The paper "Interfacial and Internal Proton Conduction of Weak-acid Functionalized Styrene-based Copolymer with Various Carboxylic Acid Concentrations" by Ms. SUWANSOONTORN, Athchaya (3rd-year doctoral student in Nagao Lab of Materials Chemistry Area) published in the journal Electrochemistry by the Electrochemical Society of Japan was selected as the most downloaded paper among all papers published in the journal from May to June 2021.
JAIST published the research results presented in the paper in a press release titled "Proton's Travel Route in Polymers Could Lead the Way to Clean Fuels" on May 28, 2021.　

The Electrochemical Society of Japan was founded in 1933 to foster scientific and industrial progress in the fields of electrochemistry and industrial physical chemistry.

■Date Awarded
July 20, 2021

■Title
Interfacial and Internal Proton Conduction of Weak-acid Functionalized Styrene-based Copolymer with Various Carboxylic Acid Concentrations

■Authors
Athchaya Suwansoontorn, Katsuhiro Yamamoto, Shusaku Nagano, Jun Matsui, Yuki Nagao

■Abstract
Investigation of interfacial proton transport is necessary to elucidate biological systems. As commonly found in biomaterials, the carboxylic acid group was proven to act as a proton conducting group. This study investigated the influence of carboxylic acid concentration on both interfacial and internal proton transport. Several styrene-based polymers containing the carboxylic acid group were synthesized. The amount of carboxylic acid group in the polymer chain was varied to explore the effects of weak acid concentration on polymer thin films' electrical properties. The IR p-polarized multiple-angle incidence resolution spectrometry (pMAIR) spectra show the higher ratio of the free carboxylic acid groups rather than cyclic dimers in polymers with a higher concentration of carboxylic acid group, facilitating the more hydrogen bonding networks in films. The water uptake results reveal the similar number of adsorbed water molecules per carboxylic acid group in all thin films. Remarkably, polymer thin films with high carboxylic acid concentration provide internal proton conduction because of the relative increase in the amount of the free carboxylic acid group. In contrast, interfacial proton conduction was found in low carboxylic acid concentration polymers because of the relatively large amount of cyclic dimer carboxylic acid group and poor amount of free carboxylic acid group. This study provides insight into interfacial proton transport behavior according to the weak acid concentration, which might explain proton transport in biological systems.

■Comment
We are greatly honored to receive the award for Most Downloaded Papers for "Electrochemistry". First, I want to express my appreciation to Assoc. Prof. Katsuhiro Yamamoto, Prof. Shusaku Nagano, Prof. Jun Matsui, and Assoc. Prof. Yuki Nagao for their valuable comments and guidance. And I am also grateful to Nagao LAB members for their support. We expect that our research can contribute to developing bio-conductive materials for eco-friendly devices.

July 30, 2021