advanced-nanotechnology-materials-2018-tracks

Volume 4

Nano Research & Applications

ISSN: 2471-9838

JOINT EVENT

October 04-05, 2018 Moscow, Russia

Edition of International Conference on

International Conference on

Advanced Nanotechnology

Materials Technology and Manufacturing Innovations

Advanced Nanotechnology 2018

& Materials-Manufacturing 2018

October 04-05, 2018

Page 32

Controlling microgel size by electrochemically induced volume phase transition

icrogels are polymer hydrogels or macromolecules that form, in a micro scale, three-dimensional networks filled with

a solvent. Microgels are characterized by low viscosity and very high surface area, but the most intriguing property of

these materials is their ability to change substantially their volume. This phenomenon is called the volume phase transition

and is observed as the response of a polymer network to an external stimulus, such as change in temperature, pH, ionic

strength and magnetic/electric field. In microgels, the change in volume is great and it is much quicker compared to regular-

size hydrogels. These properties are useful in such potential applications as controlled drug delivery systems; catalysis and

have successfully synthesized a novel microgel the volume of which could be changed by using an electrochemical

trigger. At appropriate potential and at human-body temperature the volume change was unusually high by more than one

order of magnitude. The starting material was a thermoresponsive microgel built from N-isopropylacrylamide, sodium

acrylate and N, N’-bisacryloylcystine as the cross linker.The gel has beenmodified with aminoferrocene through amid-bond

formation. The influence of oxidation state of the ferrocene groups in the micro-gel on volume phase transition temperature

was determined. The -S-S- groups from the N, N’-bisacryloylcystine linker were employed in the chemisorption of the

microgels on the Au electrode surface and the formation of gel monolayers. It appeared that the microgel layers could be

either in the shrunken or the swollen state depending on the oxidation number of the iron atoms in the ferrocene groups.

The oxidation number could be changed electrochemically and the shrunken-swollen transformation could be repeated

reversibly many times. The properties of the obtained materials were examined with dynamic light scattering technique,

UV-V is spectroscopy, SEM and TEM microscopies and cyclic voltammetry.

Recent Publications

1. Karbarz M, Mackiewicz M, Kaniewska K, Marcisz K, Stojek Z (2017) Recent developments in design and

functionalizationofmicro-andnanostructuralenvironmentally-sensitivehydrogelsbasedonN-isopropylacrylamide.

Applied Materials Today 9:516-532.

Marcin Karbarz

University of Warsaw, Poland

Marcin Karbarz, Nano Res Appl 2018, Volume 4

DOI: 10.21767/2471-9838-C5-020