原子力显微镜研究聚丙烯酸的单链力学性质聚丙烯酸的单分子力谱

Mechanical Properties of Single Poly(acrylic acid) Chain Studied by Atomic Force Microscopy Single Molecule Force Spectroscopy on Poly(acrylic acid)

自从１９８６年发明原子力显微镜（ＡＦＭ）以来，ＡＦＭ已经发展成为应用最为广泛的扫描探针显微镜［１］，它给材料科学家、化学家和生物学家提供了一个极为便利的研究手段．目前，原子力显微镜的空间分辨率已经达到原子尺度，同时又具有非常高的力的敏感性，可以探测１...

The mechanical properties of polyacrylic acid are investigated on the molecular scale by use of an atomic force microscopy(AFM). Polyacrylic acid was adsorbed onto the glass substrate, then picked up at one point of the chain with an AFM tip and stretched. The elongation of individual molecules was recorded as a function of the applied load. In the force curves of PAA, the monotonically rising forces with the elongation of the polymer chain are observed. After normalization according to their contour lengths, all of the force curves can be superimposed together, and no difference can be found. The superimposion clearly shows that the mechanical properties of polyacrylic acid scale linearly with their lengths and single polyacrylic acid chain is stretched.