Effect of the Surface Charge of Stainless Steel on Adsorption Behavior of Pectin
2002 年 7 巻 1 号 p. 9-15
詳細
2002 年 7 巻 1 号 p. 9-15
The effect of the surface charge of stainless steel particles on the adsorption behavior of pectin was studied over the pH range of 2.5 to 5.0. Stainless steel particles having different surface charge properties were prepared by chemical passivation in nitric acid, ozone oxidation, and heat treatment. The degree of the ionization of pectin increased with increasing pH, inducing a more extended structure. The saturation amount of pectin adsorbed (Γ s) on all the surface-treated stainless steel particles increased with decreasing pH, showing the largest values at pH 2.5. The Γ s also depended on the apparent density of the positive surface charge of stainless steel particles. It was found that the relative binding strength of unionized pectin on positively charged stainless steel surfaces was lower than that of ionized molecules and it also depended on the apparent density of the positive surface charge of stainless steel particles. These results showed that the surface charge of stainless steel, as well as the degree of the ionization of pectin, was an important factor determining the adsorption behavior of pectin at stainless steel-water interfaces.
