Salehin Rofiques, Xu Rong-Guang, Papanikolaou Stefanos
Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523, USA.
Department of Mechanical and Aerospace Engineering, The George Washington University, Washington, DC 20052, USA.
Materials (Basel). 2021 Nov 14;14(22):6867. doi: 10.3390/ma14226867.
Complex colloidal fluids, depending on constituent shapes and packing fractions, may have a wide range of shear-thinning and/or shear-thickening behaviors. An interesting way to transition between different types of such behavior is by infusing complex functional particles that can be manufactured using modern techniques such as 3D printing. In this paper, we perform 2D molecular dynamics simulations of such fluids with infused star-shaped functional particles, with a variable leg length and number of legs, as they are infused in a non-interacting fluid. We vary the packing fraction (ϕ) of the system, and for each different system, we apply shear at various strain rates, turning the fluid into a shear-thickened fluid and then, in jammed state, rising the apparent viscosity of the fluid and incipient stresses. We demonstrate the dependence of viscosity on the functional particles' packing fraction and we show the role of shape and design dependence of the functional particles towards the transition to a shear-thickening fluid.
复杂胶体流体，取决于其组成形状和填充率，可能具有广泛的剪切变稀和/或剪切增稠行为。在不同类型的此类行为之间进行转换的一种有趣方法是注入复杂的功能粒子，这些粒子可以使用诸如3D打印等现代技术制造。在本文中，我们对注入了星形功能粒子的此类流体进行二维分子动力学模拟，这些粒子的腿长和腿的数量可变，因为它们被注入到一种非相互作用的流体中。我们改变系统的填充率（ϕ），对于每个不同的系统，我们以各种应变率施加剪切力，将流体转变为剪切增稠流体，然后在堵塞状态下，提高流体的表观粘度和初始应力。我们证明了粘度对功能粒子填充率的依赖性，并展示了功能粒子的形状和设计依赖性对向剪切增稠流体转变的作用。
