Patterning Polymer-Fullerene Nanocomposite Thin Films with Light
Patterning Polymer-Fullerene Nanocomposite Thin Films with Light
复制标题
用光对聚合物-富勒烯纳米复合薄膜进行图案化
DOI：
10.1002/adma.201203541
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发表时间：
2012
影响因子：
29.4
通讯作者：
Wong H
中科院分区：
文献类型：
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作者：
Wong H
微量的C 60富勒烯赋予稳定的薄聚合物膜对去湿的组合效果的钉扎的接触线的去湿孔，并通过有效地改变聚合物-基板的相互作用。[1，2]通过自发的聚合物-富勒烯相分离和结晶，较高分子量（Mw）的聚合物纳米复合材料薄膜产生从均匀到旋节状的明确定义的形态。[3，4]在本文中，我们报告了UV-可见光，甚至背景光暴露，是聚合物-C 60薄膜中（i）去湿抑制和（ii）纳米颗粒缔合的重要因素。我们发现一个耦合的富勒烯的光敏性和自组装过程，这导致在控制模式的形成，我们说明的效果与模型聚苯乙烯-富勒烯（PS-C 60）的电路图案。这种方法通过聚合物纳米复合材料的定向组装在软物质光刻中开辟了新的机会，并强调了它们的光活性性质，纳米粒子的脱湿抑制是有机光致变色材料（OPV）和航空航天材料在长期辐照下材料性能和稳定性的重要影响因素。填充的聚合物薄膜与纳米添加剂（包括富勒烯和衍生物、树枝状聚合物和许多其它纳米级填料颗粒）的熵驱动的基底分离（substrate segregation）[5]相关。[1，2，6，7]图1描述了在硅衬底上浇铸的低Mw PS（2k）-C 60薄膜的显著富勒烯诱导的去湿抑制（表面能σ= 69±1 mN· m− 1，称为表面“η”）。自发现以来，与生长孔的接触线钉扎相关的动力学效应和聚合物-表面相互作用的变化都被认为是这种技术上重要现象的解释[1，6]。在这里，我们证明，
Trace amounts of C 60 fullerene impart stability to thin polymer films against dewetting by the combined effects of pinning the contact lines of dewetting holes and by effectively altering the polymer-substrate interaction.[1, 2] Polymer nanocomposite thin films of higher molecular mass (M w) yield well-defined morphologies from uniform to spinodal-like, via spontaneous polymer–fullerene phase separation and crystallization.[3, 4] In this paper, we report that UV-visible, and even background, light exposure, is a strong contributing factor to (i) dewetting suppression and (ii) nanoparticle association in polymer-C 60 thin films. We find a coupling of fullerene photo-sensitivity and both self-assembly processes which results in controlled pattern formation, and we illustrate the effect with a model polystyrene–fullerene (PS–C 60) circuit pattern. This approach opens new opportunities in soft matter lithography via the directed assembly of polymer nanocomposites and underscores their photoactive nature, an effect of great interest to material performance and stability of organic photovoltaics (OPV) and aerospace materials under long-term radiation exposure.The physical mechanism responsible for dewetting suppression in nanoparticle-filled polymer thin films has been associated with an entropically driven substrate segregation [5] of the nanoadditives, including fullerenes and derivatives, dendrimers, and many other nanoscale filler particles.[1, 2, 6, 7] Figure 1 depicts the striking fullerene-induced dewetting suppression of low Mw PS (2k)-C 60 thin films cast on a silicon substrate (surface energy σ= 69±1 mN· m− 1, referred to as surface ‘σ’). Since its discovery, both kinetic effects associated with contact line pinning of growing holes and changes of the polymer-surface interaction have been suggested as explanations [1, 6] of this technologically important phenomenon. Here, we demonstrate that there