Research of a new metal chelating carrier preparation and papain immobilization.

A new type of magnetic metal chelating carrier (PCMM-IDA-Cu2+) was prepared for the immobilization of papain, using chitosan as raw material, nano Fe3O4 as magnetic material, SiO2 as porogen, iminodiacetic acid (IDA) as a chelating ligand, and binding with transition metal ion (Cu2+). The resulting products were well characterized by optical microscopy, scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The BBD (Box-Behnken Design) of RSM (Response Surface Methodology) was applied to analyze the optimum enzyme immobilization conditions. The results showed that the enzyme immobilization capacity was 94.18mg/g of PCMM-IDA-Cu2+, with 7.976U/mg of relative immobilized enzyme activity under the optimum conditions (pH6.73, 1.56mg enzyme/15.0mg carrier, 30.9°C), and the recovery of enzyme activity was reached 87.21%. Compared with the free papain, the immobilized papain displayed enhanced enzyme activity, superior enzymatic properties, good operational stability and reusability. It is worth mentioning that the novel carriers exhibited selectively biological adsorption capacity, and this technique is an alternative method for the immobilization of enzyme, making the process more efficient and economic.

[Effect of Raw Materials and Preparing Process on the Composition of Lime-Ash].

As the saying goes that "no ash, no glaze", lime-ash has been the core material widely used to prepare glaze in ancient China. Among all the lime-ashes, those made in Jingdezhen are the most influential and representative ones. Not only did lime-ash contribute greatly to the prosperity of porcelain making of Jingdezhen in Song, Yuan, Ming and Qing Dynasty, but also it has a complicated, rigorous and a touch of "mysterious" in its preparation process, technical principle and glaze mechanism. Therefore, the research of the lime-ash has been an important subject in exploring the "secret" of ancient Chinese porcelain production by Chinese and foreign researchers. In this paper, four representative firewood and two lime stones as the raw materials were collected for the comparative studies, and three kinds of lime-ash with different smolder times were collected from one of the only two traditional lime-ash workshops in Shou'an town nearby Jingdezhen urban area. The chemical composition and phase composition of the raw materials and lime-ash with different smolder times made in Jingdezhen were discussed by testing with the Energy Dispersive X Ray Fluorescence (EDXRF) and X-Ray Diffraction (XRD). The results showed that Fe(2)O(3), MnO contents reaches 1.41% and 1.52% respectively, but the P(2)O(5) content is just 0.54% of Langqi grass which is lower than other firewood that is not only benefited to form the characteristic of "Green in the white" in Jingdezhen traditional glaze, but also is favor to enhance the transparency of glaze and promote the coloration of traditional under-glazed color painted porcelain, such as the blue and white porcelain. The CaO content of grey lime stone is lower than that of the black lime stone with MgO content of 35.79%.This could be the main reason why the craftsmen prefer to use black lime stone to prepare lime-ash. In addition, the EDXRF results show that the K(2)O, P(2)O(5), MnO and Fe(2)O(3) contents have increased as the time of smoldering increases. In the meanwhile, the calcium carbonate (CaCO(3)) phase has also increased, but the calcium hydroxide (Ca(OH)(2)) phase has decreased. The study helps Jingdezhen porcelain "look like jade" and is also good to avoid the "thickness" of glaze when there is a certain amount of Ca(OH)(2) in glaze. So it could be concluded that the unique raw materials and smolder technology of the lime-ash which have provided the technical support for the development of lime-ash glaze are the unique features of ancient Jingdezhen ash glaze.