Search results for "kelvin probe"
showing 4 items of 44 documents
Forces Between Solid Surfaces Across Polymer Melts as Revealed by Atomic Force Microscopy
2007
Forces between solid surfaces across polymer melts are poorly understood despite their fundamental importance and their relevance for making composite materials. Such force measurements reveal information on the structure of polymers at surfaces and of confined polymers. Experiments with the atomic force microscope and polyisoprene (PI) confirmed theoretical predictions that no long‐range force should be present in thermodynamic equilibrium. In poly(dimethyl siloxane) (PDMS) repulsive forces are observed at high molar mass. We attribute this to the formation of an immobilized layer caused by a slow release of adsorbed segments enhanced by entanglement. In low molar mass PDMS attractive forc…
Influence of organic material and sample parameters on the surface potential in Kelvin probe measurements
2019
Financial support provided by ERDF 1.1.1.1 activity project Nr. 1.1.1.1/16/A/046 “Application assessment of novel organic materials by prototyping of photonic devices” as well as Scientific Research Project for Students and Young Researchers Nr. SJZ2016/20 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged.
Conduction properties of thin films from a water soluble carbon nanotube/hemicellulose complex.
2018
We have examined the conductive properties of carbon nanotube based thin films, which were prepared via dispersion in water by non-covalent functionalization of the nanotubes with xylan, a type of hemicellulose. Measurements of low temperature conductivity, Kelvin probe force microscopy, and high frequency (THz) conductivity elucidated the intra-tube and inter-tube charge transport processes in this material. The measurements show excellent conductive properties of the as prepared thin films, with bulk conductivity up to 2000 S cm−1. The transport results demonstrate that the hemicellulose does not seriously interfere with the inter-tube conductance. peerReviewed
Direct Visualization of Molecule Deprotonation on an Insulating Surface
2012
Elucidating molecular-scale details of basic reaction steps on surfaces is decisive for a fundamental understanding of molecular reactivity within many fields, including catalysis and on-surface synthesis. Here, the deprotonation of 2,5-dihydroxybenzoic acid (DHBA) deposited onto calcite (101;4) held at room temperature is followed in situ by noncontact atomic force microscopy. After deposition, the molecules form two coexisting phases, a transient striped phase and a stable dense phase. A detailed analysis of high-resolution noncontact atomic force microscopy images indicates the transient striped phase being a bulk-like phase, which requires hydrogen bonds between the carboxylic acid moie…