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Modifications in the correlation function in poly(vinyl alcohol)/silica hybrid wet gels
Author(s) -
Vollet Dimas R.,
Donatti Dario A.,
Ibañez Ruiz Alberto
Publication year - 2009
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889808034900
Subject(s) - vinyl alcohol , fractal , fractal dimension , scattering , mass fraction , materials science , correlation function (quantum field theory) , power law , molar mass , small angle x ray scattering , polymer chemistry , chemistry , composite material , optics , physics , polymer , mathematics , dielectric , mathematical analysis , optoelectronics , statistics
Small‐angle X‐ray scattering was used to study structural modifications in tetraethoxysilane‐derived poly(vinyl alcohol) (PVA)/silica hybrids. The basic structure of the wet gels can be described as a mass‐fractal structure with fractal dimension D equal to 2 and characteristic length ξ, which increases with addition of PVA. Wet gels with high PVA content exhibit a positive deviation from the mass‐fractal power‐law scattering at low q ; this deviation is associated with additional scattering due to a second large correlation distance ζ, reinforced by the addition of PVA. The fraction of both contributions to the total correlation function was estimated; this is the first time that such a study has been carried out for mass‐fractal structures.