Channels standing out
Japanese researchers have used a magnetic field to line up channels in a continuous mesoporous film.
Channels in these films generally run parallel to the substrate on which the film grows. However, films with perpendicular channels would offer different properties in applications such as recording media, chemical sensors and highly selective separators.
Kazuyuki Kuroda's group, from Waseda University, used a superconducting magnet to generate a magnetic field of 12 Tesla. The samples of silica precursors cast onto glass were placed under the magnetic field, which was applied perpendicular to the glass, and dried. This prompted the channels to grow perpendicular to the glass.
The alignment is not perfect and Kuroda hopes to improve the synthesis in the future. 'Our next target is the production of mesoporous films with mesochannels aligned completely perpendicular to a substrate and with controlled uniform pore-sizes and wall thicknesses,' he says. Kuroda hopes to apply his method to other inorganic oxides.