Related Experiment Video
Updated: Sep 22, 2025

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
Surface Layer Dynamics in Miscible Polymer Blends
Bradley Frieberg, Jenny Kim, Suresh Narayanan
1Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States.
Abstract:
In thin film A/B polymer/polymer mixtures, the formation of a layer at the free surface, with average composition that differs from the bulk, due to the preferential segregation of the lower cohesive energy density component, is well understood. While much is also understood about this surface layer formation and growth to date, virtually nothing is known about the surface dynamics of the chains in such mixtures. Questions about the surface chain dynamics in relation to the bulk have remained unanswered. With the use of X-ray photon correlation spectroscopy (XPCS) we show that the dynamics of poly(vinyl methyl ether) (PVME) chains at the free surface of polystyrene (PS)/PVME thin film mixtures can be orders of magnitude larger than the PVME chains in the bulk. These dynamics manifest from differences between the local compositions of the blend at the free surface and the bulk, as well as film thickness constraints.
Related Concept Videos
Theories of Dissolution: Diffusion Layer Model
This process starts with a thin layer, saturated with the drug, forming at the interface between the solid and liquid. The solute then diffuses from this layer into the main solution. The Noyes-Whitney equation suggests that the rate of dissolution relies on the diffusion...
Polymer Classification: Crystallinity
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
Step-Growth Polymerization: Overview
Many natural and synthetic polymers are produced by...
Intermolecular Forces and Physical Properties
Boundary Layer Characteristics

