By assembling 140 nm-sized fluorescent nanodiamonds (FNDs) in a thin-film on (3-aminopropyl) triethoxysilane functionalized glass surface, we prepare magnetically-sensitive FND-fiber probes for endoscopy. The obtained FND layers show good uniformity over large surfaces and are characterized using confocal, fluorescence, and atomic force microscopes. Further, FNDs are assembled on single large-core multimode optical fibers and imaging fiber bundles end face to detect optically detectable magnetic resonance (ODMR) signals. The ODMR signals are recorded through the fiber’s far end in magnetic fields between 0 to 2.5 mT. A multi-channel sensor is demonstrated with the capability of parallel-in-time mapping and instantaneous readout from individual pixel and enabling magnetic mapping at high spatial resolution. Results of this study are promising for early stage detection in bio-diagnostic applications.
The properties of shear thickening fluid (STF), based on polypropylene glycol and amorphous silica, modified by the addition of multiwalled carbon nanotubes (MWCNTs), were studied. The STF's viscosity increases abruptly during impact tests. The addition of a small amount of carbon nanotubes (CNTs) to the STF, leads to an increase of the maximal viscosity from 2128 to 12,213 Pa•s. To show the differences between various compositions, the microstructures of fluids were observed by scanning electron microscopy. A pronounced influence of the CNTs on the ability of impact force absorption was noticed. The protective structure containing 55 and 0.25 vol% of fumed silica and CNTs, respectively, is able to absorb up to 74% of impact force.
Synthesis and characterization of composite shear thickening fluids (STFs) containing carbon nanofillers are presented. Shear thickening fluids have attracted particular scientific and technological interest due to their unique ability to abruptly increase viscosity in the case of a sudden impact. The fluids have been developed as a potential component of products with high energy absorbing efficiency. This study reports on the rheological behavior, stability, and microstructure of the STFs modified with the following carbon nanofillers: multi-walled carbon nanotubes, reduced graphene oxide, graphene oxide, and carbon black. In the current experiment, the basic STF was made as a suspension of silica particles with a diameter of 500 nm in polypropylene glycol and with a molar mass of 2000 g/mol. The STF was modified with carbon nanofillers in the following proportions: 0.05, 0.15, and 0.25 vol.%. The addition of the carbon nanofillers modified the rheological behavior and impact absorption ability; for the STF containing 0.25 vol.% of carbon nanotubes, an increase of force absorption up to 12% was observed.
In this article, the novel type of dielectric elastomer made of polydimethylsiloxane, multi-walled carbon nanotubes, and carbon grease is presented. The aim of the study was the development of compliant electrodes with ability for large deformation under applied voltage. The largest deformation of 47% was obtained for electrodes made of 2 wt% of multi-walled carbon nanotubes and 20 wt% of carbon grease. Electrical conductivity achieved for this material was 4.8 S/m. Good dispersion of conductive fillers within silicone matrix was obtained by calendaring technique. It was found that electrical percolation threshold for the compound was below 0.05 wt%. The structure of the material and its mechanical properties were determined. It was described that both properties, electrical conductivity and stiffness of the nanocomposite, have a significant influence on the extent of the electrode deformation. Two actuator designs are presented as the examples of application of developed material.
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