Study On The Preparation And Multi Functiongal Properties Of Cuprous Oxide Coated With N-eicoasane Phase Change Mateials

In this paper,n-eicosane and cuprous oxide were designed as phase change material(core)and shell,respectively.And the microencapsulated n-eicosane with cuprous oxide wall was synthesized by in-situ precipitation.The inorganic copper source,surfactant,reducing agent and alkali were anhydrous cupric sulfate,hexadecyl trimethyl ammonium bromide,glucose and sodium hydroxide,respectively.It had been researched that the effects of different sodium hydroxide concentration,surfactant concentration,and different mass ratio of n-eicosane/anhydrous cupric sulfate on the microstructure,surface morphology and phase transition properties of microcapsules.In the experimental part of this paper,the surface morphology of microcapsules were analysed by scanning electron microscopy(SEM)and the microstructure of microcapsules were studied by transmission electron microscopy(TEM).the functional structure of wall materials was reaserched by Fourier transformation infrared spectroscopy(FTIR),the elements of microcapsules and the content of each element were characterized by energy-dispersive X-ray spectrometer(EDAX),and the chemical elements of the microcapsule composition was analyzed by X-ray photoelectron spectroscopy(XPS).The crystal type of cuprous oxide was studied by X-ray diffraction(XRD).The phase change performance,durability and thermal stability of the microcapsules were characterized by differential scanning calorimeter(DSC)and thermogravimetric analysis(TGA).Moreover,the solar energy-storage effectiveness of microcapsules was investigated by infrared thermographic camera and multi-channel temperature collection recorder.And the photocatalytic degradation and gas sensitive properties of cuprous oxide were studied by ultraviolet visible spectrophotometer(UV-vis)and intelligent gas sensing analysis system.It was the optimum synthesis conditions of preparing microcapsulation that the concentration of sodium hydroxide and surfactant were 5.00 mol·L-1 and 0.15 mol·L-1,and the mass ratio of n-eicosane/anhydrous cupric sulfate was 50/50.Under these conditions,the microcapsules had a complete core-shell structure,and the morphology of the microcapsules was octahedron.The microcapsule prepared under the optimum synthesis conditions had outstanding phase change properties,thermal stability,durability and anti permeability,and it could effectively realize the solar thermal conversion.N-eicosane coated by cuprous oxide,the microcapsulation prepared in this experiment has multiple functions.The microencapsulation not only had a thermal storage and thermo-regulating function,but also had photo degradation and gas sensing.In the photocatalytic experiment,when the illumination time reached 160 min,the degradation of Congo red could reach 81.12%,and the degradation rate of malachite green and fuchsin acid could reach 90.68%and 90.75%,respectively.Cuprous oxide had excellent photo degradability of the three kinds of dyes,but the photocatalytic effect of cuprous oxide on malachite green and acid fuchsin was superior to that of Congo red.Cuprous oxide had a certain degree of sensitivity response on the four kinds of toxic gases,and the order of gas sensitivity of cuprous oxide in different gas atmosphere was follows:acetone>methanol>ethanol>benzene.