Omniphobic and icephobic twin-scale surfaces based on the “urchin”-like fluorinated Al2O3 particles are presented. Combined effect of hierarchical topography and fluorination supplied to the surfaces omniphobic and icephobic properties. The study of the stability of the Cassie wetting state is reported. High apparent contact angles were accompanied with the low contact angle hysteresis and high stability of the Cassie air trapping wetting state. Time delay of the ice crystallization as high as $$88\pm 5$$ 88 ± 5  min was established when compared to the ice formation on flat aluminum and non-fluorinated “urchin”-like surfaces. Crystallized water droplets formed on the reported nano-structured surfaces were easily blown out by the air jet with the velocity of $$v=3.0\pm 1.0$$ v = 3.0 ± 1.0  m/s, (which is markedly lower than that common for exploitation of aircrafts and turbines). Heated “urchin”-like surfaces completely restored their omniphobic and icephobic surfaces after thawing. Qualitative analysis of water freezing is supplied.

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Alumina micro-spheres with mesoporous structure called porous aluminium oxide (POA) were prepared through a hydrothermal method using Al(SO)·18HO followed by a thermal decomposition process. Silver nanocomposites of POA (Ag/POAs) with high biochemical activity were synthesized by sorption of silver nanoparticles in the matrix of POA. Synthesis of Ag/POAs using photochemical reduction enables the producing silver nanoparticles preventing their aggregation. Ag/POAs demonstrated a stronger bactericidal activity than POA. The colony-forming ability of Escherichia coli was completely lost in 1 day on Ag/POAs at silver nanoparticles concentration of 0.241 ppm. Staphylococcus epidermidis displayed higher tolerance to Ag/POAs at all silver nanoparticles concentrations, the growth of Staphylococcus epidermidis was stopped at concentration of 0.374 ppm. The bactericidal activity of Ag/POAs against bacteria in drinking water was found to be highly effective, the growth of bacteria was completely lost in 1 day at silver nanoparticles concentration of 0.108 ppm.

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