Biodegradable poly(ester)urethane (PU) elastomer-based nanocomposite films incorporated with organically modified nanoclay were prepared with melt-extrusion compounding followed by a casting film process. These films were intended for application as biodegradable food packaging films, with their enhanced gas barrier, mechanical, and thermal properties and good flexibility. From both X-ray diffraction measurements and transmission electron microscopy observations, the coexistence of intercalated tactoids and exfoliated silicate layers in the compounded PU/clay nanocomposite films was confirmed. In addition, the morphology exhibited a clay dispersion state in the matrix and was influenced by the incorporated nanoclay content. The effects of the nanoclay loading level on the thermal, mechanical, and barrier properties of the compounded nanocomposites were also investigated. As a result, it was revealed that the addition of nanoclay up to a certain level resulted in a remarkable improvement in the thermal properties in terms of thermal stability and the degree of thermal shrinkage; mechanical properties, including dynamic storage modulus and tensile modulus; and oxygen/water-vapor barrier properties of the nanocomposite films.

Although non-aqueous lithium-ion batteries have a high gravimetric density, recently aqueous zinc-ion batteries (ZIBs) have been in the spotlight as an alternative. Because ZIBs have characteristics such as high volumetric...

Owing to its applicability in refractory ceramic synthesis, nanoelectronics, optoelectronic and sensing devices, and superconducting products, magnesium oxide (MgO) is recognized to be an important ceramic material. However, it has a relatively low dielectric constant compared to other metal oxide semiconductors, which restricts the range of its bandgap and limits its applicability. Therefore, in this study, we propose and verify a method to improve the dielectric constant of MgO. A sample of MgO powder doped with Be ions was prepared using the Pechini method. The crystal structure of the doped MgO powder was analyzed by x-ray diffraction. Through structural analysis, it was confirmed that a substitution amount of up to 5% of Be ions was possible without breaking the cubic structure. The bonding structure in the lattice of the sample was identified through x-ray photoelectron spectroscopy, and the change in the bonding structure according to the amount of substitution was identified. The dielectric properties of the samples were analyzed as a function of frequency at room temperature. The real and imaginary parts of the dielectric constant were studied at room temperature as a function of frequency and composition. It was confirmed that the dielectric constant increased as the Be ions were substituted. Our results show that improving the low dielectric properties of pure MgO can enable its application to wide bandgap and high voltage applications simultaneously.