On the effect of particle surface chemistry in film stratification and morphology regulation
Journal article, 2020

Combinations of colloids and binders are often used to formulate functional coatings. In these mixtures, competition between particle migration, polymer chain diffusion, evaporation and sedimentation affects their respective spatial location and therefore can govern the surface features. In addition to this, the surface chemistry of the nanoparticles (NPs) and the resulting interparticle interactions can play a significant role in dictating the morphology and the properties of resultant films. Hence it would be possible to tune the surface and bulk topology of the films by controlling these parameters. A combination of various acrylic binders with two types of silica sols, bare (BSiO2) and modified silica (MSiO2), differing in their ability to gel, were formulated and dried under controlled conditions. Factors influencing the mobility and migration of binder and silica particles were evaluated with respect to particle concentration and drying rate. MSiO2 films showed prominent pores with gradual increase in Si% across the cross-section of the films, whereas, BSiO2 films had no pores and showed a uniform Si content across the cross-section of the films. This difference is explained by the variation in gelation between BSiO2 compared to MSiO2, that hindered the NPs migration and affects the infiltration and stratification process. This study paves a path forward to achieve desired surface and bulk porosity from colloidal silica coatings by effective control of chemistry of particles along with process parameters.

Protective coatings

Surface chemistry

Binders

Association reactions

film stratification

particles

morphology regulation

Gelation

Sols

Silica

Silicon

Author

Archana Samanta

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Romain Bordes

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Soft Matter

1744-683X (ISSN) 1744-6848 (eISSN)

Vol. 16 27 6371-6378

SilCoTex: Hållbart smutsavvisande textilier (del 2)

Ludvig Svensson AB, 2017-12-01 -- 2020-01-30.

VINNOVA, 2017-12-01 -- 2020-01-30.

Subject Categories

Polymer Chemistry

Polymer Technologies

Materials Chemistry

Infrastructure

Chalmers Materials Analysis Laboratory

Areas of Advance

Materials Science

DOI

10.1039/d0sm00317d

More information

Latest update

1/21/2021