Nanocomposites of Au/Disentangled UHMWPE: A Combined Optical and Structural Study

Molecules

Oreste Tarallo¹  Ignacio Martin-Fabiani²  StavrosX. Drakopoulos²  Linlin Guan²  Sara Ronca² 

[1] Department of Chemical Sciences, University of Naples Federico II, 80126 Napoli, Italy;Department of Materials, Loughborough University, Leicestershire LE11 3TU, UK;

关键词: polymer nanocomposites;    ultra-high molecular weight polyethylene;    structural analysis;    X-ray scattering;    optical absorption;    Au nanoparticles;   

DOI  :  10.3390/molecules25143225

来源: DOAJ

【 摘 要 】

The term disentangled refers to polymers with fewer entanglements in the amorphous regions, a metastable condition that can significantly affect the material’s properties and processing behavior. The lower entanglement density in ultra-high molecular weight polyethylene (dis-UHMWPE) facilitates the solid-state processability into uniaxially-oriented specimens reaching very high draw ratios and crystallinities. In this study, Au/dis-UHMWPE nanocomposites were formulated and processed at variable draw ratios. Polarized light microscopy suggests gold nanoparticles are oriented in arrays following the drawing of polymer chains. The structural features, upon orientation, are studied by means of Raman spectroscopy, wide- and small-angle X-ray scattering, and near-infrared spectrophotometry. Crystallinity is found to increase by 15%, as calculated by wide-angle X-ray scattering. The change in optical absorbance in the visible spectrum indicates that, with orientation, the average size of gold aggregates increases, supported quantitatively by small-angle X-ray scattering. Since the gold nanoparticles are expected to be found within amorphous chain segments, the aforementioned findings are attributed to the increase of crystallinity and thus the decrease of available (amorphous) space.

【 授权许可】

Unknown