Size Effect of Nanoparticle Diffusion in a Polymer Melt

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• 作者：Christopher A. Grabowski ; Ashis Mukhopadhyay
• 刊名：Macromolecules
• 出版年：2014
• 出版时间：October 28, 2014
• 年：2014
• 卷：47
• 期：20
• 页码：7238-7242
• 全文大小：262K
• ISSN：1520-5835

文摘

We investigated the dynamics of gold nanoparticles (NPs) within an entangled liquid of poly(n-butyl methacrylate) (PBMA) above the glass transition temperature (T_g). The experiments were performed by using a modified version of fluctuation correlation spectroscopy (FCS), which measured the translational diffusion (D) of the isolated NPs as a function of their size (2R₀ = 5鈥?0 nm) and temperature (T). We probed the most interesting but sparsely investigated length regime where the particle size/tube diameter (d_t) ratio ranges between 鈭?鈥?. This allowed us to put into direct test recently developed theories and simulations. By measuring the bulk viscosity of the melt, the ratio D/D_SE was determined, where D_SE is the continuum prediction from Stokes鈥揈instein (SE) relation. Our results indicate gradual recovery to SE behavior and full coupling to entanglement relaxation would require 2R₀ 鈮?7鈥?0d_t.