This chapter is an attempt at an excursion into the world of keratins with the help of thermodynamics.After briefly introducing some of the thermodynamic concepts involved in deciphering the behaviour of keratins, we will use them to look into the process of aggregation of keratin molecules into intermediate filaments, and keratin fibres, and then for analysing how keratin materials react to mechanical, thermal and moisture stresses, respectively.In most of the cases entropy appears to be the major driving force of the response occurring in keratins under environmental assault. This fact points to the important role played for keratins by temperature, which, aside from influencing the kinetics of the processes (accelerating or decelerating the rates of the rates), helps increase or decrease the entropic contribution to the Gibbs free energy and, thus, allows thermodynamically the occurrence of the observed behaviour of keratins.
Keywords: Alpha helix-beta sheet transition; Glass transition; KIF assembling; Keratin denaturation; Keratin fibre mechanics; Moisture sorption–desorption.