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Micro‐ and nanocomposites of Keggin heteropolymetalates in cellulose esters
Author(s) -
Oliveira Francílio de C.,
Schneider José,
Siervo Abner,
Landers Richard,
Plepis Ana M. G.,
Pireaux JeanJacques,
RodriguesFilho Ubirajara Pereira
Publication year - 2002
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.1364
Subject(s) - phosphomolybdic acid , phosphotungstic acid , x ray photoelectron spectroscopy , nanocomposite , magic angle spinning , keggin structure , differential scanning calorimetry , decomposition , chemical engineering , chemistry , spinning , cellulose , polymer chemistry , materials science , organic chemistry , composite material , nuclear magnetic resonance spectroscopy , catalysis , physics , engineering , thermodynamics
Composites of Keggin heteropolymetalates have been prepared and characterized by SEM, XPS, 31 P‐magic angle spinning/nuclear magnetic resonance and differential scanning calorimetry. The phosphotungstic acid and phosphomolybdic acid form nanocomposites where the oxocluster structure is preserved and is highly dispersed over the material, probably inserted between the polymeric chains. Phosphovanadotungstic clusters suffer partial decomposition during composite formation, resulting in a biphasic microcomposite. The decomposition product, phosphotungstic acid presents surface segregation as shown by comparison of XPS and nuclear magnetic resonance results. Copyright © 2002 John Wiley & Sons, Ltd.