RECENT PROGRESS IN NANOFISHING OF SINGLE POLYMER CHAINS
Single molecule force spectroscopy (SMFS) realized by atomic force microscope (AFM) on a single polymer chain (quasi-static nanofishing), where a polymer chain is picked up and pulled at its chemically modified terminals, only gives structural information such as persistence length and contour length.1) Beyond this technique, dynamic nanofishing, where an AFM cantilever is imposed on the forced oscillation at its resonant frequency (～10 kHz), enables us to investigate more fruitful information. The method gave extension-dependent changes of entropic elasticity and frictional coefficient with solvent molecules for mono-disperse living-polymerized polystyrene (PS).2) The solvent temperature dependence revealed that the frictional coefficient could be correlated with macroscopic intrinsic viscosity. The further possibility to detect dynamics of a single polymer chain was realized by the noise power spectrum density (PSD) analysis of an AFM cantilever at wider dynamic range (1-100 kHz). The PSD signals at elevated extension length varied depending on the force exerted on the single polymer chain as shown in Figure 1.3) The obtained data was analyzed to give the frictional coefficient of a single polymer chain as well as its effective spring constant. These values were compared with those obtained by static and forced-oscillation nanofishing.
Ken Nakajima Toshio Nishi
WPI Advanced Institute for Materials Research,Tohoku University,Sendai,Japan
国际会议
International Symposium on Polymer Physics(2008年国际高分子物理学术会议PP2008)
厦门
英文
36-37
2008-06-08（万方平台首次上网日期，不代表论文的发表时间）