| Abstract
| - We report in this paper the synthesis and characterization of a new class of biopolymer−claynanocomposites based in the assembling of chitosan to sepiolite, which is a natural magnesium silicateshowing a microfibrous texture. CHN and ICP/AES chemical analyses, XRD, FTIR spectroscopy, 13Csolid-state NMR, LT-SEM, and thermal analysis have been employed in the characterization of the resultingnanocomposites. The adsorption isotherm of chitosan on sepiolite in acidic medium reveals a significantcoverage of the biopolymer at high equilibrium concentration values indicating a multilayer adsorption.The arrangement of chitosan chains on the surface of the silicate microfibers is discussed on the basis ofphysicochemical data obtained by application of the different techniques. The potentiometric responseof this new type of bio-nanocomposites incorporated in carbon paste electrodes toward aqueous saltsolutions was employed for the first time as a valuable technique for a rapid assessment of the ion-exchange behaviors. Thermal behaviors and mechanical properties have been determined by DTA-TGand DMTA, respectively. As these materials are well-processed as self-supporting films, in view of theirproperties they show potential interest as membranes for different processes related to separation of ionsand gases, as well as components in electrochemical devices (fuel-cell, potentiometric sensors).
- A new class of bio-nanocomposites based on the assembling of chitosan with the microfibrous clay sepiolite is here reported. They are stable compounds that can be processed as films, showing ability to act as ion-exchange materials that can be applied as a component of potentiometric sensors or membranes for fuel-cells.
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