(5az) Interfacial Forces in Nanoparticle and Biological Systems at the Micro- and Nano-Scales

The overall theme of my research is to understand the molecular and nanoparticle behavior at the interface of surfaces. As the size of particles reaches characteristic length scales, novel physical properties (compare to bulk properties) start to emerge [1]. The carbon nanotubes are one candidate and I will present a study of aqueous film of carbon nanotubes on mica surfaces, and discuss the frictional properties and structure formation of this system.

Another interesting interfacial system is bio-membrane. We have focused on the myelin membrane. The myelin sheath is a multilamellar membrane surrounding the axon of neurons in the nervous system. This sheath acts as an electrical insulator, which allows for faster and more efficient conduction of nerve impulses than unmyelinated nerves. Myelin dysfunctions vary from deterioration of signal transduction to demyelinating diseases such as multiple sclerosis (MS). We want to understand the molecular synergistic interaction responsible for a healthy myelin membrane structure. Using a Surface Forces Apparatus we have studied the interaction forces and adhesion between supported myelin lipid bilayers mediated by myelin basic protein [2].

In the last part of this poster I want to present the development and implementation of new devices for interfacial science and how to integrate them into a Surface Forces Apparatus [3].

[1] Min Y J, Akbulut M, Kristiansen K, Golan Y, and Israelachvili J; ?The role of interparticle and external forces in nanoparticle assembly?. Nature Materials 7 (2008) 527-538.

[2] Min Y, Kristiansen K, Boggs J M, Husted C, Zasadzinski J A, and Israelachvili J; ?Interaction forces and adhesion of supported myelin lipid bilayers modulated by myelin basic protein?. Proceeding of the National Academy of Science 106 (2009) 3156-3159.

[3] Kristiansen K, McGuiggan P M, Carver G, Meinhart C, and Israelachvili J; ?3D Force and Displacement Sensor for AFM and SFA measurements?. Langmuir 24 (2008) 1541-1549.