Nanostructured Titanium Oxide Fabricated via Block Copolymer Template

Titanium tetrachloride vapor was selectively introduced into hexagonally arranged PEO cylinders in PEOm-b-PMA(Az)(n) ((m, n) = (272, 116), (272, 94), and (114, 67)) thin films by simply exposing the films to the vapor in a glass vessel. TEM images of PEOm-b-PMA(AZ)(n) thin films with m = 272 and 114 after the exposure showed hexagonally arranged dark spots with 14-nm diameter and 38-nm distance, and 10-nm diameter and 20-nm distance, respectively. FTIR measurement indicated a change in the peak shape at stretching vibration of C-O-C in the PEO chain as titanium tetrachloride was introduced. The film weight during the vapor process was increased in QCM measurement. XPS analysis was carried out for the films before and after hydrolysis with water vapor. It was found that titanium oxide with some different oxidation states existed in the hydrolysis treatment. FESEM revealed that calcination of the hydrolyzed film gave titanium oxide nanowires with about 10-nm diameter. XRD pattern of the calcined film suggested that the process demonstrated here generated the titanium oxide nanowires consisting of polymorph mixture with brookite, rutile. and anatase.