Vitrification, relaxation and free volume in glycerol–water binary liquid mixture: Spin probe ESR studies

• Published in: Journal of non-crystalline solids Vol. 355; no. 50; pp. 2433 - 2438
• Main Authors: Banerjee, Debamalya, Bhat, S.V.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01.12.2009; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Electron spin resonance; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Fragility; Glass transition; Glass transitions; Physics; Specific phase transitions; Structural relaxation; Glass transition; Electron spin resonance; Structural relaxation; 64.70. P; 61.43.−j; 76.30.−v; Fragility; Temperature dependence; Binary systems; Electron paramagnetic resonance; Structure relaxation; Glass transition temperature; 61.43.-j; 76.30.-v
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2009.08.045

Glass transition and relaxation of the glycerol–water (G–W) binary mixture system have been studied over the glycerol concentration range of 5–85 mol% by using the highly sensitive technique of electron spin resonance (ESR). For the water rich mixture the glass transition, sensed by the dissolved spin probe, arises from the vitrified mesoscopic portion of the binary system. The concentration dependence of the glass transition temperature manifests a closely related molecular level cooperativity in the system. A drastic change in the mesoscopic structure of the system at the critical concentration of 40 mol% is confirmed by an estimation of the spin probe effective volume in a temperature range where the tracer reorientation is strongly coupled to the system dynamics.