Polymer-Nanoparticle Complexes : from Dilute Solution to Solid State

TL;DR

This paper investigates the formation, structure, and stability of mineral nanoparticle-polyelectrolyte complexes in solution and solid state, revealing their size, stability, and structural integrity during film casting.

Contribution

It provides detailed characterization of mineral nanoparticle-polymer complexes and demonstrates their stable incorporation into solid films without structural change.

Findings

Complexes have sizes around 100 nm

Exhibit remarkable colloidal stability

Nanoparticle structure remains unchanged in films

Abstract

We report on the formation and the structural properties of supermicellar aggregates also called electrostatic complexes, made from mineral nanoparticles and polyelectrolyte-neutral block copolymers in aqueous solutions. The mineral particles put under scrutiny are ultra-fine and positively charged yttrium hydroxyacetate nanoparticles. Combining light, neutron and x-ray scattering experiments, we have characterized the sizes and the aggregation numbers of the organic-inorganic complexes. We have found that the hybrid aggregates have typical sizes in the range 100 nm and exhibit a remarkable colloidal stability with respect to ionic strength and concentration variations. Solid films with thicknesses up to several hundreds of micrometers were cast from solutions, resulting in a bulk polymer matrix in which nanoparticle clusters are dispersed and immobilized. It was found in addition that the structure of the complexes remains practically unchanged during film casting.