Studies of ferroelectric properties of collagen.

: Dielectric hysteresis loop and differential thermal analysis (DTA) studies of collagen were performed for temperatures ranging from a room temperature to 393 K. The material studied was collagen from Achilles tendon of a bullock, which contained 10% of water. The DTA curve for collagen with 10% of water showed a clear minimum at 353 K. The character of the curve proved that around 353 K an endothermic transformation of collagen took place which could be connected with the transition spiral-ball. A hypothetical dielectric hysteresis loop shows a maximum shift along the direction of the electric field applied in the vicinity of 375 K. Low frequencies of the applied electric field are connected with a great dielectric loss influencing the interpretation of collagen ferroelectricity.