The study of the particle size effect on the physical properties of TiO 2 /cellulose acetate composite films

The cast method was used to synthesize cellulose acetate (CA)/titanium oxide (TiO 2 ) composites by varying TiO 2 particle sizes at different weight ratios of 1, 1.5, 2, 2.5, and 3 wt%. The relationship between structural diversity and performance was explored. Microstructures and chemical composition of as-prepared composite films were revealed using field-emission scanning electron microscopy and Fourier-transform infrared spectroscopy. The tensile strength increased from 46.8 MPa for pure CA to 54.7 MPa for the CA-1% micro-TiO 2 composite and 81.7 MPa for the CA-2% nano-TiO 2 composite, according to the mechanical properties. The tensile strength decreased due to some degrees of agglomeration of filler particles above a critical content. UV-vis transmittance spectra showed that pure CA was almost transparent, CA-micro-TiO 2 films were less transparent than pure CA, and CA-nano-TiO 2 films could efficiently block the light. XRD diffraction for the synthesized membranes was performed. The patterns of micro-TiO 2 and nano-TiO 2 were shown as 2 θ = 25° for the anatase phase and 2 θ = 18.5 for the pure CA film, respectively. The hydrophilicity of films was also measured using the sessile drop technique. The contact angle value for the pure CA was 61.3°. As the amount of TiO 2 added to the films increased, the contact angles of the CA-micro TiO 2 and CA-nano TiO 2 films reduced from 53.2° to 29° and from 51.5° to 27°, respectively. The produced films’ improved wettability indicated that these films could be employed as filters.