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This work investigated the use of water hyacinth fiber (WHF), extracted from the leaves of Eichhornia crassipes, to produce chitosan-based biocomposites for removal of copper(II) ions from water. The WHF was extracted by shredding, alkaline treatment, neutralization, and filtering. This yielded cellulosic fibers with an average diameter of 11 ± 2 μm. WHF/chitosan composite films were prepared using a solution casting method in which WHF was mixed with chitosan in an acidic aqueous solution and air-dried. X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared spectroscopy were used to characterize the biocomposites obtained. Tensile tests demonstrated a significant improvement in the Young's modulus when the composite was loaded with fiber at 5%. At a 10% loading, the composite film was found to adsorb approximately five times more copper(II) ions from water than the neat chitosan film (Cu2+adsorption increased from 6.4 ± 2.4 mg/g for the chitosan film to 34.1 ± 2.2 mg/g for the composite containing 10% fibers). The equilibrium adsorption time was 240 min. The study successfully demonstrated the use of this aquatic weed in treatment of water with heavy metal ion-contamination.

Materials with Ruddlesden-Popper structure (A2BO4) such as La2NiO4 system have been identified as the new cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs) as their coefficient of thermal expansion values match those of the currently used electrolytes. Moreover, such materials have shown mixed ionic and electronic conductivity desirable for cathodes. The low electronic conductivity of La2NiO4 remains a challenge. To improve this property, investigations on La2-xSrxNiO4+δ (x = 0, 0.4, and 0.8) prepared via sol-gel and solid state reaction processes were carried out in this study. Effects of Sr substitution on A sites on physical and electrical properties of the compound were investigated and compared. A simple preparation sol-gel process, carried out at room temperature and using water as solvent for the synthesis of La2-xSrxNiO4+δ, was successfully developed. The solgel synthesis method yielded more homogenous samples with higher conductivity compared to those synthesized via the solid state reaction method. Conductivity as high as 160 S/cm at 500oC was observed for La1.2Sr0.8NiO4+δ synthesized via the sol-gel process.