Synthesis and Characterization of Polymeric (PMMA-PVA) Hybrid Thin Films Doped with TiO2 Nanoparticles Using Dip-Coating Technique

Abstract

We report the synthesis of hybrid thin films based on Poly(MethylMethAcrylate) (PMMA) and Poly(VinylAlcohol) (PVA), doped with different concentrations of titanium dioxide nanoparticles (TiO2 NPs). As-prepared thin films of (PMMA-PVA) doped by TiO2 NPs (wt.% = 2%, 4%, 8%, and 16%) are deposited on glass substrate. Transmittance (T%), reflectance (R%), absorption coefficient (α), optical constants (n and k), and optical dielectric functions (ε1 and ε2) are deduced using the experimental transmittance and reflectance spectra. Furthermore, a combination of classical models such as Tauc, Urbach, Spitzer-Fan, and Drude models are applied to calculate the optical and optoelectronic parameters and the energy gaps of the prepared nanocomposite thin films. The optical bandgap energy of PMMA-PVA thin film is found to be 4.101 eV. Incorporation of TiO2 NPs into PMMA-PVA polymeric thin films leads to a decrease in the optical bandgap and thus bandgap engineering is possible. Fourier-transform infrared spectroscopy (FTIR) transmittance spectra of thin films are measured and interpreted to identify the vibrational modes. To elucidate the chemical stability, thermogravimetric (TGA) curves are measured. We found that (PMMA-PVA)/TiO2 NPs polymeric thin films are thermally stable below 110 °C enable them to be attractive for a wide range of optical and optoelectronic applications.

Tunable High Refractive Index Polymer Hybrid and Polymer–Inorganic Nanocomposite Coatings

“…The refractive index reported here is also higher than for other nanocomposite coatings where nanoparticles were incorporated into a host polymer containing bromine atoms and aromatic rings in order to obtain high refractive index films. 66 , 67 Furthermore, the refractive index attained in the current investigation is larger than earlier values for low loading of polymer–inorganic nanocomposite coatings (≤10 wt % inorganic material): n = 1.73 (8 wt % TiO 2 ), 54 n = 1.81 (8 wt % HfO 2 ), 68 and n = 1.833 (10 wt % carbon black). 33 Synthesis of coatings containing titania where the refractive index was slightly higher than the 1.936 value reported in the present study includes wet preparation by nanoparticle dispersion into polymers 32 and the sol–gel method.…”

“…The slight drop in refractive index toward lower wavelengths has also been previously observed for other systems, for example, wet-coated polymer–titania composite films, where it is attributed to the incident photon frequency becoming approximately equal to the plasma frequency leading to anomalous dispersion. 54 For a fixed nanoparticle loading, the refractive index could be increased further by raising the toluene content ( n 635 nm = 1.836 ± 0.022 for 5% w/v titania nanoparticles dispersed in a 3:2 v/v 4-bromostyrene/toluene mixture)—this can be attributed to a better dispersion of nanoparticles in the precursor mixture by using larger amounts of toluene. Control experiments with the titania loading kept constant at 5% w/v while lowering the 4-bromostyrene/toluene ratio further did not lead to any additional improvement in the refractive index beyond this optimal 3:2 v/v value (for instance, 5% w/v TiO 2 nanoparticles in a 2:3 v/v 4-bromostyrene/toluene mixture gave n 635 nm = 1.819 ± 0.015).…”

Synthesis of Optically Tunable and Thermally Stable PMMA–PVA/CuO NPs Hybrid Nanocomposite Thin Films

“…Table 3 presents a comparison between the values of key optical and optoelectronic parameters of PMMA–PVA/CuO NPs nanocomposites with the corresponding values of PMMA–PVA doped withTiO 2 and SiO 2 NPs reported in our previous works [ 17 , 19 ]. The most striking finding is simply evidenced by the ability to tune the values of the refractive index measured at 550 nm for optical device applications according to the type of NPs inserted homogenously into the polymeric matrix.…”

“…Using a simple approach to introduce CuO nanoparticles into PMMA–PVA polymer-matrix composites, distinguished mechanical, thermal, physical, electrical and optical properties are obtained. Integrating this work with previously published works on PMMA–PVA doped with other types of nanoparticles [ 16 , 17 , 18 , 19 ] is expected to provide the industrial market with a wide spectrum of novel materials having a wide range of distinguished optical, mechanical, and physical properties. Numerous efforts could then be performed to expand this approach for the fabrication of highly efficient devices.…”

“…To elucidate the necessity of exploring the PMMA–PVA thin films doped with CuO NPs, we summarize the key optical and optoelectronic parameters of the PMMA–PVA/TiO 2 and PMMA–PVA/SiO 2 NPs nanocomposites published previously [ 17 , 19 ]. The significant influence of the type of the NPs introduced on the refractive index, high-frequency dielectric constant, extinction coefficient, optical resistivity, and optical mobility of the doped polymeric thin films motivates us to investigate the effect of introducing CuO NPs on the optical and optoelectronic properties of PMMA–PVA host polymer.…”