Surface structural and solar absorptance features of nitrate-based copper-cobalt oxides composite coatings: Experimental studies and molecular dynamic simulation

The copper and cobalt oxides composites coatings on aluminum substrates have been successfully synthesized via sol-gel method using nitrate-based sol precursors. The composites were characterized by X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FESEM), Atomic Force Microscopy (AFM), and UV–Vis–NIR spectrophotometry. The sol-gel reactions were discussed and Molecular Dynamics (MD) simulation was integrated into the study to predict molecules assembly properties. The XRD analyses revealed that the CuO and the Co₃O₄ composites were formed after the annealing process with the average difference of the calculated lattice parameters compared to ICDDs was 1.17%. The surface electronic structure was mainly consisted of tetrahedral Cu(I), octahedral Cu(II), tetrahedral Co(II), octahedral Co(III) as well as surface, sub-surface and lattice oxygen O^?. The XRD, XPS and MD simulation results showed that there was minimal (or possibly non-existing) indication of copper-cobalt mixed phase oxides formations. FESEM and AFM surveys revealed that the coating had a porous surface composed of interlinked nanoparticles in the range of ~?10 to ~?40?nm. UV–Vis–NIR reflectance spectra showed that the sol precursors concentration and the dip-drying cycle significantly influenced the absorptance value with optimum absorptance (α) of 88.7% exhibited by coating synthesized using sol concentration of 0.1?M and 10 dip-drying cycles. High absorptance value and simplicity in the synthesis process render the coatings to be very promising candidates for solar selective absorber (SSA) applications.     

Evaluation of Antibacterial Activity of Whey Protein Isolate Coating Incorporated with Nisin,Grape Seed Extract,Malic Acid,and EDTA on a Turkey Frankfurter System

ABSTRACT: The effectiveness of whey protein isolate (WPI) coatings incorporated with grape seed extract (GSE), nisin (N), malic acid (MA), and ethylenediamine tetraacetic acid (EDTA) and their combinations to inhibit the growth of Listeria monocytogenes, E. coli O157:H7, and Salmonella typhimurium were evaluated in a turkey frankfurter system through surface inoculation (approximately 10⁶ CFU/g) of pathogens. The inoculated frankfurters were dipped into WPI film forming solutions both with and without the addition of antimicrobial agents (GSE, MA, or N and EDTA, or combinations). Samples were stored at 4 °C for 28 d. The L. monocytogenes population (5.5 log/g) decreased to 2.3 log/g after 28 d at 4 °C in the samples containing nisin (6000 IU/g) combined with GSE (0.5%) and MA (1.0%). The S. typhimurium population (6.0 log/g) was decreased to approximately 1 log cycles after 28 d at 4 °C in the samples coated with WPI containing a combination of N, MA, GSE, and EDTA. The E. coli O157:H7 population (6.15 log/g) was decreased by 4.6 log cycles after 28 d in samples containing WPI coating incorporated with N, MA, and EDTA. These findings demonstrated that the use of an edible film coating containing nisin, organic acids, and natural extracts is a promising means of controlling the growth and recontamination of L. monocytogenes, S. typhimurium, and E. coli O157:H7 in ready‐to‐eat poultry products.     

<Emphasis Type="Italic">Trans</Emphasis>–<Emphasis Type="Italic">trans</Emphasis> Conjugated Linoleic Acid Enriched Soybean Oil Reduces Fatty Liver and Lowers Serum Cholesterol in Obese Zucker Rats

Conjugated linoleic acid (CLA) is a collection of octadecadienoic fatty acids that have been shown to possess numerous health benefits. The CLA used in our study was produced by the photoisomerization of soybean oil and consists of about 20% CLA; this CLA consists of 75% trans–trans (a mixture of t8,t10; t9,t11; t10,t12) isomers. This method could be readily used to increase the CLA content of all soybean oil used as a food ingredient. The objective of this study was to determine the effects of trans–trans CLA-rich soy oil, fed as a dietary supplement, on body composition, dyslipidemia, hepatic steatosis, and markers of glucose control and liver function of obese fa/fa Zucker rats. The trans–trans CLA-rich soy oil lowered the serum cholesterol and low density lipoprotein–cholesterol levels by 41 and 50%, respectively, when compared to obese controls. Trans–trans CLA-rich soy oil supplementation also lowered the liver lipid content significantly (P < 0.05) with a concomitant decrease in the liver weight in the obese rats. In addition, glycated hemoglobin values were improved in the group receiving CLA-enriched soybean oil in comparison to the obese control. PPAR-γ expression in white adipose tissue was unchanged. In conclusion, trans–trans CLA-rich soy oil was effective in lowering total liver lipids and serum cholesterol.     

纳米材料改性自抛光海洋防污涂料的制备与性能

纳米材料具有量子尺寸效应、表面效应、体积效应和宏观量子隧道效应等优点,其会改善传统材料的诸多性能。针对纳米材料是否增效防污的问题,为了深入理解纳米材料的添加对无锡自抛光防污涂料的主要性能的影响,通过超声-机械共混方法将纳米氧化锌与氧化石墨烯纳米材料添加到无锡自抛光防污涂料中,研究了纳米材料对无锡自抛光防污涂料表面性能、机械性能尤其是粘结强度和实海防污性能以及铜离子释放速率等的影响。浸泡前后,添加纳米材料的防污涂层的表面由疏水(接触角90°)变为亲水(接触角约为70°),与未加纳米材料的防污涂层一致。添加0.1wt%纳米材料的防污涂层的粘接强度约在3.0～4.5 MPa,与未加纳米材料的防污涂层(约3.8 MPa)相比,粘接强度没有显著变化。添加纳米材料的防污涂层中铜离子释放速率稳定在约15～25μg/(cm~2·d)。此外,长达约180 d的实海浸泡挂板表面无任何海洋生物的附着。总之,少量纳米材料的添加可以在不明显牺牲表面性能、粘接强度等物理化学性能的前提下提高了无锡自抛光防污涂料的防污性能。     

Pitting corrosion of intermetallic compound Ni3(Si,Ti) in sodium chloride solutions

The pitting corrosion of intermetallic compound Ni₃(Si,Ti) was investigated as functions of test temperature and chloride concentration in sodium chloride solutions by using a potential step method. In addition, the pitting corrosion of solution-annealed austenitic stainless steel type 304 and pure nickel was also studied under the same experimental condition for comparison. The pitting potential obtained for the intermetallic compound decreased with increasing chloride concentration and test temperature. A critical chloride concentration below which no pitting corrosion took place was found to exist and to decrease with increasing test temperature. The specific pitting potential at the critical chloride concentration also decreased with increasing test temperature. In addition, the pitting potential at various constant chloride concentrations above the critical chloride concentration decreased with increasing test temperature. The pitting potential of Ni₃(Si,Ti) was higher than pure nickel, but lower than that of type 304.     

Pitting corrosion of intermetallic compound Ni3(Si,Ti) with 2 at% Mo in sodium chloride solutions

The pitting corrosion of Ni₃(Si,Ti) with 2 at% Mo consisting of a single intermetallic compound Ni₃(Si,Ti) phase of L1₂ structure and a two phase mixture of L1₂ and fcc nickel solid solution was investigated as functions of test temperature and chloride concentration in sodium chloride solutions by using a potential step method and compared with that of intermetallic compound, Ni₃(Si,Ti). The pitting potential obtained for the Ni₃(Si,Ti) with 2 at% Mo decreased with increasing chloride concentration and test temperature. A critical chloride concentration below which no pitting corrosion took place was found to exist and to decrease with increasing test temperature. The specific pitting potential at the critical chloride concentration also decreased with increasing test temperature. The pitting potential of Ni₃(Si,Ti) with 2 at% Mo was higher than pure nickel, but lower than that of Ni₃(Si,Ti). A critical chloride concentration was found to be lower than that of Ni₃(Si,Ti), whereas the specific pitting potentials at the critical chloride concentration was found to be higher than that of Ni₃(Si,Ti). Pitting corrosion occurred in the two phase mixture region.