Chitosan/TiO2 nanocomposites: Effect of microwave heating and solution mixing techniques on physical properties

Abstract

C HITOSAN/titanium oxide nanocomposite (CS/TiO 2 nanocomposite) could be prepared by different physical and chemical methods for various applications. CS/TiO 2 nanocomposite has been chemically prepared via microwave heating technique and physically prepared through solution mixing method. Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction spectroscopy (XRD), transmission electron microscopy (TEM) and dynamic light scattering (DLS) were used as spectral tools to characterize the functionality, phase, morphology and particles size of the prepared nanocomposites, respectively. The thermal stability was investigated by the thermogravimetric analysis (TGA), while optical properties were studied using ultraviolet-visible spectroscopy (UV-vis).The results have confirmed that CS/TiO 2 nanocomposite was chemically and physically prepared via the outer sphere complexation and the electrostatic repulsion between chitosan and titanium oxide nanoparticles surface (TiO 2 NPs), respectively. The thermal stability was enhanced with nanocomposite prepared by chemical method when compared to that prepared by the physical method. In addition, a significant shift in the peak of the chemically prepared nanocomposite from the UV region to visible region was observed. This shift could be attributed to the surface modification of TiO 2 NPs by the chemical reaction.

Linear and Nonlinear Optical Properties of PVA:SA Blend Reinforced by TiO2 Nanoparticles Prepared by Flower Extract of Aloe Vera for Optoelectronic Applications

“…The growth o the TiO2 NPs in the host blend is thought to cause this attitude. In general, TiO2 NPs hav absorption peaks at wavelengths less than 400 nm, one at around 275 nm and the other in a range from 320 nm to 382 nm, according to the published literature [39,40]. For th nanocomposites of the current study, Figure 5b shows a small peak observed around 27 ± 1.4 nm for all the samples.…”

Functionalized Titanium Dioxide Nanoparticle-Based Electrochemical Immunosensor for Detection of SARS-CoV-2 Antibody

“…TiO 2 -CS bio-nanocomposite has an absorption peak of nearly 257 nm. The absorbance peak was red-shifted in the bio-nanocomposite, which may be ascribed to the surface alteration of TiO 2 NPs generated by the chemical adsorption of CS on the TiO 2 NPs surface [ 60 ].…”

Polymeric Nanocomposites for Environmental and Industrial Applications

“…In a similar report, a nanocomposite comprising Ct and magnetic nanoparticles was prepared by performing the functionalization of nanoparticles with carboxylic groups, which allowed the covalent bonding of the nanoparticles with the Ct amine groups [47]. In another report, Ct/TiO 2 nanocomposite was prepared via the outer-sphere complexation reaction between the positive charges of the Ct chains and the negative charges present on the surface of TiO 2 nanoparticles [31]. A related study reported the preparation of starch/multi-walled carbon nanotubes via covalent bond formation between the hydroxyl groups of starch and the groups present on the surface of the nanomaterial [48].…”

“…Conversely, the surface becomes negatively charged when the solution pH is higher than the pH at PZC. In solutions with pH lower than the pH at PZC of TiO 2 nanoparticles and the pKa of Ct, electrostatic repulsion would occur between the charged surface of the TiO 2 nanoparticles and the chains of Ct, which would enable the complete stretching of the flexible Ct chains, thereby resulting in the dispersion of TiO 2 nanoparticles into the Ct matrix [31].…”