Microscopic origins of the crystallographically preferred growth in evaporation-induced colloidal crystals.
Microscopic origins of the crystallographically preferred growth in evaporation-induced colloidal crystals.
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蒸发诱导胶体晶体中晶体学择优生长的微观起源。
DOI：
10.1073/pnas.2107588118
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发表时间：
2021-08-10
影响因子：
11.1
通讯作者：
Aizenberg J
中科院分区：
文献类型：
--
作者：
Li L;Goodrich C;Yang H;Phillips KR;Jia Z;Chen H;Wang L;Zhong J;Liu A;Lu J;Shuai J;Brenner MP;Spaepen F;Aizenberg J
自组装是生物控制合成的中心主题之一，在制造各种先进工程材料中也发挥着关键作用。特别是，蒸发诱导的胶体颗粒自组装能够实现高度有序的二维或三维纳米结构的多功能制造，用于光学、传感、催化和其他应用。众所周知，这个过程会导致面心立方（fcc）晶格的形成，其密排{111}面平行于基底，但胶体晶体的晶体织构发展却知之甚少。在这项研究中，我们表明，通过蒸发诱导组装合成的面心立方胶体晶体中的优选<110>生长是通过机械应力诱导的几何必要位错促进的逐渐晶体学旋转来实现的。与结晶原子和离子固体不同，由于胶体晶体中晶体学上优选的生长而导致的织构发展研究较少。在这里，我们通过实验、建模和理论分析研究了蒸发诱导的胶体组装过程中纹理演变的基本机制。在这种广泛使用的获得大面积胶体晶体的方法中，胶体颗粒通过溶剂或基质前体溶液的蒸发被驱动到弯月面，在那里它们紧密堆积形成面心立方胶体组件。通过二维大面积晶体学映射，我们表明初始晶体取向由粒子与弯月面的相互作用决定，从而导致密排方向与局部弯月面几何形状的预期一致。通过结合单粒子水平的晶体结构分析，我们进一步揭示，在自组装的后期，胶体晶体在几何必要位错（GND）的促进下经历逐渐旋转，并实现大面积均匀晶体取向，密排方向垂直于弯月面且平行于生长方向。经典滑移分析、基于有限元的机械模拟、计算胶体装配建模和连续介质理论明确表明，这些 GND 是由于胶体晶体在干燥过程中受到约束收缩而沿弯月面方向产生拉应力场而产生的。在单个晶粒内产生具有特定滑移系统的 GND 会导致晶体旋转以适应机械应力。本文报道的机理理解可用于控制胶体组件的晶体学特征，并可提供对合成、生物和地质晶体中晶体学优选生长的进一步见解。
Self-assembly is one of the central themes in biologically controlled synthesis, and it also plays a pivotal role in fabricating a variety of advanced engineering materials. In particular, evaporation-induced self-assembly of colloidal particles enables versatile fabrication of highly ordered two- or three-dimensional nanostructures for optical, sensing, catalytic, and other applications. While it is well known that this process results in the formation of the face-centered cubic (fcc) lattice with the close-packed {111} plane parallel to the substrate, the crystallographic texture development of colloidal crystals is less understood. In this study, we show that the preferred <110> growth in the fcc colloidal crystals synthesized through evaporation-induced assembly is achieved through a gradual crystallographic rotation facilitated by mechanical stress-induced geometrically necessary dislocations. Unlike crystalline atomic and ionic solids, texture development due to crystallographically preferred growth in colloidal crystals is less studied. Here we investigate the underlying mechanisms of the texture evolution in an evaporation-induced colloidal assembly process through experiments, modeling, and theoretical analysis. In this widely used approach to obtain large-area colloidal crystals, the colloidal particles are driven to the meniscus via the evaporation of a solvent or matrix precursor solution where they close-pack to form a face-centered cubic colloidal assembly. Via two-dimensional large-area crystallographic mapping, we show that the initial crystal orientation is dominated by the interaction of particles with the meniscus, resulting in the expected coalignment of the close-packed direction with the local meniscus geometry. By combining with crystal structure analysis at a single-particle level, we further reveal that, at the later stage of self-assembly, however, the colloidal crystal undergoes a gradual rotation facilitated by geometrically necessary dislocations (GNDs) and achieves a large-area uniform crystallographic orientation with the close-packed direction perpendicular to the meniscus and parallel to the growth direction. Classical slip analysis, finite element-based mechanical simulation, computational colloidal assembly modeling, and continuum theory unequivocally show that these GNDs result from the tensile stress field along the meniscus direction due to the constrained shrinkage of the colloidal crystal during drying. The generation of GNDs with specific slip systems within individual grains leads to crystallographic rotation to accommodate the mechanical stress. The mechanistic understanding reported here can be utilized to control crystallographic features of colloidal assemblies, and may provide further insights into crystallographically preferred growth in synthetic, biological, and geological crystals.
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影响因子：
3.9
作者：
Born, Philip;Munoz, Andres;Kraus, Tobias
通讯作者：
Kraus, Tobias
影响因子：
8.6
作者：
Holland, BT;Blanford, CF;Stein, A
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Stein, A
影响因子：
3.9
作者：
Dufresne, E. R.;Stark, D. J.;Weitz, D. A.
通讯作者：
Weitz, D. A.
影响因子：
3.9
作者：
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通讯作者：
NAGAYAMA, K
影响因子：
9.4
作者：
Bastos, A.;Zaefferer, S.;Schuh, C.
通讯作者：
Schuh, C.