idw – Informationsdienst Wissenschaft
Nachrichten, Termine, Experten
Nachrichten, Termine, Experten
Abstract: Direct force measurements have contributed in recent years much to our understanding on how surface forces influence processes like adhesion, adsorption or colloidal aggregation. Direct force measurements based on the atomic force microscope (AFM) allow for determining the underlying processes and dominating interaction mechanisms.
The first series of examples are originating from electrochemistry. By modifying gold electrodes with a thiol layer we can study the influence of externally applied potentials in combination with the terminating functional groups on the long-range interaction forces. This approach allows studying ion or polymer adsorption as well as tuning the adhesion behavior. As direct application we will show how micrometer-sized colloidal particles can be manipulated by AFM in combination with electrochemical control.
The second series of examples are related to biomaterials: Chitosan films bearing adamantane and cyclodextrin moieties, respectively, allow in principle for the preparation of multilayer films based on non-electrostatic interactions. In order to determine their interaction on the single polymer level, these modified polysaccharides have been covalently immobilized to flat surfaces and AFM-cantilevers. A pronounced increase in adhesion is observed for combination of films where host-guest interactions are possible. This adhesion can be analyzed in terms of the breaking of single host/guest complexes as well as in terms of the work of adhesion. Another example are the colloidal properties of particles prepared from spider silk proteins. We can decompose the contributions of charging behavior and of steric interactions on the colloidal stability. The former contribution can be directly related to the amino acid composition of the spider silk proteins.
Information on participating / attending:
Einladende: Prof. Dr. Christiane Helm und Prof. Dr. Fritz Scholz sowie
PD Dr. Heike Kahlert, Vorsitzende des Ortsverbandes der GDCh, hkahlert@uni-greifswald.de
Date:
06/17/2013 16:15 - 06/17/2013 17:15
Event venue:
Institut für Biochemie, Großer Hörsaal
Felix-Hausdorff-Straße 4
17489 Greifswald
Mecklenburg-Vorpommern
Germany
Target group:
Scientists and scholars, Students
Relevance:
regional
Subject areas:
Chemistry, Physics / astronomy
Types of events:
Presentation / colloquium / lecture
Entry:
06/07/2013
Sender/author:
Sabine Köditz
Department:
Presse- und Informationsstelle
Event is free:
yes
Language of the text:
German
URL of this event: http://idw-online.de/en/event43934
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