Chitosan nanoparticles loaded with Eucommia ulmoides seed essential oil: Preparation, characterization, antioxidant and antibacterial properties.

Eucommia ulmoides seed essential oil (EUSO) is a natural plant oil rich in various nutrients, which has been widely used due to its unique medicinal effects. However, it is prone to oxidation and rancidity under many adverse environmental influences. Nanoencapsulation technology can protect and slow down the loss of its biological activity. In this study, chitosan nanoparticles (CSNPs) loaded with EUSO were prepared by emulsification and ionic gel technology. EUSO-CSNPs were characterized by Fourier transform infrared (FTIR) spectroscopy, Thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The results confirmed the success of EUSO encapsulation and the encapsulation rate ranged from 36.95 % to 67.80 %. Nanoparticle size analyzer, Scanning electron microscope (SEM) and Transmission electron microscopy (TEM) showed that CSNPs were spherical particles with a range of 200.6-276.0 nm. The results of in vitro release study indicated that the release of EUSO was phased, and EUSO-CSNPS had certain sustained-release properties. Furthermore, EUSO-CSNPs had higher antioxidant and antibacterial abilities than pure EUSO and chitosan, which was verified through free radical scavenging experiments and bacteria biofilm experiments, respectively. This technology can enhance the medicinal value of EUSO in biomedical and other fields, and will provide support for in vivo research of EUSO-CSNPs in the future.

Optoelectronic and ferroelectric properties of cerium-doped (Na(0.5)Bi(0.5))(Ti(0.99)Fe(0.01))O3 nanocrystalline films on (111) Pt/TiO2/SiO2/Si: a composition-dependent study.

The optical and ferroelectric properties of (Na0.5Bi0.5)1-xCex(Ti0.99Fe0.01)O3 (NBCTFx; 0 ≤ x ≤ 0.10) nanocrystalline films deposited on platinized silicon (Pt/TiO2/SiO2/Si) substrates using a sol-gel method were investigated. The microstructure, surface, and cross-sectional morphology and compositions of the films were analyzed by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy, respectively. The X-ray diffraction patterns indicate that all films are polycrystalline and show the single perovskite structure. The dielectric functions of the NBCTFx films can be uniquely extracted by fitting the measured ellipsometric spectra with a four-phase-layered model (air/surface rough layer/NBCTFx/Pt) in the photon energy range of 0.6-6.4 eV. The Tauc-Lorentz model was successfully applied and reasonably describes the spectral response behavior of ferroelectric NBCTFx films in the light-frequency region. It was found that the optical band gap and grain size decrease with increasing cerium composition because of the introduction of disorder and defects. The electrical results show that the leakage current density of the films was decreased with increasing cerium composition by reducing the density of oxygen vacancies and forming the defect complexes. The optimal ferroelectric properties were obtained in the film doped with x = 0.10, whose remnant polarization and coercive field values are 14.9 µC/cm(2) and 217.3 kV/cm, respectively. The present results could be crucial for future applications of lead-free ferroelectric and optoelectronic devices.