Effects of emulsifiers on preparing spherical urea-formaldehyde paraffin capsules modified by β-cyclodextrin for energy storage

Abstract

Urea-formaldehyde (UF) paraffin capsules (B-UPCS) modified by β -cyclodextrin (β -CD) were successfully prepared with excellent energy storage capacity using different emulsifiers. B-UPCS were characterized by FT-IR, DSC SEM, optical microscopy, and laser particle size distribution analyzer. The effects of different emulsifiers and the stirring rate of emulsion on the microstructure, average particle diameter, and the content of paraffin were discussed in details. The results show that OP-10 for use with PCMs as emulsifier has a better emulsifying capacity, thermal stability, and mechanical stirring stability than SDBS for use with PCMs as emulsifier. As a result, the optimum dosage of OP-10 was 3% to 7%, and the suitable stirring rate of emulsion was 7500 to 12500 rpm. At this time, the spherical particle diameter of B-UPCS was about 1.0 m, the paraffin content was 78%, and the enthalpy of B-UPCS can reach 161.0 J/g. © 2014 Xin Yu et al.