Liu Qingkun, Smalyukh Ivan I
Department of Physics, University of Colorado, Boulder, CO 80309, USA.
Department of Electrical, Computer, and Energy Engineering, Materials Science and Engineering Program, and Soft Materials Research Center, University of Colorado, Boulder, CO 80309, USA.
Sci Adv. 2017 Aug 18;3(8):e1700981. doi: 10.1126/sciadv.1700981. eCollection 2017 Aug.
Physical properties of composite materials can be pre-engineered by controlling their structure and composition at the mesoscale. However, approaches to achieving this are limited and rarely scalable. We introduce a new breed of self-assembled nematogels formed by an orientationally ordered network of thin cellulose nanofibers infiltrated with a thermotropic nematic fluid. The interplay between orientational ordering within the nematic network and that of the small-molecule liquid crystal around it yields a composite with highly tunable optical properties. By means of combining experimental characterization and modeling, we demonstrate submillisecond electric switching of transparency and facile responses of the composite to temperature changes. Finally, we discuss a host of potential technological uses of these self-assembled nematogel composites, ranging from smart and privacy windows to novel flexible displays.
复合材料的物理性质可以通过在中尺度上控制其结构和组成来预先设计。然而，实现这一目标的方法有限，且很少具有可扩展性。我们引入了一种新型的自组装丝状凝胶，它由被热致向列型流体渗透的薄纤维素纳米纤维的取向有序网络形成。向列型网络内的取向有序与周围小分子液晶的取向有序之间的相互作用产生了一种具有高度可调光学性质的复合材料。通过结合实验表征和建模，我们展示了该复合材料亚毫秒级的透明度电切换以及对温度变化的便捷响应。最后，我们讨论了这些自组装丝状凝胶复合材料的一系列潜在技术用途，从智能和隐私窗户到新型柔性显示器。
