posted on 2022-06-01, 20:29authored byAna Aguzin, Gisela C. Luque, Ludmila I. Ronco, Isabel del Agua, Gregorio Guzmán-González, Bastien Marchiori, Agustina Gugliotta, Liliana C. Tomé, Luis M. Gugliotta, David Mecerreyes, Roque J. Minari
Iongels
are soft ionic conducting materials, usually composed of
polymer networks swollen with ionic liquids (ILs), which are being
investigated for applications ranging from energy to bioelectronics.
The employment of iongels in bioelectronic devices such as bioelectrodes
or body sensors has been limited by the lack of biocompatibility of
the ILs and/or polymer matrices. In this work, we present iongels
prepared from solely biocompatible materials: (i) a biobased polymer
network containing tannic acid as a cross-linker in a gelatin matrix
and (ii) three different biocompatible cholinium carboxylate ionic
liquids. The resulting iongels are flexible and elastic with Young‘s
modulus between 11.3 and 28.9 kPa. The morphology of the iongels is
based on a dual polymer network system formed by both chemical bonding
due to the reaction of the gelatin’s amines with the polyphenol
units and physical interactions between the tannic acid and the gelatin.
These biocompatible iongels presented high ionic conductivity values,
from 0.003 and up to 0.015 S·cm–1 at room temperature.
Furthermore, they showed excellent performance as a conducting gel
in electrodes for electromyography and electrocardiogram recording
as well as muscle stimulation.