Electromechanical response of ionic polymer-metal composites
Electromechanical response of ionic polymer-metal composites
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DOI：
10.1063/1.372343
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发表时间：
2000-04-01
影响因子：
3.2
通讯作者：
Li, JY
中科院分区：
文献类型：
--
作者：
Nemat-Nasser, S;Li, JY
一种离子聚合物-金属复合材料（IPMC），由一个薄的Nafion片组成，两面镀有铂，当在其厚度上施加电场时，它会发生大的弯曲运动。相反，当它突然弯曲时，在其表面上产生电压。一个微观力学模型的开发，占耦合离子传输，电场，和弹性变形预测IPMC的响应，定性和定量。首先，基本的三维耦合场方程，然后将其结果应用于预测IPMC的薄板的响应。该理论的核心是认识到不平衡的电荷密度和主链聚合物之间的相互作用可以通过本征应力场呈现（Nemat-Nasser和Hori，微观力学，异质材料的整体性质，第2版，Elsevier，Amsterdam，1999）。连接本征应力的电荷密度的本构参数计算直接使用一个简单的微结构模型的Nafion。将所得结果用于预测IPMC样品的响应，与实验数据具有良好的相关性。实验表明，由突然施加的曲率引起的电压比产生相同曲率所需的电压小两个数量级。理论准确地预测了这一结果。该理论还显示了不同反离子的相对影响，例如，钠对锂，取决于复合材料对施加电压或曲率的响应。(C)2000年美国物理学会。[S0021-8979（00）09005-8]。
An ionic polymer-metal composite (IPMC) consisting of a thin Nafion sheet, platinum plated on both faces, undergoes large bending motion when an electric field is applied across its thickness. Conversely, a voltage is produced across its faces when it is suddenly bent. A micromechanical model is developed which accounts for the coupled ion transport, electric field, and elastic deformation to predict the response of the IPMC, qualitatively and quantitatively. First, the basic three-dimensional coupled field equations are presented, and then the results are applied to predict the response of a thin sheet of an IPMC. Central to the theory is the recognition that the interaction between an imbalanced charge density and the backbone polymer can be presented by an eigenstress field (Nemat-Nasser and Hori, Micromechanics, Overall Properties of Heterogeneous Materials, 2nd Ed., Elsevier, Amsterdam, 1999). The constitutive parameter connecting the eigenstress to the charge density is calculated directly using a simple microstructural model for Nafion. The results are applied to predict the response of samples of IPMC, and good correlation with experimental data is obtained. Experiments show that the voltage induced by a sudden imposition of a curvature, is two orders of magnitude less than that required to produce the same curvature. The theory accurately predicts this result. The theory also shows the relative effects of different counter ions, e.g., sodium versus lithium, on the response of the composite to an applied voltage or a curvature. (C) 2000 American Institute of Physics. [S0021-8979(00)09005-8].