Spectroscopic studies of poly(vinyl alcohol) films filled with a lanthanum/N‐ethylmorpholine complex

Abstract

Poly(vinyl alcohol) (PVA) films with different concentrations of lanthanum ions were prepared with a casting technique. The thickness of the prepared samples was 0.25 mm. Optical absorption and transmission measurements were performed for these samples. The ultraviolet-visible absorption spectra of pure PVA showed absorption bands at 200, 275, and 325 nm, which were assigned to the presence of carbonyl groups. The absorption spectra of doped PVA films showed an observable change in the band position with the filling levels. This was due to the link between the lanthanum metal ion and the polymer OHÀ À groups. The dependence of the absorption coefficient on the photon energy was determined, and the band tails and energy gaps were calculated. The band tail increased, whereas the optical gaps decreased, as the concentration of lanthanum ions increased. X-ray diffraction was used to characterize the prepared films. The results indicated the appearance of several new bands not existing for the lanthanum ions or PVA. Direct current/voltage characterization curves were measured for PVA-lanthanum films with different concentrations, and they showed remarkable increases in the conduction current of about 3 orders of magnitude in comparison with that of the pure PVA film.

Structural, thermal and electrical properties of plasticised PVA based polymer electrolyte

“…These OH groups can be a source of hydrogen bonding and hence assist the formation of polymer electrolytes (PEs). 5,6 However, monovalent ions like lithium capture must work in this field. The use of multivalent cations like magnesium will offer new technological applications with low cost and metal less reactive than lithium.…”

Fabrication of poly(vinyl alcohol) nanocomposites having different contents of modified SiO2 by vitamin B1 as biosafe and novel coupling agent to improve mechanical and thermal properties

“…For the pure PVA (Fig. a), an absorption peak is found within 200–300 nm, which was attributed to π–π* transitions of CO and/or CC, which was originated from unsaturated bonds . The appearance of absorption peaks about 215 and 280 nm for all three prepared NCs (Fig.…”

Properties of poly(vinyl alcohol)–borax gel doped with neodymium and praseodymium

“…Some studies have also been reported on poly(vinyl alcohol) thin films doped with a single rare-earth viz. Ho 3+ , Er 3+ , Sm 3+ , Eu 3+ and Ce 3+ (Kumar et al 1997;Seeta Rama Raju et al 2006;Abdel-Kader and Anwer 2007;Abdelaziz 2011). We have not come across studies on PVA matrices with combinations of different rare-earth dopant species.…”