Investigation of the interface characteristics and frosting properties of the nanoporous alumina sheets

Nanoporous alumina sheets exhibit frost suppression capabilities in low-temperature environments and have potential applications in air-conditioning heat exchangers. However, the correlation between interface characteristics and frost inhibition efficiency remains insufficiently explored. In this study, nanoporous alumina sheets with controlled pore diameters (30, 100, 200, 300, and 400 nm) were fabricated via anodic oxidation, using polished aluminum sheets as the baseline. A dedicated experimental platform was developed to quantitatively evaluate frosting behavior through gravimetric analysis, achieving a measurement uncertainty of 6.20–7.19 %. Mechanistic insights into frost formation were systematically investigated by correlating interface characteristics—including contact angle, specific surface area, and fractal dimension—with observed frost growth dynamics. Notably, the 100 nm pore alumina sheet demonstrated a 28 % reduction in average frosting rate compared to the polished counterpart. The experimental data exhibited good agreement with predictions from the Wu model, with deviations within acceptable limits (≤8 %). These findings provide critical design guidelines for anti-frosting surfaces in refrigeration systems.