论文标题
平面波接近胶体颗粒之间的精确范德华相互作用
Plane-wave approach to the exact van der Waals interaction between colloid particles
论文作者
论文摘要
范德华相互作用的数值精确评估（包括延迟效应）构成了一项具有挑战性的任务。我们提出了一种基于平面波的新方法，并证明它在更常用的多极基础上具有优势。可以通过离散的傅立叶变换来利用平面球和球形几何形状的旋转对称性。新技术应用于对聚苯乙烯或汞制成的胶体颗粒与水溶液中的聚苯乙烯球或聚苯乙烯壁之间的相互作用的研究。特别注意由培养基中盐浓度可变的筛查影响。发现特别是对于低盐浓度，接近力近似所隐含的误差比通常假设的误差大。对于汞液滴，如果筛查可以忽略不计，则发现对足够大的距离进行排斥相互作用。我们强调的是，有效的Hamaker参数显着取决于其所基于的散射几何形状。
The numerically exact evaluation of the van der Waals interaction, also known as Casimir interaction when including retardation effects, constitutes a challenging task. We present a new approach based on the plane-wave basis and demonstrate that it possesses advantages over the more commonly used multipole basis. The rotational symmetry of the plane-sphere and sphere-sphere geometries can be exploited by means of a discrete Fourier transform. The new technique is applied to a study of the interaction between a colloid particle made of polystyrene or mercury and another polystyrene sphere or a polystyrene wall in an aqueous solution. Special attention is paid to the influence of screening caused by a variable salt concentration in the medium. It is found that in particular for low salt concentrations the error implied by the proximity force approximation is larger than usually assumed. For a mercury droplet, a repulsive interaction is found for sufficiently large distances provided screening is negligible. We emphasize that the effective Hamaker parameter depends significantly on the scattering geometry on which it is based.
