Role of Adsorbed Polymers on Nanoparticle Dispersion in Drying Polymer Nanocomposite Films.

Sunhyung Kim,So Youn Kim,Jun Dong Park,Sol Mi Oh

doi:10.3390/polym13172960

Abstract

Polymers adsorbed on nanoparticles (NPs) are important elements that determine the dispersion of NPs in polymer nanocomposite (PNC) films. While previous studies have shown that increasing the number of adsorbed polymers on NPs can improve their dispersion during the drying process, the exact mechanism remained unclear. In this study, we investigated the role of adsorbed polymers in determining the microstructure and dispersion of NPs during the drying process. Investigation of the structural development of NPs using the synchrotron vertical-small-angle X-ray scattering technique revealed that increasing polymer adsorption suppresses bonding between the NPs at later stages of drying, when they approach each other and come in contact. On the particle length scale, NPs with large amounts of adsorbed polymers form loose clusters, whereas those with smaller amounts of adsorbed polymers form dense clusters. On the cluster length scale, loose clusters of NPs with large amounts of adsorbed polymers build densely packed aggregates, while dense clusters of NPs with small amounts of adsorbed polymers become organized into loose aggregates. The potential for the quantitative control of NP dispersion in PNC films via modification of polymer adsorption was established in this study.

Highlights

Polymer nanocomposites (PNCs) are used in a variety of fields, including energy and packaging materials [1,2,3,4,5]
We investigated the role of adsorbed polymers in improving NP dispersion during drying in solution-casted PNC films
Two aqueous dispersions constituting mixtures of nano-silica particles and polyvinyl alcohol (PVA), which lead to different extents of PVA adsorption, were employed as a model PNC system for performing drying experiments

Summary

Introduction

Polymer nanocomposites (PNCs) are used in a variety of fields, including energy and packaging materials [1,2,3,4,5]. PNCs, which consist of nanoparticles (NPs), polymers, and solvents, exhibit excellent physical properties resulting from the synergistic combination of NPs and polymers. It has been reported that yields and tensile strengths of polymers can be significantly improved by adding NPs to the polymers [6,7]. Many previous studies have shown that PNC materials exhibit improved optical and electrical performances compared to neat polymers [8]. Since NPs with various features have become ubiquitous, researchers are investigating the effects of the size, shape, and surface characteristics of NPs on the properties of PNCs. An important research goal is to develop design principles for PNCs to achieve the required properties

Methods

Results

Conclusion