Paper BI+AS-ThA10
Determination of Confined Molecular Structure by using X-ray-Surface Force Apparatus (XSFA) Study in Bio-interface Application

Thursday, November 2, 2017, 5:20 pm, Room 12

In biology system, understanding of molecular dynamics at confined interface such as medicine diffusion across inter-cellular channel, lubrication at joints and electric signal transmission from nerves to nerves is boosting the modern medical and biomaterial study. To study the behavior of confined molecules in detail, a home-build X-ray surface force apparatus (XSFA) which combines a synchrotron X-ray with white light interferometry is used. In our first step, an imidazolium chloride based ionic liquid, which consists of a clear water induced phase change, was used as a modeling system to test the detection limit of XSFA. The result shows that the liquid phase change from liquid to liquid crystal can be clearly distinguished within a 50 to 100 nm confinement. Meanwhile, the application of X-ray reflectivity (XRR) reveal furthermore in-plane ordering information of the liquid crystal structure. Secondly, shear force were applied to study how confined liquids react to the friction to mimic the motion of joint. We found that friction behavior and molecular dynamics are strongly related to the gap size of the confinement, which is a useful information for artificial joint design. The combination of SFA and synchrotron X-ray has shown a great analytical potential to solve the interfacial molecular dynamic, which provides scientists another powerful tool to peer the world of molecule.