ABSTRACT
This study concerns the development and charaterization of Silica-based aldehyde Chitosan hybrid material as an adsorbent for biodiesel purification. This biocomposite was prepared by sol-gel route and oxidation with periodate, and then characterized. FTIR experiments showed that the hybrid formed presents absorption bands similar to those of Chitosan-Silica, with the exception of the vibrations at 1480 cm-1 and 1570 cm-1 attributed to the symmetrical angular deformation in the N-H plane, and possess large N2 Brunauer-Emmett-Teller (BET) surface areas. Thermogravimetric analysis (TG) and scanning electron microscopy (SEM) was also carried out. Adsorption studies of bioadsorbents involving the analysis of free glycerol, soap, acidity, diglycerides, triglycerides, and fluorescence spectroscopy showed that silica-based aldehyde chitosan has a good affinity for glycerol and a good purification process.
ABSTRACT
A line-tunable CO(2) laser system is described producing repeatable pulses with selectable widths from 2 to 60 nsec. High energy contrast ratio (minimum of 10) is achieved in both the P and R branches of the 9- and 10-microm bands making this system a valuable source for photochemical studies.
