Kühner Ferdinand, Erdmann Matthias, Gaub Hermann E
Chair for Applied Physics and Center for NanoScience, Ludwig-Maximilians Universität München, Munich, Germany.
Phys Rev Lett. 2006 Nov 24;97(21):218301. doi: 10.1103/PhysRevLett.97.218301. Epub 2006 Nov 20.
The end-to-end distance and the contour length of single polymers in dynamic adsorbate layers were measured with a mechanical approach. Individual polysaccharide chains were covalently pinned to the surface with one segment and picked up randomly with an atomic force microscope tip. The polymer section between pinpoint and the pickup point was stretched by retracting the tip from the surface. The pinpoint was derived by measuring the normal force while laterally scanning the surface at constant height. For carboxy-methyl-amylose, a Kuhn length of 0.44 nm and a scaling exponent of 0.74 were found.
采用机械方法测量了动态吸附层中单个聚合物的端到端距离和轮廓长度。单个多糖链的一段被共价固定在表面，并用原子力显微镜尖端随机拾取。通过将尖端从表面缩回，拉伸针尖与拾取点之间的聚合物部分。通过在恒定高度横向扫描表面时测量法向力来确定针尖位置。对于羧甲基直链淀粉，发现其库恩长度为0.44 nm，标度指数为0.74。
