Glass transition and relaxation following PhotoPerturbation in thin polymeric films
نویسندگان
چکیده
In this letter we employ null ellipsometry on Langmuir Blodgett multilayers of a glass forming photosensitive side chain polymer to investigate both the structural changes and the related time relaxation as a function of temperature and sample thickness following isothermal optical perturbation. Below a thickness of a few layers the glassy multilayer system collapses to a smecticlike crystal. This effect is discussed in the context of the glass transition in restricted dimensionality.
منابع مشابه
The Effect of Substrate on Structural and Electrical Properties of Cu3N Thin Film by DC Reactive Magnetron Sputtering
The aim of this paper is to study the effect of substrate on the Cu3N thin films. At first Cu3N thin films are prepared using DC magnetron sputtering system. Then structural properties, surface roughness, and electrical resistance are studied using X-ray diffraction (XRD), the atomic force microscope (AFM) and four-point probe techniques respectively. Finally, the results are investigated and c...
متن کاملDielectric and Dilatometric Studies of Glass Transitions in Thin Polymer Films
Dielectric relaxation and thermal expansion spectroscopy were made for thin polystyrene films in order to measure the temperature Tα corresponding to the peak in the loss component of susceptibility due to the α-process and the α-relaxation time τ as functions of film thickness d. While the glass transition temperature Tg decreases with decreasing film thickness, Tα and τ were found to remain a...
متن کاملStudying the Adhesion Force and Glass Transition of Thin Polystyrene Films by Atomic Force Microscopy
The relaxation behaviors of thin polymer films show a strong dependence on temperature and film thickness. Direct quantitative detection of the relaxation behaviors of thin polymer films at nanometer scale by traditional instruments is however challenging. In this study, we employed atomic force microscopy (AFM)-based force-distance curve to study the relaxation dynamics and the film thickness ...
متن کاملNovel Vitrifiable Liquid Crystals as Optical
Due to the spontaneous molecular self-assembly into various mesophases and the associated optical anisotropy, liquid crystals (LCs) have found numerous electro-optical and optoelectronic applications. There are several generic device concepts. In the now almost mature LC display technology, these materials function in the fluid state where an applied field induces molecular reorientation with a...
متن کاملInfluence of Co and Fe substitution on optical and structural properties of zinc oxide thin films
Zn0.97TM0.03O (TM = Co, Fe) thin films were deposited onto glass substrates by the sol–gel method and the effects of transition metals substitution on structural and optical properties of ZnO films were investigated. The X-ray diffraction patterns revealed that the films have wurtzite structure. Optical transmittance of the films was recorded in the range of 200 -800 nm wave length and the band...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 85 23 شماره
صفحات -
تاریخ انتشار 2000