Polypyrrole-coated melamine sponge as a precursor for conducting macroporous nitrogen-containing carbons

0554694 - ÚMCH 2023 RIV CH eng J - Journal Article
Stejskal, Jaroslav - Vilčáková, J. - Jurča, M. - Fei, H. - Trchová, M. - Kolská, Z. - Prokeš, J. - Křivka, I.
Polypyrrole-coated melamine sponge as a precursor for conducting macroporous nitrogen-containing carbons.
Coatings. Roč. 12, č. 3 (2022), č. článku 324. E-ISSN 2079-6412
Institutional support: RVO:61389013
Keywords : conducting polymer * polypyrrole * carbonization
OECD category: Polymer science
Impact factor: 3.4, year: 2022
Method of publishing: Open access
https://www.mdpi.com/2079-6412/12/3/324

Macroporous open-cell melamine sponges were coated with a conducting polymer, polypyrrole, during in-situ oxidative polymerization of pyrrole. Two samples, differing in polypyrrole content, 8.2 and 27.4 wt%, were prepared. They were exposed to various temperatures up to 700 °C in an inert atmosphere. The macroporous structure and mechanical integrity were preserved after this process. This converted both the polypyrrole coating and the melamine sponge to macroporous nitrogen-containing carbons. The changes in molecular structure in the course of carbonization were followed by elemental analysis and FTIR and Raman spectra. The specific surface area of polypyrrole-coated sponge increased from ca. 90 to ca. 300 m2 g−1 along with accompanying increase in the porosity. The conductivity of the sponges was recorded as a function of compression in a newly developed apparatus. The sponge containing 27.4 wt% pyrrole had conductivity of the order of 10−2 S·cm−1 at 0.1 MPa pressure, which was reduced by four orders of magnitude when exposed to 400–500 °C and nearly recovered after the temperature reached 700 °C. The sponges were tested in electromagnetic radiation shielding and displayed both radiation absorption and, to a lower extent, radiation reflection proportional mainly to the samples’ conductivity.
Permanent Link: http://hdl.handle.net/11104/0330270