Synthesis of gluconate modified layered titanate particles using hydrolysis reaction of Ti alkoxide and characterization of their swelling behavior and structural color

Abstract

Gluconate modified layered titanate particles and their sol were prepared using titanium tetraisopropoxide (TIP) and gluconic acid aqueous solution. A mixture of ethylene glycol solution of TIP and gluconic acid aqueous solution was heated at 368 K for 24 h to obtain sol. The particles, which had a layered structure, were dispersed stably in the sol. Furthermore, dialysis of the sol with H2O formed sol with stable dispersion of the layered titanate particles in H2O. Fourier -Transform Infrared Spectroscopy (FT-IR) and Raman spectra of the obtained particles indicated that they were layered titanate particles with gluconic acid on the surface, that is, the particles were gluconate modified layered titanate. Drying the sol spontaneously formed plate morphology. The aggregated structure of the layered titanate particles swelled with H2O and formed gel. The addition of H2O to the aggregated structure finally lead to a stable dispersion of the layered titanate particles in H2O, when the weight ratio of H2O to the layered titanate was higher than 15. According to SEM observation of the freeze dried gels, the layered titanate particles had also plate morphology with a high aspect ratio and lamellar structure. Furthermore, when glycerol was dissolved into the sol of the layered titanate particles and the sol was heated to evaporate H2O, alternately integrated layered structures were obtained and they showed structural color, which depended on the weight ratio of the layered titanate particles and glycerol. UV–VIS transmittance spectra and photographs of the complex gel plate between the gluconate modified layered titanate particles and glycerol. The structural color depends on the weight ratio of (layered titanate sol/glycerol).