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Synthesis of conductive doubly filled poly(N-isopropylacrylamide)-polyaniline-SiO2 hydrogels

SYSNO ASEP	0469851
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Synthesis of conductive doubly filled poly(N-isopropylacrylamide)-polyaniline-SiO2 hydrogels
Author(s)	Depa, Katarzyna (UMCH-V) Strachota, Adam (UMCH-V)_{RID, ORCID} Šlouf, Miroslav (UMCH-V)_{RID, ORCID} Brus, Jiří (UMCH-V)_{RID, ORCID} Cimrová, Věra (UMCH-V)_{RID, ORCID}
Source Title	Sensors and Actuators B - Chemical. - : Elsevier Roč. 244, June (2017), s. 616-634
Number of pages	19 s.
Language	eng - English
Country	CH - Switzerland
Keywords	PNIPAm hydrogel ; polyaniline ; silica
Subject RIV	CD - Macromolecular Chemistry
OECD category	Polymer science
R&D Projects	LD14010 GA MŠMT - Ministry of Education, Youth and Sports (MEYS)
	GA13-26542S GA ČR - Czech Science Foundation (CSF)
Institutional support	UMCH-V - RVO:61389013
UT WOS	000395963300071
EID SCOPUS	85009083411
DOI	10.1016/j.snb.2016.12.121
Annotation	Temperature-responsive and electrically conductive doubly filled highly porous poly(N-isopropylacrylamide)/SiO2/polyaniline hydrogels were successfully prepared. They contained 2.5–44 wt.% PANI in dry gel and 6 wt.% SiO2 in the PANI-free part of the dry gel. These materials are of interest as potential actuators (generating movement or pressure change), because of their ultra-fast volume changes, which can be triggered by ohmic- or by induction heating (remote triggering in the latter case), as well as in the function of electrical switches controlled by heating/cooling (shrinking and expanding conductive element). The prepared doubly filled porous gels display reversible and symmetrical response to temperature jumps as fast as 6 s for 75% of the swelling change, and conductivities as high as 74 000 mu S/cm. After testing several synthesis approaches, an efficient two-step route was developed, consisting in the impregnation of porous PNIPAm/SiO2 precursor gels with PANI precursors, which led to a highly selective PANI incorporation into the pore walls (as sub-micrometre-sized irregular and branched filaments). The incorporation of the ‘first filler’, nano-SiO2, was crucial in the developed synthesis, which required an ultra-fast T-responsivity of the PANI-free precursor gel. In order to achieve optimal conductivities, the PANI filler was reduced to the emeraldine form using SnCl2. Conductivity measurements indicated, that PANI percolation is approached near 20 wt.%, and achieved between 20 and 44 wt.%. At such loadings, PANI also acts as a distinct mechanical reinforcement in the gels.
Workplace	Institute of Macromolecular Chemistry
Contact	Eva Čechová, cechova@imc.cas.cz ; Tel.: 296 809 358
Year of Publishing	2017

Number of the records: 1