Griffiths Samuel, Turci Francesco, Royall C Patrick
School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom.
H. H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL, United Kingdom.
J Chem Phys. 2017 Jan 7;146(1):014905. doi: 10.1063/1.4973351.
The formation of colloidal gels is strongly dependent on the volume fraction of the system and the strength of the interactions between the colloids. Here we explore very dilute solutions by the means of numerical simulations and show that, in the absence of hydrodynamic interactions and for sufficiently strong interactions, percolating colloidal gels can be realised at very low values of the volume fraction. Characterising the structure of the network of the arrested material we find that, when reducing the volume fraction, the gels are dominated by low-energy local structures, analogous to the isolated clusters of the interaction potential. Changing the strength of the interaction allows us to tune the compactness of the gel as characterised by the fractal dimension, with low interaction strength favouring more chain-like structures.
胶体凝胶的形成强烈依赖于系统的体积分数以及胶体之间相互作用的强度。在此，我们通过数值模拟的方法研究了极稀溶液，并表明，在不存在流体动力学相互作用且相互作用足够强的情况下，在极低的体积分数值时就能实现渗流胶体凝胶。通过表征被捕集物质网络的结构，我们发现，当降低体积分数时，凝胶由低能量局部结构主导，类似于相互作用势的孤立簇。改变相互作用强度使我们能够调整以分形维数表征的凝胶致密性，低相互作用强度有利于形成更多链状结构。
