To improve the compatibility of asphalt-epoxy and mechanical properties of cold-mixed epoxy asphalt (CEA), epoxy-ended hyperbranched polymer (EHBP) was grafted on the surface of graphene oxide (GO) nanoplates to synthesize GOEHBP as a compatilizer. The chemical structures and micromorphology of GOEHBP were analysed through Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, thermo gravimetric analysis and transmission electron microscopy. The CEA modified by EHBP and GOEHBP was investigated by tensile test, dynamic thermomechanical analysis, viscosity test, fluorescence microscope experiment, FTIR analysis and XPS analysis. The results showed that the EHBP was successfully grafted onto the surface of GO via chemical reaction, and the GO was partially reduced. The mechanical properties of CEA modified by EHBP are obviously improved, and the elongation at break was increased by 74.5%. The glass transition temperature of CEA modified by GOEHBP was increased to 62.58°C. At high temperature (≥40°C), the E′ of CEA modified by GOEHBP was larger than that of the CEA, indicating that GOEHBP can improve the high-temperature deformation resistance of CEA. The addition of GOEHBP can improve the compatibility of asphalt-epoxy, thus improving the toughness of CEA.
Enzyme immobilization is believed to provide an excellent base for increasing environmental tolerance of enzyme and considerable period of time. In this work, a kind of nonporous silica nanoparticles functionalized with amino group was synthesized to immobilize proline-specific endoprotease (PSEP). PSEP is known to specifically cleave peptides (or esters) at the carboxyl side of proline, thus can prevent the formation of haze and prolong the shelf life of beer. After immobilization, the environmental tolerance (temperature and pH, respectively) was obviously improved, and the immobilized enzyme can retain above 90 % of its original activity after 6 uses. Moreover, the immobilized enzyme can effectively prevent the formation of chill-haze using fresh beer fermentation liquid.
危险品化学品经营许可证（带存储）