论文标题
高度不对称二元电荷胶体混合物中的结构相关性
Structural correlations in highly asymmetric binary charged colloidal mixtures
论文作者
论文摘要
我们探讨了在电解质的原始模型中，考虑到大电荷和尺寸比为10及更高的电解质模型中，二元电荷胶体的强烈不对称混合物的结构相关性。使用具有显式微观的计算机模拟，我们获得了类似的胶体宏之间的部分对相关函数。有趣的是，大小相关的峰值幅度小于大型和小的小宏观相关峰的幅度，这不熟悉加性排斥相互作用。在宏观之间提取最佳有效的微载体平均成对的相互作用，我们发现在非添加的Yukawa样排斥力之上，需要在小型宏之间进行额外的移动高斯的吸引力，以准确地重现其正确的成对相关性。对于小的库仑耦合，在粗粒理论中复制了该行为，而微颗粒之间的有效相互作用。但是，该理论的准确性随着库仑耦合的增加而恶化。我们强调了微观在宏观上实施的熵相互作用的相关性。我们的结果在微米大小的胶体和类似的纳米颗粒的二进制混合物中进行了实验性证实
We explore structural correlations of strongly asymmetric mixtures of binary charged colloids within the primitive model of electrolytes considering large charge and size ratios of 10 and higher. Using computer simulations with explicit microions, we obtain the partial pair correlation functions between the like-charged colloidal macroions. Interestingly the big-small correlation peak amplitude is smaller than that of the big-big and small-small macroion correlation peaks, which is unfamiliar for additive repulsive interactions. Extracting optimal effective microion-averaged pair interactions between the macroions, we find that on top of non-additive Yukawa-like repulsions an additional shifted Gaussian attractive potential between the small macroions is needed to accurately reproduce their correct pair correlations. For small Coulomb couplings, the behavior is reproduced in a coarse-grained theory with microion-averaged effective interactions between the macroions. However, the accuracy of the theory deteriorates with increasing Coulomb coupling. We emphasize the relevance of entropic interactions exerted by the microions on the macroions. Our results are experimentally verifiable in binary mixtures of micron-sized colloids and like-charge nanoparticles
