Binary mixtures of charged colloids: a potential route to synthesize disordered hyperuniform materials
Binary mixtures of charged colloids: a potential route to synthesize disordered hyperuniform materials
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带电胶体的二元混合物：合成无序超均匀材料的潜在途径
DOI：
10.1039/c8cp02616e
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发表时间：
2018
影响因子：
3.3
通讯作者：
Torquato, Salvatore
中科院分区：
文献类型：
--
作者：
Chen, Duyu;Lomba, Enrique;Torquato, Salvatore
无序超均匀材料是一种新的、奇异的非晶态物质，它表现出类似晶体的行为，在这个意义上，体积分数的涨落在很大的尺度上被抑制，但它们是各向同性的，不显示衍射Bragg峰。这些材料具有新颖的光子学、声子学、输运和力学性能，具有广泛的应用前景。出于在纳米尺度上制备无序超均匀体系大样本的需要，我们研究了悬浮液中带电胶体二元混合物的光谱密度的小波数行为。胶体之间的相互作用可以用排斥的硬核汤川势来近似。我们发现，当无量纲温度低于0.05，无量纲逆屏蔽长度低于1.0(实验上可以达到)时，无序系统实际上变得超均匀。此外，随着温度和反向筛选长度的降低，超均匀程度增加，这是由“超均匀指数”来量化的。我们的结果提出了一种在标准实验室条件下在纳米尺度上合成有效无序的超均匀材料的大样本的替代方法。与通常通过阻塞粒子来合成无序超均匀材料的方法不同，这种方法没有施加高压来压缩系统的负担。
Disordered hyperuniform materials are a new, exotic class of amorphous matter that exhibits crystal-like behavior, in the sense that volume-fraction fluctuations are suppressed at large length scales, and yet they are isotropic and do not display diffraction Bragg peaks. These materials are endowed with novel photonic, phononic, transport and mechanical properties, which are useful for a wide range of applications. Motivated by the need to fabricate large samples of disordered hyperuniform systems at the nanoscale, we study the small-wavenumber behavior of the spectral density of binary mixtures of charged colloids in suspension. The interaction between the colloids is approximated by a repulsive hard-core Yukawa potential. We find that at dimensionless temperatures below 0.05 and dimensionless inverse screening lengths below 1.0, which are experimentally accessible, the disordered systems become effectively hyperuniform. Moreover, as the temperature and inverse screening length decrease, the level of hyperuniformity increases, as quantified by the “hyperuniformity index”. Our results suggest an alternative approach to synthesize large samples of effectively disordered hyperuniform materials at the nanoscale under standard laboratory conditions. In contrast with the usual route to synthesize disordered hyperuniform materials by jamming particles, this approach is free from the burden of applying high pressure to compress the systems.