Role of copper content on EPR, susceptibility and optical studies in poly(vinylalcohol) (PVA) complexed poly(ethyleneglycol) (PEG) polymer films

التفاصيل البيبلوغرافية
العنوان: Role of copper content on EPR, susceptibility and optical studies in poly(vinylalcohol) (PVA) complexed poly(ethyleneglycol) (PEG) polymer films
المؤلفون: I. Omkaram, T. Rajavardhana Rao, K. Veera Brahmam, Ch. Linga Raju
المصدر: Journal of Molecular Structure. 1036:94-101
بيانات النشر: Elsevier BV, 2013.
سنة النشر: 2013
مصطلحات موضوعية: Thermogravimetric analysis, Absorption spectroscopy, Organic Chemistry, Analytical chemistry, chemistry.chemical_element, Copper, Analytical Chemistry, law.invention, Inorganic Chemistry, Crystallinity, Differential scanning calorimetry, chemistry, law, Curie constant, Electron paramagnetic resonance, Glass transition, Spectroscopy
الوصف: Polymer films of poly(vinylalcohol) (PVA) complexed with poly(ethyleneglycol) (PEG) with different dopant concentrations of Cu 2+ ions are prepared by solution casting technique. Improvement in the crystallinity of the samples is observed with the X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. Thermal transition and thermal degradation of the films with respect to copper concentration were studied by Differential Scanning Calorimetry (DSC) and thermo gravimetric analysis (TGA). The change in glass transition temperature ( Tg ) as a function of copper concentrations ( x = 1–5 mol%) has been attributed to branching and steric effects in PVA + PEG complexes. In TGA curves low thermal degradation in the samples has been observed with high copper content. The EPR spectra of all the polymer samples exhibit resonance signals characteristic of Cu 2+ ions. The spin-Hamiltonian parameter, indicate that the ground state of Cu 2+ ions is d x 2 - y 2 and the site symmetry around Cu 2+ ions is tetragonally distorted octahedral site. The spin concentration ( N ) participating in the resonance is measured as a function of temperature and it obeys Boltzmans law. The paramagnetic susceptibility ( χ ) is calculated from the EPR data at various temperatures and the Curie constant ( C ) is evaluated. The optical absorption spectrum exhibits a broad band at 784 nm which is assigned to the 2 B 1 g → 2 B 2 g transition.
تدمد: 0022-2860
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::b5f1e16614bea4d563307b23513bb15b
https://doi.org/10.1016/j.molstruc.2012.09.079
حقوق: CLOSED
رقم الأكسشن: edsair.doi...........b5f1e16614bea4d563307b23513bb15b
قاعدة البيانات: OpenAIRE