Preparation of Transparent Bulk TiO₂/PMMA Hybrids with Improved Refractive Indices via an in Situ Polymerization Process Using TiO₂ Nanoparticles Bearing PMMA Chains Grown by Surface-Initiated Atom Transfer Radical Polymerization

Abstract

Transparent TiO/PMMA hybrids with a thickness of 5 mm and improved refractive indices were prepared by in situ polymerization of methyl methacrylate (MMA) in the presence of TiO nanoparticles bearing poly(methyl methacrylate) (PMMA) chains grown using surface-initiated atom transfer radical polymerization (SI-ATRP), and the effect of the chain length of modified PMMA on the dispersibility of modified TiO nanoparticles in the bulk hybrids was investigated. The surfaces of TiO nanoparticles were modified with both m-(chloromethyl)phenylmethanoyloxymethylphosphonic acid bearing a terminal ATRP initiator and isodecyl phosphate with a high affinity for common organic solvents, leading to sufficient dispersibility of the surface-modified particles in toluene. Subsequently, SI-ATRP of MMA was achieved from the modified surfaces of the TiO nanoparticles without aggregation of the nanoparticles in toluene. The molecular weights of the PMMA chains cleaved from the modified TiO nanoparticles increased with increases in the prolonging of the polymerization period, and these exhibited a narrow distribution, indicating chain growth controlled by SI-ATRP. The nanoparticles bearing PMMA chains were well-dispersed in MMA regardless of the polymerization period. Bulk PMMA hybrids containing modified TiO nanoparticles with a thickness of 5 mm were prepared by in situ polymerization of the MMA dispersion. The transparency of the hybrids depended significantly on the chain length of the modified PMMA on the nanoparticles, because the modified PMMA of low molecular weight induced aggregation of the TiO nanoparticles during the in situ polymerization process. The refractive indices of the bulk hybrids could be controlled by adjusting the TiO content and could be increased up to 1.566 for 6.3 vol % TiO content (1.492 for pristine PMMA).

Vision Improvement Using Titanium Dioxide Nanoparticles-Doped PMMA for Contact Lenses

“…This is because of the high bandgap of TiO 2 NP which in turn provides these particles excellent optical transmittance. The observed higher transmittance (99%) for prepared TiO 2 -PMMA nanocomposites is much better than what has been obtained in earlier researchers investigations (80%) [30,31].…”

Structure and Optical Properties of Titania-PDMS Hybrid Nanocomposites Prepared by In Situ Non-Aqueous Synthesis

“…At constant wavelength ( λ = 589 nm, Figure 8 c), the refractive index of the hybrid materials increases with the volume content of titania. Linear increase of the refractive index of polymer nanocomposites as a function of volume content of TiO 2 have previously been observed [ 47 , 48 , 49 , 50 , 51 ]. A theoretical refractive index of the TiO 2 -PDMS nanocomposites n comp can thus be estimated using [ 52 , 53 ]: where φ and n are the volume fraction and the refractive index, respectively and using 2.49 and 1.406 as refractive indices for anatase TiO 2 [ 54 ] and PDMS-OH precursors (value given by the manufacturer), respectively.…”

Characterization of As-Prepared (PMMA-PVA)/CuO-NPs Hybrid Nanocomposite Thin Films

“…Combining metal nanoparticles and polymers enhances the optical properties and alters the mechanical behavior of the polymer composite [1]. Employing a high refractive index material in optical applications frequently requires higher optical transparencies [1][2][3][4]. Polymers with high refractive index have fascinated several research groups due to their potential applications in cutting-edge optoelectronic devices such as organic light emitting diode devices [5], high performance substrates for advanced display devices [6], antireflective coatings for advanced optical applications [7] and micro lens components for charge coupled devices or complementary metal oxide semiconductor [8].…”