“…To date, metal nanoparticles, nanowire and graphene oxides have been reported as efficient nanofillers to improve the thermal conductivity of organic PCMs. However, the drawbacks of such method are apparent as the preparation of either nanofillers or subsequent PCMs composites frequently need the multisteps and complicated process.…”
Section: Resultsmentioning
confidence: 99%
“…In addition, such method takes great advantages over other methods for its designable flexibility as well as easy availability of a wide range of fillers for creation new high performance organic PCMs systems with high thermal conductivity. Metal nanoparticles, nanowire and graphene oxides have been reported as efficient nanofillers to improve the thermal conductivity of organic PCMs. However, the drawbacks of such method are also apparent as the preparation of either nanofillers or subsequent PCMs composites frequently need the multisteps and complicated process, thus increasing both the production cost and technological difficult in practical operation.…”
Phase change materials (PCMs) have been widely used as efficient materials in latent heat thermal storage systems for various applications. The poor thermal conductivity of most organic PCMs, however, has long been considered as one of big obstacles hindering their practical applications. Here, we report the first example of in situ reduction of AgNO3 precursor by PEG for preparation of polyethylene glycol/silver nanoparticles (PEG/Ag) PCMs nanocomposites with enhanced thermal conductivity only though a simple blending and heating process, without using any complicated techniques. The prepared Ag nanoparticles show a well dispersion in PEG matrix and the Ag is mainly existed in a zero of valence status. As expected, a maximum value of 211.7 % of that of pure PEG in thermal conductivities of the resulting PEG/Ag PCMs were achieved. The latent heat for PEG/Ag PCMs nanocomposites were evaluated in the range from 121.9 J g−1 to 141.9 J g−1. Owing to high latent heat and excellent thermal conductivity, such PEG/Ag PCMs may have great potentials for energy saving applications. Especially, the in situ preparation of PEG/Ag makes it possible for site operation and scaled‐up production, which is of great technologically significance for realization of PCMs into real applications.
“…To date, metal nanoparticles, nanowire and graphene oxides have been reported as efficient nanofillers to improve the thermal conductivity of organic PCMs. However, the drawbacks of such method are apparent as the preparation of either nanofillers or subsequent PCMs composites frequently need the multisteps and complicated process.…”
Section: Resultsmentioning
confidence: 99%
“…In addition, such method takes great advantages over other methods for its designable flexibility as well as easy availability of a wide range of fillers for creation new high performance organic PCMs systems with high thermal conductivity. Metal nanoparticles, nanowire and graphene oxides have been reported as efficient nanofillers to improve the thermal conductivity of organic PCMs. However, the drawbacks of such method are also apparent as the preparation of either nanofillers or subsequent PCMs composites frequently need the multisteps and complicated process, thus increasing both the production cost and technological difficult in practical operation.…”
Phase change materials (PCMs) have been widely used as efficient materials in latent heat thermal storage systems for various applications. The poor thermal conductivity of most organic PCMs, however, has long been considered as one of big obstacles hindering their practical applications. Here, we report the first example of in situ reduction of AgNO3 precursor by PEG for preparation of polyethylene glycol/silver nanoparticles (PEG/Ag) PCMs nanocomposites with enhanced thermal conductivity only though a simple blending and heating process, without using any complicated techniques. The prepared Ag nanoparticles show a well dispersion in PEG matrix and the Ag is mainly existed in a zero of valence status. As expected, a maximum value of 211.7 % of that of pure PEG in thermal conductivities of the resulting PEG/Ag PCMs were achieved. The latent heat for PEG/Ag PCMs nanocomposites were evaluated in the range from 121.9 J g−1 to 141.9 J g−1. Owing to high latent heat and excellent thermal conductivity, such PEG/Ag PCMs may have great potentials for energy saving applications. Especially, the in situ preparation of PEG/Ag makes it possible for site operation and scaled‐up production, which is of great technologically significance for realization of PCMs into real applications.
“…Thermal stability of PEG of different molecular weights was comprehensively investigated . The degradation of PEG starts over 250°C, and the most significant decrease in mass is observed from 350°C to 450°C, regardless of molar mass of PEG.…”
The high polymerization temperature of acrylic bone cements can cause arthroplasty failure because of the thermal necrosis of surrounding bone tissue. To reduce this undesired effect we have developed novel acrylic bone cement composites containing a phase change material (PCM). As PCM poly(ethylene glycol) (PEG) of different molecular weight was applied and the effect of its incorporation on curing parameters, mechanical and morphological properties of acrylic bone cement was investigated. A significant decrease in maximum temperature from 65.8°C to 47.4°C and slight increase of setting time were observed. PEG introduction also contributed to the thermal stability of acrylic bone cement increase. SEM investigation of modified bone cement confirmed that the microstructure does not alter considerably because of PEG content. It was found that both PEG addition and incubation test contribute to an inconsiderable decrease in mechanical strength of bone cement. However, the mechanical strength increase can be caused by the fresh bone tissue incorporation into the pores appearing in bone cement.
“…The similar signals at ~ 1600 cm −1 and 3000–3700 cm −1 are induced from the skeletal vibration of the graphene basal plane and the O–H stretching vibration of adsorbed water [18–20]. A remarkable difference between these two profiles is that an additional obvious peak at 1335 cm −1 arising from the O=C–OH can be seen only for the RGO nanosheets resulting from the surface functional groups [21]. After combining with the ER, the O=C–OH signal disappears absolutely, manifesting that the carboxyl on the surface of the RGO nanosheets reacts with hydroxyl of the ER to form a close chemical contact, which contributes to the phonon fast transport at the interface between them.Fig.…”
With the development of microelectronic devices, the insufficient heat dissipation ability becomes one of the major bottlenecks for further miniaturization. Although graphene-assisted epoxy resin (ER) display promising potential to enhance the thermal performances, some limitations of the reduced graphene oxide (RGO) nanosheets and three-dimensional graphene networks (3DGNs) hinder the further improvement of the resulting thermal interface materials (TIMs). In this study, both the RGO nanosheets and 3DGNs are adopted as co-modifiers to improve the thermal conductivity of the ER. The 3DGNs provide a fast transport network for phonon, while the presence of RGO nanosheets enhances the heat transport at the interface between the graphene basal plane and the ER. The synergy of these two modifiers is achieved by selecting a proper proportion and an optimized reduction degree of the RGO nanosheets. Moreover, both the high stability of the thermal conductivity and well mechanical properties of the resulting TIM indicate the potential application prospect in the practical field.Electronic supplementary materialThe online version of this article (10.1186/s11671-017-2298-z) contains supplementary material, which is available to authorized users.
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