Fresh MnO2 was prepared by oxide reduction using KMnO4 and MnSO4. The structure and property of the products were characterized by TEM, SEM, XRD and BET, and the effect of pH value was studied on the removal of both A...Fresh MnO2 was prepared by oxide reduction using KMnO4 and MnSO4. The structure and property of the products were characterized by TEM, SEM, XRD and BET, and the effect of pH value was studied on the removal of both As and As. The results show that δ-MnO2 is spherical, its specific surface is 325 m2·g-1 with lots of hydroxyl on the surface. Adsorption of fresh MnO2 of As(III)was a corporate action of both oxide reaction and electrostatic adsorption, but the adsorption of As was due to electrostatic and anion exchange adsorption.展开更多
The elucidation of key influence factors for electrostatic adsorption is very important to control protein nonspecific adsorption on modified surfaces. In this study, real time surface plasmon resonance technique is u...The elucidation of key influence factors for electrostatic adsorption is very important to control protein nonspecific adsorption on modified surfaces. In this study, real time surface plasmon resonance technique is used to characterize the electrostatic adsorption of two proteins (mouse IgG and protein A) on carboxymethyldextran modified surface. The results show that protein solution pH and ionic strength are key influence factors for efficient electrostatic adsorption. The influence of protein solution pH on the amount of electrostatic adsorption depends on the type of the charge and the charge density of both protein and modified matrix on the surface. The electrostatic adsorption process involves a competition between the positively charged protein and other positively charged species in the buffer solution. A decrease of ionic strength leads to an increasing electrostatic adsorption. The kinetic adsorption constants of protein A at different pH values were also calculated and compared.展开更多
文摘Fresh MnO2 was prepared by oxide reduction using KMnO4 and MnSO4. The structure and property of the products were characterized by TEM, SEM, XRD and BET, and the effect of pH value was studied on the removal of both As and As. The results show that δ-MnO2 is spherical, its specific surface is 325 m2·g-1 with lots of hydroxyl on the surface. Adsorption of fresh MnO2 of As(III)was a corporate action of both oxide reaction and electrostatic adsorption, but the adsorption of As was due to electrostatic and anion exchange adsorption.
文摘The elucidation of key influence factors for electrostatic adsorption is very important to control protein nonspecific adsorption on modified surfaces. In this study, real time surface plasmon resonance technique is used to characterize the electrostatic adsorption of two proteins (mouse IgG and protein A) on carboxymethyldextran modified surface. The results show that protein solution pH and ionic strength are key influence factors for efficient electrostatic adsorption. The influence of protein solution pH on the amount of electrostatic adsorption depends on the type of the charge and the charge density of both protein and modified matrix on the surface. The electrostatic adsorption process involves a competition between the positively charged protein and other positively charged species in the buffer solution. A decrease of ionic strength leads to an increasing electrostatic adsorption. The kinetic adsorption constants of protein A at different pH values were also calculated and compared.
