Basu Abhirup, Okello Lilian B, Castellanos Natasha, Roh Sangchul, Velev Orlin D
Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA.
Soft Matter. 2023 Apr 5;19(14):2466-2485. doi: 10.1039/d3sm00090g.
The long-ranged interactions induced by magnetic fields and capillary forces in multiphasic fluid-particle systems facilitate the assembly of a rich variety of colloidal structures and materials. We review here the diverse structures assembled from isotropic and anisotropic particles by independently or jointly using magnetic and capillary interactions. The use of magnetic fields is one of the most efficient means of assembling and manipulating paramagnetic particles. By tuning the field strength and configuration or by changing the particle characteristics, the magnetic interactions, dynamics, and responsiveness of the assemblies can be precisely controlled. Concurrently, the capillary forces originating at the fluid-fluid interfaces can serve as means of reconfigurable binding in soft matter systems, such as Pickering emulsions, novel responsive capillary gels, and composites for 3D printing. We further discuss how magnetic forces can be used as an auxiliary parameter along with the capillary forces to assemble particles at fluid interfaces or in the bulk. Finally, we present examples how these interactions can be used jointly in magnetically responsive foams, gels, and pastes for 3D printing. The multiphasic particle gels for 3D printing open new opportunities for making of magnetically reconfigurable and "active" structures.
在多相流体-颗粒系统中，磁场和毛细作用力所引发的长程相互作用有助于组装出种类丰富的胶体结构和材料。在此，我们回顾通过单独或联合运用磁性和毛细相互作用，由各向同性和各向异性颗粒组装而成的多样结构。磁场的运用是组装和操控顺磁性颗粒最有效的手段之一。通过调节场强和配置，或改变颗粒特性，可以精确控制组件的磁相互作用、动力学以及响应性。同时，源自流体-流体界面的毛细作用力可作为软物质系统中可重构结合的手段，如皮克林乳液、新型响应性毛细凝胶以及用于3D打印的复合材料。我们进一步讨论了如何将磁力作为辅助参数与毛细作用力一起，在流体界面或本体中组装颗粒。最后，我们给出实例，说明这些相互作用如何在用于3D打印的磁响应泡沫、凝胶和糊剂中联合使用。用于3D打印的多相颗粒凝胶为制造磁可重构和“活性”结构带来了新机遇。
