The fabrication and properties of magnetorheological elastomers employing bio-inspired dopamine modified carbonyl iron particles

Abstract

To obtain magnetorheological elastomers (MREs) with improved mechanical properties and exhibiting an enhanced magnetorheological (MR) effect, bio-inspired dopamine modification has been used to improve the functionality at the surface of carbonyl iron (CI) particles. Various techniques including x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to confirm that a polydopamine (PDA) layer of about 27.5 nm had been successfully deposited on the surface of the carbonyl iron particles prior to their inclusion in the MRE composites. The magnetic properties of PDA modified CI particles were shown to be almost the same as those for untreated CI particles. With the introduction of a PDA layer to the surfaces of the particles, both the tensile strength and the elongation at break of the MREs were improved. Furthermore, the MRE composites filled with PDA-coated CI particles exhibited lower zero-field storage moduli but higher magnetic field induced storage moduli when magnetization saturation was reached. The absolute and relative MR effect for the MREs reached 0.68±0.002 MPa and 294% respectively, which were higher than those of MREs with pristine CI particles whose absolute and relative MR effect were 0.57±0.02 MPa and 187% respectively. The findings of this work provide insights into enhanced fabrication of MREs with both improved mechanical properties and magneto-induced performance.

Design, Fabrication and Analysis of Magnetorheological Soft Gripper

“…The stiffness (Young modulus, ) of the tested materials increases nonlinearly with the increase of iron content in the composites. This is consistent with the literature [ 26 , 27 ], because inorganic fillers introduced to polymer matrix cause stiffening of the polymer matrix. For materials containing up to 50% by weight, this increase is slight, while 70% by weight of the filler has a greater impact on this parameter—it rises almost four times.…”

A review on magneto-mechanical characterizations of magnetorheological elastomers

“…Moreover, surface modifications of CIPs are also one of the emerging areas to improve the properties of MREs [163]. MREs made of the surface-modified CIPs exhibit higher MR effects than those with pristine CIPs [163].…”

Lightweight and highly conductive silver nanoparticles functionalized meta-aramid nonwoven fabric for enhanced electromagnetic interference shielding

“…It is widely known that dopamine is easily oxidized by dissolved oxygen in an aqueous solution, which then initiates a self-polymerization-crosslinking reaction to form a tightly adhered layer on almost all types of organic/inorganic surfaces [40,41]. When the PMIA nonwoven fabric was put into a freshly prepared dopamine aqueous solution and soaked for a period of time, surface modified PMIA nonwoven fabric with a polydopamine layer attached to the surface would be obtained.…”