Okuzaki Hidenori, Suzuki Hiroki, Ito Takamichi
Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-4-37 Takeda, Kofu 400-8511, Japan.
J Phys Chem B. 2009 Aug 20;113(33):11378-83. doi: 10.1021/jp902845x.
Free-standing films made of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrene sulfonate) (PEDOT/PSS) were prepared by casting water dispersion of its colloidal particles. Morphology, water vapor sorption, and electro-active polymer actuating behavior of the resulting films were investigated by means of atomic force microscopy, sorption isotherm, thermal mechanical analysis, and electromechanical analysis. It was found that the PEDOT/PSS film sorbed 60% of moisture at relative water vapor pressure of 0.95. Upon application of 10 V, the film underwent contraction of 2.4% in air at 50% relative humidity (RH) which significantly increased to 4.5% at 90% RH. The principle lay in desorption of water vapor sorbed in the film due to Joule heating, where electric field was capable of controlling the equilibrium of water vapor sorption. The film generated contractile stress as high as 17 MPa under isometric conditions and work capacity attained 174 kJ m(-3), where Young's modulus of the film increased from 1.8 to 2.6 GPa by application of 6 V at 50% RH.
通过浇铸聚（3,4 - 乙撑二氧噻吩）掺杂聚（4 - 苯乙烯磺酸盐）（PEDOT/PSS）的胶体颗粒水分散体制备了独立的薄膜。通过原子力显微镜、吸附等温线、热机械分析和机电分析等手段研究了所得薄膜的形态、水蒸气吸附和电活性聚合物驱动行为。结果发现，在相对水蒸气压力为0.95时，PEDOT/PSS薄膜吸附了60%的水分。施加10 V电压时，该薄膜在50%相对湿度（RH）的空气中收缩了2.4%，而在90%RH时显著增加到4.5%。其原理在于由于焦耳热导致薄膜中吸附的水蒸气解吸，电场能够控制水蒸气吸附的平衡。在等容条件下，该薄膜产生的收缩应力高达17 MPa，功容量达到174 kJ m(-3)，其中在50%RH下施加6 V电压时，薄膜的杨氏模量从1.8 GPa增加到2.6 GPa。
