Preparation and performances of palmitic acid/diatomite form‐stable composite phase change materials

Abstract

Summary Using palmitic acid (PA) as an organic phase change material (PCM), a series of PA/diatomite composite PCMs (CPCMs) composed of PA absorbed into diatomite mesopores with different mass contents were made through direct impregnation method. Nitrogen adsorption‐desorption curves indicated the porous structure of diatomite with the specific surface area and the mesopore peak at 40 m2/g and 3 to 5 nm, respectively. The form‐stability measurement indicated that the maximum mass loading capacity of PA was 55 wt%. The melting temperature and fusion enthalpy of the PA/diatomite CPCM (55 wt%) were calculated from DSC at 63°C and 88 J/g, respectively. The thermal cycle test implied that the PA/diatomite CPCM with 55‐wt% PA loading showed excellent thermal reliability after 1000 thermal cycles. Moreover, the composite has thermal conductivity at 0.5810 W/m·K and enhanced thermal storage/release rate. PA/diatomite CPCM (55 wt% PA) was a suitable candidate for modern building energy saving and industrial solar energy.

On the diatomite-based nanostructure-preserving material synthesis for energy applications

“…The nPCM based on calcined opal showed greater latent heat than the one based on the raw opal. Other previous and recent reports that utilized the direct impregnation method in the preparation of DE based nPCMs are by Liu et al 132,133 and Jia et al, 134 which are presented in Table 1. It must be emphasized that in all these reports, the interaction between the PCMs and the diatomite was conrmed to be physical, without any chemical interaction from FTIR measurements.…”

Thermal energy data monitoring system based on data collection of thermal metering equipment of internet of things

“…When SDN = 0, Ti3367 is at a Normal working state and when SDN = 1, the system is in a power-down state. When the system is power-off, the memory content is lost, and the SPI interface is in sleep mode [6]. When the system continues to supply power, the SDN level state will automatically switch and follow the control command automatically switch working mode.…”

Carbonized waste hazelnut wood‐based shape‐stable composite phase change materials for thermal management implementations

“…During the melting and solidification phase transformations, PCMs perform LHTES function, while the supporter materials prevents PCM seepage in liquid state and ensures the solid shape to be fully preserved 12‐16 . Some of the porous materials commonly used in the production of shape stable composites are attapulgite, 17 expanded perlite, 18 sepiolite, 11 vermiculite, 19 diatomite 14,20 and silica fume 8,21 . However, many of these materials themselves have low thermal conductivity and hence it is obvious that they cannot help increase the thermal conductivity of PCMs.…”