Role of Co-Vapors in Vapor Deposition Polymerization

Abstract

Polypyrrole (PPy)/cellulose (PPCL) composite papers were fabricated by vapor phase polymerization. Importantly, the vapor-phase deposition of PPy onto cellulose was assisted by employing different co-vapors namely methanol, ethanol, benzene, water, toluene and hexane, in addition to pyrrole. The resulting PPCL papers possessed high mechanical flexibility, large surface-to-volume ratio, and good redox properties. Their main properties were highly influenced by the nature of the co-vaporized solvent. The morphology and oxidation level of deposited PPy were tuned by employing co-vapors during the polymerization, which in turn led to change in the electrochemical properties of the PPCL papers. When methanol and ethanol were used as co-vapors, the conductivities of PPCL papers were found to have improved five times, which was likely due to the enhanced orientation of PPy chain by the polar co-vapors with high dipole moment. The specific capacitance of PPCL papers obtained using benzene, toluene, water and hexane co-vapors was higher than those of the others, which is attributed to the enlarged effective surface area of the electrode material. The results indicate that the judicious choice and combination of co-vapors in vapor-deposition polymerization (VDP) offers the possibility of tuning the morphological, electrical, and electrochemical properties of deposited conducting polymers.

Surfactant-Templated Synthesis of Polypyrrole Nanocages as Redox Mediators for Efficient Energy Storage

“…Conducting polymers that can store electric charge by a redox pseudo-capacitive mechanism have been explored for use in rechargeable energy storage devices due to their exclusive advantages, such as facile synthesis, structural diversity, low weight, and flexibility 29 30 31 . Recent advances in nanotechnology have allowed for the widespread use of nanoparticles in electrodes for energy storage and conversion applications 32 33 . In particular, nanostructuring of conducting polymers can increase the contact area between the polymer and the electrolyte, resulting in enhanced kinetic characteristics and charge storage capacity.…”

The Comparative Study on Vapor‐Polymerization and Pressure‐dependent Conductance Behavior in Polypyrrole‐hybridized Membranes

“…Briefly, cellulose membranes were immersed into an aqueous oxidant solution (FeCl 3 ) leading to the yellow membrane after drying in the air, and placed inside a closed container where the pyrrole monomer is vaporized at room temperature for in situ polymerization on the membrane surface (Figure (a)). While the oxidative polymerization of pyrrole monomer vapor was in progress, the whole surface of cellulose fibrous networks turned black indicating that PPy was synthesized (Figure (b)) . Note that the pristine cellulose membrane is sufficiently hydrophilic, thus the wetting by aqueous solution enables the uniform deposition of oxidant throughout the fibrillary cellulose networks.…”

Nanostructured Electrode Materials for Electrochemical Capacitor Applications

“…As a conjugated polymer, PPy shows practical potential for a diverse and promising range of future technologies. Free-standing, flexible, and large-area PPy/cellulose (PPCL) papers were readily prepared using VDP ( Figure 9 ), and PPy coatings on cellulose microfibers were influenced by the properties of co-vapors introduced together with pyrrole during polymerization [ 66 ].…”