Direct force measurements between cellulose surfaces and colloidal silica particles

Title data

Radtchenko, Igor L. ; Papastavrou, Georg ; Borkovec, Michal:
Direct force measurements between cellulose surfaces and colloidal silica particles.
In: Biomacromolecules. Vol. 6 (2005) Issue 6 . - pp. 3057-3066.
ISSN 1526-4602
DOI: https://doi.org/10.1021/bm050371d

Official URL:

Abstract in another language

The interaction of cellulose layers with colloidal silica particles was investigated by direct force measurements with the atomic force microscope (AFM). Upon approach, repulsive forces were found between the negatively charged silica particles and the cellulose surface. The forces were interpreted quantitatively in terms of electrostatic interactions due to overlap of diffuse layers originating from negatively charged carboxylic groups on the cellulose surface. The diffuse layer charge density of cellulose was estimated to be 0.80 mC/m2 at pH 9.5 and 0.21 mC/m2 at pH 4. The forces upon retraction are characterized by molecular adhesion events, whereby individual cellulose chains desorb from the probe surface. The retraction profiles are dominated by well-defined force plateaus, which correspond to single-chain desorption forces of 35-42 pN. We surmise that adsorption of cellulose to probe surfaces is dominated by nonelectrostatic forces, probably originating from hydrogen bonding. Electrostatic contributions to desorption force could be detected only at high pH, where the silica surface is highly charged.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Institutions of the University:	Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Physical Chemistry II Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Former Professors > Chair Physical Chemistry II - Univ.-Prof. Dr. Andreas Fery Faculties Faculties > Faculty of Biology, Chemistry and Earth Sciences Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Physical Chemistry II Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Former Professors
Result of work at the UBT:	No
DDC Subjects:	500 Science > 540 Chemistry
Date Deposited:	13 Sep 2017 08:38
Last Modified:	22 Apr 2022 10:30
URI:	https://eref.uni-bayreuth.de/id/eprint/39583