# Bridging Molecular Modeling Insights and Experimental Findings: A Comparative Study on Surfactant Effects in Al2O3 Nanofluids

## TL;DR

This study compares how different surfactants affect the stability and thermal properties of Al2O3 nanofluids, combining experiments and molecular modeling.

## Contribution

The paper introduces a comparative analysis of six surfactants in Al2O3 nanofluids using both experimental and DFT modeling approaches.

## Key findings

- Al2O3-SDS and Al2O3-CTAC nanofluids showed high colloidal stability and favorable thermophysical properties.
- Surfactant type significantly influences the zeta potential, viscosity, and thermal conductivity of nanofluids.
- DFT analysis confirmed the stability rankings observed in experimental measurements.

## Abstract

This study aimed to prepare water-based nanofluids using Al2O3 nanoparticles with different types of surfactants, and to investigate the colloidal and thermophysical properties of the obtained nanofluids. In this context, water-based Al2O3 nanofluids have been prepared using six surfactants with anionic, cationic, and nonionic characteristics SDS, CTAC, PVP, Tween 80, PVA, and Triton X-100. The electrostatic colloidal stability of the prepared samples has been determined by zeta potential and particle size measurements. To understand the interactions at the molecular level and the stabilities in terms of interaction Gibbs free energy, nanoparticle–surfactant interactions have been modeled using the DFT (Density Functional Theory) method. The overall colloidal stability rankings of nanofluids have been performed using both zeta potential measurements and DFT analysis. Furthermore, the thermophysical properties of nanofluids, which are crucial for industrial applications, have been measured. The results showed that the type of surfactant has a significant effect on the colloidal and thermophysical properties of nanofluids. It has been concluded that Al2O3-SDS and Al2O3-CTAC nanofluids can be used in cooling systems due to their high zeta potential and thermal conductivity, and low viscosity and size.