Ultraviolet photodetector using pn junction formed by transferrable hollow n-TiO nano-spheres monolayer.

We report an ultraviolet (UV) photodetector with a universally transferable monolayer film with ordered hollow TiO spheres on p-GaN. After forming a TiO monolayer film by unidirectional rubbing of hollow TiO spheres on a polydimethylsiloxane (PDMS) supporting plate, we used a 5% polyvinyl alcohol (PVA) aqueous solution to transfer the film onto the target substrate. The PVA/TiO monolayer film was detached from the PDMS film and transferred to the p-GaN/AlO substrate.

Correction: Highly lithium-ion conductive battery separators from thermally rearranged polybenzoxazole.

Correction for 'Highly lithium-ion conductive battery separators from thermally rearranged polybenzoxazole' by Moon Joo Lee et al., Chem. Commun.

Highly lithium-ion conductive battery separators from thermally rearranged polybenzoxazole.

High power density lithium ion battery (HLIB) separators were fabricated for the first time from thermally rearranged poly(benzoxazole-co-imide) (TR-PBOI) nanofibrous membranes coated with TR-PBOI nanoparticles, which show distinct thermal and dimensional stabilities as well as excellent cycle retention and rate capability.

Method for detecting the reactivity of chemicals towards peptides as an alternative test method for assessing skin sensitization potential.

Cosmetics are normally composed of various ingredients. Some cosmetic ingredients can act as chemical haptens reacting toward proteins or peptides of human skin and they can provoke an immunologic reaction, called as skin sensitization. This haptenation process is very important step of inducing skin sensitization and evaluating the sensitizing potentials of cosmetic ingredients is very important for consumer safety.

One-pot template-free synthesis of monodisperse hollow hydrogel microspheres and their resulting properties.

Monodisperse poly(methacrylic acid/ethyleneglycoldimethacrylate) (MAA/EGDMA) hollow microcapsules, which exhibit pH-responsive behavior, are prepared by diffusion of cationic surfactants and hydrophobic interaction. During the association of the negatively charged hydrogel microspheres and an oppositely charged surfactant (cetyltrimethylammonium bromide, CTA(+)B), the hydrophobic polymer-surfactant complexes that form are separated from the internal water; consequently, a hollow structure can be formed. Confocal laser scanning microscopy, UV spectro-scopy and zeta potential are employed to study the formation of the hollow structure during the diffusion of the cationic surfactant.

Biofilm-forming ability of Staphylococcus aureus strains isolated from human skin.

Background: Staphylococcus aureus produces various toxins and enzymes, and its presence can exacerbate skin conditions. Previous studies have shown that S. aureus is involved in skin deterioration, even in normal tissue.

Depigmenting activities of kojic acid derivatives without tyrosinase inhibitory activities.

We synthesized benzoate ester derivatives of kojic acid with and without adamantane moiety. Benzoate derivatives 2a-e that did not contain an adamantane moiety showed potent tyrosinase inhibitory activities. However, depigmenting activity was not noted in a cell-based assay.

Monodisperse conducting colloidal dipoles with symmetric dimer structure for enhancing electrorheology properties.

This study introduces an electrorheological (ER) approach that allows us to obtain remarkably enhanced ER properties by using monodisperse colloidal dimer particles. Two sets of colloidal particles, which are spheres and symmetric dimers, were synthesized employing the seeded polymerization technique. The aspect ratio of dimer particles was ~1.

Depigmenting activity of new kojic acid derivative obtained as a side product in the synthesis of cinnamate of kojic acid.

We synthesized cinnamate derivatives of kojic acid for use as depigmenting agents by various esterification methods. The cinnamate of 5-position of kojic acid (6) was obtained by EDC coupling, DCC coupling, acid chloride, and mixed anhydride methods. To obtain the cinnamate of the 2-position of kojic acid (7), we carried out the nucleophilic addition of the potassium salt of cinnamic acid to kojyl chloride.

Discrete dipole moments and enhanced electro-rheological properties of dumbbell-shaped, non-spherical particles.

In this study, uniform dumbbell-shaped non-spherical particles are produced by seeded polymerization, and the electro-rheological (ER) properties are compared to those of spherical-shaped particles after surface coating with functionalized multiwall carbon nanotubes (f-MWCNTs). The non-spherical particles formed linear chains under an applied electric field. The yield stress of the non-spherical particles is five-times as high as that of the spherical particles.

A facile process for generating monolithic-structured nano-silica/polystyrene multi-core/shell microspheres by a seeded sol-gel process method.

Monodisperse "monolithic-structured" organic-inorganic composite microspheres were produced by a seeded sol-gel process method. A large number of nano-silica particles were generated and dispersed in the inner domains of the obtained microspheres. Seed particles were prepared by dispersion co-polymerization of styrene and (trimethoxysilyl)propyl 2-methylprop-2-enoate (TMSPM).

The design of polymer-based nanocarriers for effective transdermal delivery.

This study reports a facile and practical means to non-invasively deliver biologically active ingredients through the skin using polymer-based nanocarriers. For this, polymer nanocapsules were fabricated with different surface charges as well as glass transition temperatures and we observed their ability to deliver the encapsulated active ingredient, coenzyme Q10, through the skin layer. Direct imaging of a probe molecule, Nile Red, and a matrix polymer labeled with fluorescence moiety, Lucifer Yellow, allowed us to demonstrate that the probe molecule readily permeates into the deep skin, while the matrix polymer stays in the stratum corneum layer due to electrostatic interactions.

Fabrication and characterization of pseudo-ceramide-based liposomal membranes.

We present a facile and straightforward method to fabricate liposomal membranes with a significantly stable lamellar structure consisting of pseudo-ceramide, fatty acid, and cholesterol. Characterizing their membrane properties, in which we have used differential scanning calorimetry, X-ray diffraction, and FT-IR spectra, enables us to demonstrate that pseudo-ceramide with appropriate amounts of stearic acid and cholesterol can assemble to form a stable lamellar alpha-phase. Moreover, we show that cholesterol is indeed important and plays a role in controlling the melting entropy of lipid membranes, which is attributed to a disordered molecular packing, thus creating more flexible liposomal membranes.

Control over micro-fluidity of liposomal membranes by hybridizing metal nanoparticles.

This study introduces a facile method to hybridize metal nanoparticles with lipid vesicles, which allows us to control over their membrane micro-fluidity. We have fabricated these hybrid liposomes by directly hybridizing metal nanoparticles with lipid bilayers solely consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC). For this, we have used the dehydration and rehydration method.

Electrorheological properties of carbon nanotube/ polyelectrolyte composite silica nanoparticles by layer-by-layer self-assembly.

Multiwall carbon nanotubes (MCNTs)/silica (SiO2) composite particles were prepared by layer-by-layer (LbL) self-assembly method using polyelectrolytes and functionalized MCNTs (fMCNTs). The fMCNTs prepared by chemical oxidation method were incorporated on the outermost layer of polyelectrolyte-coated SiO2 particles. The amount of fMCNTs was varied by LbL self assembly.

A facile approach to synthesize uniform hydrogel shells with controllable loading and releasing properties.

We present a facile and straightforward method to synthesize uniform poly(vinyl amine) hydrogel shells with excellent loading capability for active materials and controllable responsiveness to applied stimuli, providing tunable releasing properties.

Quantitative characterization of degradation behaviors of antioxidants stabilized in lipid particles.

This study describes a flexible approach that allows us to characterize the long-term stability of antioxidants by using a thermodynamically extended Arrhenius equation. We use retinol, Vitamin A, as a model antioxidant and its degradation behaviors are characterized for both stabilized and non-stabilized systems; in this study, by using a fluid bed technique, we immobilize the retinol in lipid particles, thus increasing its thermal stability in complex formulations, such as aqueous polymer gels and emulsions. Our approach demonstrates that the degradation behaviors of the retinol show a functional relationship with temperature and time, which makes it possible to use the Arrhenius approach.

Bidisperse electrorheological fluids using hydrolyzed styrene-acrylonitrile copolymer particles: synergistic effect of mixed particle size.

Monodisperse micron-sized styrene-acrylonitrile copolymer (SAN) particles with three different sizes (about 5, 10, and 15 microm) were prepared by a two-step seeded polymerization and used for a study of bidisperse electrorheological (ER) suspensions. The effect of the particle size and the size-mixing fraction on ER properties was studied with varying the size of these monodisperse copolymer particles. When the two particle sizes were mixed, the suspension generally showed a decrease in the shear yield stress, reaching a minimum value.

The stabilization of L-ascorbic acid in aqueous solution and water-in-oil-in-water double emulsion by controlling pH and electrolyte concentration.

This study presents a new approach that can stabilize effectively L-ascorbic acid in water-in-oil-in-water (w/o/w) double emulsions. Basically, the behavior of L-ascorbic acid in the aqueous phase was observed, considering its molecular deformation. Then, it was found that the stability determined in the aqueous phase by high-performance liquid chromatography (HPLC) showed that the collapse of ionization of L-ascorbic acid played a crucial role in protecting the molecular deformation.

Nano-structured biphasic polymer film on the hair surface from PEGylated polymer latexes.

In this study, biphasic polymer latexes were synthesized by surfactant-free-emulsion polymerization of butyl methacrylate, poly(ethylene glycol) methyl ether methacrylate, and 2-(methacryloyloxy) ethyl trimethyl ammonium chloride. The latexes synthesized were composed of hydrophobic core phase and hydrophilic shell phase. Nano-structured film morphology could be obtained by annealing the biphasic polymer latexes between the two transition temperatures.