标题： 纳米颗粒之间的有效相互作用 显示英文标题

标题： Effective interactions between a pair of nanoparticles

摘要： 我们研究了在表现出两相分离的溶剂中，两个纳米颗粒（或胶体）之间的有效相互作用。 使用非局部密度泛函理论，我们确定了当溶剂接近体相两相共存时，有效势能与纳米颗粒分离距离的依赖关系。 如果相同的纳米颗粒优先吸附相$\alpha$被插入相$\beta$中，则其表面会形成厚的优先相$\alpha$润湿层。 在纳米颗粒的某个特定分离距离$h_b$时，润湿层连接形成一个单一的桥，对于所有距离$h<h_b$，诱导的有效势能变得非常吸引。 桥接是所有半径大于临界半径$R_c$的纳米颗粒的第一阶毛细凝聚类似转变，其值被估计为大约$R_c\approx20\sigma$对于温度$T/T_c\approx0.9$，其中$\sigma$是溶剂（平方势）粒子的大小。 对于半径$R<R_c$，桥接过程是连续的。 如果相同的颗粒被插入到优选相$\alpha$中，它们之间的唯一有效相互作用是由短程耗尽势引起的。 如果纳米颗粒具有相反的吸附偏好，则只会在其中一个纳米颗粒周围形成单层润湿层，而在两种相中有效相互作用都是强烈的排斥。 由第二个颗粒的存在破坏润湿膜而引起的排斥力在低密度状态下更大且稍远距离。 显示英文摘要

摘要： We investigate the effective interactions between two nanoparticles (or colloids) immersed in a solvent exhibiting two-phase separation. Using a non-local density functional theory, we determine the dependence of the effective potential on the separation of the nanoparticles when the solvent is near bulk two-phase coexistence. If identical nanoparticles preferentially adsorbing phase $\alpha$ are inserted into phase $\beta$, thick wetting layers of the preferable phase $\alpha$ develop at their surfaces. At some particular separation $h_b$ of the nanoparticles, the wetting layers connect to form a single bridge, and the induced effective potential becomes strongly attractive for all distances $h<h_b$. The bridging is a first order capillary condensation like transition for all radii of the nanoparticles greater than the critical radius $R_c$, the value of which was estimated to be approximately $R_c\approx20\sigma$ for a temperature $T/T_c\approx0.9$, where $\sigma$ is the size of the solvent (square-well) particles. For radii $R<R_c$ the process of bridging is continuous. If the same particles are inserted into the preferable phase $\alpha$, the only effective interaction between them is induced by the short-ranged depletion potential. If the nanoparticles have opposite adsorption preferences, only a single wetting layer forms around one of the nanoparticles and the effective interaction is strongly repulsive in both phases. The repulsion, induced by a disruption of the wetting film by the presence of the second particle, is larger and slightly longer-ranged in a low density state.