Construction of a Robust Radiative Cooling Emitter for Efficient Food Storage and Transportation.

Nowadays, food safety is still facing great challenges. During storage and transportation, perishable goods have to be kept at a low temperature. However, the current logistics still lack enough preservation ability to maintain a low temperature in the whole. Hence, considering the temperature fluctuation in logistics, in this work, the passive radiative cooling (RC) technology was applied to package to enhance the temperature control capability in food storage and transportation. The RC emitter with selective infrared emission property was fabricated by a facile coating method, and Al2O3 was added to improve the wear resistance. The sunlight reflectance and infrared emittance within atmospheric conditions could reach up to 0.92 and 0.84, respectively. After abrasion, the sunlight reflection only decreased by 0.01, and the infrared emission showed a negligible change, revealing excellent wear resistance. During outdoor measurement, the box assembled by RC emitters (RC box) was proved to achieve temperature drops of ∼9 and ∼4 °C compared with the corrugated box and foam box, respectively. Besides, the fruits stored in the RC box exhibited a lower decay rate. Additionally, after printing with patterns to meet the aesthetic requirements, the RC emitter could also maintain the cooling ability. Given the superior optical properties, wear resistance, and cooling capability, the emitter has great potential for obtaining a better temperature control ability in food storage and transportation.

Electrospun quercetin-loaded zein nanoribbons.

This study investigates quercetin-loaded zein nanoribbons, which were fabricated using different types of electrospinning processes. Using ethanol aqueous solutions as sheath fluids, the widths of quercetin-loaded zein nanoribbons (D, nm) could be manipulated simply through the adjustment of water contents(C) in the sheath fluids according to an equation of D=958-8.01C(r=0.9977), as indicated by the field emission scanning electron microscopic observations. X-ray diffraction and attenuated total reflectance Fourier transform infrared analysis suggested that the quercetin presented in the zein nanoribbons in an amorphous state due to their high compability resulted from hydrogen bonds. In vitro dissolution tests verified that nanoribbons from the coaxial process and single fluid process could provide drug sustained release profiles via a typical Fickian diffusion mechanism, and the former exhibited better performance than the later in terms of small initial burst effect and leveling-off release. Coaxial electrospinning with solvents can expand the capability of electrospinning in generating nanoproducts and provide a way for improving the nanoproducts' quality and functional performance.