Taku Ogura

NIKKO CHEMICALS CO., LTD.

Photoresist stripping is the final step in the photolithography process that forms fine patterns for electronic devices. Recently, a mixture of ethylene carbonate (EC) and propylene carbonate (PC) has attracted attention as a new stripper based on its eco-friendliness and anti-corrosiveness. However, the EC/PC mixture causes re-adsorption of the ph...

Melanins are the main pigments found in mammals. Their synthesis and transfer to keratinocytes have been widely investigated for many years. However, analysis has been mainly carried out using fixed rather than live cells. In this study, we have analysed the melanosomes in living mammalian cells using newly developed scanning electron-assisted diel...

The polyol dilution (PD) method is an approach for preparing liposomes by pre-mixing a lipid/polyol binary mixture, followed by hydration, and is widely used in the cosmetics industry. In this method, polyols play an important role in the formulation design and application, however, the effect of the polyol type on liposomes (PD-liposomes) is yet t...

Liposomes, which are formed from phospholipids, have been widely applied in cosmetics for skin enhancement. The polyol dilution (PD) method is commonly used to prepare liposomes in the cosmetic industry. An understanding of liposome physicochemical properties is essential for cosmetic-formulation design and application. However, there have been few...

This study aimed to evaluate the membrane structure of distearoylphosphatidylcholine (DSPC) liposomes dispersed in water containing various types of polyols with low molecular weight such as glycerin (Gly), 1,3-butandiol (BG), and propylene glycol (PG). To clarify the detailed membrane structure, generalized indirect Fourier transformation (GIFT) a...

Hypothesis Nanostructured fluids (NSFs) based on water, organic solvents and surfactants are a valid alternative to the use of neat unconfined organic solvents for polymer coatings removal in art conservation. The physico-chemical processes underpinning their cleaning effectiveness in terms of swelling/dewetting of polymer films were identified as...

Perfume solubilization is an important process in the production of commercial products such as beverages, foods, and cosmetics. In the present study, small-angle neutron scattering (SANS) experiments were performed to investigate the solubilization behavior of perfumes in cetyltrimethylammonium bromide (CTAB) micelles. The solubilization of linalo...

The hydrocarbon-chain packing structure of intercellular lipids in the stratum corneum (SC) is critical to the skin’s barrier function. We previously found that formation of V-shaped ceramide reduces the barrier function of skin. There are few agents, apart from ceramides and fatty acids that can improve the orthorhombic packing (Orth) ratio of the...

Zinc oxide (ZnO) particles were synthesized in the presence of anionic surfactants (ASs). The effect of ASs on the morphology of the ZnO particles was investigated by using ASs with various alkyl chain lengths and changing the molar ratio of AS/ZnSO4. Hexagonal plate-like ZnO particles were formed in the presence of ASs. Adsorption of the AS on the...

Hypothesis The removal of over-paintings or graffiti is a priority for conservators and restorers. This operation is complex, especially when over-paintings lay on painted surfaces that must be preserved, as in the case of vandalism on street art, where the layers are usually chemically similar. Traditional methodologies do not usually provide sati...

Intercellular lipids in the stratum corneum protect the living body from invasion by allergens and pathogens, and also suppresses water evaporation within the body. It is important to understand how differences in the microstructure of intercellular lipids arise. This microstructure is affected by lipid composition. Studies using intercellular lipi...

New ester functionalized branched anionic surfactant—sodium citronellyl sulfoacetate (SCSA) is developed from naturally occurring acyclic monoterpene citronellol. This new surfactant is investigated for its self-aggregation, detergent, and biodegradation properties. Surface properties of the SCSA are determined by surface tension and conductivity m...

In this study, we synthesized ZnO particles using anionic amphiphiles as an additive. While the single-crystal particles prepared in the absence of such amphiphiles had a hexagonal rod-like shape, those fabricated using anionic amphiphilic molecules had a hexagonal plate-like shape. The anionic amphiphiles inhibited crystal growth in the c-axis dir...

The use of nanostructured fluids (NSFs, i.e. micellar solutions and microemulsions) in art conservation is often associated to cleaning purposes, as the removal of polymeric coatings and/or soil from artistic surfaces. In both cases, the use of NSFs grants significant improvements over the use of traditional cleaning techniques that employ neat unc...

Surfactants are active or essential ingredient of several industrial and consumer formulations. These amphiphilic organic molecules demonstrate unique ability to adsorb at the interface and self-aggregate or self-assemble into different phases in aqueous or nonaqueous solution. In recent years, environmental concerns coupled with increased consumer...

Mineralization is the most fundamental process in vertebrates. It is predominantly mediated by osteoblasts, which secrete mineral precursors, most likely through matrix vesicles (MVs). These vesicular structures are calcium and phosphate rich and contain organic material such as acidic proteins. However, it remains largely unknown how intracellular...

Ester based anionic surfactant - sodium lauryl sulfoacetate (SLSA) is one of the most important surface-active ingredients in several personal care products however no scientific report is available regarding its lyotropic and thermotropic phase behavior in water. In the present study, SLSA and its congener sodium myristyl sulfoacetate (SMSA) are i...

Like how static surface tension indicates various basic properties of surfactants, dynamic surface tension is an indicator for various features of surfactants under transient and non-equilibrium conditions such as concentration dependency or detergent foaming. Such features are key factors in industrial application. For example, determining the dyn...

Dialkylchain cationic surfactant forms the so-called α-gel in water showing virtually no fluidity, which is transformed into a highly fluidic dispersion upon addition of a tiny amount of salt. This intriguing phenomenon is utilized in household industries. However, the underlying mechanisms remain unclear. Here, we use dielectric relaxation spectro...

Industrially relevant systems for household and personal-care products often involve a large number of components. Such multiple component formulations are indispensable and effective for functionalization of the products, but may simultaneously provide more complex structural features compared to those in ideal systems comprising a smaller number...

Alveolar bone - the bony ridge containing the tooth sockets – stands out by its remodeling activity where bone is being formed and resorbed at a much higher rate that in any other bony tissue. Teeth that are anchored in the jaw through the periodontal ligament exert very large localized loads during mastication that could lead to a unique adaptatio...

Using dielectric relaxation spectroscopy (DRS), small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), and viscometry, we have investigated hydration behavior, static structures, Brownian dynamics, and mechanical properties of aqueous solutions of alcohol ethoxylate (C12E15) and methyl ester ethoxylate (C12MEE), hereafter abbreviated...

Aqueous micellar solution of piperidinium gemini surfactants was investigated by small angle X-ray scattering (SAXS) and the real space structural information of the micelles was deduced by indirect Fourier transformation (IFT) method. The maximum dimension of the micelles and their shape were determined by evaluating the pair distance distribution...

Silica nanotubes are synthesized through a sol-gel reaction of tetraethyl orthosilicate (TEOS) using myelin figures of Pluronic P123 as the structure-directing agent. The simultaneous progression of the formation of molecular assemblies that act as templates and the formation of silica frameworks though a sol-gel reaction of the silica precursor is...

We prepared pH-sensitive anionic liposomes composed solely of anionic bilayer membrane components that were designed to promote efficient release of entrapped agents in response to acidic pH. The pH-sensitive anionic liposomes showed high dispersion stability at neutral pH, but the fluidity of the bilayer membrane was enhanced in an acidic environm...

In this study, we successfully prepared titania/silica composite films modified with silane coupling agents having amino groups and investigated their bovine serum albumin (BSA) adsorption/desorption behavior under light irradiation. XRD patterns and ATR/FT-IR spectra of the films revealed the formation of titania/silica composite films modified wi...

O/W nano-emulsions can be used as effective drug carriers of hydrophobic active ingredients in an aqueous solution, because nano-emulsions are comparatively stable and their structure can be controlled by changing the compositions and the preparation methods. In this paper, we focused on vitamin A and its derivatives (VA), which are among the widel...

In this study, we demonstrate a facile method for the synthesis of mesoporous Au/silica composite particles. TEM images clearly reveal that the solvent evaporation of ethanol solution of F127, Au colloid particles, TEOS and HCl results in the synthesis of highly-ordered mesoporous composite particles. Diffuse reflectance UV-vis absorption spectrum...

We investigated the location of cholesterol (Chol) in liposomes and its interaction with phospholipids using small-angle x-ray scattering (SAXS) data and applying the generalized indirect Fourier transformation (GIFT) method. The GIFT method has been applied to lamellar liquid crystal systems and it gives quantitative data on bilayer thickness, ele...

Large-pore mesoporous silica particles were synthesized through a solvent evaporation process using hydrophobic fumed silica particles and tetraethyl orthosilicate (TEOS) as silica sources. The solvent evaporation of an ethanol solution of fumed silica particles, TEOS, HCl and triblock copolymer (F127) resulted in mesoporous silica particles with p...

Mesostructured titania particles modified with phthalocyanine (Pc) were prepared by using molecular self-assemblies of cetyltrimethylammonium bromide (CTAB) with solubilized Pc as a template. Low-angle X-ray diffraction pattern and transmission electron microscopy (TEM) image clearly show the formation of Pc/titania particles with hexagonal mesopor...

This article examines the relative stability of five surfactant-free water-in-oil (w/o) emulsions produced by 1-min irradiation of the mixture with 42-kHz ultrasounds; it also reports on the synthesis of hollow silica nanospheres in such emulsions. The oily phase in these w/o emulsions consisted of cyclohexane, dodecane, benzene, octane, and hexane...

Mesostructured zirconia particles having monoclinic-type crystalline walls were prepared using a low-temperature crystallization technique. Crystalline zirconia particles with highly-ordered mesostructures were obtained through the sol–gel process of zirconium sulfate tetrahydrate at 333K in the presence of molecular self-assemblies of cetyltrimeth...

Highly ordered multilayer silica nanocapsules were prepared, pared using spontaneous vesicles formed by cationic surfactant mixtures as template. Transmission electron microscopy (TEM) and cryogenic transmission electron microscopy (Cryo-TEM) observation confirmed that the geometry of the silica particles was in good agreement with that of the vesi...

Crystalline mesoporous titania particles were prepared and their photocatalytic activity under visible light irradiation was investigated. A novel method including a low-temperature crystallization technique of titania in the presence of cationic surfactants supplied mesoporous titania particles having crystalline walls. The obtained titania showed...

Highly ordered lamellar-type mesoporous silica was prepared by using molecular assemblies formed in an aqueous mixture of cationic cetyltrimethylammonium bromide (CTAB) and anionic sodium octylsulfate (SOS) as structure-directing agents. The mesoporous silica prepared at the composition of CTAB:SOS = 7.5:2.5 (in mol ratio) possessed high surface ar...

We applied a molecular assembly formed in an aqueous surfactant mixture of cationic cetyltrimethylammonium bromide (CTAB) and anionic sodium octylsulfate (SOS) as templates of mesoporous silica materials. The hexagonal pore size can be controlled between 3.22 and 3.66 nm with the mixed surfactant system. In addition, we could observe the lamellar s...

The synthesis of basic magnesium carbonate was examined under ultrasonic irradiation and was performed by the soda ash method using magnesium sulfate and sodium carbonate as starting materials. The particulate product was evaluated using SEM observations. Ultrasonic irradiation in the preparation of basic magnesium carbonate was found to give fine...

Mesoporous titania particles having anatase-type crystalline wall were prepared using a low-temperature crystallization technique. Crystalline mesoporous titania was obtained through the sol−gel process of titanium oxysulfate sulfuric acid hydrate (TiOSO4·xH2SO4·xH2O) at 333 K in the presence of cetyltrimethylammonium bromide (C16TAB), a cationic s...

In this study, we demonstrate a novel method for preparing crystallized mesoporous titania by using a low-temperature synthesis technique in the presence of cationic surfactant. XRD patterns showed that the titania particles obtained had both hexagonal structure and a wall with anatase crystalline structure. Transmission electron microscopy (TEM) o...

We have prepared copper-containing mesoporous silica (Cu/MS) using solubilization of copper oleate in nonionic surfactant aggregates. The amount of copper loading in calcined Cu/MS corresponded to the amount of copper oleate solubilized in surfactant aggregates of the mixed solution.