Junsong Fu,Mengjie Zhang,Lin Jin,Liu Liu,Na Li,Lei Shang,Ming Li,Linghan Xiao,Yuhui Ao
To enhance the interfacial properties of carbon fibers (CFs) reinforced epoxy composites without sacrificing fiber strength. A facile and effective Layer-by-Layer (LbL) self assembly method was proposed to deposit graphene oxide/silica (GO/SiO 2 ) multilayers films onto CFs surface. The negatively charged GO and positively charged SiO 2 can be assembled on the surface of fiber based on electrostatic interactions. Surface microstructures of CFs were characterized systematically. Scanning electron microscopy (SEM) revealed the GO/SiO 2 multilayers films compact and homogeneous coverage onto CFs surface. This coverage significantly increases the roughness and surface energy of the fibers, improving the wettability and mechanical interlocking between fibers and resin. The optimal interfacial shear strength (IFSS) of composites with 5 layers (CF-L5) was 84.40 MPa, which increased by 86.1% compared to that of Untreated-CF composites (45.36 MPa), and the interlaminar shear strength (ILSS) of CF-L5 composites (76.34 MPa) increased by 89.3% compared to that of Untreated-CF composites (40.33 MPa). In addition, the flexural strength of CF-L5 composites (765.57 MPa) was 30.4% higher than that of Untreated-CF composites (587.19 MPa). The fractured surface, energy dispersive spectroscopy (EDS) mapping and dynamic mechanical properties of CFs composites also show a great improvement in interfacial adhesion. Moreover, the tensile strength (TS) of single fiber increased from 3.52 GPa to 3.68 GPa after LbL assembly of GO/SiO 2 . Our work suggested that such LbL self assembly is a green and promising approach toward preparing high interfacial properties in CFs composites.
Haiyun Zhai,Lu Huang,Zuanguang Chen,Zihao Su,Kaisong Yuan,Guohuan Liang,Yufang Pan
A novel solid-phase extraction chip embedded with array columns of molecularly imprinted polymer-coated silanized graphene oxide (GO/SiO 2 -MISPE) was established to detect trace rhodamine B (RB) in chili powder. GO/SiO 2 -MISPE monolithic columns for RB detection were prepared by optimizing the supporting substrate, template, and polymerizing monomer under mild water bath conditions. Adsorption capacity and specificity, which are critical properties for the application of the GO/SiO 2 -MISPE monolithic column, were investigated. GO/SiO 2 -MIP was examined by scanning electron microscopy (SEM) and Fourier transform-infrared spectroscopy. The recovery and the intraday and interday relative standard deviations for RB ranged from 83.7% to 88.4% and 2.5% to 4.0% and the enrichment factors were higher than 110-fold. The chip-based array columns effectively eliminated impurities in chili powder, indicating that the chip-based GO/SiO 2 -MISPE method was reliable for RB detection in food samples using high-performance liquid chromatography. Accordingly, this method has direct applications for monitoring potentially harmful dyes in processed food.
A GO-SiO 2 hybrid interface layer was prepared by electrostatic adsorption to synergistically improve the weak interface bonding between carbon fiber (CF) and poly(phthalazinone ether ketone) (PPEK). FTIR, Raman and XPS confirmed that GO-SiO 2 interface layer is constructed on CF surface. SEM and AFM indicated that the synergistic effect of GO-SiO 2 could obviously improve the CF surface roughness. CF-GO-SiO 2 /PPEK composite exhibits excellent interlaminar shear strength (84.2 MPa), flexural strength (1620 MPa), storage modulus (132.9 GPa) and T g (285 °C). The GO-SiO 2 interface layer improves the mechanical interlocking and wettability between CF and PPEK, and the failure mechanism of the composite changes from interfacial debonding for Untreated CF/PPEK composite to matrix cohesive destruction and fiber breakage for CF-GO-SiO 2 /PPEK composite. Moreover, the layer is beneficial to the hydrothermal ageing resistance of the composite. This study provides a promising strategy for improving the interfacial properties of advanced thermoplastic composites.
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