Interfacial studies using drop image processing techniques

Abstract

A novel method for measuring the boundary tension, based on the line by line digitisation of the video image of a pendant drop, has been developed. The method is equivalent to measuring about 1000 pairs of (X,Y) coordinates of the drop profile. From this, the boundary tension can be calculated using the following computational sequence: 1) the location of the inflexion plane, 2) the calculation of the cross-sectional diameter and the slope of the tangent of the drop at the inflexion plane, 3) the calculation of the volume of fluid hanging between the inflexion plane and the apex and 4) the calculation of the boundary tension. The first part of this thesis describes this method and its mathematical basis as well as an attempt of error analysis. A description of the image recording system, the line by line digitiser and the computing equipment used is also given, together with the complete system calibration procedure. The second part is dedicated to the study of the ion free or compact layer at the interface between organic solvents having a low mutual miscibility with water and electrolyte solutions. Measurements of the surface excess concentration of water at the interface are carried out for alkali metal chloride solutions in contact with nitrobenzene, 1,2-dichloroethane and n-heptane. The results obtained indicate that the interface should be considered as a continuous transition region rather than a compact layer. The final part illustrates the possibilities of using the line by line digitiser to investigate the kinetics of adsorption at the fluid-liquid interfaces. Cytochrome-c is used in this study.

More information

Identifiers

Catalogue record

Export record

ASCII CitationAtomBibTeXData Cite XMLDublin CoreDublin CoreEP3 XMLEndNoteHTML CitationHTML CitationHTML ListJSONMETSMODSMPEG-21 DIDLOpenURL ContextObjectOpenURL ContextObject in SpanRDF+N-TriplesRDF+N3RDF+XMLRIOXX2 XMLReferReference ManagerSimple Metadata