Dynamic phase transitions in freestanding polymer thin films

نویسندگان
چکیده

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Chain entanglement in thin freestanding polymer films.

When a thin glassy film is strained uniaxially, a shear deformation zone (SDZ) can be observed. The ratio of the thickness of the SDZ to that of the undeformed film is related to the maximum extension ratio, lambda, which depends on the entanglement molecular weight, M(e). We have measured lambda as a function of film thickness in strained freestanding films of polystyrene as a probe of M(e) in...

متن کامل

Local and average glass transitions in polymer thin films

In the companion paper to this we presented a quantitative theory for the suppression of the glass transition in a thin polymer film. Our Delayed Glassification (DG) model follows a proposal by de Gennes that free volume can be transmitted from surface to film interior via kinks transported along molecular strands or loops. In this paper we use the DG model to predict the effects of molecular w...

متن کامل

Phase-Separation-Induced Surface Patterns in Thin Polymer Blend Films

Atomic force microscopy (AFM), neutron reflection (NR) and secondary ion mass spectroscopy (SIMS) are used to examine phase separation in symmetrically segregating thin polymer blend films (e1000 Å). Phase separation in the film leads to undulations of the liquid-air interface, provided the film is sufficiently thin to suppress surface-directed spinodal decomposition waves. Flattened droplets a...

متن کامل

On plastic strain recovery in freestanding nanocrystalline metal thin films

In a recent article [J. Rajagopalan, J.H. Han, M.T.A. Saif, Science 315 (2007) 1831–1834], we have reported substantial (50–100%) plastic strain recovery in freestanding nanocrystalline metal films (grain size 50–65 nm) after unloading. The strain recovery was time dependent and thermally activated. Here we model the time evolution of this strain recovery in terms of a thermally activated dislo...

متن کامل

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 ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Proceedings of the National Academy of Sciences

سال: 2020

ISSN: 0027-8424,1091-6490

DOI: 10.1073/pnas.2006703117