| Autor: |
Xiaodong Xu, Jose Jesus Agustin Flores Cuautle, Mansour Kouyate, Nicolaas Bernardus Roozen, Jozefien Goossens, Preethy Menon, Maju Kuriakose Malayil, Robbe Salenbien, Ravindran Nair Rajesh, Christ Glorieux, Pascal Griesmar, Loïc Martinez, Stéphane Serfaty |
| Předmět: |
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| Zdroj: |
Journal of Physics D: Applied Physics; 3/2/2016, Vol. 49 Issue 8, p1-1, 1p |
| Abstrakt: |
The evolution of the elastic and thermal properties of a tetramethylorthosilicate (TMOS)-based gel that exhibits an extraordinary ringing effect when enclosed in a bottle is investigated during the sol–gel transition. The results demonstrate the feasibility of three proposed experimental methods for monitoring of gels during their formation. The shear stiffening evolution during gelation is monitored by ringing bottle, resonant acoustic spectroscopy and by an ultrasonic technique using piezo electric excitation and detection. The evolution of the longitudinal modulus and the thermal diffusivity of the gel during stiffening are simultaneously determined by a combined photoacoustic and photothermal method based on heterodyne diffraction detection of impulsive stimulated scattering by, respectively, a propagating acoustic wave grating and a decaying thermal expansion grating that were both thermo elastically generated using a pulsed laser. Also, the feasibility of an inverse photopyroelectric method and a hot ball technique to monitor the thermal transport efficiency and thermal impedance of a forming gel by tracking the thermal conductivity, the thermal diffusivity, and the thermal effusivity is demonstrated. The network polymerization and stiffening during the sol–gel transition in TMOS-gel corresponds with substantial changes in the shear acoustic velocity and in all thermal properties, while the longitudinal acoustic velocity is only weakly affected. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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