Sol–gel preparation and properties of hydroxypropylcellulose–titania hybrid thin films
- 268 Downloads
Hydroxypropylcellulose (HPC)–titania hybrid thin films were prepared by sol–gel method where titanium tetraisopropoxide Ti(OC3H 7 i )4 was hydrolyzed under acidic conditions in the presence of HPC, followed by dip-coating and drying at 120 °C for 24 h. The viscosity average molecular weight of HPC was 55,000–70,000 or 110,000–150,000, and the TiO2/(HPC + TiO2) mass ratio ranged from 0 to 1, which was calculated on the assumption that all Ti(OC3H 7 i )4 is converted into TiO2. The films were 0.35–1.0 μm thick, transparent in visible region and opaque in ultraviolet (UV) region, where the optical absorption coefficient in UV region increased with increasing titania content. The refractive index increased with increasing titania content, ranging from 1.6 to 1.8 for the hybrid thin films. The pencil hardness increased from 6B to 5H, the durability in hot water significantly increased and the contact angle of water on films increased from 35° to 89° with increasing titania content. Crack-free films could be deposited on organic polymer substrates irrespective of titania or HPC contents, where cracking did not occur at higher HPC contents even when the substrate was bent.
KeywordsSol–gel process Thin films Coating Hydroxypropylcellulose Titania Organic–inorganic hybrids Hardness Wettability Durability UV absorption
This work is financially supported by the High Technology Research Center of Kansai University.
- 1.Sequeira S, Evtuguin DV, Portugal I, Esculcas AP (2007) Mater Sci Eng C-Biomim Supramol Syst 27:172Google Scholar
- 5.Wojciechowski P, Halamus T, Pietsch U (2006) Mater Sci Poland 24:507Google Scholar
- 6.Yano S, Iwata K, Kurita K (1998) Mater Sci Eng C-Biomim Supramol Syst 6:75Google Scholar
- 7.Nagpal VJ, Davis RM, Desu SB (1995) J Mater Res 10:3068Google Scholar
- 9.Borgo CA, Lazarin AM, Kholin YV, Landers R, Gushikem Y (2004) J Brazilian Chem Soc 15:50Google Scholar
- 11.Lazarin AM, Gushikem Y (2002) J Brazilian Chem Soc 13:88Google Scholar
- 12.Shojaie SS, Rials TG, Kelley SS (1996) J Appl Polym Sci 6:151Google Scholar
- 17.Schnitzler DC, Zarbin AJG (2004) J Brazilian Chem Soc 15:378Google Scholar
- 23.Almeida RM, Marques AC (1994) In: Sakka S (ed) Handbook of sol–gel science and technology: processing and characterization and applications, vol II. Kluwer Academic Publishers, Boston, p 81Google Scholar
- 24.Colthup NB, Daly LH, Wiberly SE (1990) Introduction to infrared and raman spectroscopy, 3rd edn. Academic Press, San DiegoGoogle Scholar