Dispersion Properties Of Nanoparticles Research Articles

Tungsten-based hybrid nanocomposite thin film coated fabric for gamma, neutron, and X-ray attenuation

Ionizing radiation such as x-ray, γ-ray and neutron ray have serious negative health effects on human being. Hence, new and smart textile fabric nanocoating was facilely developed and coated on lab coat cloth. The newly hybrid nanocoatings were fabricated from uniform dispersion of PbWO4 NPs and Bi2WO6 NPs of an average sizes of 47.38 ± 7.6 and 9.1 ± 1.8 nm, respectively in chitosan solution. The dispersion of tungsten-based nanoparticles was performed using ultrasonication process, then well dispersed hybrid nanocoatings were coated on textile fabrics derived lab coat. The mass ratio of nanoparticles in nanocoatings were altered and optimized. The attenuation properties of x-ray/gamma ray and neutron ray were studied and achieving good shielding properties compared to uncoated fabrics. Additionally, the antibacterial and mechanical properties of coated fabrics were evaluated. The coated textile fabrics achieved clear inhibition zone of 4 mm compared to zero clear inhibition zone for uncoated ones against E-Coli. Moreover, the developed coating layer achieved good reinforcement effect recording superior tensile strength by 11.5% than uncoated sample. The dispersion properties of nanoparticles in coating nanocomposites were investigated using microscopic tools.

Evaluation of synergistic effects of the single walled carbon nanotube and CeO2-hybrid based-nanocomposite against X-ray radiation in diagnostic radiology

Unwanted exposure during irradiation in diagnostic procedures can be very harmful to health. Researchers have done extensive studies on heavy metals and their composites to prevent or reduce this risk. However, the disadvantages, such as high weight, rigidity or toxicity, limit the use of heavy metals. So far, great efforts have been devoted to designing and manufacturing lightweight/effective protective coatings that could attenuate or absorb radiation. In this regard, polymer composites are considered as potent materials. In the present study, the protective properties of polydimethylsiloxane hybrid nanocomposites containing single wall carbon nanotube (SWCNT) and cerium oxide nanoparticles (nanoceria) have been evaluated. The exposure tests on these coatings were performed by a diagnostic X-ray machine in the radiology department of the Urmia Imam Khomeini Hospital. To evaluate the amount of attenuation, beam intensity was measured at two narrow and broad beam geometries (NBG & BBG). The measurement procedures were well chosen according to the related Standards. The Field Emission Scanning Electron Microscope (FESEM) was applied in order to investigate the nanocomposite morphology and dispersion properties of nanoparticles. Thermal stability and chemical composition of the nanocomposites were studied by thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FTIR), respectively. FTSEM images and elemental analysis proved that nanoparticle showed excellent dispersion into the polymeric matrix. The attenuation in the nanocomposite samples improved significantly compared to the polydimethylsiloxane pure coating. The rate of attenuation increases with increasing nanoceria percentage and ultimately the hybrid sample has a better efficiency than the sample with a similar percentage of the nanoceria.

高速攪拌機により高分散化した微粒子組成物の光物性

粒子径がサブミクロン領域にある顔料微粒子は, 透明感, 光沢感, および紫外線遮蔽能などの光学的特性に優れ, 化粧品素材として汎用されてきた。しかしながら, 微粒子化に伴い表面エネルギーが高くなるため, 粒子相互の付着性, 凝集性が高くなり, 分散の不均一化に伴う機能低下を生じる場合がある。これまで, 分散性の向上のため, 粒子の表面処理や形状の制御など, 素材レベルでの改良は盛んに行われている反面, 機械的な処理の効果についてはあまり検討されていない。本研究では, 薄膜旋回型ミキサーを用いて, 高速攪拌による微粒子酸化チタンの分散性変化と, 分散系に対する入射光の減衰, 散乱挙動との相関について検討した。その結果, 顔料微粒子が分散した散乱吸収性媒体の場合, 高速攪拌により高度に均一分散することによって, その光学物性パラメータが変化する現象が認められたので報告する。