Preparation of boehmite-silica composite particles using heterocoagulation was studied to improve the packing ratio and flowability of the particles used as fillers and flame retardants in resins. By measuring the zeta potential of each particle, silica showed a negative charge at pH > 2, and boehmite showed a positive charge at pH < 9. Therefore, mixing of each suspension of silica and boehmite prepared at pH 4 successfully produced boehmite-silica composite particles by heterocoagulation. We used two different silica particle sizes. Using smaller silica particles, composite particles uniformly coated with silica were obtained. The composite particles showed excellent fluidity in liquid paraffin, which suggested improved packing ratio.

Magnetorheological Fluids (MRF) whose apparent viscosity is controllable by applying magnetic fields are known as a kind of functional fluids. It is generally considered that such viscosity changes are caused by the formation of chain-like clusters of magnetic particles dispersed in the fluid. Many researches have been conducted to understand the mechanism of the viscosity change of MRF but there are few report which directly indicate the relation between the cluster formation and the viscosity change because of the difficulty of the observation such phenomena simultaneously. In this study, the relation between particle clustering and viscosity change has been investigated using DEM-DNS simulation. The simulations are conducted just a few chain-like clusters of magnetic particles in simple shear flow and the simulation results indicate that the apparent viscosity corresponds to both of the chain length and the angle between magnetic field direction and chain axis which depend on the Mason number.

Surface modification of functional polymers onto liposomes is effective strategy to obtain functional liposomes that release drugs at target site or intracellular compartments. Here, design of pH-sensitive liposomes for cell-specific intracellular drug delivery was summarized. Liposomes modified with hyaluronic acid derivatives exhibited selective anticancer drug delivery to CD44-expressing cancer cells. Furthermore, liposomes modified with curdlan derivatives were efficiently recognized by dendritic cells, leading to efficient antigen delivery, activation of dendritic cell and induction of antitumor immunity on tumor-bearing mice. Therefore, functional polymer-modified liposomes are promising for cell-selective cancer chemotherapeutic system or immunotherapeutic systems.

Thermally conductive polymer composites offer new possibilities for the thermal management in electronic devices. An approach of current interest to improve the thermal conductivity of polymer composites is the addition of high thermally conductive fillers with different shape and size. This paper described an overview of the microstructural design techniques for polymer composites with high thermal conductivity, and recent progress and advances that have been made on the enhancement of thermal conductivity of the polymer composites.

In an industrial incinerator, suppression of ash emission is of great importance from a viewpoint of environment preservation. In some of the incinerators, a control plate is equipped to suppress the ashes, where it is designed based on engineers’ experience. The control plate is assumed to recoil the ash particles. On the other hand, effect of the control plate has not been examined sufficiently, and besides behavior of ash particles has not been figured out in the incinerator. This is because the incinerator scale is so large that validation tests cannot be performed. In the present study, a numerical technology is applied to an industrial incinerator to examine the effect of the control plate and to analyze the ash particle behavior. In the numerical simulations modeling of an arbitrary shape wall boundary and large-scale simulation technique are required. In this study, advanced DEM-CFD method is employed, where coarse grain model of the DEM is used as scaling law modeling and signed distance function and immersed boundary method are applied to arbitrary shape wall boundary in the DEM-CFD method. The numerical simulations illustrate that the control plate works effectively, whereas, against all expectations, the ash particles are shown to remain in the incinerator not by collision to wall but by settling on the plate due to vortex.

The choking prevention effect on dense-phase pneumatic conveying has been investigated experimentally while moisture and particle diameter are changed. Consequently, the adhesion force between particles and pipe wall has been increased drastically with increasing of moisture content. However, it has been reduced with ultrasonic in spite of experimental condition. This means the possibility of choking can be removed with ultrasonic vibration. Additionally particle motion on the ultrasonic vibration plate was analyzed. This result showed that particle velocity increases along with particle diameter and moisture content influences on only large-sized particle. This cause was considered that heavy particle which includes a lot of water cannot jump in long distance and water makes the meniscus between particle and wall.

To understand the detail structure of the pulverized coal flame, it is necessary to apply the carefully controlled optical diagnostics because the significant signal disturbance from the fuel particles would reduce the accuracy of data. In this paper, the highlight results obtained by applying shadow Doppler particle analyzer (SDPA) and laser induced incandescence (LII) and time-resolved LII (TiRe-LII) to the pulverized coal flame were summarized.

This study aims to evaluate granules and tablets properties prepared by twin-screw continuous granulation (TSG) by comparing with those by fluidized-bed granulation (FBG) and high shear granulation (HSG). During FBG, mass median diameter increased in proportional to moisture content of wet granules. In HSG and TSG, granules growth was observed with an increase in mass ratio of liquid to solid. The mass median diameter was affected by the blade rotation speed at higher level of water content in HSG. By contrast, granule growth was less affected by the screw rotation speed in TSG. Friability and density of granules prepared by TSG remained between FBG and HSG. Scanning electron microscopy and cross-sectional 3D X-ray tomography images suggested that granules prepared by TSG did not receive high shear force as HSG during the granulation. The tablet strength and the percentage of dissolution were similar with those by FBG. It was because granules prepared by TSG had relatively porous structure as FBG. Under practical operation conditions, the tablet properties were comparable with those by FBG and HSG.

The method to improve the properties of dry granules was investigated by introducing pre-coating process with an active pharmaceutical ingredient (API) and a submicron-sized binder prior to conventional roller compaction. Hydroxypropylcellulose (HPC) and acetaminophen (APAP) were used as models of a binder and a low-compactible API, respectively. The submicron-sized HPC (HPC-subMP) was obtained by a lab-scale spray dryer. The APAP particles were pre-coated with 5–10% of the HPC-subMP by a high shear mixer, formed into granules using a lab-scale roller compactor, mixed with other excipients and then compressed to make them tablets containing 50% APAP. The tablets prepared with the HPC-subMP showed a high tensile strength without significant retardation of the disintegration time in comparison to those with a raw HPC particle, indicating that the use of API particles pre-coated with submicron-sized binder particles in roller compaction was effective to prepare granules suitable for tableting without any fundamental changes of materials and manufacturing processes.

Recently, ferroelectrics with relatively small bandgap energy have been receiving much attention because of the characteristic photoinduced electrical responses under visible light irradiation. However, such photoresponsive materials have serious problems such as poor photoelectric conversion properties, especially low photocurrent. It revealed that incorporation of silver (Ag) nanoparticles in the film as a surface plasmon excitation agent is effective to enhance photocurrent of narrow bandgap ferroelectric (such as BiFeO₃) thin films. The synthesized BiFeO₃ and Ag nanoparticle/BiFeO₃ thin films demonstrated rapid on/off responses of photocurrent to visible light. The Ag nanoparticle-embedded BiFeO₃ film exhibited a several times higher photocurrent than the BiFeO₃ film.

In this study, a novel reversible control method for particle dispersion/flocculation was developed. We found that the conformation of a polymer with solubility pressure dependencies on the side chain changed from random coil to fibril-like with ambient pressure. On the contrary, as we reported in our previous paper, the dispersion state of slurry changes with changes in the conformation of adsorbed polymers. Based on these results, we hypothesized that the dispersion state of the slurry can be reversibly controlled by ambient pressure. The sample used was aqueous slurry of alumina with a sodium salt of sulfonic acid copolymer with a relative molecular mass of 10000. The results showed that the dispersion state of slurry at atmospheric pressure was flocculated with a specific additive amount of polymer. On the contrary, after pressurization, the dispersion state was changed into a well dispersion state. Therefore, it was confirmed that the slurry was responsible for the pressure; thereby, a novel reversible control method for particle dispersion state was successfully developed.

The control of powder flowability with fine particles is important for tablets prepared by direct compaction. In the present study, the addition ratio of two types of fine particles of silicic acid compounds that can be used as glidants was examined to improve powder flowability. The powder sample, lactose, with a count median diameter (D_P50) of 103 μm, was used as an excipient, while magnesium aluminometasilicate (MA; D_P50 = 1.2 μm) and magnesium silicate (MS; D_P50 = 0.6 μm) were used as glidants. MA or MS was added to the excipient at different ratios in a range from 0.2 to 3.0 mass%. Powder flowability was evaluated by a vibrating tube method, which can characterize both the static and dynamic friction properties, and by conventional methods, i.e., measuring the angle of repose and compressibility. From a series of experiments, it was found that MA is more effective than MS in improving powder flowability, but with a strong dependence of addition ratio.

Xerogels were prepared from mixed aqueous ethanol solutions of Tetraethyl orthosilicate (TEOS) and hydrated iron nitrate, and their properties were investigated using XRD, TEM, FTIR, and VSM. As the heat treatment temperature of the iron oxide particles increased, the γ-Fe₂O₃ and the ε-Fe₂O₃ were precipitated, and the particle diameters increased.

For heat treatment at 1100°C, the α-Fe₂O₃ was observed when the Si/Fe ratio was 1.5, while the ε-Fe₂O₃ was formed when the Si/Fe ratio was 2.8, 5.7, and 11.4. The particle diameter of the ε phase increased with decreasing Si/Fe ratio. By adding yttrium, crystal growth of the iron oxide particles was promoted, and the particle diameters and the coercivity consequently became larger than that of the sample without yttrium present.

Preparation of Mg particles were carried out by using a pulsed wire discharge method, which is a physical vapor method in organic matter fume/vapor and is beneficial for passivated metal nanosized powders. From results of powder X-ray diffraction, the sample consisted of single-phase Mg. Electron diffraction and transmission electron microscopy observations revealed that Mg submicron particles were seen even though the presence of fine MgO particles. After an oxidation test at room temperature in air for one month, the oxidation did not progress. From these results, it was concluded that alkaline earth metal particles can be mass-produced by the pulsed wire discharge.

Electrostatic levitation allows a monitoring of solidification behavior of single levitated microdroplet. In this paper, novel designed slim-type electrodynamic balance (EDB) coupled with the microscope is evaluated. It enabled us in situ observation of internal mixing of microdroplet with sufficient spatial and time resolutions. With this instrument, we directly observed the crystal growth from the micodroplet of inorganic salt such as NaCl, NaBr, NaI, KCl, KBr and KI, respectively. The morphologies of produced crystal particles were divided into three types, 1) rectangular solid crystal for KCl or KBr with high crystallization relative humidity (CRH), 2) multi-crystalline particle with crystal habit for NaCl and KI with medium CRH and 3) hollow particles for NaBr and NaI droplets with low CRH. The morphologies of the produced particles were more strongly influenced by CRH rather than supersaturation.

In order to characterize the emission behavior of PM2.5/PM10 mass concentration from stationary sources, such as power plants, factories and waste incinerator plants, two-stage virtual impactors were developed for in-stack separation and collection of PM2.5/PM10 in flue gas. This method was adopted as international standard, ISO 13271 (2012) to determine the actual emission behavior of PM2.5/PM10 from stationary sources. PM2.5 separation performance of a virtual impactor was compared with that of a real impactor, which was also international standard method as ISO 23210 (2009). With the conventional cascade real impactor method PM2.5 mass concentration was overestimated by the particle bounce and re-entrainment of coarse particles from the collection plates.

Technology which can monitor states of granular systems will become a key to optimize manufacturing systems for developing functional materials such as for battery and medicine. Several methods are already available including process tomography and PIV. This paper focuses and discusses mixing index by Shannon Entropy, Shannon mixing index termed in the paper, by comparing the Lacey mixing known as standard mixing index based on statistics and experimental data. The following results are obtained: 1) Shannon mixing index can handle multi-component systems, instead of Lacey mixing index being limited to binary systems. 2) Shannon mixing index can evaluate really small amount of component quantitatively as well as qualitatively, which is not available by statistically based methods. 3) Shannon mixing index can be calculated experimentally by material sampling method, which is comparable to predictions by DEM (Discrete Element Method) simulation. The results obtained through the research indicates that Shannon Entropy can be qualified to the standard mixing index.

Reaction of mono calcium phosphate monohydrate (MCPM) and calcium carbonate at 36.5°C was applied to prepare octacalcium phosphate (OCP) porous compact expected to be a bioresorbable bone precursor in accord with autologous bone recycling process. XRD analysis confirmed that intermediate product of porous dicalcium phosphate dihydrate (DCPD) compact is synthesized practically in the first period of 2 hours, and that DCPD crystalline is reasonably decomposed into OCP through the hydrolysis reaction within 7 days. The pH value of phosphate buffered solution exerts an influence on the CO₂ gas evolution reaction and hence the transformation rate of DCPD crystalline into OCP. OCP porous compacts were evaluated in simulated body fluid (SBF) for its transformation ability to hydroxyapatite (HAp). SEM micrographs, XRD and EDS analyses demonstrated that petaloid shaped calcium-deficient HAp should be crystallized on the basis of the bone-like apatite layers in OCP crystalline structure.

Microstructural observation using transmission electron microscopy (TEM) is a promising technique for obtaining new findings with atomic-scale and developing phenomenological theory for ceramic materials. This paper reports on observation techniques and diverse findings obtained by observations of several ceramics. The knowledge obtained here is expected to be useful in the design of future materials.

A single cell contains a variety of organelles, including a nucleus, mitochondria, the golgi apparatus and others. If it were possible to prepare a nano craft that could specifically target a specific organelle, it would open a new field of research directed toward therapeutic treatments for a variety of diseases. We recently developed a new concept that we refer to as “Programmed Packaging”, by which we succeeded in creating a multifunctional envelope-type nano device (MEND) as a non-viral vector. Our attempts to target mitochondria are discussed here, mainly focusing on a MITO-Porter, a MEND for delivering cargoes to mitochondria. A variety of human diseases, including various neurodegenerative disorders, ischemic heart disease, diabetes and cancer have been reported to be associated with mitochondrial dysfunction. Because of this, mitochondrial therapy would be expected to be useful and productive in the treatment of such diseases. Our findings regarding mitochondrial drug delivery systems that are directed toward mitochondrial nano medicine development are summrized herein.