For the first time, ZnO/C composites were synthesized using zinc glycerolate as a precursor through one-step calcination under a nitrogen atmosphere. The effect of the heat treatment conditions on the structure, composition, morphology as well as on the electrochemical properties regarding application in lithium-ion batteries are investigated. The products obtained by calcination of the precursor in nitrogen at 400—800 °C consist of zinc oxide nanoparticles and amorphous carbon that is in-situ generated from organic components of the glycerolate precursor. When used as anode material for lithium-ion batteries, the as-prepared ZnO/C composite synthesized at a calcination temperature of 700 °C delivers initial discharge and charge capacities of 1061 and 671 mAh g−1 at a current rate of 100 mA g−1 and hence 1.5 times more than bare ZnO, which reaches only 749/439 mAh g−1. The native carbon improves the conductivity, allowing efficient electronic conductivity and Li-ion diffusion. By means of ex-situ XRD studies a two-step storage mechanism is proven.
Gelatin nanoparticles found numerous applications in drug delivery, bioimaging, immunotherapy, and vaccine development as well as in biotechnology and food science. Synthesis of gelatin nanoparticles is usually made by a two-step desolvation method, which, despite providing stable and homogeneous nanoparticles, has many limitations, namely complex procedure, low yields, and poor reproducibility of the first desolvation step. Herein, we present a modified one-step desolvation method, which enables the quick, simple, and reproducible synthesis of gelatin nanoparticles. Using the proposed method one can prepare gelatin nanoparticles from any type of gelatin with any bloom number, even with the lowest ones, which remains unattainable for the traditional two-step technique. The method relies on quick one-time addition of poor solvent (preferably isopropyl alcohol) to gelatin solution in the absence of stirring. We applied the modified desolvation method to synthesize nanoparticles from porcine, bovine, and fish gelatin with bloom values from 62 to 225 on the hundreds-of-milligram scale. Synthesized nanoparticles had average diameters between 130 and 190 nm and narrow size distribution. Yields of synthesis were 62–82% and can be further increased. Gelatin nanoparticles have good colloidal stability and withstand autoclaving. Moreover, they were non-toxic to human immune cells.
New water-soluble nanocomposites consisting of silver nanoparticles and N-vinylpyrrolidone-N,Ndiallyl-N '-acetylhydrazine copolymer, exhibiting cytotoxic activity toward MS melanoma cells, were prepared.
The influence of the production conditions on the properties of coke is considered. Coke is pro duced in a pilot plant at the Institute of Technical Chemistry, Ural Branch, Russian Academy of Sciences, in a 200 L reactor equipped with an air supply valve and heating elements. The first stage in coke production is air blowing of the batch with constant temperature rise at 10-12°C/h from 290-310°C; the air flow rate is 45-55 L/kg h. At this stage, the final air blowing temperature and the batch composition are varied. The sec ond stage is coking, with temperature rise at 25°C/h to 550-600°C. The batch consists of industrial air blown pitch (ABP), modified by pitch tar (PT). Oxidation of the ABP, even with a very high final temperature (434°C), does not permit the production of isotropic coke. An analogous result is obtained on adding small portions of PT to the batch (15%). On adding >50% PT, totally isotropic coke may be produced. To obtain coke of isotropic microstructure, the optimal content of PT is 36-41%, and the final air blowing temperature should be high (>390°C). The influence of PT on the structural parameters of the coke is associated with the formation of nonmesogenic structures on air blowing. On coking, these structures suppress the growth of large mesophase. The isotropic coke produced has the following characteristics: limited expansion in the range 1300-2400°C; high structural strength; and optimal density. Graphite based on such coke is consider ably superior to graphite based on industrial pitch coke in terms of its compressive strength, density, and elec trical resistivity.
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