Micellar nanoreactors for hematin catalyzed synthesis of electrically conducting polypyrrole.
Enzymatic synthesis of doped polypyrrole (PPy) complexes using oxidoreductases (specifically peroxidases) is very well established "green" methods for producing conducting polypyrrole. The importance of this approach is realized by the numerous potential opportunities of using PPy in biological applications. However, due to very high costs and low acid stability of these enzymes, there is need for more robust alternate biomimetic catalysts. Hematin, a hydroxyferriprotoporphyrin, has a similar iron catalytic active center like the peroxidases and has previously shown to catalyze polymerization of phenol monomers at pH 12. The insolubility of hematin due to extensive self-aggregation at low pH conditions has prevented its use in the synthesis of conjugated polymers. In this study, we have demonstrated the use of a micellar environment with sodium dodecylbenzenesulfonate (DBSA) for biomimetic synthesis of PPy. The micellar environment helps solubilize hematin, generating nanometer size reactors for the polymerization of pyrrole. The resulting PPy is characterized using UV-visible, Fourier transform infrared, and X-ray photoelectron spectroscopy and reveals the formation of an ordered PPy/DBSA complex with conductivities approaching 0.1 S/cm.
Department of Chemistry, University of Massachusetts, Lowell, Massachusetts 01854, USA.
Sethumadhavan
S
Ravichandran
Subhalakshmi
S
Nagarajan
Akshay
A
Kokil
Timothy
T
Ponrathnam
Ryan M
RM
Bouldin
Ferdinando F
FF
Bruno
Lynne
L
Samuelson
Jayant
J
Kumar
Ramaswamy
R
Nagarajan
D002384:Catalysis; D004553:Electric Conductivity; D006427:Hemin / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008823:Micelles; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry*; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry
D008823:Micelles; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D006427:Hemin