Cellulose nanofibrils (CNFs) have attracted much attention because of their renewability and potential biocompatibility. However, CNFs are extremely hydrophilic due to the presence of a large number of hydroxyl groups, limiting their use as a water-resistant material. In this work, we controlled the adsorption behavior of silica nanoparticles on the surface of CNFs by adjusting the synthesis conditions.
View Article and Find Full Text PDFPolypropylene (PP) has poor oxygen barrier properties, therefore it is manufactured in a multi-layer structure with other plastics and metals, and has been widely used as a packaging material in various industries from food and beverage to pharmaceuticals. However, multi-layered packaging materials are generally low in recyclability and cause serious environmental pollution, therefore we have faced the challenge of improving the oxygen barrier performance as a uni-material. In this work, PP/nanoclay nanocomposites were prepared at nanoclay contents ranging from 0.
View Article and Find Full Text PDFSince the plastic-based multilayer films applied to food packaging are not recyclable, it is necessary to develop easily recyclable single materials. Herein, polypropylene (PP)-based cellulose nanofiber (CNF)/nanoclay nanocomposites were prepared by melt-mixing using a fixed CNF content of 1 wt %, while the nanoclay content varied from 1 to 5 wt %. The optimum nanoclay content in the PP matrix was found to be 3 wt % (PCN3), while they exhibited synergistic effects as a nucleating agent.
View Article and Find Full Text PDFPoly(lactic acid) (PLA) is a relatively brittle polymer, and its low melt strength, ductility, and thermal stability limit its use in various industrial applications. This study aimed to investigate the effect of poly(methyl methacrylate) (PMMA) and PMMA/silica hybrid particles on the mechanical properties, interfacial adhesion, and crystallization behavior of PLA/block acrylic elastomer. PLA/block acrylic elastomer blends exhibit improved flexibility; however, phase separation occurs between PLA and block acrylic elastomer domains.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
April 2011
Purpose: To measure the absorbed dose rate to water of (60)Co gamma rays of a Gamma Knife Model C using water-filled phantoms (WFP).
Methods And Materials: Spherical WFP with an equivalent water depth of 5, 7, 8, and 9 cm were constructed. The dose rates at the center of an 18-mm helmet were measured in an 8-cm WFP (WFP-3) and two plastic phantoms.