Durham Lectures 2011
(11 August 2011)
The Durham Lectures for 2011 were presented by Professor Jacob Israelachvili FRS (University of Santa Barbara). Over a series of three lectures between 21st and 23rd June 2011, Prof. Israelachvili gave a fascinating account of the chemistry and physics of soft matter at interfaces and discussed cutting-edge scienctific issues with several staff and postgraduate students.
In his first lecture he described his “surface forces apparatus” and how this was used to measure the forces between surfaces at short distances. This was used to good effect to investigate the adhesion of vesicles to hydrophobic surfaces under different temperature and ion regimes in order to understand how hydrophobic interactions contribute to adhesion. DLVO theory (a combination of electrostatic repulsion and van der Waals attraction) is sufficient to account for a small number of observations; hydrophobic effects operating over short distances (< 10 Å) provide a better rationale.
In his second lecture he developed the theory of vesicle adhesion to surfaces to include a description of depletion attraction, where effectively the lower interfacial density of water provides a force that can adhere surfaces and may be involved in phenomena such as membrane fusion.
The third lecture covered the mechanism of vesicle adhesion to surfaces to form supported lipid bilayers. Bilayers of this kind are increasingly being used as models for cell membranes as they permit study using a range of surface spectroscopies and microscopies that would otherwise be unavailable. The mechanisms by which vesicles adhere to the surface and then flatten was discussed at length by Prof. Israelachvili. The movement of water and ions holds the key to the shape changes and fusion that occurs to bring about fusion.
In addition to his lectures, Prof. Israelachvili held discussions with staff and postgraduate students during informal poster sessions, held over two days on themes of Soft Matter and Biophysical Sciences. Two students (David Woods and Adam Hayward) received signed copies of his book following these poster sessions.