Experimental investigation of synthesized Al<inf>2</inf>O<inf>3</inf> Ionanofluid's energy storage properties: Model-prediction using gene expression programming

In this work, 3-hydroxy-1-(4-(1-methyl piperidine-1-ium-1-yl) butyl) quinuclidine-1-ium bromide ionic liquid (IL) is synthesized. Al2O3 (~50 nm) nanoparticles (NPs) were dispersed in the IL as base fluid to prepare Ionanofluids (INF). The experiments were undertaken to determine the stability, viscosity (VST), and thermal conductivity (TC) of IL and INF in the temperature and concentration range of 30 to 60 °C and 0 to 10 wt%, respectively. The IL is characterized by nuclear magnetic resonance (NMR) spectroscopy. The pH and zeta potential values of INF are determined. The experimental outcomes show the maximum TC and VST enhancement of 32.9 and 76.3 % at 60 and 30 °C compared to IL. Additionally, the experimental data of TC and VST is compared with the theoretical models presented in the literature. The correlations are presented for the evaluation of the TC and VST of the studied INF based on experimental data. Furthermore, the gene expression programming (GEP) model is adopted. The predicted values of TC and VST of INF are attained with R2 = 0.9978 and 0.9972, respectively. The performance enhancement ratio (PER) indicates that studied INFs are beneficial for energy storage applications.