Effect of the pH on the piezoelectric properties of collagen films

In this paper, we did a study of the physicochemical, dielectric and piezoe lectric properties of collagen films, considering the development of new bi omaterials which have potential applications in coating of cardiovascular p rostheses, support for cellular growth and in systems for controlled drug d elivery. The piezoelectric strain tenser element d(14), the elastic constan t S-55, and the dielectric permittivity epsilon (11) were measured for coll agen films. it was observed that the collagen samples submitted to differen t pH treatment lead to different electrical behavior. For sample S2. (pH = 5.2) one has a higher denaturation temperature (T-d = 80.55 degreesC), lowe st density (rho = 909.6 kg m(-3)), highest dielectric function, lowest freq uency constant product (f x L = 320.33 kHz.m) and higher piezoelectricity ( d(14) = 0.122 pC/N) which is our major interest in this study. The loss fac tor Q(-1) measured for all the samples shows that for all the electrodes di mensions sample S2 present the highest loss factor which is between 0.68 an d 0.76. We believe that the different pH treatment is critical to the final level of organization of the microscopic structure of the sample. which co uld result in an increase of the piezoelectricity. (C) 2001 Elsevier Scienc e B.V. All rights reserved.