Ohio Aerospace Institute , Cleveland, Ohio, USA.
ACS Appl Mater Interfaces. 2011 Jul;3(7):2686-93. doi: 10.1021/am200468t. Epub 2011 Jun 28.
Organically modified superparamagnetic MnFe(2)O(4)/thermoplastic polyurethane elastomer (TPU) nanocomposites (0.1-8 wt %) were prepared by solvent mixing followed by solution casting. Linear aliphatic alkyl chain modification of spherical MnFe(2)O(4) provided compatibility with the TPU containing a butanediol extended polyester polyol-MDI. All MnFe(2)O(4)/TPU nanocomposite films were superparamagnetic and their saturation magnetization, σ(s), increased with increasing MnFe(2)O(4) content. All nanocomposite films exhibited large deformations (>10 mm) under a magneto-static field. This is the first report of large actuation of magnetic nanoparticle nanocomposites at low-loading levels of 0.1 wt % (0.025 vol %). The maximum actuation deformation of the MnFe(2)O(4)/TPU nanocomposite films increased exponentially with increasing nanoparticle concentration. An empirical correlation between the maximum displacement, saturation magnetization, and magnetic nanoparticle loading is proposed. The cyclic deformation actuation of a 6 wt % surface modified MnFe(2)O(4)/TPU, in a low magnetic field 151 < B(y) < 303 Oe, exhibited excellent reproducibility and controllability. MnFe(2)O(4)/TPU nanocomposite films (0.1-2 wt %) were transparent and semitransparent over the wavelengths from 350 to 700 nm.
通过溶剂混合和溶液浇铸制备了有机改性超顺磁 MnFe(2)O(4)/热塑性聚氨酯弹性体 (TPU) 纳米复合材料 (0.1-8wt%)。球形 MnFe(2)O(4) 的线性脂肪烷基链修饰提供了与含有丁二醇扩链聚酯多元醇-MDI 的 TPU 的相容性。所有 MnFe(2)O(4)/TPU 纳米复合材料薄膜均具有超顺磁性，其饱和磁化强度 σ(s) 随 MnFe(2)O(4) 含量的增加而增加。所有纳米复合材料薄膜在静磁场下均表现出大变形 (>10mm)。这是在低负载水平 (0.1wt%（0.025 体积%）) 下首次报道磁性纳米颗粒纳米复合材料的大致动。MnFe(2)O(4)/TPU 纳米复合材料薄膜的最大致动变形随纳米颗粒浓度的增加呈指数增加。提出了最大位移、饱和磁化强度和磁性纳米颗粒负载之间的经验相关性。6wt%表面改性 MnFe(2)O(4)/TPU 在低磁场 151 < B(y) < 303 Oe 下的循环变形致动表现出优异的可重复性和可控性。MnFe(2)O(4)/TPU 纳米复合材料薄膜 (0.1-2wt%) 在波长为 350 至 700nm 范围内是透明和半透明的。
