Unveiling Solvent Effects on Femtosecond Laser-Irradiated Au/Fe3O4 Colloidal Nanoparticles: The Acetone Effect

TL;DR

This study investigates how solvent properties and laser wavelength influence the stability and size of Au/Fe3O4 nanoparticles during femtosecond laser irradiation, revealing solvent effects as key factors in nanoparticle modification.

Contribution

It demonstrates that solvent choice, especially acetone-water mixtures, significantly affects nanoparticle stability and size tuning under femtosecond laser irradiation, highlighting solvent effects as a dominant factor.

Findings

Acetone prevents nanoparticle aggregation.

Laser wavelength influences nanoparticle size and composition.

Solvent effects can be used to predict and control nanoparticle outcomes.

Abstract

The interplay between laser parameters and liquid environments dictates the outcome of femtosecond laser-induced nanoparticle modification. We present a study of gold and iron oxide nanoparticles in water and a water-acetone mixture, irradiated with femtosecond lasers at 808 nm and 404 nm. While aggregation was observed in pure water at both wavelengths, the results revealed a strong stability and a rather unexpected wavelength-dependency in the acetone-water mixture. In this case, 808 nm irradiation produced some decrease in nanoparticle sizes, while 404 nm led to some nanoparticle growth. As a result, the acetone effect is found to be twofold: (i) on one hand, it helps to prevent aggregation; (ii) on the other hand, it acts as a reactive medium allowing to tune the nanoparticle size and composition simply by changing laser wavelength. So, this work emphasizes that solvent physical properties as well as laser-induced chemical processes in the solvent are not merely secondary effects but can dominate the final morphological outcome, providing a predictive framework for nanoparticle synthesis.