In this study, Fe3O4/ZnO/chitosan magnetic nanoparticles were synthesized by an ultrasound-assisted coprecipitation method. The magnetic nanoparticles were characterized by XRD, FT-IR, FESEM, and VSM techniques. The effects of ultrasonication time and content of chitosan on crystal size and lattice parameters of the nanoparticles were also studied via XRD spectra. FESEM measurements revealed that the coating consists of Fe3O4/ZnO nanoparticles of 15-20 nm in diameter homogeneously dispersed on the surface of chitosan substance. The VSM measurements at room temperature showed that the Fe3O4/ZnO/chitosan nanoparticles had superparamagnetic properties. These results indicated that ultrasonication time and chitosan content had a significant effect on the characteristics of nanoparticles. The antibacterial activities of the Fe3O4/ZnO/chitosan were tested against both gram-positive Saccharomyces cerevisiae and Bacillus subtilis and gram-negative E. coli bacteria using a disk diffusion method.

In this study, the introduction of Origanum majorana L. essential oil into a polyamidoamine (PAMAM) G4.0 dendrimer was performed for creation of a potential nanocide against Phytophthora infestans. The characteristics of marjoram oil and PAMAM G4.0 was analyzed using transmission electron spectroscopy (TEM), nuclear magnetic resonance spectroscopy (1H-NMR) and gas chromatography mass spectrometry (GC-MS). The success of combining marjoram oil with PAMAM G4.0 was evaluated by FT-IR, TGA analysis, and the antifungal activity of this system was also investigated. The results showed that the antifungal activity of oil/PAMAM G4.0 was high and significantly higher than only PAMAM G4.0 or marjoram essential oil. These results indicated that the nanocide oil/PAMAM G4.0 helped strengthen and prolong the antifungal properties of the oil.

In this study, PEG-Fe3O4/ZnO magetic nanocomposties were synthesized by a ultrasound assisted co-precipitation method. The magnetic nanocomposites were characterized by XRD, FT-IR, FESEM and VSM techniques. The effect of Fe3O4:ZnO ratio on the crystallite size and the lattice parameter of the nanoparticles was also studied using XRD. Magetic nanoparticles of PEG-Fe3O4/ZnO nanocomposites exhibit the particles size in the range of 20-30 nm. The VSM measurements at room temperature showed that PEG-Fe3O4/ZnO nanocomposites had superparamagnetic properties. These results indicated that ultrasonication time and ration (Fe3O4/ZnO) greatly affect the characteristics of the nanoparticles. The antibacterial efficiency of PEG-Fe3O4/ZnO nanoparticles was tested against Sacharomyces cerevisiae, Bacillus subtilis and E. coli bacteria using disc diffusion method.

This article presents the properties of the silver plating on A6061 aluminum alloy. The structure, chemical composition, phase composition, thickness and corrosion durability of the plating are determined by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction, corrosion current measurement, frost acceleration and hygrothermal test. The results show that the silver plating has good corrosion resistance, is not blistered, remains white, light, no appearance of rust and other abnormalities. These parameters meet the technical requirements laid out for resonator of ultra -high frequency filter.

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Bài báo giới thiệu kết quả nghiên cứu một số yếu tố ảnh hưởng tới quá trình tạo màng và tính chất của màng phủ chống mờ cho kính quang học trên cơ sở hợp chất cơ silic. Một số tính chất của màng phủ như góc tiếp xúc giọt nước, chiều dày màng, độ truyền quang được nghiên cứu bằng các phương pháp đo góc tiếp xúc giọt nước, kính hiển vi lực nguyên tử (AFM), máy quang phổ UV-2550 và các tính chất cơ lý khác. Kết quả cho thấy, với điều kiện tạo màng bằng phương pháp quét, ở nhiệt độ phòng, thời gian để khô 2 giờ thu được màng phủ có cấu trúc đồng nhất, chiều dày màng đạt 0,0113 µm, góc tiếp xúc giọt nước lớn hơn 115o.