Dr. Niki Prastomo, Dept. of Chemistry Education, Surya College of Education, 1 February 2012, 14.00-15.30
Abstract
Low temperature processes attract considerable interests for designing advanced ceramic materials. Recently, the
need of low energy consumption production and environmentally friendly process is becoming a great issue in a
modern technology. Furthermore, the application of polymer material in conjunction with ceramic products
establishes a certain requirement in term of temperature in the production processes. To overcome this issue, one of
the most popular processes that have been well studied and modified is a sol-gel technique. Various materials,
including inorganic, organic, metallic and hybrids, are covered by this method. Wide ranges of applications from
advanced to generally used materials are also included in the sol-gel technology and it is useful to fabricate various
morphologies such as nanoparticles, film coatings, fibers, and aerogels. To acquire dense oxide materials as final
products, heat treatments of the gels at high temperatures are usually carried out. The main point which is needed
for densification and/or crystallization of sol-gel derived products is dehydration promotion and rearrangements of
the atomic network of the gel. In conventional heating processes, the dehydration and rearrangement were done
through the vibration excitation of the atomic bonds. Many works have been reported as an alternative to
conventional heat treatment to perform low temperature gel densification process particularly for sol-gel derived thin
films. One promising way lowering the temperature process for sol-gel based thin films is hot-water treatment
(HWT). Substrates with thin film coatings were immersed into hot, pure water and kept at rest for a given time. The
main background of this research work is the utilization of HWT upon preparation of oxide materials via sol-gel
process and the interest point of this treatment is the application of low temperature process assisted by solution
system as a medium for dissolution and reprecipitations of hydrolyzed metal oxide species. With this background,
low temperature titania crystallization on silica-titania gel films topic was studied. Mechanism of precipitation of
anatase crystal on the surface of silica-titania gel films was successfully analyzed. Introduction of external field
during HWT provides different crystal and morphological structure. Furthermore, the obtained films showed
promising future to be used in the application for dye sensitized solar cells (DSSC) and room temperature optical
hydrogen sensor. In addition, study on super-hydrophobic transparent alumina coating was also performed. Water
contact angle higher than 150° was successfully obtained, which provide high potential to be applied for self cleaning
coatings.
Keywords: Sol-gel; Low temperature synthesis; Hot-water treatment; Metal oxide functional materials.
Dr. Prastomo has h-index of 7 as of April 2017
