Preparation and characterisation of carboxymethyl-chitosan/sodium phytate composite membranes for adsorption in transformer oil.

Adsorption of metal impurities from transformer oil was studied using a novel porous membrane. A solution of N, O­carboxymethyl­chitosan (CMC) and sodium phytate (SP) was blended to prepare a novel porous membrane for the metal impurities adsorption from transformer oil. The chemical structure of the membranes was characterised by their FTIR spectra, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and video camera observations. The effects of the SP content of the membrane, contact time, and contact temperature on adsorption of copper, iron, and aluminium impurities were studied. The FTIR spectra and thermogravimetric curves of the membranes indicated good compatibility between CMC and SP. The SEM and video camera observations suggested that CMC-SP composite membranes had a mature, porous structure. The experimental results showed that the SP content significantly affected the adsorption capacity of a CMC membrane. The maximum adsorption percentages of elemental copper, iron, and aluminium were 88.12%, 82.35%, and 80.36% when the SP ratio was 80% at 60 °C.

Physical, antibacterial and antioxidant properties of chitosan films containing hardleaf oatchestnut starch and Litsea cubeba oil.

More and more attention was attached to food safety, it is necessary to endow food packaging films with good antibacterial and antioxidant properties Edible films based on chitosan (CH), hardleaf oatchestnut starch (HOS) and Litsea cubeba oil (LEO) were prepared by solution casting. The properties and structures of the blend film with different proportion (xCH/yHOS) were evaluated. The CH-HOS films were firstly prepared by blending CH solution with HOS paste. The tensile strength (TS) and DPPH radical scavenging ability of CH-HOS films increased from 27.33 MPa to 33.54 MPa and 20.67% to 52.34%, respectively, and water vapor permeability (WVP) decreased from 1.531 × 10-11 g m-1 pa-1 s-1 to 1.491 × 10-11 g m-1 pa-1 s-1, with the HOS content increased from the ratio of 1:0 to 1:1. Then, the LEO was added to 1CH-1HOS films. Tensile strength (TS), water vapor permeability, moisture absorption and total soluble matter (TSM) of the 1CH-1HOS film were remarkably decreased with 16%LEO. Meanwhile, the static contact angle and antimicrobial activity of 1CH-1HOS-16LEO film increased significantly. Hence, this blend film system has great potential for food packaging in the future.