No abstract

No abstract

No abstract

No abstract

A strategy of electrostatic self-assembly and two-step synergism was proposed to significantly improve the thermal conductivity of the PI composite film.

The effects of chelating agents and salts on the interfacial characteristics and oxidative stability of oil-in-water emulsions containing an endogenous concentration of metal ions were investigated. Emulsions were fabricated by high-pressure homogenization of 10% oil phase (sacha inchi oil) and 90% aqueous phase (1% Tween 60 in phosphate buffer solution, pH 7, 50 mM). The oxidative stability of the emulsions was characterized by measuring peroxide values and thiobarbituric acid reactive substances throughout storage. Endogenous iron and copper ion levels in the emulsions were detected by atom absorption spectroscopy as 1.99 and 0.86 ppm, respectively. Incorporation of chelating agents, either ethylenediaminetetraacetic acid or sodium citrate, into the emulsions effectively inhibited lipid oxidation, showing that even these low levels of endogenous metal ions ( parts per million) were sufficient to promote oxidation. Conversely, the addition of monovalent salts, NaCl or KCl, slightly increased the rate of lipid oxidation in the emulsions, which was attributed to their impact on the physical properties of the surfactant layer at the oil droplet surfaces. The impact of chelating agents and salts on the electrical characteristics (ξ potential) and relaxation time (T R ) of the surfactant-coated lipid droplets were characterized by particle electrophoresis and nuclear magnetic resonance spectroscopy, respectively. The chelating agents and salts altered the surface potential of the droplets, indicative of a change in the adsorption of metal ions to the droplet surfaces. Moreover, they altered the arrangement of surface-active molecules at the droplet surfaces, thereby impacting the contact of pro-/antioxidants with the oil phase. These results have important implications for the formulation of emulsion-based materials that are more stable to lipid oxidation.

No abstract

No abstract