Paper Number
PO49 

Session
Poster Session

Title
Impact of silica nanorod concentration on the nonlinear rheology of aqueous poly(acrylamide)-nanoparticle suspensions

Presentation Date and Time
October 13, 2021 (Wednesday) 6:30

Track / Room
Poster Session / Ballroom 1-2-3-4

Authors (Click on name to view author profile)

  1. Neal, Christopher A. (University of Minnesota, Chemical Engineering and Materials Science)
  2. Leon, Valeria (University of Texas, Rio Grande Valley, Mechanical Engineering Department)
  3. Quan, Michelle C. (University of Minnesota, Chemical Engineering and Materials Science)
  4. Chibambo, Nondumiso (University of Minnesota, Twin Cities, Chemical Engineering and Materials Science)
  5. Calabrese, Michelle A. (University of Minnesota, Chemical Engineering and Materials Science)

Author and Affiliation Lines (in printed abstract book)
Christopher A. Neal1, Valeria Leon2, Michelle C. Quan1, Nondumiso Chibambo1 and Michelle A. Calabrese1
1Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455-0331; 2Mechanical Engineering Department, University of Texas, Rio Grande Valley, Edinburg, TX 78539

Speaker / Presenter 
Neal, Christopher A.

Keywords
composites; polymer solutions; suspensions

Text of Abstract
Recently, thorough optimization of nanoparticle synthesis procedures has introduced new methods to produce a wide variety of anisotropic structures on multiple length scales1. The combination of anisotropic nanoparticles and inducing larger-order anisotropy of these particles further increases the anisotropy of materials and can introduce complex macroscopic properties including impacts on the rheological properties, thermal and electrical conductivity2, optical3 or mechanical properties4. In this study, we examine the ability to vary the size and shape of silica nanorods and the resulting impacts on the steady shear rheological behavior of suspensions in aqueous poly(N-isopropyl acrylamide) solutions. Varying the tetraethoxysilane5 content can vary the length:diameter ratio between 2 and 15 and influence the shape and homogeneity of particles. Rheological results demonstrate that each method influences the static microstructure—demonstrated by varying yield stresses, flow curves and nonlinear rheology—such that the combination of induced and nanoparticle anisotropy can be used for even finer tuning of rheological properties. This work serves to expand the foundation of the next generation of polymer-nanoparticle composite literature, specifically by demonstrating the functionality of suspensions of silica nanorods in aqueous polymer solutions.

1Grzelczak M, et al., Chem. Soc. Rev., 37 (2008).
2Ziyin L, et al., ACS. Appl. Mater. Interfaces, 5 (2013).
3PK, et al., J. Phys. Chem. B, 110 (2006).
4Knauert ST, et al., J. Polym. Sci. Pol. Phys. (2007).
5Murphy RP, et al., Langmuir, 32 (2016).