Nanofluids are stable mixtures of nanoscale particles dispersed in base fluids with good prospects in enhanced oil recovery in the petroleum industry. In this review, the mechanisms and evaluation methods of stable nanofluids were analyzed. The effects of nanoparticles on viscosity, electrical conductivity, and surface/interfacial tension of base fluids were discussed. The results of laboratory research and field tests revealed that nanofluids could improve the oil recovery through plugging and profile control, transformation of wettability of rock surface, changes in oil−water interface properties, and increases in the viscosity ratio between fluids. On the other hand, nanoparticles might stabilize oil−water emulsions produced during the extraction stage, adversely affecting subsequent oil−water separation processes, especially the electrical dehydration. However, careful analysis suggested lack of in-depth studies regarding the impacts of nanoparticles on droplet coalescence inside electro-dehydration plants. The present analyses will hopefully assist future investigations in nanofluidics.

A novel nanopackaging film was synthesized by incorporating ZnO nanoparticles into a poly-lactic acid (PLA) matrix, and its effect on the quality of fresh-cut apple during the period of preservation was investigated at 4 ± 1 °C for 14 days. Six wt % cinnamaldehyde was added into the nano-blend film. Scanning electron microscope (SEM) analysis showed a rougher cross-section of the nano-blend films and an X-ray diffraction (XRD) was carried out to determine the structure of the ZnO nanoparticles. Compared to the pure PLA film, the nano-blend film had a higher water vapor permeability (WVP) and lower oxygen permeability. With the increase of the nanoparticles (NPs) in the PLA, the elongation at break (ε) and elastic modulus (EM) increased, while tensile strength (TS) decreased. Thermogravimetric analysis (TGA) presented a relatively good thermostability. Most importantly, the physical and biochemical properties of the fresh-cut apple were also measured, such as weight loss, firmness, polyphenol oxidase (PPO), total phenolic content, browning index (BI), sensory quality, and microbiological level. The results indicated that nano-blend packaging films had the highest weight loss at the end of storage compared to the pure PLA film; however, nanopackaging provided a better retention of firmness, total phenolic countent, color, and sensory quality. It also had a remarkable inhibition on the growth of microorganisms. Therefore, Nano-ZnO active packaging could be used to improve the shelf-life of fresh-cut produce.

In this work, a new facile and scalable strategy to effectively suppress the initial capacity fading of iron oxides is demonstrated by reacting with lithium borohydride (LiBH 4 ) to form a B-containing nanocomposite. Multielement, multiphase B-containing iron oxide nanocomposites are successfully prepared by ball-milling Fe 2 O 3 with LiBH 4 , followed by a thermochemical reaction at 25-350 °C. The resulting products exhibit a remarkably superior electrochemical performance as anode materials for Li-ion batteries (LIBs), including a high reversible capacity, good rate capability, and long cycling durability. When cycling is conducted at 100 mA g −1 , the sample prepared from Fe 2 O 3 -0.2LiBH 4 delivers an initial discharge capacity of 1387 mAh g −1 . After 200 cycles, the reversible capacity remains at 1148 mAh g −1 , which is significantly higher than that of pristine Fe 2 O 3 (525 mAh g −1 ) and Fe 3 O 4 (552 mAh g −1 ). At 2000 mA g −1 , a reversible capacity as high as 660 mAh g −1 is obtained for the B-containing nanocomposite. The remarkably improved electrochemical lithium storage performance can mainly be attributed to the enhanced surface reactivity, increased Li + ion diffusivity, stabilized solid-electrolyte interphase (SEI) film, and depressed particle pulverization and fracture, as measured by a series of compositional, structural, and electrochemical techniques.

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