Surface-initiated mechano-ATRP as a convenient tool for tuning of bidisperse magnetorheological suspensions toward extreme kinetic stability

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28610%2F21%3A63544958" target="_blank" >RIV/70883521:28610/21:63544958 - isvavai.cz</a>

Result on the web

<a href="https://pubs.rsc.org/en/content/articlelanding/2021/PY/D1PY00930C" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2021/PY/D1PY00930C</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d1py00930c" target="_blank" >10.1039/d1py00930c</a>

Result language

angličtina

Original language name

Surface-initiated mechano-ATRP as a convenient tool for tuning of bidisperse magnetorheological suspensions toward extreme kinetic stability

Original language description

&quot;A concept initially intended for mechanically controlled atom transfer radical polymerization (hereinafter referred to as &quot;&quot;mechano-ATRP&quot;&quot;) was extended in order to modify magnetic nanoparticles (NPs) with poly(methyl acrylate) (PMA) grafts, resulting in NPs@PMA hybrids which served as efficient additives in magnetorheological (MR) suspensions. In a novel procedure, magnetic NPs with an ATRP initiator anchored on their surfaces were added into a mechano-ATRP mixture, bringing about surface-initiated growth of the PMA chains after exposure to ultrasonication (35 kHz, 45 degrees C). The reaction proceeded with low concentration (at hundreds of &quot;&quot;ppm&quot;&quot;) of the CuBr2 catalyst, thereby providing the PMA chains with low dispersity of molar masses and high monomer conversions. Investigation was conducted as to the effect of hexagonal micro-ZnO and cubic-phase BaTiO3 piezoelectric transducers on the feasibility of the process. The presence of PMA on the surfaces of NPs@PMA hybrids was proven by infra-red spectroscopy, as well as thermal and magnetization analyses. The NPs@PMA hybrids were subsequently applied as additives to fabricate a bidisperse MR suspension, in which they unexpectedly enhanced accessible shear stress and yield stress values by up to similar to 840 Pa under a magnetic field (of up to 432 kA m(-1)). Notably, the MR suspension supplemented with the NPs@PMA hybrids synthesized by mechano-ATRP exhibited no sign of sedimentation when left undisturbed for 2 days, although sedimentation of the reference sample occurred within a few hours. Such enhancements were attributed to the effects of friction, formation of a 3D gel-like network and the reduced density of the NPs@PMA hybrids.&quot;

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

—

OECD FORD branch

10404 - Polymer science

Project

—

Continuities

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Publication year

2021

Confidentiality

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

Name of the periodical

Polymer Chemistry

ISSN

1759-9954

e-ISSN

—

Volume of the periodical

12

Issue of the periodical within the volume

35

Country of publishing house

GB - UNITED KINGDOM

Number of pages

13

Pages from-to

5093-5105

UT code for WoS article

000687806800001

EID of the result in the Scopus database

2-s2.0-85115124881