Bionic alumina samples were fabricated on convex dome type aluminum alloy substrate using hard anodizing technique. The convex domes on the bionic sample were fabricated by compression molding under a compressive stre...Bionic alumina samples were fabricated on convex dome type aluminum alloy substrate using hard anodizing technique. The convex domes on the bionic sample were fabricated by compression molding under a compressive stress of 92.5 MPa. The water contact angles of the as-anodized bionic samples were measured using a contact angle meter (JC2000A) with the 3μL water drop at room temperature. The measurement of the wetting property showed that the water contact angle of the unmodi- fied as-anodized bionic alumina samples increases from 90° to 137° with the anodizing time. The increase in water contract angle with anodizing time arises from the gradual formation of hierarchical structure or composite structure. The structure is composed of the micro-scaled alumina columns and pores. The height of columns and the depth of pores depend on the ano- dizing time. The water contact angle increases significantly from 96° to 152° when the samples were modified with self-assembled monolayer of octadecanethiol (ODT), showing a change in the wettability from hydrophobicity to su- per-hydrophobicity. This improvement in the wetting property chemical modification. is attributed to the decrease in the surface energy caused by the展开更多
基金The authors are grateful to the National Nature Science Foundation of China (Grant No. 50635030) and the development project on industrialization of bionic non-adhesive cooker (Grant No. 2006D90304010) for the support of this work.
文摘Bionic alumina samples were fabricated on convex dome type aluminum alloy substrate using hard anodizing technique. The convex domes on the bionic sample were fabricated by compression molding under a compressive stress of 92.5 MPa. The water contact angles of the as-anodized bionic samples were measured using a contact angle meter (JC2000A) with the 3μL water drop at room temperature. The measurement of the wetting property showed that the water contact angle of the unmodi- fied as-anodized bionic alumina samples increases from 90° to 137° with the anodizing time. The increase in water contract angle with anodizing time arises from the gradual formation of hierarchical structure or composite structure. The structure is composed of the micro-scaled alumina columns and pores. The height of columns and the depth of pores depend on the ano- dizing time. The water contact angle increases significantly from 96° to 152° when the samples were modified with self-assembled monolayer of octadecanethiol (ODT), showing a change in the wettability from hydrophobicity to su- per-hydrophobicity. This improvement in the wetting property chemical modification. is attributed to the decrease in the surface energy caused by the