A Facile In Situ Approach to Polypyrrole Functionalization Through Bioinspired Catechols

Abstract

A template‐free benign approach to modify polypyrrole (PPy) with bioinspired catechol derivatives dopamine (DA), 1,2‐dihydroxybenzene or catechol (CA), and l‐3,4‐dihydroxyphenylalanine (DOPA) is reported. It is found that PPy functionalized with these catechol derivatives (DA, CA, and DOPA) exhibited fibrous structure, smaller particle size, good water dispersibility, and enhanced film adhesion. Surprisingly, it is found that adding a small amount of catechols can also improve PPy's electrical conductivity. This rapid, one‐step, in situ, template‐free method provided an alternative strategy to the facile production of PPy fibers. Among these three catechols, functionalized PPy and DA‐PPy exhibits the smallest particle size and best performance in both adhesion and electrical conductivity. In contrast, the control phenylethlamine (PA) modification had almost negligible influence on the PPy properties, which provides strong evidence that instead of amine functional group or coexistence of both catechol and amine moieties, catechol itself is responsible for the successful functionalization of PPy and overall performance improvement. Furthermore, catechol‐PPy nanofibers are blended into polyvinyl alcohol (PVA) aqueous solution and casted to form thin films; as‐synthesized conductive films are found able to bond strongly onto the surface and may find broad applications in manufacturing biosensors and electronic devices.

Polydopamine‐Assisted Electrochemical Fabrication of Polypyrrole Nanofibers on Bone Implants to Improve Bioactivity

“…This activity strongly depends on the nature of its interaction with other molecules that are present and/or are on the electrode surface . Furthermore, strong hydrogen bonding between the ortho‐position phenolic hydroxyl on DA and N on the Py ring promotes orderly self‐assembly . In contrast, electrostatic interactions from the interaction of Py micelles with the electrode surface and ions enhance random aggregation .…”

Mussel‐Inspired Materials: Self‐Healing through Coordination Chemistry

“…Additional information concerning PDA coatings and their uses can be found in various reviews. [36,46,50] In addition recent work by Zhang et al [51] indicates that catechols can improvet he electric conductivity of specific polymers, in this case ap olypyrrole-baseds ystem. Several different types of catechols were tested.…”

Chemistry of polydopamine analogues

“…The films exhibited enhanced solvent processability, thermal stability and a low adsorption of proteins and thus were claimed promising for antifouling coatings. When DA was mixed with PEI and oxidatively polymerized in air and Tris buffer, covalent linkage between the amino groups of PEI and PDA could be assumed by Schiff base formation or Michael type addition (Scheme , bottom; Scheme ) . This methodology was used to obtain free standing films wherein the inherent rigidity of PDA is suspended and in the fabrication of organic – inorganic hybrid microcapsules useful for immobilization of enzymes, dye absorption and glucose sensing .…”

“…A conducting material combining the properties of PDA (adhesion) and polypyrrole (conduction) was obtained by oxidative polymerization of the two monomers in the presence of ammonium persulfate in Tris buffer (Scheme ). In this way, the dispersibility and stability of polypyrrole as well as its film adhesion were improved considerably . The copolymer ratio affected the shape of the nanostructures (nanosphere, nanofiber, nanorod and nanoflake).…”

“…The copolymer ratio affected the shape of the nanostructures (nanosphere, nanofiber, nanorod and nanoflake). By including structural analogues of DA, such as l‐ Dopa, phenyl ethylamine or catechol, evidence was found that the catechol moieties of DA or l‐ Dopa were responsible for the improvement of the properties …”