a b s t r a c tThis study aimed to investigate the effect of water absorption on the mechanical properties of nano-filler reinforced epoxy nanocomposites as well as to study the influence of different types of nano-fillers such as nano-clay platelets, halloysite nanotubes (HNTs) and nano-silicon carbide (n-SiC) particles on the water absorption behaviour of epoxy based nanocomposites. Results indicated that the addition of nano-fillers into epoxy matrix was found to decrease both water uptake and diffusivity compared to unfilled epoxy. Flexural strength and modulus of epoxy based nanocomposites were found to decrease due to the water absorption. However, the addition of nano-fillers enhanced the flexural strength and modulus of nanocomposites compared to wet unfilled epoxy. Surprising, fracture toughness and impact strength of all types of nanocomposites were found to increase after exposing to water. The presence of nano-fillers increased both fracture toughness and impact strength of nanocomposites compared to wet neat epoxy.Crown

No abstract

The enzyme-mimicking activity of iron oxide based nanostructures has provided a significant advantage in developing advanced molecular sensors for biomedical and environmental applications. Herein, we introduce the horseradish peroxidase (HRP)-like activity of gold-loaded nanoporous ferric oxide nanocubes (Au-NPFeONC) for the development of a molecular sensor with enhanced electrocatalytic and colorimetric (naked eye) detection of autoantibodies. The results showed that Au-NPFeONC exhibits enhanced peroxidase-like activity toward the catalytic oxidation of 3,3',5,5'-tertamethylbenzidine (TMB) in the presence of HO at room temperature (25 °C) and follows the typical Michaelis-Menten kinetics. The autoantibody sensor based on this intrinsic property of Au-NPFeONC resulted in excellent detection sensitivity [limit of detection (LOD) = 0.08 U/mL] and reproducibility [percent relative standard deviation (% RSD) = <5% for n = 3] for analyzing p53-specific autoantibodies using electrochemical and colorimetric (naked eye) readouts. The clinical applicability of the sensor has been tested in detecting p53-specific autoantibody in plasma obtained from patients with epithelial ovarian cancer high-grade serous subtype (EOCHGS, number of samples = 2) and controls (benign, number of samples = 2). As Au-NPFeONC possess high peroxidase-like activity for the oxidation of TMB in the presence of HO [TMB is a common chromogenic substrate for HRP in enzyme-linked immunosorbent assays (ELISAs)], we envisage that our assay could find a wide range of application in developing ELISA-based sensing approaches in the fields of medicine (i.e., detection of other biomarkers the same as p53 autoantibody), biotechnology, and environmental sciences.

No abstract

Epoxy hybrid-nanocomposites reinforced with recycled cellulose fibers (RCF) and halloysite nanotubes (HNTs) have been fabricated and investigated. The dispersion of HNTs was studied by synchrotron radiation diffraction (SRD) and transmission electron microscopy (TEM). The influences of RCF/HNTs dispersion on the mechanical properties and thermal properties of these composites have been characterized in terms of flexural strength, flexural modulus, fracture toughness, impact toughness, impact strength, and thermogravimetric analysis. The fracture surface morphology and toughness mechanisms were investigated by SEM. Results indicated that mechanical properties increased because of the addition of HNTs into the epoxy matrix. Flexural strength, flexural modulus, fracture toughness, and impact toughness increased by 20.8, 72.8, 56.5, and 25.0%, respectively, at 1 wt% HNTs load. The presence of RCF dramatically enhanced flexural strength, fracture toughness, impact strength, and impact toughness of the composites by 160%, 350%, 444%, and 263%, respectively. However, adding HNTs to RCF/epoxy showed only slight enhancements in flexural strength and fracture toughness. The inclusion of 5 wt% HNTs into RCF/epoxy ecocomposites increased the impact toughness by 27.6%. The presence of either HNTs or RCF accelerated the thermal degradation of neat epoxy. However, at high temperature, samples reinforced with RCF and HNTs displayed better thermal stability with increased char residue than neat resin. POLYM. COMPOS.,