Search

Magnetite (Fe³O⁴) and Cobalt-doped Fe³O⁴ nanoparticles were obtained by hydrothermal reaction. The synthesized products were characterized by X-ray diffraction, Energy dispersive spectroscopy, Scanning electron microscopy, and Zeta potential. The results show that Co was substituted in the Fe³O⁴ crystal structure as CoFe₂O₄ phase. The synthesized materials are nanometer in size having uniform morphology, negatively charged and cobalt concentration varied from 2.5 to 7.5 wt.%. The magnetite and Co-doped magnetite nanoparticles at a low concentration (3 wt.%) were dispersed in the epoxy resin. The effect of the magnetite and Co-doped magnetite nanoparticles on the anticorrosion performance of the protective epoxy coatings covered on carbon steel surface was characterized by Electrochemical Impedance Spectroscopy (EIS) and salt fog exposure. Codoped magnetite nanoparticles at 2.5 wt.% provided high protection of the coatings. In addition, Pull-off tests confirmed an adhesion improvement of the epoxy coating filled by the Co-doped Fe³O⁴ nanoparticles.

Here we report on the structural characterization and the hydrogen storage performance of naturally derived halloysite nanotubes (HNTs). HNTs were mined from different deposits in Australia and purified with different processes including crushing, blunging, reblunging, sedimentation and filtration. The clay materials were characterized by different techniques such as powder XRD, TGA, XPS, FTIR spectroscopy, SEM, TEM, and N₂ sorption. Characterization results revealed that they are highly porous in nature with tubular morphology and exhibited excellent thermal stability. Among the halloysite materials studied, HNT1 which is having higher halloysite content and less kaolinite exhibited hydrogen uptake of 0.5 wt.% at 1 bar and -196 °C, which is increased to 1.33 wt.% when the pressure raised to 48 bar. High hydrogen uptake was linked with the high surface area, hollow tubular aluminosilicate structure and the large interlayer spacing of the HNTs as they favour physisorption of hydrogen. It was also demonstrated that HNT1 is considered to be better material than some of the materials reported so far in terms of their cost-effectiveness and environmental safety for the hydrogen storage.

Recently, drug delivery using natural and biodegradable nanoparticles has attracted huge attention. This study focused to deliver an anti-cancer and anti-inflammatory drug Ginsenoside Rb1 through chitosan-Alginate nanocomposite film prepared by solution method. Ginsenoside Rb1 is a dammaran saponin group, which is extracted from an herbaceous plant Panax notoginseng . Ginsenoside loaded alginate-chitosan nanocomposite films were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) methods. The FTIR spectra of alginate/chitosan/ginsenoside Rb1 nanocomposite films show that chitosan, alginate, and ginsenoside Rb1 are linked through the hydrogen bonding and dipolar-dipolar interactions. The FESEM image indicates that the chitosan and ginsenoside Rb1 dispersed well in the alginate matrix. The DSC diagrams display that melting temperature of alginate/chitosan/ginsenoside Rb1 nanocomposite films higher than that of chitosan and lower than that of alginate. It means that alginate and chitosan interact together. Investigation of the ginsenoside Rb1 release from alginate/chitosan/ginsenoside Rb1 nanocomposite films at different pH solutions and different ginsenoside Rb1 content has been carried out by ultraviolet-visible spectroscopy method. The rate of drug release is proportional to the increase in pH solution and inversely proportional to the content of loaded ginsenoside Rb1. The Rb1 release process includes two stages: burst release in the first 10 hours, then constant release afterwards. The suitable ratio of alginate/chitosan to prepare the alginate/chitosan/ginsenoside Rb1 nanocomposite films for further investigations was found out to be 8:2. Ginsenoside Rb1 release process from alginate/chitosan/ginsenoside Rb1 nanocomposite films was believed to be first-order kinetics in the first stage, and then the Rb1 release complies with Higuchi kinetic model in the slow release stage. This study demonstrated the novel synthesis methodology to design drug delivery system based on ginsenoside Rb1 loaded to chitosan/alginate nanocomposite films.