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Dopant‐induced microstructural, optical, and electrical properties of TiO 2 /PVA composite
Author(s) -
Praveena S.D.,
Ravindrachary V.,
Bhajantri R.F.
Publication year - 2016
Publication title -
polymer composites
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.577
H-Index - 82
eISSN - 1548-0569
pISSN - 0272-8397
DOI - 10.1002/pc.23258
Subject(s) - materials science , crystallinity , dopant , vinyl alcohol , composite number , microstructure , doping , fourier transform infrared spectroscopy , composite material , band gap , chemical engineering , polymer , optoelectronics , engineering
The optical, electrical, and microstructurtal properties of pure and TiO 2 /Poly(vinyl alcohol) (PVA) composite polymer films were carried out using FTIR, XRD, UV‐Visible, DC electrical conductivity, and Positron annihilation lifetime spectroscopy (PALS) techniques. The FTIR study reveals that the Ti + ions of TiO 2 interacts with the OH groups of PVA via intra / inter molecular hydrogen bonding and forms charge transfer complex (CTC). These formed CTC will affect the optical property of the composite film, which is reflected from UV‐Visible study. Using the observed UV–Visible spectra, optical energy band gap is estimated and its value decreases with increasing dopant concentration. The positron annihilation studies show that the considerable effect on free volume related microstructure of the PVA due to doping and complex formation. These microstructural modifications are also enhances PVA crystallinity which is reflected from XRD studies. It is also observed that the TiO 2 particle forms cluster within the PVA due to the aggregation of particles and these particle cluster size increases with dopant concentration. These microstructural variations due to doping affects the DC electrical conductivity and its variations are understood based on the intra chain one‐dimensional interpolaron hopping conduction mechanism. POLYM. COMPOS. 37:987–997, 2016. © 2014 Society of Plastics Engineers