Utrecht University, Debye Institute for Nanomaterials Science, Padualaan 8, 3584CH Utrecht, The Netherlands.
Soft Matter. 2015 Feb 14;11(6):1067-77. doi: 10.1039/c4sm02375g.
The self-assembly of anisotropic patchy particles with a triangular shape was studied by experiments and computer simulations. The colloidal particles were synthesized in a two-step seeded emulsion polymerization process, and consist of a central smooth lobe connected to two rough lobes at an angle of ∼90°, resembling the shape of a "Mickey Mouse" head. Due to the difference in overlap volume, adding an appropriate depletant induces an attractive interaction between the smooth lobes of the colloids only, while the two rough lobes act as steric constraints. The essentially planar geometry of the Mickey Mouse particles is a first geometric deviation of dumbbell shaped patchy particles. This new geometry enables the formation of one-dimensional tube-like structures rather than spherical, essentially zero-dimensional micelles. At sufficiently strong attractions, we indeed find tube-like structures with the sticky lobes at the core and the non-sticky lobes pointing out as steric constraints that limit the growth to one direction, providing the tubes with a well-defined diameter but variable length both in experiments and simulations. In the simulations, we found that the internal structure of the tubular fragments could either be straight or twisted into so-called Bernal spirals.
采用实验和计算机模拟的方法研究了具有各向异性的三角形嵌段粒子的自组装行为。胶体粒子是通过两步种乳液聚合过程合成的，由一个中心光滑叶与两个在约 90°处的粗糙叶相连组成，形状类似于“米老鼠”的头。由于重叠体积的差异，添加适当的耗散剂只会在胶体的光滑叶之间产生吸引力，而两个粗糙叶则作为空间位阻。米老鼠粒子的基本平面几何形状是哑铃形嵌段粒子的第一个几何偏差。这种新的几何形状使得能够形成一维管状结构，而不是球形的、基本上零维的胶束。在足够强的吸引力下，我们确实发现了具有粘性叶作为核心和非粘性叶作为空间位阻的管状结构，这些空间位阻限制了生长方向，为管状结构提供了明确的直径，但在实验和模拟中，长度都是可变的。在模拟中，我们发现管状片段的内部结构可以是直的，也可以扭曲成所谓的伯纳尔螺旋。
