Thermal conductivity enhancement of polyethylene glycol/expanded vermiculite shape-stabilized composite phase change materials with silver nanowire for thermal energy storage

Polyethylene glycol/Cu/SiO2 form stable composite phase change materials: preparation, characterization, and thermal conductivity enhancement

“…Fig. A comparison of the thermal properties between the previously reported CPCMs and those obtained in this study (Table 3) shows that the phase change latent heat of the latter was lower than the former 12,32,34 , and the thermal conductivity of the latter was also lower than the former 18 . The phase change parameters obtained from the DSC evaluation are shown in Table 2, including the onset melting temperature (T M ), latent heat during the heating (H M ), onset freezing temperature (T S ), and latent heat during the cooling (H S ).…”

“…10a shows the melting and solidifying DSC curves of PEG and the FS-CPCMs. However, the prepared CPCMs had a [18] used Ag nanowires to increase the thermal conductivity of CPCMs. A comparison of the thermal properties between the previously reported CPCMs and those obtained in this study (Table 3) shows that the phase change latent heat of the latter was lower than the former 12,32,34 , and the thermal conductivity of the latter was also lower than the former 18 .…”

“…To solve the main drawbacks of PEG, form-stable organic-inorganic hybrid PCMs mixed with materials of high thermal conductivity prepared via the ultrasound-assisted sol-gel method have become popular because they are easy to prepare and can be used directly without additional encapsulation 16,17 . Carbon-based nanostructures (nanofibers, nanoplatelets, and graphene flakes), metals (Ag, Fe, Au, and Cu), metal oxides (Al 2 O 3 , CuO, MgO, and TiO 2 ), and metallic nanowires (Ag, Au, and Cu) have been investigated as the materials to enhance the thermal conductivity [18][19][20][21][22][23][24] . Carbon-based nanostructures (nanofibers, nanoplatelets, and graphene flakes), metals (Ag, Fe, Au, and Cu), metal oxides (Al 2 O 3 , CuO, MgO, and TiO 2 ), and metallic nanowires (Ag, Au, and Cu) have been investigated as the materials to enhance the thermal conductivity [18][19][20][21][22][23][24] .…”

“…Several studies have been carried out to improve the thermal conductivity of PCMs. Moreover, Cu powder has a higher thermal conductivity (400 W m −1 K −1 ) than graphite, Fe powder, and metal oxides 18,20,22 . Cu powder is inexpensive than metallic nanowires, graphene flakes, and Ag and Au powders.…”

Electrolytic ammonia removal and current efficiency by a vermiculite-packed electrochemical reactor

“…The XRD pattern shows that five intensive diffraction peaks at 2θ of 8.9°, 17.9°, 26.6°, 35.8° and 45.1° were indexed to (001), (002), (003), (113) and (006) diffraction planes, which is characteristic of phlogopite (JCPDS 10-0495) relating to the characteristics of interlayer distance of 9.9, 5.0, 3.3, 2.5 and 2.0 Å, respectively. This result was similar to Deng et al ., in which two strong diffraction peaks at 2θ = 8.7° and 27.5° were observed for expanded vermiculite31. Another low-intense diffraction peak is found nearly at 6.1° and assigned as (001) diffraction plane of vermiculite (JCPDS 74-1732) with the basal spacing of 14.4 Å, similar with natural vermiculite characterized by Yu et al 32…”