A binary eutectic mixture composed of tetradecanol(TD)and myristic acid(MA)was maximally absorbed into the microstructures of expanded perlite(EP)and expanded vermiculite(EVMT),respectively,through a self-made vacuum ...A binary eutectic mixture composed of tetradecanol(TD)and myristic acid(MA)was maximally absorbed into the microstructures of expanded perlite(EP)and expanded vermiculite(EVMT),respectively,through a self-made vacuum adsorption roller to prepare phase change material(PCM)particle(PCP).Then EP and EVMT-based composite PCM plates were respectively fabricated through a mold pressing method.The thermal property,chemical stability,microstructure and durability were characterized by differential scanning calorimeter(DSC),Fourier transform infrared spectroscope(FT-IR),scanning electron microscope(SEM)and thermal cycling tests,respectively.The results show that both PCPs have high latent heats with 110 J/g for EP-based PCP and more than 130 J/g for EVMT-based PCP,compact microstructure without PCM leakage,stable chemical property and good durability.The research results have proved the feasibility for the vacuum adsorption roller used in the composite PCM fabrication.Results of thermal storage performance experiment indicate that the fabricated PCM plates have better thermal inertia than common building materials,and the thermal storage performance of PCM plates has nonlinearly changed with outside air velocity and temperature increase.Therefore,PCM plates show a significant potential for the practical application of building thermal storage.展开更多
In this work the statistical mechanical equation of state was developed for volumetric properties of crystalline and amorphous polymer blends.The Ihm-Song-Mason equations of state(ISMEOS) based on temperature and dens...In this work the statistical mechanical equation of state was developed for volumetric properties of crystalline and amorphous polymer blends.The Ihm-Song-Mason equations of state(ISMEOS) based on temperature and density at melting point(T_m and ρ_m) as scaling constants were developed for crystalline polymers such as poly(propylene glycol) + poly(ethylene glycol)-200(PPG + PEG-200),poly(ethylene glycol) methyl ether-300(PEGME-350) + PEG-200 and PEGME-350 + PEG-600.Furthermore,for amorphous polymer blends containing poly(2,6-dimethyl-1,4-phenylene oxide)(PPO) + polystyrene(PS) and PS + poly(vinylmethylether)(PVME),the density and surface tension at glass transition(ρ_g and γ_g) were used for estimation of second Virial coefficient.The calculation of second Virial coefficients(B_2),effective van der Waals co-volume(b) and correction factor(α) was required for judgment about applicability of this model.The obtained results by ISMEOS for crystalline and amorphous polymer blends were in good agreement with the experimental data with absolute average deviations of 0.84%and 1.04%,respectively.展开更多
基金Project(51408184)supported by the National Natural Science Foundation of ChinaProject(E2017202136)supported by the Natural Science Foundation of Hebei Province,China+1 种基金Project(BSBE2017-05)supported by Opening Funds of State Key Laboratory of Building Safety and Built Environment and National Engineering Research Center of Building Technology,ChinaProject(QG2018-3)supported by Hebei Provincial Department of Transportation,China
文摘A binary eutectic mixture composed of tetradecanol(TD)and myristic acid(MA)was maximally absorbed into the microstructures of expanded perlite(EP)and expanded vermiculite(EVMT),respectively,through a self-made vacuum adsorption roller to prepare phase change material(PCM)particle(PCP).Then EP and EVMT-based composite PCM plates were respectively fabricated through a mold pressing method.The thermal property,chemical stability,microstructure and durability were characterized by differential scanning calorimeter(DSC),Fourier transform infrared spectroscope(FT-IR),scanning electron microscope(SEM)and thermal cycling tests,respectively.The results show that both PCPs have high latent heats with 110 J/g for EP-based PCP and more than 130 J/g for EVMT-based PCP,compact microstructure without PCM leakage,stable chemical property and good durability.The research results have proved the feasibility for the vacuum adsorption roller used in the composite PCM fabrication.Results of thermal storage performance experiment indicate that the fabricated PCM plates have better thermal inertia than common building materials,and the thermal storage performance of PCM plates has nonlinearly changed with outside air velocity and temperature increase.Therefore,PCM plates show a significant potential for the practical application of building thermal storage.
文摘In this work the statistical mechanical equation of state was developed for volumetric properties of crystalline and amorphous polymer blends.The Ihm-Song-Mason equations of state(ISMEOS) based on temperature and density at melting point(T_m and ρ_m) as scaling constants were developed for crystalline polymers such as poly(propylene glycol) + poly(ethylene glycol)-200(PPG + PEG-200),poly(ethylene glycol) methyl ether-300(PEGME-350) + PEG-200 and PEGME-350 + PEG-600.Furthermore,for amorphous polymer blends containing poly(2,6-dimethyl-1,4-phenylene oxide)(PPO) + polystyrene(PS) and PS + poly(vinylmethylether)(PVME),the density and surface tension at glass transition(ρ_g and γ_g) were used for estimation of second Virial coefficient.The calculation of second Virial coefficients(B_2),effective van der Waals co-volume(b) and correction factor(α) was required for judgment about applicability of this model.The obtained results by ISMEOS for crystalline and amorphous polymer blends were in good agreement with the experimental data with absolute average deviations of 0.84%and 1.04%,respectively.
