Ferrogels based on entrapped metallic iron nanoparticles in a polyacrylamide network: extended Derjaguin-Landau-Verwey-Overbeek consideration, interfacial interactions and magnetodeformation / Shankar Ajay,Safronov Alexander P.,Mikhnevich Ekaterina A.,Beketov Igor V.,Kurlyandskaya Galina V. // SOFT MATTER. - 2017. - V. 13, l. 18. - P. 3359-3372.

ISSN/EISSN:

1744-683X / 1744-6848

Type:

Article

Abstract:

A new kind of ferrogel with entrapped metallic iron nanoparticles causing unusual magnetodeformation is presented. Crosslinked polyacrylamide (PAAm) based ferrogels embedded with iron nanoparticles (MNPs) were synthesized by free radical polymerization in aqueous medium. Spherical iron MNPs with average diameter 66 nm were synthesized by the electrical explosion of wire and modified by interfacial adsorption of linear polyacrylamide (LPAAm). Extended Derjaguin-Landau-Verwey-Overbeek (xDLVO) calculations based on the superposing of van der Waals, electrostatic, steric, and magnetic contributions showed that polymeric encapsulation of nanoparticles by LPAAm is one of the most suitable pathways for preparing stable aqueous dispersions of iron nanoparticles. Microcalorimetry confirmed the presence of strong interfacial adhesion forces between LPAAm chains and the surface of iron nanoparticles. By keeping the same crosslinking density of a polymer network (i.e. 100 : 1, monomer to crosslinker ratio) and varying the initial monomer concentration, an influence of the extent of polymer network reticulation on the mechanical properties and subsequently, magneto-elastic properties was demonstrated. It was found that the upper limit of the shear modulus for the synthesis of a new kind of polyacrylamide based ferrogel to exhibit any usable magnetodeformation under the application of a uniform external magnetic field of 420 mT is ca. 1 kPa. Magnetodeformation of cylindrical ferrogel samples was observed in the form of an overall volume contraction accompanied by a homogeneous decrease in all dimensions. The deformation was found to be maximum (around 10\%) for the aspect ratio of 1/1 and it was lower and similar for the samples with 1/2 and 2/1 aspect ratios. Such a type of magnetic response is significantly different from the behavior observed in the existing reports on ferroelastomers.

Author keywords:

MAGNETIC-FIELD; MAGNETORHEOLOGICAL ELASTOMER; CROSS-LINKERS; HYDROGELS; COMPOSITE; MAGNETOSTRICTION; FERROHYDROGELS; TEMPERATURE; POLYMER

DOI:

10.1039/c7sm00534b

Web of Science ID:

ISI:000401101300011

Соавторы в МНС:

Другие поля

Поле	Значение
Month	MAY 14
Publisher	ROYAL SOC CHEMISTRY
Address	THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND
Language	English
EISSN	1744-6848
Keywords-Plus	MAGNETIC-FIELD; MAGNETORHEOLOGICAL ELASTOMER; CROSS-LINKERS; HYDROGELS; COMPOSITE; MAGNETOSTRICTION; FERROHYDROGELS; TEMPERATURE; POLYMER
Research-Areas	Chemistry; Materials Science; Physics; Polymer Science
Web-of-Science-Categories	Chemistry, Physical; Materials Science, Multidisciplinary; Physics, Multidisciplinary; Polymer Science
Author-Email	ashankar@urfu.ru
ORCID-Numbers	Kurlyandskaya, Galina/0000-0002-3712-1637
Funding-Acknowledgement	Grant RFBR {[}17-54-33015]; Basque Country Government ELKARTEK {[}KK-2016/00030]; UrFU
Funding-Text	The work was supported in part by Grant RFBR 17-54-33015 onco-a and ELKARTEK grant KK-2016/00030 of the Basque Country Government. Authors appreciate the special support of Dr A. I. Medvedev in XRD characterization, Dr A. M. Murzakayev in TEM studies and Dr A. G. Galyas for optical microscopy measurements. AS is thankful to UrFU for the postdoctoral fellowship.
Number-of-Cited-References	48
Usage-Count-Last-180-days	13
Usage-Count-Since-2013	13
Journal-ISO	Soft Matter
Doc-Delivery-Number	EU5VD