Paper Number
SC5 

Session
Suspensions and Colloids

Title
Discontinuous shear-thickening of highly-loaded polymer-ceramic suspensions

Presentation Date and Time
October 10, 2022 (Monday) 11:10

Track / Room
Track 1 / Sheraton 4

Authors (Click on name to view author profile)

  1. Corder, Ria D. (Purdue University, School of Mechanical Engineering)
    Corder, Ria D. (Purdue University, School of Materials Engineering)
  2. Ardekani, Arezoo (Purdue University, School of Mechanical Engineering)
  3. Erk, Kendra A. (Purdue University, School of Materials Engineering)

Author and Affiliation Lines (in printed abstract book)
Ria D. Corder1,2, Arezoo Ardekani1 and Kendra A. Erk2
1School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907; 2School of Materials Engineering, Purdue University, West Lafayette, IN 47907

Speaker / Presenter 
Corder, Ria D.

Keywords
experimental methods; additive manufacturing; gels; suspensions

Text of Abstract
Suspensions of ceramic particles are used in electronics manufacturing to improve heat and/or electron transfer between components, with polymers often added to improve the flow behavior at high particle loadings. Using the additive manufacturing technique of direct-ink-writing, these suspensions can be rapidly fabricated into custom and precise structures. In this work, we examine the rheology of depletion-stabilized aqueous suspensions containing >50 vol% alumina nanoparticles and polyvinylpyrrolidone (PVP). Discontinuous shear-thickening (DST) is observed at increased shear rates for suspensions containing high alumina loadings. We demonstrate how varying the relative component volume fractions and the PVP molecular weight affect the presence and onset of DST. Dynamic oscillatory and stress relaxation tests were conducted both prior to and after the DST transition to characterize how shear history affects the measured rheology. Finally, we present results from direct-ink-writing tests and observe how both suspension composition and varying printing parameters (e.g. nozzle diameter, flow rate, print speed) affect the quality of printed parts. The process-structure-property relationships elucidated herein can help to inform the design of 3D-printable polymer-ceramic suspensions and better understand their potential processing limitations.