Preparation of attapulgite carriers with different pore structures and their effects on thermophysical properties of composite phase change materials

In this research, attapulgite was used as the carrier base materials for adsorbing phase change materials. By introducing isocyanate (-NCO) and different amino (-NH2) functional groups, ATP was chemically grafted. A series of porous ATP carriers with different pore structures were constructed based on the reactions between functional groups. The composite phase change materials of different ATP porous carriers were prepared by using stearic acid as phase change material. The TEM, FTIR, XPS, XRD, BET, TG and DSC were used to characterize the morphology, chemical structure and thermophysical properties of the prepared samples. The TEM results showed that the ATP carriers demonstrated favourable porous structure. The results of FTIR, XPS and XRD revealed that the characteristic functional groups isocyanate and amino formed joint molecules successfully, and a dealcoholization condensation reaction took place between the ethoxy groups and silicon hydroxyl on the surface of the ATP. Particularly, according to the characterization results, the enthalpy value of the CPCM reduced with the decrease of the pore size of the ATP carriers, it can also be found that the phase transition temperature of the CPCM declined as long as the pore size of the ATP carriers decreased.