Conducting polypyrrole-coated macroporous melamine sponges: a simple toy or an advanced material?

Abstract

The present feature article offers a concise overview of recent research progress of the authors working in the design of macroporous conducting materials represented by polypyrrole-coated melamine sponges. The article highlights innovative results from the authors and suggests a perspective for future directions in the field of macroporous conducting polymer composites. The article also overviews this particular subject area and defines key challenges for this emerging field. The feasibility of diverse applications of polypyrrole/melamine sponges is demonstrated and includes deformation-sensitive materials, electromagnetic radiation shielding and electrically heated insulation materials. Cytotoxicity is addressed with respect to applications in biomedicine, and the adsorption of an organic dye serves as an example of the uses in environmental water-pollution treatment. A single-step deposition of polypyrrole during the oxidative polymerization of pyrrole provides the uniform coating of the sponge with an organic conducting phase. The conductivity of sponges was of the order of 10 -3 S cm -1 , increased with polypyrrole loading, and also by two orders of magnitude after the compression. Derived materials have also been prepared and tested. They are represented by polypyrrole-coated sponge converted by pyrolysis to a macroporous nitrogencontaining carbon, magnetic ferrosponge obtained by incorporation of magnetite, or the conventional globular polypyrrole coating replaced with polypyrrole nanotubes. Polypyrrole can also be simply decorated with silver nanoparticles. The macroporous conducting polypyrrole/melamine sponges and derived materials are considered to be of future scientific interest with broad application potential.

Adsorption of organic dyes on macroporous melamine sponge incorporating conducting polypyrrole nanotubes

“…The set is completed by methyl orange, which has a special role in polypyrrole chemistry. The ability is this dye to convert in the synthesis the globular morphology of polypyrrole to nanotubes at the simultaneous improvement of conductivity has been known and exploited for two decades 23,43 . Concerning anionic dyes, the following observations can be made.…”

“…Polypyrrole of any morphology is produced as an intractable powder, and the deposition on suitable carriers affording the materials properties is required by the particular application. A commercial macroporous open‐cell melamine/formaldehyde sponge (Figure 1b) coated with polypyrrole nanotubes or nanotubes alone have already proved to be useful in diverse applications 17,18,23–25 . Having in mind especially the design of a potential dye adsorbent, the melamine sponge has been selected as a substrate for the deposition of polypyrrole nanotubes.…”

Polypyrrole-Coated Melamine Sponge as a Precursor for Conducting Macroporous Nitrogen-Containing Carbons

“…The yield therefore improved after the sponge was coated with polypyrrole. The results are important for the application of conducting sponges as materials heated by Joule heat produced by passing an electrical current [6,14,26,30].…”

Progress in research and applications of conducting polymers: topical issue

“…In order to meet the materials properties required by applications, the conducting polymers are deposited on substrates providing the desired structure and mechanical parameters. The preparation of conducting sponges (Stejskal et al 2021) or surface-modified inorganic oxides (Falletta et al 2021;Cogal et al 2021) serves as examples.…”

“…Conducting polymers are not just conducting, and many applications do not exploit the conductivity. These include their electrochemistry applied in sensors (Cogal et al 2021) or battery electrodes (Kondratiev and Holze 2021), pollutant adsorption in environmental issues (Mahmud et al 2021;Stejskal et al 2021;Zaghlol et al 2021) or polarizability in electro-responsive suspensions (Dong et al 2021). The list can be extended by electrocatalysis and photocatalysis, electromagnetic radiation shielding, antibacterial performance, stimuli responsivity, flame retardation, and other uses.…”