Surface modified carbonyl iron particles (SMCIPs) were synthesized by coating carbonyl iron particles with an organic reagent (N-polyether, N, N, N,-acetyloxy) 2, 6-aminion-1, 3, 4-thiadiazole dimer. The properties of these SMCIPs, including morphology, structure, and magnetic behavior, were characterized using scanning electron microscopy and a vibrating sample magnetometer. Aqueous magnetorheological (MR) fluids were prepared using SMCIPs. MR properties were measured via a strain-controlled parallel disk rheometer equipped with a magnetic field source. Addition of the organic surface coating layer was found to greatly improve sedimentation stability of the aqueous MR fluids at a small cost of a reduction in field dependent yield stress.

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. (2016). Dynamic response of symmetrical and asymmetrical sandwich plates with shear thickening fluid core subjected to penetration loading. Materials and Design,[94][95][96][97][98][99][100][101][102][103][104][105][106][107][108][109][110] Dynamic response of symmetrical and asymmetrical sandwich plates with shear thickening fluid core subjected to penetration loading AbstractSymmetrical and asymmetrical sandwich plates with a shear thickening fluid (STF) core were designed to be penetrated by a cylindrical projectile at various impact velocities. These STFs consist of SiO2/PEG400, and the volume fractions of SiO2 nano-particles are 54% and 56%, respectively. Failure mode of the rear face sheet of the symmetrical sandwich plate is petal perforation, but the rear face sheet of the asymmetrical sandwich plate failed in plug perforation mode at the velocity of less than 80 m/s and in the petal perforation mode at the velocity faster than 90 m/s. The results showed that both the face sheet and the STF core played different roles in impact resisting properties and energy absorption of the sandwich plate at different impact velocities. The thickness of the rear sheet has a significant influence on the energy absorption at low impact velocity, while this influence can be ignored at high impact velocity. The effects of the particle volume fraction, impact velocity and thickness of rear face sheet on the deformation mechanism and energy absorption of the sandwich plate were also discussed. Abstract: Symmetrical and asymmetrical sandwich plates with a shear thickening fluid (STF) core were designed to be penetrated by a cylindrical projectile at various impact velocities. These STFs consist of SiO 2 /PEG400, and the volume fractions of SiO 2 nano-particles are 54% and 56%, respectively. Failure mode of the rear face sheet of the symmetrical sandwich plate is petal perforation, but the rear face sheet of the asymmetrical sandwich plate failed in plug perforation mode at the velocity of less than 80 m/s and in the petal perforation mode at the velocity faster than 90 m/s. The results showed both the face sheet and the STF core played different roles in impact resisting properties and energy absorption of the sandwich plate at different impact velocities. The thickness of the rear sheet has a significant influence on the energy absorption at low impact velocity, while this influence can be ignored at high impact velocity. The effects of the particle volume fraction, impact velocity and thickness of rear face sheet on the deformation mechanism and energy absorption of the sandwich plate were also discussed. Disciplines Engineering | Science and Technology Studies

Electrospinning is an effective technique for fabricating submicron to nanoscale fibers from synthetic polymer as well as natural proteins. In this study, multiwalled carbon nanotubes (MWNTs) were embedded via electrospinning by adding MWNTs into the spinning dope, and found to be well aligned along the fiber axis in the silk fibroin nanofibers. The morphology and microstructure of the electrospun nanofibers were characterised using a field emission scanning electron microscope (FESEM) and Transmission electron microscopy (TEM). X-ray diffraction (XRD) and TG-DTA were used to study the crystal structure of the silk/MWNTs composite nanofibres, carried out to alter the strength, toughness and electrical conductivity of silk nanofibers by adding a small amount of MWNTs. The electrospun random silk mats with 1% MWNTs had a Young’s modulus, ultimate tensile strength and strain of 107.46 ± 9.15MPa, 9.94 ± 1.2MPa and 9.25 ± 1.5%, respectively, and electrical conductivity increased to 1.2×10-4S/cm. The silk/MWNTs composite nanofibres could potentially be applied in nerve repair materials owing to their excellent mechanical properties and electrical conductivity.