Authors
|
Dominguez-Espinosa, G. ; Synytska, A. ; Drechsler, A. ; Gutsche, C. ; Kegler, K. ; Uhlmann, P. ; Stamm, M. ; Kremer, F.
|
Title
|
Optical tweezers to measure the interaction between poly(acrylic acid) brushes
|
Date
|
10.10.2008
|
Number
|
17942
|
Abstract
|
Optical tweezers are employed to measure the forces of interaction within single pairs of poly(acrylic acid) (PAA) grafted colloids with an extraordinary resolution of ±0.5 pN. Parameters varied are the concentration and valency of the counterions (KCl, CaCl2) of the surrounding medium as well as its pH. The data are quantitatively described by a recently published model of Jusufi et al. [Colloid Polym Sci 2004; 282:910] for spherical polyelectrolyte brushes which takes into account the entropic effect of the counterions. For the scaling of the brush height a power law is found having an exponent of 0.25 ± 0.02 which ranges between the values expected for spherical and planar brushes. From the model the ionic concentration inside the brush is estimated in reasonable agreement with the literature.
|
Publisher
|
Polymer
|
Wikidata
|
|
Citation
|
Polymer 49 (2008) 4802-4807
|
DOI
|
https://doi.org/10.1016/j.polymer.2008.09.007
|
Tags
|
polymer brushes optical tweezers polyacrylic acid brushes spherical polyelectrolyte brushes charged polymer brushes salt-free solution diblock copolymers adsorption friction surfaces solvent forces model
|