RESUMO
Research on phase change material (PCM) for thermal energy storage is playing a significant role in energy management industry. However, some hurdles during the storage of energy have been perceived such as less thermal conductivity, leakage of PCM during phase transition, flammability, and insufficient mechanical properties. For overcoming such obstacle, researchers have been concentrating on composite PCM, where PCM is combined with metal or non-metal particles, fibrous materials, expanded or porous materials, and flame retardants. The main purpose of the current paper is to review the properties enhanced paraffin-based composite PCM. In the literature review, paraffin is selected as a thermal energy storage material, which is mixed with property-enhancing material to prepare composite. Structural and thermal properties of composite have been explored with the help of scanning electron microscope, X-ray diffractometer, transmission electron microscope, polarizing optical microscope, Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. Mechanical properties of the material are also portrayed using different testing techniques. Nevertheless, numerical methods have also been adopted for characterization of composite. It is found from the literature review that with incorporation of property-enhancing material, thermal conductivity, phase transition rate, and shape stability of PCM increased at the same time flammability, heat storage capacity, and mechanical properties reduced.
RESUMO
In this work, GFRPs with layer-up [+22/-22/90n]s were prepared and hybridized with 0.5wt% of GNPs to introduce in-situ crack suppression ability. Optimization of the processing parameters of ultrasonic dual mode mixing (UDM) process was adopted to disperse GNPs uniformly in the epoxy system and place them evenly at the interfacial zones of GFRPs. Test results show that 102% and 153% enhancement in tensile strength and Young's modulus has been achieved by the proposed method. Low stirring speed and low pulse-off time show significant effect on properties of the GFRPs. The fragmentation behaviour was investigated under optical microscope for GNP infused hybrid GFRPs and compared to that of the control. Failure investigation examined under FESEM showed reduced delamination for hybrid GFRPs having randomly oriented GNPs in their interfacial zone. This work exposes the effective espousal of the process to prepare GNP infused hybrid GFRPs having crack suppression ability at the interfaces.
