Cosmeceuticals are the fastest growing sector of the personal care industry, and the use of several topical cosmeceutical treatments has increased significantly over the years. Nanotechnology has an impact on the cosmetics industry. Novel nanocarriers, such as liposomes, niosomes, nanoemulsions, gold and silver nanoparticles (NPs), solid lipid NPs, and nanospheres, have superseded the use of conventional delivery systems. In nano-cosmetics and nano-cosmeceuticals for skin, hair, nails, lips, and teeth, nanomaterials (NMs) have improved product performance and customer satisfaction. Nanotechnology-based cosmeceuticals offer the advantages of product diversity, improved bioavailability of active ingredients, and higher visual attractiveness of cosmeceutical products with long-lasting effects. However, the increasing use of nanotechnology in cosmeceuticals has raised concerns about potential health risks and ability of NPs to pass through the skin. This review discusses the various types of NPs used in various classes of cosmeceuticals, the availability of nanotechnology-based cosmeceuticals, the potential dangers associated with exposure to NPs, and the most recent developments in their regulation. The purpose of this review article is to provide consumers and regulators with an overview of nano-cosmetics and nano-cosmeceuticals and their applications in the cosmetic industry, as well as information on toxic effects associated with continued and sustained use of these products, which may help them gain a better understanding of benefits and encourage prudent use.

For the first time, the temperature dependence of transverse magnetoresistance oscillations of heterostructured semiconductors based on quantum wells was determined by temperature variation of the two-dimensional energy state density. A new analytical expression was developed to calculate the temperature dependence of the transverse electrical conductivity and magnetoresistance of the quantum well. A mathematical model has been developed that determines the temperature dependence of the first and second order differential magnetoresistance oscillations due to magnetic field induction. Using the proposed model, dissociation of continuous ρ_⊥^2d(E, B, T, d) at constant low temperatures into amplitudes of quantum oscillations is substantiated based on the proposed model. It has been observed that the results of experiments on ∂(ρ_⊥^2d(E, B, T, d)/∂B obtained at consistently low temperatures of a narrow band quantum winding (In_xGa_1−xSb) are transformed into a continuous energy spectrum in the dynamics of high temperatures.

Ag-doped Ca aluminate with different Ag dopant content and polycrystalline structure were obtained via a direct one-step chemical approach using Ag acetate as Ag doping source. Ag-doped Ca aluminate is composed of orthorhombic Ca₅Al₆O₁₄ and monoclinic CaAl₂O₄ phases. The morphology transformation of Ag-doped Ca aluminate from nanoflakes to microscale and nanoscale particles closely depends on Ag dopant content. Ag doping effectively improves visible-light absorption ability and 8 wt% Ag-doped Ca aluminate exhibits the lowest band gap of 1.97 eV. Ag-doped Ca aluminate shows enhanced visible-light photocatalytic activity towards gentian violet than un-doped Ca aluminate under natural sunlight irradiation. 20 mL gentian violet solution (10 mg L⁻¹) is totally degraded using 20 mg of 8 wt% Ag-doped Ca aluminate with sunlight irradiation for 30 min and reaction rate constant k of 0.034 min⁻¹. Visible-light photocatalytic activity is greatly enhanced by Ag doping owing to narrow band gap, low recombination efficiency of charge carriers, high charge transfer efficiency.

Metal-based nanoclusters (NCs) have unique physicochemical properties, and they have been applied to various fields. Gold NCs (Au NCs) show fluorescence ranging from blue to red under ultraviolet (UV) irradiation. Bovine-serum-albumin (BSA)-capped Au NCs (BSA-Au NCs) have specific fluorescence properties, and they are expected to be used for biomedical applications. However, the environment of BSA-Au NCs is hydrophilic because hydrophilic BSA covers the Au NC surface, limiting their applications. To overcome this drawback, we developed hydrophobic BSA-Au NCs (h-BSA-Au NCs) using (formylmethyl)triphenylphosphonium chloride as the hydrophobic agent by reductive amination reaction. Resulting h-BSA-Au NCs were encapsulated in polystyrene nanoparticles (Au PS NPs) by the typical swelling method under mild conditions. The Au PS NPs showed orange fluorescence under UV irradiation. Therefore, Au PS NPs are promising fluorescent materials for biomedical applications.

Barreling methods are suitable for small pieces. Electroplating aluminum (Al) using copper (Cu) is less costly than using a bar of Cu as a small part. Cu barreling electroplating was conducted on an Al alloy. Various rotating speeds were applied during the plating process. Barreling plating of the Cu onto Al alloy substrates was performed in 0.5 M CuSO₄ with 40 mA cm⁻² of current density for 2 h. Scanning electron microscopy-energy dispersive spectroscopy, a MATLAB software, X-ray diffraction, and potentiostat were used to investigate the properties of the Cu layer. In addition, the deposition rate, current efficiency, and thickness were examined. By increasing the barrel rotating speed, the deposition rate, cathodic current efficiency, thickness, roughness, and crystallite size were all reduced. The sample without rotation has a deposition rate, cathodic current efficiency, and average layer thickness of 32.49 µm h⁻¹, 92.08%, and 74.32 µm, respectively. The specimen was made using a barrelling speed of 50 rpm, which shows a more compact morphology, a more positive open circuit potential, and a lower corrosion rate.

The structure of monolayer Pt nanoparticles (Pt NPs) dispersed on a flat highly oriented pyrolytic graphite surface prepared by two-phase reduction method as a model catalyst for fuel cell systems was studied by a bent crystal Laue analyzer enhanced back-illuminated X-ray absorption fine structure (BCLA+BI-XAFS) technique. The BCLA+BI-XAFS technique enables us to investigate the in situ Pt NPs structure in 0.1 M HClO₄ solutions while applying a wide range of potentials. We found that Pt NPs have a stable framework of a cuboctahedron with about 309 Pt atoms and a Pt–Pt bond length of 2.76 ± 0.06 Å independent of applied potential. The application of high energy resolution fluorescence detection back-illuminated X-ray absorption near edge structure (HERFD+BI-XANES) successfully elucidated the relationship between surface species and applied potential. We revealed the origin of the high stability of the Pt NPs prepared by the two-phase liquid reduction method. This developed BI-XAFS method provides a new way to investigate Pt NPs on flat substrates as a model catalyst for fuel cell catalyst studies.

The electronic structure and field emission characteristics of spray-coated single-walled carbon nanotubes (sprayed-SWCNTs) and vertically aligned multiwalled carbon nanotubes (VA-MWCNTs) were evaluated to discuss the feasibility of applying carbon nanotubes (CNTs) to electrodes in organic electronics. For the electronic structure evaluation, high-sensitivity ultraviolet photoelectron spectroscopy and constant final state yield spectroscopy (CFS-YS) were used. For the field emission characterization, ultraviolet photoelectron spectroscopy (UPS) and field emission spectroscopy (FES) were used simultaneously (UPS/FES). As a result, the work functions of the sprayed-SWCNTs and VA-MWCNTs were determined as 4.75 and 4.64 eV, respectively, which are comparable to those of materials used as anodes in organic devices. CFS-YS measurement allowed a detailed characterization of the electronic structure near the Fermi level and showed that there were no defects that could affect the electrical conducting properties. Furthermore, the transmission probability of field emission was experimentally determined using UPS/FES. It was also confirmed that the sprayed-SWCNTs started emitting at approximately 1.1 V µm⁻¹. This electric field is less than those for operating organic thin-film devices. This indicates that using CNT transparent electrodes as cathodes can improve the injection efficiency of organic devices such as inverted organic light-emitting diodes.

It is important to realize electron and ion emitters with small source sizes for high-spatial-resolution microscopy applications. Field-assisted oxygen etching is one of the methods used to form an ultra-sharp tip or nano-protrusion on a large tip; however, the emitting surface that emits electrons and ions is also oxidized. The composition of the tungsten tips fabricated using the two field-assisted etching methods was analyzed using a pulsed-voltage atom probe. The tip, sharpened using the decreasing bias method during etching, consisted of only tungsten atoms. In the other method, a large base tip with a nano-protrusion, fabricated by applying the fixed bias method during etching, was covered with tungsten oxide, even though the nano-protrusion comprised only tungsten atoms. These differences in composition are attributed to changes in the field strength and region of oxidation during the etching process, which agrees with previously reported models for the analyzed etching methods.

This study aimed to develop a high-performance liquefied petroleum gas (LPG) sensor based on the Fe₂O₃:ZnO material. A solid-state synthesis of the ceramic target with Fe₂O₃ and ZnO nanopowders is presented. LPG sensing nanostructured films were obtained by the high-frequency magnetron sputtering method. The thickness and surface morphology of the sensing layers were determined by thickness measuring profilometer and scanning electron microscope, respectively. The crystallographic properties and elemental mapping analysis of the Fe₂O₃:ZnO material were investigated by transmission electron microscopy. Energy-dispersive X-ray elementary analysis highlighted the presence of single elements available in the Fe₂O₃:ZnO material. Further, a chemo-resistive sensor based on a thin film of the Fe₂O₃:ZnO nanostructure was fabricated onto the Multi-Sensor-Platform, and its gas sensing properties were investigated towards LPG. The sensor with Pd catalytic particles showed the highest gas response at 200°C. The LPG sensing parameters like sensor response and response/recovery times were investigated at different operating temperatures. The minimum response and recovery times of the sensor corresponding to an LPG concentration of 2000 ppm were found to be 26 and 15 s, respectively. The investigated sensing parameters demonstrate that the fabricated LPG sensor based on the Fe₂O₃:ZnO semiconductor nanostructures is challenging for the detection of low concentrations of LPG at relatively low temperatures.

Real-space time evolution of an electron wave packet through single- and multi-layer graphene is numerically calculated with taking the effect of inelastic scattering into account for the first step of numerical simulation of graphene-insulator-semiconductor (GIS)-structured electron source. The incident electron energy is ∼10 eV supposing the typical experimental condition. Wave packet inevitably introduces an energy uncertainty, which is rather preferable for the simulation of real electron source with energy spread. The graphene potential for the incident electron is calculated from the electron density obtained by the density functional method and the screened Coulomb potential. The inelastic scattering effect is included in the calculation by assuming the imaginary potential proportional to the real graphene potential with a proportionality constant a. Comparing the obtained simulation results with the experimental ones, the inelastic parameter is determined as a ≃ 0.03. Simulation of realistic three-layer GIS structure remains as a future work, where the effects of inelastic scattering should be included by the above method with a ≃ 0.03.

In this study, optical second-harmonic generation (SHG) microscopy of one-dimensional linear arrays of spherical Au nanoparticles (NPs) at the submicron scale was performed. Nine spherical Au NPs with a particle size of ∼100 nm were arrayed one-dimensionally in a groove on a glass substrate, and the array structure was observed by atomic force microscopy (AFM). The second-harmonic (SH) intensity distribution in the linear array was non-uniform and varied with photon energy. To understand the relationship between the SH signal and the local electric field related to the surface plasmon (SP) modes on the array, we calculated the local electric field generated between NPs based on the array structure of the particles observed by AFM. The SH intensity distribution and its wavelength dependence could be qualitatively explained by the local electric field distribution reflecting the spatially separated SP modes due to array inhomogeneity. SHG microscopy can be used to understand the details of SP interactions that reflect the microstructure of linear arrays, which are applied to nanoscale waveguides, filters, and antennas.

We have developed a novel photoemission microscopy apparatus employing a vacuum ultraviolet laser. This setup combines photoemission electron microscopy (PEEM) with a time-of-flight detector, facilitating rapid visualization of electronic states in both real and momentum space. Achieving a spatial resolution of 70 nm, attributed to the PEEM lens system, we showcase the full band mapping of a Bi(111) single crystal film using angle-resolved photoemission spectroscopy within a short acquisition time.

Silver decoration is a highly reliable experimental method that has been used for a long time to confirm the location of hydrogen on metal. In order to measure hydrogen permeation through vanadium membranes, we made a cell for electrochemical charge of hydrogen on back side of the sample of silver decoration experiment. A small aquarium pump circulates the solution for electrochemical hydrogen charging and prevents hydrogen gas bubbles from interfering hydrogen charging to the sample. By placing this cell on the sample stage of an optical microscope, we can conduct silver decoration experiments while observing the microscope image.

Currently Ba scandate cathodes exhibit the highest electron emission capability of all thermionic cathodes and are very promising for future applications. They are essentially based on Ba dispenser matrix cathodes modified with differently distributed additions of scandia. The high emission capability is due to a very low work function of 1.15 eV for different types of Ba scandate cathodes but is also accompanied by a low Richardson constant in the range from 2 to 8 A cm⁻² K⁻², depending on the type, and is also an indication of incomplete surface coverage. High resolution characterization after activation and some operation time have shown that Sc is concentrated in small patches on the surface, which also contain Ba and O. Based on the beamlet effect first introduced by Hasker, it is shown by model calculations that the high emission and the corresponding Richardson constant of a given type can be quantitatively explained from the sum of beamlets or micro-beams originating from these fine patches, which are rather uniformly distributed over the impregnated cathode surface.