Rubbing-induced molecular alignment and its relaxation in polystyrene thin films

Direct measurement of molecular motion in freestanding polystyrene thin films.

An optical photobleaching technique has been used to measure the reorientation of dilute probes in freestanding polystyrene films as thin as 14 nm. Temperature-ramping and isothermal anisotropy measurements reveal the existence of two subsets of probe molecules with different dynamics. While the slow subset shows bulk-like dynamics, the more mobile subset reorients within a few hundred seconds ...

Aging phenomena in polystyrene thin films

The aging behavior is investigated for thin films of atactic polystyrene through measurements of complex electric capacitance. During isothermal aging process the real part of the electric capacitance increases with aging time, while the imaginary part decreases with aging time. This result suggests that the aging time dependence of the real and imaginary parts are mainly associated with change...

Isothermal Relaxation of Rubbed Polystyrene Thin Films Probed with Optical Birefringence Measurements

Optical birefringence measurements were used to observe the isothermal relaxation of rubbed polystyrene films on silica substrates below the glass transition temperature. The relaxation dynamics were described by the Kohlrausch–Williams–Watts relaxation function with Arrhenius temperature dependence on relaxation time. The isothermal results were in good agreement with results obtained using a ...

Stress relaxation mechanisms in thin Sn films and its alloys – Sn whisker formation and its mitigation

Relaxation effects in HTc-Superconducting Thin Films

Mechanical relaxation experiments have been widely applied to bulk high temperature (HT,) superconducting materials. In contrast to that only few results obtained on HT, superconducting thin films were reported. None dealt with stress driven phenomena due to the high background damping from the substrate materials used. In applied magnetic fields, however, a host reed technique can be used and ...