Liu Shanqiu, Pandey Anupam, Duvigneau Joost, Vancso Julius, Snoeijer Jacco H
Materials Science and Technology of Polymers, MESA+ Institute for Nanotechnology, and Physics of Fluids Group, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands.
Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands.
Macromolecules. 2018 Apr 10;51(7):2411-2417. doi: 10.1021/acs.macromol.7b02353. Epub 2018 Mar 16.
Adhesion of nanoparticles to polymer films plays a key role in various polymer technologies. Here we report experiments that reveal how silica nanoparticles adhere to a viscoelastic PMMA film above the glass transition temperature. The polymer was swollen with CO, closely matching the conditions of nanoparticle-nucleated polymer foaming. It is found that the degree by which the particles sink into the viscoelastic substrate is strongly size dependent and can even lead to complete engulfment for particles of diameter below 12 nm. These findings are explained quantitatively by a thermodynamic analysis, combining elasticity, capillary adhesion, and line tension. We argue that line tension, here proposed for the first time in elastic media, is responsible for the nanoparticle engulfment.
纳米颗粒与聚合物薄膜的粘附在各种聚合物技术中起着关键作用。在此，我们报告了一些实验，这些实验揭示了二氧化硅纳米颗粒在高于玻璃化转变温度时如何粘附到粘弹性聚甲基丙烯酸甲酯（PMMA）薄膜上。聚合物用二氧化碳进行溶胀，这与纳米颗粒成核的聚合物发泡条件密切匹配。研究发现，颗粒沉入粘弹性基质的程度强烈依赖于尺寸，对于直径小于12纳米的颗粒甚至可能导致完全吞没。通过结合弹性、毛细粘附和线张力的热力学分析对这些发现进行了定量解释。我们认为，线张力（首次在此弹性介质中提出）是导致纳米颗粒被吞没的原因。
