Bistervels Marloes H, Kamp Marko, Schoenmaker Hinco, Brouwer Albert M, Noorduin Willem L
AMOLF, Science Park 104, Amsterdam, 1098 XG, The Netherlands.
Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, 1090 GD, The Netherlands.
Adv Mater. 2022 Feb;34(5):e2107843. doi: 10.1002/adma.202107843. Epub 2021 Dec 16.
Controlling self-assembly of nanocomposites is a fundamental challenge with exciting implications for next-generation advanced functional materials. Precursors for composites can be generated photochemically, but limited insight in the underlying processes has hindered precise hands-on guidance. In this study, light-controlled nucleation and growth is demonstrated for self-assembling composites according to precise user-defined designs. Carbonate is generated photochemically with UV light to steer the precipitation of nanocomposites of barium carbonate nanocrystals and amorphous silica (BaCO /SiO ). Using a custom-built optical setup, the self-assembly process is controlled by optimizing the photogeneration, diffusion, reaction, and precipitation of the carbonate species, using the radius and intensity of the UV-light irradiated area and reaction temperature. Exploiting this control, nucleation is induced and the contours and individual features of the growing composite are sculpted according to micrometer-defined light patterns. Moreover, moving light patterns are exploited to create a constant carbonate concentration at the growth front to draw lines of nanocomposites with constant width over millimeters with micrometer precision. Light-directed generation of local gradients opens previously unimaginable opportunities for guiding self-assembly into functional materials.
控制纳米复合材料的自组装是一项具有挑战性的基础工作，对下一代先进功能材料有着令人兴奋的影响。复合材料的前驱体可以通过光化学方法生成，但对其潜在过程的了解有限阻碍了精确的实际操作指导。在本研究中，根据用户精确的自定义设计，展示了自组装复合材料的光控成核和生长。利用紫外光通过光化学方法生成碳酸盐，以引导碳酸钡纳米晶体和无定形二氧化硅（BaCO₃/SiO₂）纳米复合材料的沉淀。使用定制的光学装置，通过优化碳酸盐物种的光生成、扩散、反应和沉淀过程，利用紫外光照射区域的半径和强度以及反应温度来控制自组装过程。利用这种控制方法，可以诱导成核，并根据微米级定义的光图案塑造生长中复合材料的轮廓和单个特征。此外，利用移动光图案在生长前沿创造恒定的碳酸盐浓度，以微米级精度绘制宽度恒定、长达数毫米的纳米复合材料线条。光导向产生局部梯度为将自组装引导到功能材料中开辟了以前无法想象的机会。
