Complex Materials, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland.
Science. 2012 Jan 13;335(6065):199-204. doi: 10.1126/science.1210822.
The orientation and distribution of reinforcing particles in artificial composites are key to enable effective reinforcement of the material in mechanically loaded directions, but remain poor if compared to the distinctive architectures present in natural structural composites such as teeth, bone, and seashells. We show that micrometer-sized reinforcing particles coated with minimal concentrations of superparamagnetic nanoparticles (0.01 to 1 volume percent) can be controlled by using ultralow magnetic fields (1 to 10 milliteslas) to produce synthetic composites with tuned three-dimensional orientation and distribution of reinforcements. A variety of structures can be achieved with this simple method, leading to composites with tailored local reinforcement, wear resistance, and shape memory effects.
微米级的增强颗粒，表面涂覆有低浓度的超顺磁纳米颗粒（0.01 到 1 体积百分比），在超低磁场（1 到 10 毫特斯拉）的作用下，可以实现三维空间中增强体的取向和分布的可控调节，从而制备出具有可调增韧、耐磨和形状记忆效应的复合材料。这种简单的方法可以实现多种结构，为复合材料的局部增强、耐磨性和形状记忆效应的定制提供了可能。
