Dielectric properties of slightly hydrated collagen: Time–water content superposition analysis

Abstract

SynopsisThe frequency dependences of the dielectric constant, E ' , and the loss factor, E", in collagen were measured a t several water contents from 0.1 to 0.3 g/g collagen over a frequency range of 30 Hz to 100 kHz and at a temperature of 20°C. Remarkable dispersion was observed at the lower frequencies for higher water contents. According to accumulated results on the thermodynamic and structural investigations, the dispersion has some analogy to the surface conduction proposed by B. V. Hamon [(1953) Awt. J. Phys. 6, 304-3151. An empirical relation bewteen E" and frequency, E"= f", where 0 < n < 1, suggests that the dielectric and conductive properties of hydrated collagen are related to carrier jumps between neighboring sites. For the polarization mechanism of this dispersion, we supposed a model of the transfer of protons between absorbed water molecules, and found that the t i m e w a t e r content superposition procedure is applicable to slightly hydrated collagen. The results derived from the superposition procedure show that the water content, +, is related to the conductivity, r , or the dielectric loss factor by the following equations: r (+, f , = const. x +,zm-lf' and el' (+, f, = const.+""'f", respectively, where rn is a constant independent of + and f: These results agree with that derived by another treatment of the same data. The role of water molecules in the conduction and polarization in slightly hydrated collagen is considered to be not far from that assumed in the model.

Possible Further Evidence for the Thixotropic Phenomenon of Water

“…Similarly, Guckenberger et al [22] using scanning tunneling microscopy based on the lateral conductivity of ultrathin water films next to biological specimens, and Sasaki [23] by exploring the dielectric properties of slightly hydrated collagen found increased conductivity values in aqueous solutions under constrained conditions where the lifetime of a hydrogen bond is prolonged.…”

Collagen films from swim bladders: Preparation method and properties

“…These properties are relevant for the design of biocompatible polymer materials with potential application in coating cardiovascular prostheses, support for cell growth and in systems for controlled drug delivery [22]. These properties have been extensively investigated for collagen material from bovine and pig skin [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38].…”

Illuminating Water and Life

“…He estimated that pure water's dissociation constant is 10 −5 that of adsorbed water; i.e., adsorbed water is five orders of magnitude more likely to let go of protons. Similarly, Naoki Sasaki in Japan found that the conductivity of collagen increased markedly with water absorbed, at an exponent of 5.1-5.4, between a water content of 0.1 to 0.3 g/g [51]. These results make sense in light of the recent observations on proton superconduction in nanospace confined water; and new measurements on hydrated collagen fibres need to be done.…”