Dynamic viscoelastic properties of silica alkoxide during the sol-gel transition.
Eur Phys J E Soft Matter
; 12(2): 275-282, 2003 Oct.
Article
en En
| MEDLINE
| ID: mdl-15007663
The viscoelastic properties of silica alkoxide gel during the sol-gel transition (SGT) are analysed using an extended shear relaxation modulus expression with a functional form based on a product of power law and Debye-Maxwell relaxation kernels. The dynamic properties are probed by small-amplitude oscillatory shear measurements in three viscoelastic domains (pre-SGT, SGT, post-SGT). Using analytical expressions for the storage G'(omega) and loss G''(omega) moduli in these three domains, it is shown that the divergence of the mean characteristic relaxation time in the pre-SGT domain can be successfully described by a percolation with bond fluctuation dynamics. It is also shown that the equilibrium shear modulus in the post-SGT domain can be successfully described by a percolation model based on an analogy with an electrical network. The amplitude and the critical exponent of the power law relaxation at the gelation time first introduced by Winter and Chambon are estimated in the pre- and post-SGT domains.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Eur Phys J E Soft Matter
Asunto de la revista:
BIOFISICA
Año:
2003
Tipo del documento:
Article
País de afiliación:
Francia
Pais de publicación:
Francia