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Focus on the safety of herbal medicines has mainly been directed towards the presence of intrinsic toxicity, as found in the cases of renal and hepatic dysfunction caused by aristolochic acids. However, contamination from extrinsic hazards may impart an even greater reduction in their safety and efficacy. This study reveals that pesticides were present in the majority (88%) of a comprehensive cross-section (n = 1771) of herbal medicine samples. Alarmingly, more than half (59%) contained pesticides over the European Pharmacopoeia (EP) limit, and 43% of them contained 35 varieties of banned, extremely toxic pesticides, eight of which were detected at levels over 500 times higher than the default Maximum Residue Limit (MRL). DDTs, carbofuran, and mevinphos were confirmed as being among the most risk-inducing pesticides by three different risk assessment methods, reported to produce carcinogenic, genotoxic, reproductive, and developmental effects, in addition to carrying nephrotoxicity and hepatotoxicity. In light of these findings, and withstanding that extrinsic hazards can be controlled unlike intrinsic toxicity, the authors here strongly recommend the application of herbal medicine quality-control measures and solutions to safeguard against a neglected but certainly potentially serious health risk posed to the majority of the global population that consumes herbal medicines.

Four kinds of liquid-like polyhedral oligomeric silsesquioxanes derivatives (liquid-Ds) were fabricated and characterized by FTIR, XPS, TGA, and Rheometer. The liquid-Ds/epoxy nanocomposites were prepared and their thermal resistance properties were tested by TGA. As a result, the thermal resistances properties were improved sharply and influenced by particle sizes, flow abilities, and bonding types of liquid-Ds. The glass transition temperature improved via adding liquid-Ds. The increase of crosslinking density was thought as an important factor to these improvements, which was studied by FTIR spectra and gel content of curved nanocomposites. POLYM. COMPOS., 2016. © 2016 Society of Plastics Engineers

A polyether amine (M2070) was covalently grafted onto the surface of graphene nanosheets (GNS) decorated by zinc hydroxystannate boxes (ZHS) to obtain an organic hybrid material (GNS-ZHS-M2070) with solvent-free and liquid-like behavior. It was subsequently incorporated into epoxy resin (EP) to investigate the flame-retardant property. The GNS-ZHS-M2070, which was a homogeneous sticky fluid at room temperature without any solvent, could stably disperse in a broad spectrum of solvents. Most importantly, the GNS-ZHS-M2070/EP composites possessed superior flame-retardant performance, such as the lowest peak heat release rate and fire growth rate index values. Furthermore, it had been demonstrated that the superior flame-retardant performance of GNS-ZHS-M2070/EP should be ascribed to the excellent processability and good compatibility of GNS-ZHS-M2070 derived from the unique flowability and soft organic shell. All of these advantages along with the solvent-free nature of GNS-ZHS-M2070 provided a green, efficient and environment-friendly way to fabricate high flame-retardant performance composite materials.

A solvent-free liquid-like nanocrystal-functionalized graphene oxide was successfully prepared. Its morphology, chemical structure and multifunction were extensively characterized by various analysis technologies. It was found that the liquid-like nanocrystal-functionalized graphene oxide could flow at room temperature without any solvents and remained magnetic with a saturation magnetization about 2.57 emu/g. Moreover, it exhibited good dispersion in various solvents and polymer matrix. Subsequently, it was incorporated into epoxy matrix to investigate the toughness and glass transition temperature of the resulting nanocomposites. The results indicated that it could simultaneously improve the impact toughness and glass transition temperature of neat epoxy by 138.12% and 33.05 °C at the 1.0 wt.% fraction. Keywords: Graphene oxide, Liquid-like behavior, Toughness, Glass transition temperature, Epoxy nanocomposites

A solvent-free graphene oxide nanoribbons colloids (GONRs-M2070) was achieved and evaluated by grafting organosilanes (KH560) and polyether amine (M2070). Epoxy composites were then prepared with the GONRs-M2070 colloids based on the in-situ blending method to investigate its effect on the mechanical, thermal and tribological properties of the resulting composites, as well as the distribution of GONRs-M2070 in the host materials. The results suggested that the GONRs-M2070, which could disperse and exfoliate well in the epoxy resin, had been successfully synthesized based on the graphene oxide nanoribbons. In addition, it was found that the addition of 0.6 wt% GONRs-M2070 can simultaneously enhanced mechanical, thermal and tribological performance of the resulting epoxy composites. For example, compared with neat epoxy resin, the 0.6 wt% GONRs-M2070 improved the flexural strength, impact strength and glass transition temperature by 16.2%, 83.9% and 32.5%, respectively. Moreover, a lower friction coefficient (0.19) and wear rate (7.65 × 10 −5 g min −1 ) were also observed at 0.6 wt% GONRs-M2070. The obtained results along with the solvent-free nature indicated that combining epoxy resin with GONRs-M2070 specially provided a green and efficient route to improve the wear resistance and decrease the friction coefficient of resin-based composites.

Novel multifunctional graphene@Fe3O4 hybrid nanofluid with liquid-like behavior at room temperature and low viscosity (5.5 Pa.s at 25°C) has been developed by using GO@Fe3O4 as a core, sulfuric acid-terminated organosilanes as corona, and polyether amine as canopy. The obtained nanofluid has been extensively characterized by various analytical techniques. The content of graphene@Fe3O4 reaches up to 13.78 wt% in the hybrid nanofluid, which is a superparamagnetism material with specific magnetization of 0.39 emu/g. In addition, it shows excellent dispersion and exfoliation in solvents and polymer matrixes. It is then compounded with an epoxy resin for the development of liquid-like graphene@Fe3O4 hybrid nanofluid/epoxy nanocomposites. It is found that liquid-like graphene@Fe3O4 hybrid nanofluid/epoxy nanocomposites demonstrate better mechanical property than those of unmodified graphite/epoxy nanocomposites at the same fraction. For example, the multifunctional liquid-like graphene@Fe3O4 hybrid nanofluid at 1.5 wt% improves the impact toughness of epoxy by 125%. This new interface modification also enhanced the Tg of neat epoxy from 98.37 to 129.46°C. POLYM. COMPOS., 2015. © 2015 The Authors Polymer Composites published by Wiley Periodicals, Inc. on behalf of Society of Plastics Engineers

Flow softening mechanism in the isothermal compression of Ti-42.9Al-4.6Nb-2Cr with duplex structure was investigated. True stress-strain curves of Ti-42.9Al-4.6Nb-2Cr exhibited evident flow softening behavior when isothermal compression was conducted at the strain rate of 0.001–1.0 s−1, and the flow softening effect was assessed via flow softening index. Results show that kinking of α2/γ lamellar colonies and periodic morphology variation of β0 phase mainly contributed to the initial flow softening, while DRX of γ phase and periodic morphology variation of β0 phase contributed to the lateral flow softening of Ti-42.9Al-4.6Nb-2Cr with duplex structure. Kinking of lamellar colonies was caused by appearance of stacking faults pairs in γ lamellae and fracture of α2 lamellae. Lamellar colonies were decomposed by DRX of γ phase and growth of adjacent lamellae in the kinked area. Additionally, periodic morphology variation of β0 phase was related to intensive deformation systems, which can be easily-activated, and fast DRX behavior via rotation of subgrains during isothermal compression. Keywords: Titanium aluminides, Thermomechanical processing, Flow softening, Microstructure