Latent thermal energy storage plays an indispensable role in exhaust heat recycles in various industries which is useful for reducing energy consumption . Different phase change temperatures and high thermal conductivities of composite phase change materials were required for various domains. In the present work, Alum as phase change material and Ala as melting point modifier, a series of phase change materials with adjustable melting temperatures were prepared by physical mixing method. Moreover, EG as porous skeleton and thermal conductive enhancer, composite with high thermal conductivity was obtained with simple physical adsorption method. The XRD and SEM were applied to characterize the phase crystal and microstructure of the composite phase change material. DSC results revealed that phase change temperatures of Alum-Ala mixtures could be adjustable from 91.11 °C to 74.61 °C and thermal conductivity of the composite was improved to 10.93 W·m −1 ·K −1 , which is 21.9 times of pristine Alum-Ala mixture. The infrared thermography and temperature-time curves were obtained to represent the heat transfer performance and the subcooling degree intuitively. The subcooling degree was decreased from 2.238 K to 1.866 K. The result of TGA indicated that the composite possessed favorable thermal stability during the operating temperature. From the result, the composite obtained in the present work is a prospective candidate for exhaust heat recycles.
Zihui Wang,Langming Bai,Jinlong Wang,Qian Zhao,Heng Liang,Guibai Li
Improving the nanofiltration (NF) performance of membrane-based treatment is conducive to promoting environmental water recycling and addressing water resource depletion. Combinations of light, electricity, and heat with traditional techniques of preparing membranes should optimize membrane performance. Interfacial polymerization and photopolymerization were integrated to construct a photopolymerized thin-film composite NF membrane with a ridged surface morphology. Under visible light initiation, 2-acrylamido-2-methyl-1-propanesulfonic acid was crosslinked with the polyamide network. The control effects of light on the membrane surface and physicochemical properties were revealed via infrared thermal images and response surface methodology. To present the diffusion motion of piperazine molecules, molecular dynamics simulations were implemented. Through density functional theory simulations, the crosslinking mechanism of the photoinduced NF network was identified and verified. The surface physicochemical characteristics and perm-selectivity performance were systematically illustrated. The photopolymerized membrane outperformed the pristine in permeability and selective separation competence; without degradation of solute repulsion, the water permeation was enhanced to 33.5 L m–2 h–1 bar–1, 6.6 times that of the initial membrane. In addition, the removal of organic contaminants and antifouling capacities were improved. This work represents a novel lead for applying sustainable resources in constructing high-performance membranes for environmental challenges.