Enhanced magnetorheological effect of suspensions based on carbonyl iron particles coated with poly(amidoamine) dendrons

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28610%2F21%3A63529078" target="_blank" >RIV/70883521:28610/21:63529078 - isvavai.cz</a>

Result on the web

<a href="https://link.springer.com/article/10.1007/s00397-021-01269-1" target="_blank" >https://link.springer.com/article/10.1007/s00397-021-01269-1</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00397-021-01269-1" target="_blank" >10.1007/s00397-021-01269-1</a>

Result language

angličtina

Original language name

Enhanced magnetorheological effect of suspensions based on carbonyl iron particles coated with poly(amidoamine) dendrons

Original language description

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

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

20301 - Mechanical engineering

Project

<a href="/en/project/ED2.1.00%2F19.0409" target="_blank" >ED2.1.00/19.0409: CPS - strengthening research capacity</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Rheologica Acta

ISSN

0035-4511

e-ISSN

—

Volume of the periodical

60

Issue of the periodical within the volume

5

Country of publishing house

US - UNITED STATES

Number of pages

14

Pages from-to

263-276

UT code for WoS article

000636914000001

EID of the result in the Scopus database

2-s2.0-85103646714