interactions from effects due to changes in micelle length in flow. These comparisons are used to provide an outlook for whether the length distribution of wormlike micelles is significantly affected by flow. The development of the scattering model opens up new possibilities for obtaining microstructural information from flow-SANS experiments of semiflexible chains.