Single molecule force spectroscopy on poly(vinyl alcohol) by atomic force microscopy

The elastic properties of poly(vinyl alcohol) (PVA) were investigated on th e nanoscale using the new technique of single molecule force spectroscopy b y atomic force microscopy (AFM). It was found that the elastic properties o f PVA molecules scale linearly with their contour lengths. This finding cor roborates that the deformation of individual PVA chains is measured. The fo rce spectra of PVA show a kink at around 200 pN and cannot be fitted by an extended Langevin function. The deviation of the elastic behavior of PVA fr om a freely jointed chain model may indicate the presence of a suprastructu re of PVA in NaCl solution.