Abstract
Molecular layer deposition is increasingly used to functionalize the surface of planar and 3D porous substrates. This study explores functionalized ‘alucone’ hybrid layers grown on ceramic substrates to enhance their surface hydrophobicity. The layers were made from trimethyl-aluminum as a precursor with five different alcohols as a co-reactant: aliphatic (ethane-1,2-diol, 2,2-oxydiethanol, 1,6-hexanediol), and aromatic (4-aminophenol, benzene-1,4-diol). After post-deposition annealing in N2 atmosphere at 250 and 350 ◦C, the changes in the physical properties and the chemical affinity of the layers were studied and compared to those of the as-depositedhybrid layers. Differential thermal analysis of the hybrid layers showed higher decomposition temperatures for the layers grown from aromatic alcohols than for those grown from aliphatic alcohols. Additionally, Fouriertransform infrared and X-ray photoelectron spectroscopy showed that an increase in annealing temperature decreased the concentrations of surface hydroxyl-groups and caused changes in the carbon-related groups. These results could be correlated to the hydrophobicity of the layers: higher water contact angles (>90◦) were measured for annealed samples, compared to those (<90◦) of the as-deposited samples grown at 150 ◦C. Thesefindings confirm that the proposed method of MLD functionalization and post-deposition annealing can be used to tune the surface hydrophobicity of ceramic membranes