佐藤根 大士

Bicellar mixtures containing diacetylene molecules, such as diynoic acids, can be used as parent materials for functional membranes. A bicellar mixture consisting of a diynoic acid-10,12-tricosadiynoic acid (TCDA)-, a phospholipid-1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)-, and a detergent-3-[(3-cholamidopropyl) dimethylammonio]-2-hydroxypropanesulfonate (CHAPSO)-was evaluated for its morphology and packing of TCDA molecules in its bicellar mixture. A TCDA/DMPC vesicle was prepared at different molar ratios, TCDA/DMPC = 2/8, 5/5, and 8/2; a TCDA/DMPC/CHAPSO bicellar mixture was prepared by mixing a CHAPSO solution with a TCDA/DMPC vesicle solution as a detergent at different composition ratios, x TCDA/DMPC = [TCDA/DMPC]/([TCDA/DMPC]+[CHAPSO]), of 1.0, 0.70, 0.50, and 0.30. A DMPC molecule formed a bilayer membrane structure and was used to suppress its precipitation. The packing density of the TCDA/DMPC/CHAPSO bicellar mixtures was increased by mixing a CHAPSO molecule in x TCDA/DMPC = 1.0 to 0.70 or 0.50. A TEM image of a TCDA/DMPC/CHAPSO bicellar mixture showed many discoidal assemblies at x TCDA/DMPC = 0.5 of TCDA/DMPC = 5/5. Polymerization of the TCDA molecules in the bicellar mixture by UV light suggested an ordered arrangement of TCDA. Polymerization at x TCDA/DMPC = 0.70 and 0.50 correlated with improved packing density.

To fabricate fully printed carbon-based multiporous-layered-electrode perovskite solar cells (MPLE-PSCs), a polymer binder thickener had to be added to the carbon paste for the conductive carbon electrode. The polymer binder thickener is a key material to control the dispersion of carbon particles, viscosity for screen printing, and thickness and porosity of carbon electrodes. In this work, the role and effect of polymer binder thickeners for high-temperature carbon porous electrodes on MPLE-PSCs have been investigated in detail. Several carbon pastes with/without polymer binder thickeners (4 types of ethyl cellulose and 2 types of hydroxypropyl cellulose, which have different viscosities) were compared. What we understand in this paper are (1) Aggregation and dispersion of carbon particles are controlled by the polymer binder thickener (ethyl cellulose and/or hydroxypropyl cellulose); (2) For the porous carbon electrodes, the polymer binder thickeners are carbonized during the sintering procedure at 400 °C and can be kept on the surface of carbon particles as the additional carbon surface skin, which improves the conductivity; (3) The polymer binder thickeners can help the formation of a fine mesoporous structure in the annealed carbon electrodes. Combinations of results between viscosity, thermal, and specific surface area analyses revealed the close relationship between device performance and printability, dispersibility, and porosity brought by the polymer binder thickeners. As a result, the addition of a 20 wt % polymer binder thickener improved the average power conversion efficiency (PCE) from 9.52 ± 2.04 to 10.86 ± 0.85%, achieving a champion PCE of 12.06%.

In this study, a novel reversible control method of particle dispersion/flocculation for nonaqueous solvent was developed. Titanium oxide was used as sample powder. Cyclopentasiloxane was used as solvent and Polyoxyethylene polyalkylsiloxane was used as a dispersant. First, a well-dispersed slurry was prepared by adding dispersant. After preparation, alcoholic amphiphilic molecule was added to the well-dispersed slurry to convert it from liquid to a gel-like consistency, which was caused by the hydrogen bond of dispersant on the surface of the particles. The resultant gel could easily be changed to liquid state by shaking. In addition, the slurry reverted back to gel state after a certain period of time. It was found that the relative permittivity and the additive amount of amphiphilic molecule has an influence on the strength of the gel.

The effect of terephthalic acid particle properties on particle fracture phenomena was investigated in this study. Furthermore, to evaluate the fracture characteristics in real process, the effect of the particle impact angle on particle fracture phenomena was also investigated. The results of this study indicated that: (i) the crystallite size correlated with the fracture stress of the particle; (ii) the crystallite size also showed a correlation with the critical fracture velocity and the kinetic energy of the particle; and (iii) the particle fractured more easily at impact angles under 45°.

Evaluation of powder wettability is important to prepare well dispersed slurries. Therefore, in this study, a technique for evaluating powder wettability was developed to analyze the increase in the internal pressure of a closed powder bed due to capillary suction to determine the contact angle of the powder. The effect of the powder-bed-preparation method and powder surface area estimation method on the determined value of the contact angle was discussed. We demonstrated that the improved air permeation test proposed in this research can accurately determine the powder surface area, resulting in a faithful determination of the contact angle of the powder. It was also shown that compression under the shearing method could result in a denser and more homogeneous powder bed when compared to the conventional tapping method, indicating high reproducibility for estimating the contact angle.

これまでにわれわれは，軟凝集性サスペンションの調製について報告している。高分子電解質分散剤を使用してサスペンション中の微粒子を良分散状態とした後，Mg²⁺イオンを添加して粒子表面に吸着した分散剤間を架橋させることで，静置時は粒子がゲルとして振舞いながら，軽い振とうで一時的に液状に戻るサスペンションである。今回は，この軟凝集性サスペンションに関し，化粧品用粉体として汎用性が高い二酸化チタンを用いた低粘度サスペンションへの応用を試みた。球状の二酸化チタンを用い，わずかな降伏値をもたせることで，粒子の沈降，堆積がない軟凝集性サスペンションの開発に成功した。さらに，このサスペンションをインクジェット用白色インクとして応用したところ，ピエゾタイプカートリッジを用いた粉末固形製品への加飾成型，およびサーマルタイプカートリッジを用いた家庭用プリンターによる印刷実験，ともに良好な結果を得た。

Micellization of the Gemini surfactant sodium dilauramidoglutamide lysine (SDGL) in the presence of an antihistamine drug, diphenhydramine hydrochloride (DPC) was investigated. The anionic surfactant sodium dodecyl sulfate (SDS) was used for comparison. DPC significantly decreased the critical micelle concentration (cmc) of both SDGL and SDS in aqueous media and increasing the DPC concentration decreased the pyrene excimer/monomer polarity ratio in SDGL micelles but increased it in SDS micelles, suggesting that SDGL and SDS micelles have different shapes. The counterion binding and binding constant values reveal that SDGL micelles interact more strongly with DPC than SDS micelles. Thus, DPC, as an organic counterion, can enhance surfactant micellization. The evaluation of the solubility of a poorly water-soluble drug (clotrimazole) in SDGL and SDS micelles containing DPC revealed that the drug was more soluble in SDS micelles than SDGL micelles, indicating that the cmc and the shape and size of micelles are essential factors for controlling drug solubilization.

To minimize retention of nuclear fuel materials in glove box components and curtail the external exposure dose, plutonium and uranium mixed oxide powder adhesion prevention technology involving nanoparticle coating of the acrylic panels of the glove box is developed. The nanoparticle coating reduces the van der Waals force between alumina particles and the acrylic test piece surface because of formation of nano-sized rugged surfaces. The nanoparticle coating reduces the minimum adhesion force normalized by the particle diameter between the uranium dioxide particle and the acrylic test piece surface, for the smallest particle of about 5 µm associated with desorption, this minimum adhesion force reduced to about 5%. The nanoparticle coating also lowers the adhered plutonium and uranium mixed oxide powder amounts on the acrylic test piece to about 10%. This study reveals that applying the nanoparticle coating to the acrylic panels of the glove box prevents adhesion of nuclear fuel materials. This method effectively reduces the retention of nuclear fuel materials in the glove box, lowers the external exposure dose, and improves the visibility of the acrylic panels.

We examined the effect of high pressure on the sol–gel phase transition of a resorcinol–formaldehyde (RF) aqueous solution to a RF hydrogel, which was hold under a certain pressure varied in the range from the ambient pressure to 400 MPa. By employing the dynamic light scattering method, we analyzed the scattered intensity of a He–Ne laser which was irradiated to the RF solution to determine the hydrodynamic diameter of the structure formed during the phase transition. Before the completion of the phase transition, we measured the transient change in the size of colloidal particles, i.e. the unit of the porous structure formed in the RF hydrogel. It was revealed that the size of the colloidal particles increased with the increase in the pressure added to the RF solution. After the completion of the phase transition, we prepared a RF cryogel by removing solvent from a RF hydrogel by freeze-drying. The specific surface area of the RF cryogel was found to decrease with the increase in the added pressure, as a result of the increase in the size of the unit of the porous structure.

スラリー状製品における保存時の粒子の沈降・堆積・固化防止と塗布時の低粘性実現のため，形成される堆積層は非常に疎で，なおかつ弱い撹拌で良分散状態に戻り容易に流動可能となる軟凝集性スラリーの調製を試みた。本研究では，高分子電解質分散剤を用いていったん粒子を良分散状態とした後，多価イオンを添加して粒子表面の高分子分散剤をイオン架橋させた。これにより，低い降伏応力をもつ緩いゲルが形成され，軟凝集性スラリーの調製に成功した。このスラリーは，軽く振盪するだけで容易に流動状態へと移行し，時間が経過すれば再度ゲル状態に戻るという可逆性を有していた。さらに，ゲル化の度合いは添加する多価イオンの量で調整可能であった。

We examined the degradation of aqueous phenol by ozonation in an aerated mixing vessel, which was combined with a fixed-bed reactor packed with high-silica zeolite (HSZ) pellets. Ozone-containing oxygen gas was introduced as fine bubbles through a sparger placed in the aerated mixing vessel, whereas the aqueous phenol solution was circulated between the vessel and the reactor. Measurements of transient changes in the concentration of both phenol and total organic carbon in the treated solution revealed that the degradation of phenol or total organic carbon by ozonation was enhanced by the presence of HSZ because both phenol and ozone could adsorb on the hydrophobic micropores. As a result of quantitative analysis of the treated solution, it was found that catechol, hydroquinone, humic acid, and maleic acid were the possible reaction intermediates during ozonation of aqueous phenol employing HSZ.

In this study, the mechanism of granule fracture under biaxial compression was investigated through both experimental and simulation methods. The results of the experiment indicate that the fracture behavior differs depending on the number of compressional axes. The fracture load under the biaxial condition is smaller than that under the uniaxial condition because in the latter, the compressed granule can be deformed planarly, whereas in the former, the compressed granule can be deformed into only one axial direction that is not compressed. To investigate this phenomenon in detail, finite-element method (FEM) analysis was used to analyze the tensile stress inside granules. The results of the FEM simulation indicate that the dominant factor in fracture phenomenon is tensile stress at the center of granules. From these results, it will be possible to theoretically predict, without any complicated experiments, the likelihood of fracture in granules.

<p>SnO<sub>2</sub> quantum dot was successfully synthesized at ambient temperature via ozone bubbling to suspension including Sn<sub>6</sub>O<sub>4</sub>(OH)<sub>4</sub> under pH of 12. It was clarified that use of SnF<sub>2</sub> as starting material enables to obtain clear and stable SnO<sub>2</sub> quantum dot suspension. Possible formation mechanism of quantum dot was proposed and shift of fluorescence was predicted with use of varied basic solution for neutralization and pH adjustment based on the hypothesis that shift of fluorescence is attributed to change in size. And this prediction was confirmed by experiment. Finally addition of Zn as dopant gave improved luminescence intensity without shift of fluorescence.</p><p>SnO<sub>2</sub> quantum dot developed in this work does not include any cadmium, thus application as alternative to conventional CdSe and CdS is expected.</p>

A new synthetic route to prepare yttrium barium copper oxide superconductive fibers using electrospinning in conjunction with the polymerizable complex method was developed. The as-spun fibers exhibited wool-like tactility and were 5-7 mu m thick. The fibers therefore exhibited sufficient flexibility to be fabricated into arbitrary shapes. Although the fibers shrunk and exhibited brittle tactility because of the decomposition of organic compounds during heat treatment, the fibers predominantly maintained their fibrous form. Scanning electron microscopy observations revealed the growth of metal oxide grains during sintering. Powder X-ray diffraction pattern of the annealed fibers showed good agreement with the pattern of YBa2Cu3O7-delta. Magnetic property measurements of a ground fiber sample using a superconducting quantum interference device revealed that the superconducting transition temperature of the sample was 91 K. (C) 2017 The Ceramic Society of Japan. All rights reserved.

省エネ住宅への注目の高まりから断熱材への需要が高まっている．中でも無機繊維系断熱材は種々のメリットを有しているが，生産コストの改善が要求されている．本研究では，ケイ酸ナトリウム濃厚水溶液を紡糸溶液とし遠心紡糸法を用いて水ガラス繊維を作製するプロセスを提案する．繊維径ならびに繊維径分布は遠心紡糸条件に大きく依存し，遠心加速度が大きいほど細く，均一な繊維が得られることがわかった．一方，溶液の粘度は繊維の太さや均一性に大きな影響を与えず，3 Pa·s以上，150 Pa·s以下の範囲で安定して繊維を得ることができた．100°C以上の温度で炭酸ガス雰囲気中で熱処理を行うことにより，ある程度の耐水性を付与することに成功した．熱伝導率測定の結果，0.027 W/(m·K)と空気の熱伝導率に匹敵する高断熱性を有することがわかった．また，市販のグラスウールと比較して熱伝導率の最小値に大きな差は見られなかったが，充てん量を約1/2に低減することができており，断熱材の低コスト化に対し有効であると結論づけられる．

<p>Xerogels of large specific surface area have been successfully prepared by optimizing sol-gel process without any templates. It was found that the optimum solvent to obtain gels of large specific surface area is 1-propanol and the optimum molar ratio of solvent to alkoxide is 10. It was also clarified that the consecutive addition of water to reaction system by introducing humidified air is critical to specific surface area and that with humidified air the less initial content of water can provide gel of larger specific surface area. Consequently silica gel with specific surface area of 1869 ‍m<sup>2</sup>/g could be obtained. Titania gel with specific surface area of 597 ‍m<sup>2</sup>/g was successfully prepared by using ammonium acetate as catalyst together with above mentioned strategy.</p><p>Obtained titania gel was used as support material of Ni nanoparticle and the catalytic activity was tested then compared with commercially available non-porous titania fine particle and commercially available silica gel. As a result, the significance of catalyst-support interaction and improvement of loading amount of catalyst nanoparticles attributed to porosity were confirmed.</p>

To study solute distribution at the solid-liquid (S-L) interface during melt crystallization, we examined the applicability of the interfacial solute distribution factor proposed based on a kinetic model involving both mass and heat balances at the interface. The factor derived from the model was compared with the experimental results obtained by employing a binary melt with the different species and concentrations of fatty acids as biodiesel related mixtures. As a result, we were able to reveal the empirical relation between the purity of the crystal and the solidification conditions of the melt. Based on the model, we also numerically calculated the transient changes in the interfacial solute distribution factor as well as the temperature of the S-L interface in the solidification process of the melt. The minimization of the factor was confirmed when the melt was supercooled at the S-L interface after starting solidification. (C) 2015 Elsevier Ltd. All rights reserved.

スラリーの分散・凝集状態は，得られる最終製品の品質に密接にかかわるため，スラリーの分散安定性評価は非常に重要である。これまでにさまざまな評価技術が開発されているにもかかわらず，必ずしも評価結果と最終製品の品質が対応せず，いまだに現場では技術者の経験と勘に頼る部分が少なくない。これは，スラリー評価法と実プロセスとのミスマッチ，すなわち，評価法が対象としていない場面での使用により，適切な評価が行えていないことが原因の一つであると言える。本報では，成形プロセスなど，とくに高濃度なスラリーを取り扱う場面を対象とし，見掛け粘度測定，回分沈降試験法の解説を行ったうえで，これらの分野で有用と思われる，最近開発された沈降静水圧法によるスラリーの分散安定性評価技術について解説を行った。

The preparation technique to obtain purely inorganic silica doped titania fibers using electrospinning together with sol-gel method was proposed. For the system without silicon doping, fibers were too brittle to form long fiber. And it was clarified that small amount of doped silicon could modify the flexibility of fibers drastically and long fibers with appropriate mechanical property could be obtained. After calcination at 500 degrees C for 2 h anatase phase was appeared and the specific surface area of fibers with composition of [Ti]/[Si] = 6 showed highest value 71.9m(2)/g among all the samples tested, which is even higher than typical fine particles. The result of decomposition experiment of Rhodamine B dye solution showed that the silica doped titania fiber has adequate photocatalytic activity to decompose organic matters. (C)2014 The Ceramic Society of Japan. All rights reserved.

© 2014 International Society for Industrial Process Tomography. The capping phenomenon means the powder adheres to the piston at the powder compression process and is one of the important causes of the powder molding trouble. The capping phenomena were difficult to discover in a compression molding process. The capping region can be detected from X-ray computed tomographic images and slipping angle of the capping area can be measured. From the experimental results, it’s clear that the capping phenomena easy to occur in the case of wider size distributed granules. So the capping phenomena can be prevented to use coarser mono-sized granules for compression molding.

In order to determine the preparation time for slurry in ceramic manufacturing processes, the effect of the conformation of ammonium polycarboxylate, an adsorbed anionic polymeric dispersant with a molecular weight of 8000～10000, on the dispersion stability of the slurry was investigated. The slurry preparation time was varied and the effect was investigated using and hydrostatic pressure measurement. The results of the investigation showed that the conformation of adsorbed polymers changed with time from random coil to fibril-like and that it took several days for the polymers to relax completely in the slurry. Furthermore, the dispersion state of the slurry changed with the relaxing of the conformation of adsorbed polymers. The results showed that the stretching of adsorbed polymers contributed significantly to the dispersion state of the slurry. The optimum conditions of polymers for the preparation of the slurry are also discussed.

The glass substrate is coated by the silica nanoparticle suspension using dipping or spin coat method and dried in an electric oven. The glass substrate surface is covered with nanoparticle thin layer and the transparent and tiny rugged surface can be produced on a substrate. It was experimentally confirmed to prevent dust adhesion by covering the surface of the glass substrate with nanoparticle. But the reason why the prevention of particle adhesion on nanoparticle coating substrate is not clear yet. Therefore the adhesion force between particle and substrate is measured by the centrifugal method and the relation between the adhesion force and the surface roughness is discussed from experimental and theoretical point of view. The measured and calculated results by Van der Waals force show that adhesion force decreased with the increment of the surface roughness. From the results, nanoparticle coating is very effective to prevent the dust adhesion on the substrate and the various application of nanoparticle coating can be expected.

For the purpose of this work, several types of waste coolants from fixed-abrasive wire sawing (FAS) were filtrated, and the characteristics of the coolants and the retrieved solid materials were investigated. The all coolants consisted of water and glycol series with the boiling temperature of around 200 degrees C. However, the viscosity of each coolant were different due to the difference in the ratio of coolant components. Experimental results of pressurized filtration can be explained by a rate equation which we proposed. The concentration of diamond in the retrieved solid materials was less than 0.2wt%. Metal contents in the retrieved Si were measured by an inductively coupled plasma mass spectrometry (ICP-MS). The result indicated that quality of the retrieved Si is sufficient for the use as feedstock. The shaped Si was easily melted in a resistance heating furnace. We concluded that the Si powders in waste coolants from F AS can be used as feedstock.

A new filtration method that a slurry is prepared in a well-dispersed state and filtered by a ceramic tube with a spiral guide rod has been developed in our previous paper. In this study, we attempted to concentrate various hardly filterable materials by using this new system. The sample slurries used were sericite, iron oxide, algal suspension and activated sludge of the excrement of farm animals. Their respective concentrations were 57, 74, 1.1, and 7.55 mass%. The concentrated slurry of all samples exhibited good flowability. In addition, to apply this system to real industrial processes, we attempted to calculate the required number of ceramic filters from the relationship between the filtration flux and the slurry concentration. Thus, the size of this system is expected to be significantly compact. Furthermore, in this system, there is a case that the batch operation is more effective than the continuous operation. (C) 2011 Elsevier B.V. All rights reserved.

The effects of sintering aid adsorption on the dispersion properties of aluminum oxide slurries were investigated. We considered Al2O3 slurry without additives and Al2O3 slurry with a Mg additive with 0.1 mass% in oxide equivalent as a sintering aid. In this study, we evaluated the adsorption isotherm of polyacrylic acid (PAA) onto Al2O3 and the dispersion degree of Al2O3 slurries in sedimentation tests under gravity. The adsorption isotherm featured a characteristic adsorption isothermal line with a maximum value when Mg additive was present in Al2O3. In addition, the packing fractions did not correspond to the apparent viscosity. However, in slurry that was allowed to settle for several days, both of them agreed. Therefore, the disagreement between the packing fraction and the apparent viscosity immediately after preparation arose from changes of the dispersion state, such as the decrease of the distance between particles with time. (C) 2010 Elsevier Ltd. All rights reserved.

A new synthesis route to hydroxyapatite microsphere was proposed. Starting from the W/O emulsion system, micron-sized precursor particles were formed autonomously. It was clarified that pH of water during hydrothermal treatment can affect the morphology of resultant hydroxyapatite particles. Particles of irregular shape could be obtained via hydrothermal treatment under ambient pH, by contrast under high-pH conditions resultant particles retain the spherical morphology of precursor particles. It was also clarified that obtained hydroxyapatite particles have negatively charged surface, which is opposite to those by general synthesis method such as precipitation. Eventually it was confirmed that lysozym which is positively charged protein can be adsorbed on the obtained hydroxyapatite particle but albumin which is negatively charged can never be adsorbed.

A new filtration system with a spiral guide rod in a ceramic tube and slurry prepared in a well dispersed state has been developed. This paper discusses the optimization of operating conditions such as the effects of the spiral guide rod, the pitch of the spiral guide rod, the filtration pressure and the flow rate of circulation on the filtration flux. In addition, using a filter after filtrating dense slurry, ultrasonication test and repeated filtration tests in short and long intervals were carried out. In this system, it was shown that the filtration flux was dramatically improved compared to the conventional cross-flow filtration system. The filtration flux increased with the flow rate of circulation and did not depend on the filtration pressure. The achieved optimal value of the pitch produced the maximum filtration flux. It was also shown that fouled particles can be removed easily and the filtration flux can be recovered to the initial condition by ultrasonication. (C) 2010 Elsevier B.V. All rights reserved.

A new cake-less continuous filtration system with a spiral guide rod inserted into a ceramic tube filter and slurry prepared in a well dispersion state has been developed We tried to filter some difficult to filter materials such as iron oxide and activated sludge Especially, the algal suspension and activated sludge was not able to be filtrated by a conventional filtration system like filter press Concentrated slurries of iron oxide and activated sludge were discharged at 35 vol% and 7 55 mass% respectively The concentrates of every sample retained flowability In addition, to apply this system to a real process, we tried to calculate the filter tube number from the relationship between the filtration flux and slurry concentration As a result, the size of this system can be expected to be very compact Also, in this system, the batch operation was more effective than continuous operation

The measured values of apparent viscosity of non-Newtonian fluids were discussed. Alumina slurries, CMC solutions and chocolates were used as non-Newtonian fluids, and their apparent viscosities were measured by a single cylinder rotational viscometer (B-type viscometer) and coaxial cylinder rotational viscometer (coaxial viscometer). The measured values by the B-type viscometer were larger than those by the coaxial viscometer in every sample, and the flow curves measured by the coaxial viscometer were well fitted by the power law model. The ratio of the apparent viscosities measured by both viscometers was correlated with the exponent in the power law model. Instead of the exponent, a new index defined by the measurement values of the B-type viscometer was proposed in order to estimate the true values measured by the coaxial viscometer. The ratio of the apparent viscosities could be correlated with the new index as well as the exponent. It has been revealed that the true apparent viscosity can be roughly estimated by the B-type viscometer by using the new index.

We investigated the effects of particle concentration and an additive amount of a dispersant on the adsorption behavior of dispersant. Ammonium polycarboxylate, one of the typical polyelectrolyte was used as a dispersant in this study. Alumina slurries were prepared by changing the concentrations of both the particle and dispersant and kept in a test tube for at least 2 d. After that, the adsorbed dispersant amount was calculated from the residual dispersant concentration measured by a total organic carbon analyzer. It was found that the adsorbed dispersant amount strongly depends on the additive dispersant amount on the basis of the unit mass of particles in the slurry regardless of the particle concentration. It was also shown that pollycarboxylic acid strongly absorbs onto an alumina surface and can not be desorbed by dilution, suggesting that its adsorption behavior differs from physical adsorption. (C)2009 The Ceramic Society at Japan. All rights reserved.