Proton Conduction via Water Bridges Hydrated in the Collagen Film

Hiroshi Matsui, Yasumitsu Matsuo

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


Collagen films with proton conduction are a candidate of next generation of fuel-cell electrolyte. To clarify a relation between proton conductivity and formation of water networks in the collagen film originating from a tilapia’s scale, we systematically measured the ac conductivity, infrared absorption spectrum, and weight change as a function of relative humidity (RH) at room temperature. The integrated absorbance concerning an O–H stretching mode of water molecules increases above 60% RH in accordance with the weight change. The dc conductivity varies in the vicinity of 60 and 83% RH. From those results, we have determined the dc conductivity vs. hydration number (N) per unit (Gly-X-Y). The proton conduction is negligible in the collagen molecule itself, but dominated by the hydration shell, the development of which is characterized with three regions. For 0 < N < 2, the conductivity is extremely small, because the water molecule in the primary hydration shell has a little hydrogen bonded with each other. For 2 < N < 4, a quasi-one-dimensional proton conduction occurs through intra-water bridges in the helix. For 4 < N, the water molecule fills the helix, and inter-water bridges are formed in between the adjacent helices, so that a proton-conducting network is extended three dimensional.

Original languageEnglish
Article number61
JournalJournal of Functional Biomaterials
Issue number3
Publication statusPublished - 2020 Sept


  • Bio-electrolyte
  • Biofuel cell
  • Biomaterial
  • Collagen
  • Fuel-cell electrolyte
  • Hydration
  • Hydrogen bond
  • Ionic conduction
  • Proton conduction
  • Water bridge

ASJC Scopus subject areas

  • Biomaterials
  • Biomedical Engineering


Dive into the research topics of 'Proton Conduction via Water Bridges Hydrated in the Collagen Film'. Together they form a unique fingerprint.

Cite this