Microstructure and Magnetic Properties of Ce14Fe78Co2B6 Nanopowders Prepared by Ball Milling at Low Temperature

Ce14Fe78Co2B6 nanopowders with hard-magnetic properties have been successfully prepared by ball milling at low temperatures in liquid nitrogen. The morphology, structure, and magnetic properties of Ce14Fe78Co2B6 powders have been investigated using scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometry, respectively. It was found that powder ball milling at low temperature in liquid nitrogen, has the advantage that the oxidation of powders is inhibited and the particles rapidly reach nanometric dimensions. In comparison to the Ce14Fe78Co2B6 powders prepared by ball milling at room temperature, the powders milled at low temperature present a more uniform particle size and no rare-earth oxides, which leads thus to remarkable magnetic properties. The nanocrystalline Ce14Fe78Co2B6 powders with optimum characteristics, prepared at low temperature, have the size of 153 nm or less, present a coercivity of 5.1 kOe, and a saturation magnetization of 113 emu/g after milling for 6 h at low temperature. Low temperature milling may become a promising technique for the fabrication of high performance powders used for permanent magnets preparation.

Synthesis of silver nanoparticles from electronic scrap by chemical reduction

In the present research, the use of electronic waste in the synthesis of silver nanoparticles was investigated. For this purpose, electronic scraps were used as a consumable part to synthesize silver nanoparticles. The results revealed that by optimizing the time and temperature of the dissolution process using nitric acid solution up to 90%, silver can be extracted from these parts. The temperature of 60°C and the duration of one hour were determined as the optimum conditions for this phase. Afterward, the synthesis of silver nanoparticles was checked using silver nitrate solution. The results indicated that the concentration of initial silver nitrate had a significant impact on the quality of the final product so that the best conditions for the synthesis of silver nanoparticles with suitable properties were provided at 1 molar concentration. Phase studies indicated that the main phase of the synthesized silver particles had an FCC structure and no unwanted phase was observed. Ultraviolet-visible analysis of the synthesized powder revealed that the main peak for the silver nanoparticles appeared in the wavelength range of 400 to 450 nm. DLS analysis revealed that precursor's particles inside the sol were below 15 nm. Based on AFM and TEM investigations, the particles synthesized under these conditions had nanometric spherical morphology with uniform particle size distribution.

ANALYSIS OF THE WAYS OF GRINDING OF BEAN CULTURES SEEDS

Рассмотрены способы измельчения семян люпина и эспарцета на существующем в кондитерском производстве оборудовании – дезинтеграторе, валковой дробилке и трехвалковой мельнице с целью повышения эффективности дробления семян бобовых культур и, как следствие, их биологической ценности после дезинтегральной обработки. Установлено, что с увеличением зазора между валками возрастает среднее значение размеров дробленых частиц, т. е. доля крупных фракций увеличивается, мелких – снижается, при этом дисперсия существенно не меняется. При использовании валковой дробилки, варьируя величину зазора между валками и частоту вращения, можно оптимизировать режим дробления. Доказано, что применение для дробления семян вертикальной трехвалковой мельницы с засыпанными в нее вместе с семенами бобовых культур металлическими твердосплавными шарами за счет комбинаций ударных и истирающих воздействий на частицы семян интенсифицирует процесс, снижает время помола и способствует получению равномерного гранулометрического состава, обеспечивая высокий эффект измельчения сырья с сохранением его качественных показателей. The ways of grinding of seeds lupine and cock's head on the existing in the confectionery industry equipment, disintegrator, roller crusher and three-roll mill with the purpose of increase of efficiency of the grinding bean cultures seeds and, consequently, their biological value after disintegrating treatment were considered. It is established that with increase in gap between the rolls, the average value of the sizes of crushed particles increase, i.e. the share of large fractions increases, small – decreases, this variance does not change significantly. When using roll crusher, by varying the size of the gap between the rolls and the rotational speed can optimize the crushing mode. It is proved that use for crushing seeds vertical three-roll mill with filled in it along with the seeds of legumes metal carbide balls due to the combinations of impact and abrasive effects on the particles of seed intensifies process reduces grind time and helps to ensure a uniform particle size distribution, providing a high effect grinding of raw materials while maintaining its quality.

Microencapsulation of Photochromic Solution with Polyurea by Interfacial Polymerization

Photochromic materials are interesting materials because of their color-changing property under UV light and visible light irradiation. However, they are vulnerable to many factors, such as pH oxygen, ion, solvent, etc. because of the unsaturated bonds existing on the photochromic molecular. Microencapsulation of the photochromic materials can separate them from the surroundings. Here, photochromic microcapsules using 3,3-Diphenyl-3H-naphtho[2,1-b] pyran (NP)/solution as core and polyurea as shell via interfacial polymerization were prepared, and bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate (HALS 770) was used as photostabilizer. Fourier transform infrared spectroscopy (FTIR), a laser particle size analyzer, a scanning electron microscope (SEM), a thermogravimetric analyzer and an ultraviolet-visible spectrophotometer were used for characterization. The results showed that the microcapsules had a uniform particle size of about 0.56 μm when the percentage of the oil phase (core) in the emulsion was less than 15%, the addition amount of the emulsifier was 0.4%, and the stirring rate was 1800r/min. The microcapsules showed better performance in thermal stability when the core/shell ratio was 1:1. The photostabilizer had little impact on the color-changing property of the microcapsule, but it could protect the microcapsules from UV light radiation aging.

Study on the synthesis and application of BaTiO3 nanospheres

In the present study, BaTiO3 nanospheres with a uniform particle size of around 100 nm were prepared by a hydrothermal route using Ba(OH)2.8H2O and TiO2 nanoparticles. Experimental results revealed that the main influencing factors for the formation of BaTiO3 nanospheres were molar Ba/Ti ratio (R Ba/Ti), hydrothermal temperature, and time. Highly-dispersed BaTiO3 nanospheres (100 nm) were obtained under the optimum hydrothermal conditions at temperature = 200°C, time = 12 h, and R Ba/Ti = 1.5. Under these optimum conditions, BaTiO3 ceramics were synthesized from the as-prepared BaTiO3 nanospheres, and their structural, microstructural, and electrical properties were investigated. The BaTiO3 ceramics exhibited a high dielectric constant of 7300 at a Curie temperature of 125 °C, great density (ρ), 5.83 g cm–3; large dielectric constant at room temperature er = 3586 and tan d = 0.03, high remanant polarization P r = 10.6 μC cm–2, low coercive field E c = 4.5 kVcm–1.

Polyethyleneimine- -Tocopherol Hydrogen Succinate/Hyaluronic Acid-Quercetin (PEI-TOS/HA-QU) Core–Shell Micelles Delivering Paclitaxel for Combinatorial Treatment of MDR Breast Cancer

Multidrug resistance (MDR) remains a significant impediment to chemotherapy during cancer therapy. In this study, the amphiphilic biomaterials PEI-TOS and HA-QU were synthesized to self-assemble into PEI-TOS/HA-QU core–shell micelles for the targeted codelivery of paclitaxel (PTX) and quercetin (QU) to alleviate multidrug drug resistance and enhance therapeutic efficacy. The PTX-loaded micelles possessed a uniform particle size (167.60 ± 8.185 nm), stable negative charge (–19.13 ± 0.321 mV), and pH-responsive drug release with good compatibility. The drug-loaded micelles increased the chemosensitivity of MDR tumor cells (MDA-MB-231/MDR1) to PTX and activated mitochondria-dependent apoptotic pathways (the IC50 was 2.22-fold lower than that of PTX alone). Moreover, PEI-TOS/HA-QU micelles increased the cellular uptake of lipophilic antitumor drugs by downregulating P-gp expression in MDA-MB-231/MDR1 cells. Compared with Taxol, PTX-loaded PEI-TOS/HA-QU micelles presented excellent antitumor efficacy in tumor-bearing mice, with an average tumor size that was 3.7-fold lower than that of the control group. The drug-loaded formulation showed low in vitro / in vivo toxicity and better tumor accumulation than the free drug, which led to a high tumor inhibition rate of 80.56% and considerable biocompatibility. This work describes a new platform for the codelivery of lipophilic anticancer drugs and natural active ingredients such as PTX and QU for the treatment of MDR cancer cells.

Evaluation of Minimally Invasive Arthroscopy Technology in Sports Medicine—An Evaluation of Nano Silver Disinfectants

Currently, nano silver fungicide prepared in the laboratory is used to disinfect arthroscopic surgical instruments. In this study, nano silver fungicides with stable properties were prepared and characterized. Afterwards, their bactericidal properties as well as mucus peeling properties were further tested. The results show that the nano silver fungicide prepared here contains uniform particle size and displays material stability for 60 days. Nano silver fungicide can completely kill sulfate-reducing bacteria, anaerobic bacteria, and iron reducing bacteria, while the slime stripping rate is 80.58%. Additionally, we propose the use of nano silver sterilization agents to kill the arthroscopic surgical instruments in conjunction with proper manual cleaning, as they can effectively kill all the bacteria on the surgical instruments, achieving a sterilization rate of 99.99%.