Effect of chitosan on the electrokinetic, spectroscopic, and textural properties of TiO2 nanoparticles

Abstract

Titania (TiO2) nanoparticles were synthesized using the sol-gel method and subsequently modified with chitosan (CS). FTIR spectroscopy confirmed the presence of chitosan by modifications on the 3380 cm−1 and 1630 cm−1 bands, while XRD showed a shift in the reflection peaks from titania when it was bound to chitosan. TGA revealed that the actual amount of chitosan added to the composite was about 16% wt. Hydrodynamic diameter for titania particles was 720 nm, whereas the composite exhibited mainly particles of 1098 nm. Zeta potential measurements showed a change from -13.7 to 21 mV forTiO2 -CS compared to pure titania. Physisorption analysis determined the BET specific surface area of TiO2 and TiO2 -CS being 38 m2 /g and 24 m2 /g, respectively. In the visual observation, the behavior of titania and TiO2 -CS suspended in deionized water for 24 hours was observed. Contact angle measurements were taken over calcite artificial rocks using brine, brine/TiO2, and brine/TiO2 -CS, resulting in angles of 113.73°, 106.8°, and 97.90°, respectively. Although they fall within the hydrophobic range, a decrease in contact angle was achieved by adding nanoparticles. Sedimentation and agglomeration of titanium particles were formed at shorter time than for the composite suspended particles.