Shanghai Institute of Technology

The fishscaling resistance of enameled steel is closely related to the hydrogen-related behavior of its constituent phases, in which dispersed co-precipitates are regarded as the most effective hydrogen-trapping sites.To investigate the resp. roles of the individual precipitates on the hydrogen trapping ability and locations in enameled steels containing a co-precipitate, in situ SEM (SEM), correlated with Scanning Kelvin Probe Force Microcopy (SKPFM), was employed in this work.Chem. anal. from Energy Dispersive Spectrometer (EDS) mapping showed that the co-precipitate was composed of four precipitates, namely Ti₄C₂S₂, Ti(C,N), TiN, and Al₂O₃.Changes in surface micro-potentials before and after hydrogen charging were measured for each single precipitate using SKPFM technol.There existed a significant difference in the potential change between the four composite precipitates, which could distinctly reflect the difference in hydrogen trapping abilities and fishscaling resistance.The results showed that the hydrogen trapping abilities of the four precipitates were in the following order: Ti(C,N)$\gt$>Al₂O₃$\gt$>Ti₄C₂S₂$\gt$>TiN.Furthermore, a peak anal. of the potential demonstrated that the hydrogen atoms were mainly trapped in the interface zone of the Ti₄C₂S₂ and TiN precipitates, while the dominant hydrogen trapping locations of Ti(C,N) and Al₂O₃ precipitates were primarily the center area of the particles.

The utilization of waste industrial lubricating oil can save energy and protect the environment.In this work, an exptl. study had been conducted to solve the decolorization problem, and the properties of the regenerated oil were compared with waste lubricating oil and fresh oil.CNTs/PDMS/PVDF membranes were prepared for the regeneration of waste lubricating oil, and the optimum mass ratio of PDMS/PVDF was 1:5 with 1.0 wt % carbon nanotubes.The transmittance, kinematic viscosity, condensation point and water content were measured, and the friction properties and recovery were tested.The results showed that the transmittance of regenerated oil can be increased to 94.93%, and the kinematic viscosity was close to that of fresh oil.The water content decreased from 77.7 ppm to 32.4 ppm, lower than 52.6 ppm of fresh oil.The condensation point decreased from -25°C to -27°C, which was close to -30°C of fresh oil.The wear scar diameter decreased from 0638 mm to 0.552 mm, and the friction coefficient decreased from 0.088 to 0.074.The oil recovery rate can be up to 94.60%.

Due to the low boiling point, volatilization, sensitivity to heat, and poor solubility in water, it is difficult to ensure that the aroma of products can be stably and lastingly released. Therefore, the microencapsulation of flavor and fragrance can achieve stabilization to some extent. Temperature-responsive microcapsules are a kind of micro-containers that can achieve rapid release of core materials by regulating temperature. They can not only prolong the retention time of aroma, but also realize the smart release of aroma substances by simply changing the temperature. However, since there aren't so many works about the industrialization of temperature-responsive aroma microcapsules, the applications of these microcapsules in products may face certain challenges. In this review, firstly, the classification of wall materials of temperature-responsive aroma microcapsules is summarized and sorted out. Then, the preparation methods of temperature-responsive aroma microcapsules are described, and the release mechanisms of these microcapsules made of colloidal materials are mainly discussed. According to the properties of temperature-responsive materials, the release mechanism of aroma microcapsules is explained from five aspects: phase transition temperature, cloud point, polymer molecular chain conformation transition, glass transition temperature, and Avrami's equation. In the last part of this review, challenges and prospects faced by temperature-responsive aroma microcapsules in research and applications are proposed.