Control of silver-polymer aggregation mechanism by primary particle spatial correlations in dynamic fractal-like geometry

TL;DR

This study investigates how the spatial correlations of primary silver nanoparticles within a fractal-like polymer matrix influence their aggregation mechanism and resulting nanostructure morphology, using in situ scattering measurements.

Contribution

It reveals the role of primary particle spatial correlations and dynamic fractal geometry in controlling silver nanoparticle aggregation mechanisms.

Findings

Signatures of nucleation, growth, and assembly of primary particles identified.

Reaction temperature influences crystalline morphology.

Spatial correlations affect aggregation and nanostructure formation.

Abstract

Silver nanocrystals have been prepared by reacting silver nitrate with ascorbic acid in aqueous solution containing a low concentration of a commercial polynaphtalene sulphonate polymer (Daxad 19). Various crystalline morphologies have been obtained simply by tuning the reaction temperature. We have investigated the nanoparticle formation mechanism at three different temperatures by in situ and time resolved Small Angle X ray Scattering measurements. By modeling the scattering intensity with interacting spherical particles in a fractal-like polymer-Ag matrix, we found signatures of nucleation, growth and assembly of primary particles of about 15-20 nm. We observed how the time evolution of both spatial correlations between primary particles and the dynamic fractal geometry of the polymer-Ag matrix could influence and determine both the aggregation mechanism and the morphology of forming nanostructures in solution.