Paper Number
SC47 

Session
Suspensions, Colloids, and Granular Materials

Title
Particle dynamics and structure development during paint drying

Presentation Date and Time
October 24, 2019 (Thursday) 10:50

Track / Room
Track 2 / Room 304

Authors (Click on name to view author profile)

1. Dennis, Kimberly A. (University of Delaware, Chemical and Biomolecular Engineering)
2. Brown, Scott C. (The Chemours Company)
3. Wagner, Norman J. (University of Delaware, Chemical and Biomolecular Engineering)
4. Furst, Eric M. (University of Delaware, Chemical and Biomolecular Engineering)

Author and Affiliation Lines (in printed abstract book)
Kimberly A. Dennis¹, Scott C. Brown², Norman J. Wagner¹, and Eric M. Furst^1
1Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716; ²The Chemours Company, Wilmington, DE 19805

Speaker / Presenter 
Dennis, Kimberly A.

Text of Abstract
Paints are aqueous suspensions of pigments, binders, and rheology modifiers that are designed to be cost effective, stable, and have good flowability while imparting important aesthetic and protective surface properties. The suspension must flow easily at high shear rates during painting and have a sufficient yield stress to stop flowing on the substrate. As the suspension dries, it must form a uniform film that is non-cracking and has good self-leveling properties. Critical final film properties including opacity, rub and stain resistance, and film integrity linked to the structure developed during drying. Modern approaches to measuring structure development involve mechanical rheometers and reflectometry. Mechanical rheometry provides information on system interactions but suffers from artifacts due to the mechanical manipulation of the paint film and is performed under simulated but not actual drying conditions. Reflectometry measurements, on-the-other-hand, are capable of measuring in situ drying processes however, do not convey information on important particle interactions that have the potential to predict final film performance properties. To assess in situ paint drying dynamics, structure development and system interactions, we use diffusing wave spectroscopy (multiple light scattering). The measured light intensity correlation function is interpreted using the Generalized Stokes-Einstein Relation (GSER) to determine the viscous and elastic moduli. We collect reference data for a concentration series of aqueous titanium dioxide suspensions and discuss the relationship to in situ measurements. We then discuss the effects of binder and rheology modifiers on the drying dynamics and structure development of model paint systems.