We describe direct observations of molecular cooperativity near the glass transition in poly-vinyl-acetate (PVAc), through nanometer-scale probing of dielectric fluctuations. Molecular clusters switched spontaneously between two to four distinct configurations, producing complex random-telegraph-signals (RTS). Analysis of the RTS and their power spectra shows that individual clusters exhibit both transient dynamical heterogeneity and non-exponential kinetics.
disordered systems, neural networks, molecular cooperativity, polyvinyl acetate, PVAc, dielectric fluctuations
Condensed matter, Glass transition temperature
Russell, E. Vidal and Israeloff, N. E., "Direct observation of molecular cooperativity near the glass transition" (2000). Physics Faculty Publications. Paper 130. http://hdl.handle.net/2047/d20000741
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