Template-directed colloidal crystallization
Template-directed colloidal crystallization
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DOI：
10.1038/385321a0
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发表时间：
1997-01-23
期刊：
影响因子：
64.8
通讯作者：
Wiltzius, P
中科院分区：
文献类型：
--
作者：
vanBlaaderen, A;Ruel, R;Wiltzius, P
胶体晶体是由悬浮在溶液中的小颗粒形成的三维周期性结构。它们具有重要的技术用途，如光学滤波器(1-3)、开关(4)和具有光子带隙的材料(5,6)，并且它们还为结晶和熔化的基础研究(7-10)提供方便的模型系统。不幸的是，胶体晶体的应用受到合成具有可调节晶体取向的大单晶的实际困难的极大限制(11)。在这里，我们表明，胶体颗粒在图案化基板（或模板）上的缓慢沉降可以引导大块胶体晶体的结晶，因此可以调整所得晶体的晶格结构、方向和尺寸：我们将此过程称为“胶体外延”。我们还表明，通过使用带有荧光核心合成的二氧化硅球 (12,13)，可以通过共焦显微镜研究胶体晶体中因模板故意晶格失配而产生的缺陷结构 (14)。我们认为，胶体外延将为设计和制造基于胶体晶体的材料开辟新的途径，并允许对真实空间中的异质结晶进行定量研究。
Colloidal crystals are three-dimensional periodic structures formed from small particles suspended in solution. They have important technological uses as optical filters(1-3), switches(4) and materials with photonic band gaps(5,6), and they also provide convenient model systems for fundamental studies of crystallization and melting(7-10). Unfortunately, applications of colloidal crystals are greatly restricted by practical difficulties encountered in synthesizing large single crystals with adjustable crystal orientation(11). Here we show that the slow sedimentation of colloidal particles onto a patterned substrate (or template) can direct the crystallization of bulk colloidal crystals, and so permit tailoring of the lattice structure, orientation and size of the resulting crystals: we refer to this process as 'colloidal epitaxy'. We also show that, by using silica spheres synthesized with a fluorescent core(12,13), the defect structures in the colloidal crystals that result from an intentional lattice mismatch of the template can be studied by confocal microscopy(14). We suggest that colloidal epitaxy will open new ways to design and fabricate materials based on colloidal crystals and also allow quantitative studies of heterogeneous crystallization in real space.