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Building integrated photovoltaic modules, applied to industrial and commercial buildings, generally used metal as the backsheet. In summer, the operating temperature of modules is as high as 70°C, resulting in instability of output power and service life. Therefore, it is very important to reduce the operating temperature of photovoltaic modules. In this work, Al2O3/graphene/poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) composite radiative cooling coatings were prepared and utilized for reinforcing heat dissipation of photovoltaic modules. The results indicate that 0.75 wt%Al2O3/1wt%graphene/PVDF‐HFP composite coating exhibited a thermal diffusivity of 3.24 μm2/s and an average emissivity of 0.94. The maximum temperature drop of the coating in the outer door reached 5.8°C. In addition, a mini photovoltaic module coated with the composite coating achieved the cooling effect of 2.4°C, and the output power and conversion efficiency were increased by 5.8% and 7%, respectively. This demonstrates that the heat conduction radiative cooling coating possesses potential applications for improving the reliability of photovoltaic modules. [ABSTRACT FROM AUTHOR]

In this work, gram‐scale branched‐VO2 (B‐VO2) was synthesized via a mild one‐step hydrothermal route, and the corresponding phase transition, optical and electrical performances of B‐VO2 were investigated. The differential scanning calorimeter (DSC) results revealed the defect mediated phase transition behavior of B‐VO2. The optical studies demonstrated an analogous negative thermochromic performance of B‐VO2, which was ascribed to the intense Mie scattering effect. While, ball milling treatment was an effective way to restore the regular thermochromic property, and the ball‐milled VO2 (BM‐VO2) displayed a 6.3 % increasement of the solar modulation ability. The BM‐VO2 films on flexible PET and PI substrates demonstrated both energy‐saving and UV‐shielding functions. The temperature dependent resistivity displayed about two orders of magnitude change during the phase transition of VO2. [ABSTRACT FROM AUTHOR]

Experimental and numerical study are carried out to investigate hygrothermal effects on the mechanical behavior and damage propagation of scarf repaired carbon fiber reinforced plastic (CFRP) laminates. Experimental tests were carried out under four environment conditions: room temperature/dry, room temperature/wet, elevated temperature (95°C)/dry and elevated temperature (95°C)/wet. Results showed no decrease in compression strength after moisture absorption, whereas the reduction under elevated temperature were 15.5% and 17.2% for dry and wet specimens, respectively. Furthermore, a finite element model was developed to simulate the failure process and predict structural strength, in which moisture diffusion, hygrothermal stress analysis and progressive damage model were considered. Good agreement was achieved between the predicted compression strength and experimental results. It is revealed that the damage in the adhesive initiates adjacent to 0° plies and propagates in circumferential direction. Water absorption causes initial damage in the edge of the adhesive layer, while it does not reduce the compression strength. And elevated temperature leads to earlier damage in adhesive. After large part of the adhesive layer damaged, damages in parent laminate occur and propagate transversely to the free edge sides until the final structural collapse, which is similar with the experimental phenomenon. POLYM. COMPOS., 39:904–914, 2018. © 2016 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]