To increase the thermal conductivity of organic phase change materials

the nanoparticles with high thermal conductivity

including multi-walled carbon nano-tubes (MWNTs)

Cu and Al2O3

were added into the organic composite PCMs of lauryl alcohol-capric acid (with mass ratio of 58.47:41.53)

respectively. The thermal conductivity coefficients of nano-organic composite PCMs were analyzed. The kinds and concentration of nanoparticles and the time of ultrasonic dispersion were the key influencing factors. The results showed that the thermal conductivity increased in different degree when the different mass fractions of MWNTs

Cu and Al2O3 were added. The thermal conductivity enhancement effects were in order of MWNTs

Al2O3 and Cu when mass fraction was 0.1 g·L-1 and ultrasonic dispersion time was 50 min. With the same kind of nanoparticles and ultrasonic dispersion time

the thermal conductivity enhancement effects were decreased as mass fraction was increased from 0.1 g·L-1 to 0.6 g·L-1. Excellently

compared with the original PCMs

the thermal conductivity increased by 20.5% when mass fraction of MWNTs was 0.1 g·L-1 and ultrasonic dispersion time was 90 min. The lauryl alcohol-capric acid+MWNTs (0.1 g·L-1) + sodium dodecyl bezene sulfonate (0.2 g·L-1) with good thermal stability had a limited influence on the phase change temperature of the original PCMs and decreased the degree of supercooling by 58.7%.