Preparation of epoxy-based hybrid films from an aqueous TiO2 dispersion via solvent exchange and surface modification with n-octylphosphonic acid

Taichi Kaneko, Yoshitaka Kamochi, Hiroyuki Yamamoto, Kimihiro Matsukawa, Yoshiyuki Sugahara

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2 Citations (Scopus)

Abstract

Transparent TiO2/epoxy hybrid films with high refractive indices have been prepared from a 9-mass% aqueous TiO2 (rutile form) dispersion by a combination of dispersion medium exchange and surface modification with n-octylphosphonic acid (OPA). The dispersion medium was exchanged from H2O to N-methylformamide (NMF) by distilling off H2O after the addition of NMF. The TiO2 surface was then modified with OPA by heating at 80°C for 24 h. IR and NMR spectra of the OPA-modified TiO2 nanoparticles (NPs) revealed that the OPA moiety was grafted onto the surface of the TiO2 NPs through Ti-O-P bonds. The resulting OPA-modified TiO2 NPs were employed to prepare epoxy-based hybrid films possessing excellent transparency. The transmittance in the entire visible range (400-800 nm) of the hybrid film containing 66.3 mass% TiO2 was above 94%. This hybrid film also exhibited the highest refractive index (n = 1.74), which represented a remarkable increase from that of the pure epoxy resin film (n = 1.51).

Original languageEnglish
Pages (from-to)593-601
Number of pages9
JournalComposite Interfaces
Volume19
Issue number9
DOIs
Publication statusPublished - 2012 Dec 1

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Keywords

  • Epoxy resin
  • High refractive index
  • Organic-inorganic hybrids
  • Titania

ASJC Scopus subject areas

  • Ceramics and Composites
  • Physics and Astronomy(all)
  • Surfaces, Coatings and Films

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