On the piezoelectricity of collagen-chitosan film
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 3 (18):
4154-4157 (2001)DOI: 10.1039/b100189m
Abstract
We studied the physicochemical, piezoelectric and dielectric properties
of collagen-chitosan films, with regard to the development of new
biomaterials which have potential applications in the coating of
cardiovascular prostheses, support for cellular growth and in systems
for controlled drug delivery. The piezoelectric strain tensor element
d(14), the elastic constant s(55), and the relative permittivity epsilon
(11) were obtained for the collagen and collagen-chitosan films.
Resonance measurement of the piezoelectric strain constant d(14) of
collagen gives 0.096 pC N-1, which is in good agreement with values
reported in the literature, measured using other techniques. It was
observed that addition of 15% of chitosan increased the
piezoelectricity to 0.212 pC N-1. The frequency constant f L and the
piezoelectric strain element d(14), obtained for this sample, present
the highest value for the samples under study (427.24 kHz m and 0.212 pC
N-1). This value for the d(14) element is of the same order as that obtained for bovine bone (d(14) = 0.2 pC N-1) (T.G. Netto and R.L.
Ziemmerman, Biophys..T.,1975,15, 573), which is about one-tenth of the
piezoelectric constant d(11) of quartz crystal. Our results also show
that the presence of chitosan contributes to an increase in the thermal
stability of the collagen films, which is associated with an increase in
the denaturation temperature of the collagen-chitosan samples compared
with the collagen sample. We believe that the increase in the
organization of the microscopic structure of the sample, results in an
increase in the piezoelectricity. These high values for the frequency
constant and piezoelectricity, give the possibility of using these films
in electronic devices based on acoustic waves (e.g. surface acoustic
wave devices (SAW)) which operate in the MHz frequency range using
piezoelectric substrates.