Enhanced magnetorheological effect of suspensions based on carbonyl iron particles coated with poly(amidoamine) dendrons
نویسندگان
چکیده
Particle oxidation constitutes a serious ageing phenomenon in magnetorheological suspensions, bringing about deterioration performance. This study describes commercial carbonyl iron particles that were successfully coated with poly(amidoamine) dendrons and then applied as an oxidation-resistant dispersed phase suspensions. A synthesis method was adhered to whereby the sequentially treated ethylenediamine methyl acrylate, leading formation of generation 2 2.5 dendrons; these had capacity for composite nano-scale dendritic layer be prepared on their surfaces. Success applying coating confirmed by various techniques, including XPS, TEM, EDX, FTIR Raman spectroscopy. The controlled approach adopted resulted them exhibiting sufficient stability, only ~ 4.5–4.7% decrease saturation magnetization. Of interest suspensions demonstrated ca 4.8% 4% higher dynamic yield stress than suspension based non-modified at highest intensity magnetic field investigated, i.e. 438 kA m–1. Notably, sedimentation stability evaluated unique involved use tensiometer specific testing probe. aforementioned process led enhanced possibly due overall density particles, dispersion reduction size agglomerates silicone oil mixtures optical microscopy. Modification proposed has potential overcome one primary drawbacks this being instability (which leads what is referred “in-use-thickening”), without negatively affecting performance presence field.
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ژورنال
عنوان ژورنال: Rheologica Acta
سال: 2021
ISSN: ['0035-4511', '1435-1528']
DOI: https://doi.org/10.1007/s00397-021-01269-1