Cold storage systems release huge amount of condensation heat into the ambient leading to severe environmental pollution and significant energy waste. On the other hand, research into phase change materials appropriate to heat recovery in cold storages has not yet been well reported. The paper presented a dedicated study into a novel phase change composite material appropriate to this kind of application, which has relatively larger latent heat and thermal conductivity, and appropriate phase change temperature (i.e. 80 o C). Taking Carnauba Wax (CW) as the Phase Change Material (PCM) and the highly thermal conductive porous expanded graphite (EG) as the additive, a composite was thus developed at the mass ratio of 10:1 that was recognized as the optimal mixing rate. Thermal & physical properties and interior structure of the composite were then investigated by using the scanning electron microscope (SEM), thermal constants analyzer (Hot Disk), differential scanning calorimeter (DSC), and Fourier transform infrared spectrometer (FT-IR). Furthermore, experiments on the melting & solidification and the accelerated cooling & heating cycling were also undertaken. It is found that at the optimal mass ratio, temperatures of the CW/EG composite in the melting and solidification processes were 81.98 o C and 80.43 o C respectively, while the corresponding latent heats were 150.9J/g and 142.6J/g. During both processes, the CW could retain its original vermiform structure after being completely adsorbed by the EG. Compared to the CW alone, the melting and solidification timings of the CW/EG composite were reduced by 81.7% and 55.3% respectively; while its thermal conductivity became 17.4 times higher. After undertaking around 1000 runs of accelerated cooling & heating cycling, the endothermic/exothermic phase change temperatures of the CW and CW/EG composite were increased by only 0.42%/0.42% and 0.23%/0.27% respectively; while their endothermic/exothermic latent heats were reduced by 4.96%/4.78% and 2.05%/3.

With the development of science and technology, more and more complex samples like peptides and proteins need to be separated. It is difficult to separate them by single mode chromatography. Due to the unique separation character of mixed-mode chromatography, the same separation performance can be obtained in mixed-mode chromatography in one separation as multidimensional chromatography. And some disadvantages of multidimensional chromatography can be avoided in mixed-mode chromatography, such as the complexity of the system, the poor compatibility of mobile phases and the long analytical time. More and more attention is devoted to the mixed-mode chromatography in recent years. The focus on the mixed-mode chromatography is to design new structures of mixed-mode stationary phase. At present, mixed-mode stationary phases included reversed-phase/ion-exchange, reversed-phase/hydrophilic, hydrophilic/ion-exchange, zwitterionic and trimode mixed-mode stationary phases. The kinds of mixed-mode stationary phases are summarized and their features and applications in different fields are discussed in this review.