Each array contained eight electrode elements width: 0. We designed a carboxylic acid terminated acrylamide monomer of AADDA to introduce carboxylic acids at the interlayer of the lamellae film. The average molecular weights of the copolymers were estimated using GPC. We have reported that the degree of polymerization DP needs to be greater than 15 to form a lamellar structure by humid annealing.
Furthermore it has been reported that polymers having ionic groups are strongly adsorbed on the chromatographic column, which results in Mn values smaller than the correct value. We have reported that surface wettability have no effect to the lamellar formation of pDDA by nanophase separation. All polymer films exhibited broad diffraction at low q region. The diffraction was originated from alkyl nanodomains q nd composed by aggregated alkyl side chains.
The promise of protonics
Recently, we have reported that poly alkylacrylamides formed highly ordered lamellar structure by annealing the film in the presence of water or water vapor. The annealing temperature is higher than Tg of the polymers, thus polymer have enough mobility for rearrangement. Relaxation of the rearranged structure is negligible because Tgs are higher than the measurement condition of XRD spectra.
The films were taken out from water and the absorbed water was blown off by a stream of N 2.
The latter peak is broad and its position is the same as that of q nd observed in the pristine film. As mentioned in the introduction section, the lamellar structure is constructed using nanophase separation between hydrophobic alkyl side chains and water adsorbed hydrophilic amide groups located near at the main chain.
AADDA molecule contain hydrophilic carboxyl group at the end of the alkyl side chain, thus reducing the hydrophobicity of the side chains decreases with increasing AADDA content. As a result, the copolymer with higher AADDA content could not convert the structure to lamella due to the weak segregation force. The inability of lamellar formation in copolymers of higher AADDA content were supported by following proton conductivity measurements.
The surface morphology of the films was characterized by AFM measurement. The AFM images of the water annealed films exhibited feature less surface with low roughness, which supported that the polymers were amorphous Figure S5. As a result, the proton conductivity increased with annealing time. The proton conductivity of the present films are at least four order smaller than Nafion membranes. It should be mentioned that recent re-analysis of small angle X-ray scattering data of Nafion have suggested lamellar water channel formation in the film.
The perpendicularly aligned alkyl side chains block the proton transfer, thus the conductivity decreased from 4. The polymer was spin coated on a solid substrate and the structure of the film was analyzed by XRD measurement.
The XRD pattern of the pristine films showed a broad diffraction at low q region, which indicate that the film was amorphous. It was concluded that the lamellar structure was formed by nanophase separation between a main chain and side chains of the polymer. The anisotropic conduction was stable because the lamellar structure was formed in-situ , during the proton conduction measurement. This unique anisotropic conductive film will be useful for proton conduction devices such as proton conductive transistor.
- Accelerating Trade and Integration in the Caribbean (Country Studies).
- Saving Malaya (The chosen ones series Book 1);
- How to Win Your Case In Traffic Court Without a Lawyer?
- Fuel Cells | The Grey Group.
We thank Profs. Kurihara and Ishizaki for their help with XRD measurements. This is an open access article distributed under the terms of the Creative Commons Attribution 4. User Name Password Sign In. Previous Section Next Section. View this table: In this window In a new window. Table I.
Characterization of copolymers. Figure 1. Figure 2. Figure 3. Figure 4.
Figure 5. Figure 6. Figure 7. Previous Section. Topham P. B: Polymer Physics , 49 , CrossRef Google Scholar. Nakashima N.
Miyatake K. Google Scholar.
Solid State Proton Conductors - Philippe Knauth, Maria Luisa Di Vona - Bok () | Bokus
Trigg E. Stefik M. Lazzari M. Uniquely combining both organic polymeric and inorganic proton conductors, Solid State Proton Conductors: Properties and Applications in Fuel Cells provides a complete treatment of research on proton-conducting materials. If you do not receive an email within 10 minutes, your email address may not be registered, and you may need to create a new Wiley Online Library account.
If the address matches an existing account you will receive an email with instructions to retrieve your username. Skip to Main Content. First published: 13 January About this book Proton conduction can be found in many different solid materials, from organic polymers at room temperature to inorganic oxides at high temperature. Solid state proton conductors are of central interest for many technological innovations, including hydrogen and humidity sensors, membranes for water electrolyzers and, most importantly, for high-efficiency electrochemical energy conversion in fuel cells.
Free Access. Summary PDF Request permissions. Tools Get online access For authors.
Related Solid State Proton Conductors: Properties and Applications in Fuel Cells
Copyright 2019 - All Right Reserved