Polymer Science and Engineering Department, University of Massachusetts, 120 Governors Drive, Amherst, MA 01003, USA.
Science. 2013 Oct 25;342(6157):460-3. doi: 10.1126/science.1242852.
Nanoparticles assemble at the interface between two fluids into disordered, liquid-like arrays where the nanoparticles can diffuse laterally at the interface. Using nanoparticles dispersed in water and amine end-capped polymers in oil, nanoparticle surfactants are generated in situ at the interface overcoming the inherent weak forces governing the interfacial adsorption of nanoparticles. When the shape of the liquid domain is deformed by an external field, the surface area increases and more nanoparticles adsorb to the interface. Upon releasing the field, the interfacial area decreases, jamming the nanoparticle surfactants and arresting further shape change. The jammed nanoparticles remain disordered and liquid-like, enabling multiple, consecutive deformation and jamming events. Further stabilization is realized by replacing monofunctional ligands with difunctional versions that cross-link the assemblies. The ability to generate and stabilize liquids with a prescribed shape poses opportunities for reactive liquid systems, packaging, delivery, and storage.
纳米粒子在两种流体的界面处组装成无序的液态阵列，纳米粒子可以在界面处横向扩散。通过将分散在水中的纳米粒子和油中胺封端聚合物原位生成纳米粒子表面活性剂，可以克服控制纳米粒子界面吸附的固有弱力。当液体域的形状被外部场变形时，表面积增加，更多的纳米粒子吸附到界面上。当释放该场时，界面面积减小，纳米粒子表面活性剂发生堵塞，阻止进一步的形状变化。堵塞的纳米粒子仍然是无序的液态，从而能够实现多次连续的变形和堵塞事件。通过用交联组装体的双官能版本取代单官能配体来实现进一步的稳定。生成和稳定具有规定形状的液体的能力为反应性液体系统、包装、输送和储存提供了机会。
