No abstract

Silica nanoparticles and polyethylene-block-poly were doped in sodium acetate trihydrate to in-situ synthesize stelliform nanostructure to enhance the effective specific heat capacity of sodium acetate trihydrate. Sodium dodecyl sulfate and methanol were also used in the synthesis to help the dispersion. A modulated differential scanning calorimeter was employed to characterize the specific heat capacity of pure sodium acetate trihydrate and their nano samples. The measurement was repeated multiple times on different days to confirm the repeatability of the measurement. The result shows the specific heat capacity was enhanced by 11% in comparison with pure sodium acetate trihydrate. The conventional effective specific heat capacity model was compared with the experimental result.

Recent studies have shown that doping nanoparticles (NPs) into a molten salt eutectic can induce salt molecules to form a stelliform nanostructure that can enhance the effective heat capacity of the mixture. This phenomenon can result from a unique characteristic of a eutectic molten salt system, which can self-form a nanostructure on a nanoscale solid surface. Hence, such an enhancement was only observed in a molten salt eutectic. Similarly, a stelliform nanostructure can be artificially synthesized and dispersed in other liquids. Mixing polar-ended molecules with a NP in a medium can induce the polar-ended molecules ionically bonded to a NP to form a stelliform nanostructure. Hence, this may enhance the effective heat capacity of the mixture. In this study, we disperse various NPs and polar-ended materials into a sodium acetate trihydrate (SAT) at different ratios to explore the effect of NP type and concentration as well as polar-ended materials and their concentrations on the resultant heat capacity of SAT. The result shows that the specific heat capacity was the highest with silica NP at 1% concentration of weight and polar-ended material at 4% concentration.