Investigating the Dynamic Viscoelasticity of Single Polymer Chains using Atomic Force Microscopy
Investigating the Dynamic Viscoelasticity of Single Polymer Chains using Atomic Force Microscopy
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DOI：
10.1002/polb.24908
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发表时间：
2019-11-26
影响因子：
--
通讯作者：
Nakajima, Ken
中科院分区：
文献类型：
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作者：
Liang, Xiaobin;Nakajima, Ken
在单分子力谱（SMFS）中，许多研究集中在聚合物链的弹性和构象上，但很少关注单个聚合物链的动态性质。在这项研究中，我们使用外部耦合到商用原子力显微镜（AFM）的自制压电控制和数据采集系统测量了甲苯、甲醇和N,N-二甲基甲酰胺中单个聚苯乙烯（PS）链的能量耗散和弹性特性，该系统提供了有关PS链动态特性的更准确的信息。我们使用与稀溶液中聚合物链粘弹性理论一致的唯象模型定量测量了单链的刚度和粘度随链长度的变化。聚合物链的有效粘度可以使用柯克伍德模型确定，该模型与溶剂的特性粘度无关，并且取决于聚合物和溶剂之间的相互作用。结果表明，单个 PS 链的粘度主要取决于聚合物和溶剂之间的相互作用。 (c) 2019 年 Wiley periodicals, Inc. J. Polym。科学，B 部分：聚合物。物理。 2019年
In single-molecule force spectroscopy (SMFS), many studies have focused on the elasticity and conformation of polymer chains, but little attention has been devoted to the dynamic properties of single polymer chains. In this study, we measured the energy dissipation and elastic properties of single polystyrene (PS) chains in toluene, methanol, and N,N-dimethylformamide using a homemade piezo-control and data acquisition system externally coupled to a commercial atomic force microscope (AFM), which provided more accurate information regarding the dynamic properties of the PS chains. We quantitatively measured the chain length-dependent changes in the stiffness and viscosity of a single chain using a phenomenological model consistent with the theory of viscoelasticity for polymer chains in dilute solution. The effective viscosity of a polymer chain can be determined using the Kirkwood model, which is independent of the intrinsic viscosity of the solvent and dependent on the interaction between the polymer and solvent. The results indicated that the viscosity of a single PS chain is dominated by the interaction between the polymer and solvent. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019