The objective of this study was to investigate physical and mechanical properties, such as thickness, water vapor permeability, tensile strength, elongation at break, differential scanning calorimetry (DSC) and microstructure of composite edible films. The film was prepared by casting sago starch from sago palm (Metroxylon sagu) as film base with 10-50 %w/w glycerol as plasticizer and adding bulk chitosan as a reinforcing material (0.1, 0.3, and 0.5 %w/w). The continuous, homogenous and transparent films were obtained. With regard to mechanical properties, tensile strength decreased when the percentage of glycerol increased. Elongation at break (%E) improved with increasing percentage of glycerol from 10 %w/w to 50 %w/w. However, water vapor permeability properties diminished in all samples when the percentage of chitosan increased. The morphological study of the composite films exhibited rougher surfaces with increasing chitosan in the films. DSC thermograms showed that glycerol incorporated into composite films diminished the onset temperature (T0) and degradation temperature (Td). Having these physical and mechanical properties, this edible film has a potential to apply for food packaging purposes. Moreover, this edible film is proved to be more cost-effective and environmentally friendly.

The amino group (-NH2) is one of the most important functional groups of ligands. Particularly, 3-aminopropyl-trimethoxysilane (APTMS) has relatively high affinity to bind various to metal ions. The present study was aimed to modify commercial silica gel (CSG) with the APTMS via silanization process to acquire amino groups (CSG-NH2) as an adsorbent for the removal of iron from synthetic aqueous solution. For an optimal adsorption study, the effects of the initial concentration of Fe(II) (1-80 mg/L), pH of solution (pH 1-10), contact time (1-36 hours) and temperature (30-60˚C) were investigated. The results showed that the adsorption capacity of the obtained CSG-NH2 for the Fe(II) was 60.80 mg/g at pH 4, and complete adsorption equilibrium was reached within 24 hrs. The adsorption isotherm of the CSG-NH2 for Fe(II) was well fitted by the Langmuir isotherm. In addition, thermodynamic data demonstrated that the Fe(II) adsorption onto the CSG-NH2 surface was mainly an exothermic spontaneous reaction. This implies that CSG-NH2 can be used as a high potential adsorbent for the removal of ferrous ion from contaminated wastewater.

Silver nanoparticles were synthesized by bioreduction of silver nitrate using the aqueous leaf extract of Combretum indicum (CI-AgNPs). The synthesized CI-AgNPs exhibited a distinct absorption peak at 414 nm in UV-vis spectroscopy. Various parameters such as pH, temperature and time were optimized using spectrophotometry. The particle size of the CI-AgNPs was 48 nm as evaluated from the laser particle size analyzer. The XRD and EDX analyses confirmed the presence of silver in silver nanoparticles. Synthesized CI-AgNPs revealed significant antioxidant, antimicrobial (against Escherichia coli and Staphylococcus aureus) and photocatalytic (against methylene blue under sunlight irradiation) activities. Thus, an eco-friendly method was developed to synthesize silver nanoparticles using the C. indicum leaf extract.