ABSTRACTBlending the biopolymer chitosan (CHI) with poly (aminopropilsiloxane)
oligomers (pAPS), and poly (ethylene oxide) (PEO) in the presence of lithium
perchlorate lead to ion conducting products whose conductivity depends on
the composition of the mixture. A ternary phase diagram for mixtures
containing 0.2 M LiClO4 shows a zone in which the physical
properties of the products - transparent, flexible, mechanically robust
films - indicate a high degree of molecular compatibilization of the
components. Comparison of these films with binary CHI-pAPS nanocomposites as
well as the microscopic aspect, thermal behavior, and X-ray diffraction
pattern of the product with the composition PEO/CHI/pAPS/LiClO4
1:0.5:0.6:0.2 molar ratio indicates that these films may be described as a
layered nanocomposite. In this composite, lithium species coordinated by PEO
and pAPS should be inserted into chitosan layers. Electrochemical impedance
spectroscopy measurements indicate the films are pure ionic conductors with
a maximal bulk conductivity of 1.7*10-5 Scm-1 at 40 °C
and a sample-electrode interface capacitance of about 1.2*10-9
F.
