Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China.
Langmuir. 2013 Apr 2;29(13):4315-9. doi: 10.1021/la400626x. Epub 2013 Mar 19.
We study the single-chain elasticities of three kinds of neutral polymers with a carbon-carbon (C-C) backbone by atomic force microscopy-based single-molecule force spectroscopy in a nonpolar solvent (octane), aiming at measuring the inherent chain elasticity of this very important class of polymers. The finding that the single-chain elasticities of all three polymers in octane are virtually identical in the entire force region implies that the side chains of the polymers have no detectable effects on the single-chain elasticity. By utilizing the single-chain elasticity from quantum mechanics calculations, the freely rotating chain model can provide the best fitting curve when each C-C bond is set to be the rotating unit. Although there are some exceptions when the side chain is very huge, our work provides a general result for the inherent elasticity of single neutral flexible polymer chains with C-C backbones.
我们通过原子力显微镜单分子力谱在非极性溶剂（辛烷）中研究了三种具有碳-碳（C-C）主链的中性聚合物的单链弹性，旨在测量这一非常重要的聚合物类别固有的链弹性。发现在整个力区中，所有三种聚合物在辛烷中的单链弹性几乎完全相同，这意味着聚合物的侧链对单链弹性没有可检测的影响。通过利用量子力学计算的单链弹性，当每个 C-C 键都被设置为旋转单元时，自由旋转链模型可以提供最佳拟合曲线。尽管当侧链非常大时会有一些例外，但我们的工作为具有 C-C 主链的单中性柔性聚合物链的固有弹性提供了一个普遍的结果。
