The effect of adsorption kinetics on film formation of silica/PVA suspension

The porous film microstructure of silica/PVA suspension at short mixing time became close-packed with longer mixing time because of increasing polymer adsorption. Particle/binder/solvent systems are widely used in many applications and have long been studied. Understanding and controlling polymer ad...

Full description

Saved in:
Bibliographic Details
Published in:Journal of colloid and interface science 2010-04, Vol.344 (2), p.308-314
Main Authors: Kim, Sunhyung, Sung, Jun Hee, Hur, Kangheon, Ahn, Kyung Hyun, Lee, Seung Jong
Format: Article
Language:English
Subjects:
Adsorption
Adsorption kinetics
Consolidation
Density
Dispersions
Drying
Film formation
Kinetics
Membranes, Artificial
Microstructure
Particle Size
Polyvinyl Alcohol - chemistry
Porosity
Silicon Dioxide - chemistry
Solvents
Stress development
Stresses
Surface Properties
Suspension stability
Suspensions - chemistry
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The porous film microstructure of silica/PVA suspension at short mixing time became close-packed with longer mixing time because of increasing polymer adsorption. Particle/binder/solvent systems are widely used in many applications and have long been studied. Understanding and controlling polymer adsorption in these complex material systems are important to achieve successful final performance. In this study, the effect of polymer adsorption on film formation and the relation between the microstructures of the suspension and film have been investigated by measuring the amount of polymer adsorption and the stress development during drying. In terms of mixing (or dispersion) time ( t m ), the adsorption amount ( Γ PVA), characteristic stress ( σ ch ) and dried film density ( ρ) showed a similar behavior in the form of 1 - e t m / τ with a single characteristic time τ = 45 h, which implies that the drying process is determined by this single time constant. The porous and non-uniform microstructure of the dried film at short t m became close-packed and uniform with longer t m . The polymer adsorption was found to play a key role in film formation as it introduces steric repulsion in suspension and suppresses the flocculation during solvent evaporation. It was also pointed out that enough mixing time for the saturated polymer adsorption is critical to acquire the consolidated and uniform film microstructure.
ISSN:0021-9797
1095-7103
DOI:10.1016/j.jcis.2009.12.046