Measurement of Chitosan Material Surface Charge Distribution Using Scanning Probe Microscope

In the paper, one way is put forward to measure the surface charge density on materials, which is very weak, whose distribution is not even and where there is no neutral region. Namely, during the experiment, using Electric Force Microscopy (EFM) in Scanning probe microscopy (SPM) by Tapping Mode and Left Mode the spacial distribution of the surface charging density of the organic macromolecule film was measured by the phase images, such as chitosan film (CHI). At the same time, due to the design of SPM contains unwillingly certain approximation-sinΔΦ is about equal to 1/2ΔΦ using the Taylor expansion, the obtained electric charge image on the film surface can only determine its surface charging density distribution and the approximation of the surface trapped charging density. However, the microgrooved structure of surface charge distribution is favorable to promoting nerve cell growth, especially when the distance is about 2.12μm between adjacent positive charge peaks on the material surface. Therefore, the obtained surface charging density distribution supplies the surface physicochemical properties of biomaterials.