This article introduces the synthetic methods adopted by the author in the preparation of Ho-doped BaTiO₃, vanadate compound phosphors, and a phosphor host material of fluorine-doped lithium aluminate, including the solution method, the self-flux method, and the precipitation method. The solution method had the advantages of compositional uniformity in the precursor on the atomic scale and easy introduction of Ho³⁺ into the perovskite type BaTiO₃ crystal structure. The self-flux method is a method of preparing the product phases using a starting material that forms a melt during the heat treatment, allowing the growth of crystalline grains. The incorporation of flux components in the products sometimes yielded rather unusual materials. The precipitation method was specifically effective for the ‍preparation of vanadate compound phosphors such as Ba₂V₂O₇ and Zn₃(VO₄)₂, in which insoluble salts of vanadate ions and cations such as Ba²⁺ and Zn²⁺ were precipitated in aqueous solution with a fixed composition depending on solution pH.

Mechanical synthesis of lithium titanate hydrate (LHTO: Li_1.81H_0.19Ti₂O₅·xH₂O) in liquid phase was investigated using a high centrifugal bead mill. The maximum centrifugal acceleration induced by the mill is 1000 G. LHTO is a precursor of lithium titanate (LTO: Li₄Ti₅O₁₂) which is an anode material for lithium-ion batteries. As starting materials, lithium hydroxide which was dissolved in water and titanium dioxide (TiO₂) nanoparticles were used. As bead media, 0.3, 0.5 and 1 mm diameter of zirconia beads were employed. In cases of 0.3 and 0.5 mm beads, the formation ratio of LHTO reached 90% by 60 min milling. Synthesis of LHTO proceeded in a short time. The LTO sample converted from the LHTO by 60 min milling with 0.3 mm beads contained less residual TiO₂ as compared with the sample of 0.5 mm beads. Coin-type cells were assembled using the converted LTO samples and electrode properties were evaluated.

The internal structure of Al₂O₃ green bodies during dewaxing process was directly observed by optical coherence tomography. The gas generation during dewaxing and the mechanical property of green bodies at high temperatures were further analyzed by TG and three-point bending test, respectively. Although crack formation was observed during the dewaxing process in the green body prepared by adding only PVB as an organic binder, no cracks were found in the green body prepared by simultaneous addition of PVB and basic aluminum lactate, which was an inorganic binder. Simultaneous addition of organic and inorganic binders improved the bending strength of the green bodies due to the presence of inorganic link among the particles, which prevented the green bodies from cracking. Inorganic binder was effective to control crack-formation in the green body.

The particle size effect of pesticide (penthiopyrad) on the control of plant diseases was investigated. First, monodisperse penthiopyrad particles could be prepared by the poor solvent dilution method. Next, three types of penthiopyrad particles with different median diameters were prepared and sprayed on the cut leaves of cherry tomato prior to inoculate gray mold fungi (Botrytis cinerea). As a result, it was suggested that pesticide micronization improved the control effect against plant pathogen, and that pesticides could be reduced by about 60%. In addition, when fluorescent penthiopyrad particles were exposed to the hyphae of gray mold fungi, pesticide micronization was also found to improve the penetration of pesticides into cells. From the above, it was demonstrated that the pesticide micronization increases the probability of contact with plant pathogens and uptake into fungus cells, thereby improving the control effect of pesticides.

Interparticle photo-cross-linkable ZrO₂ slurry which can be photo-cured by near-infrared (nIR) light irradiation was successfully designed by mixing small amounts of multifunctional acrylate (MA), photo radical initiator, and nIR-absorbing dye into a concentrated ZrO₂ slurry stabilized by a partial complex of polyethyleneimine and oleic acid. The reaction of MA to PEI-OA modified ZrO₂ particles induced by nIR light irradiation was confirmed through the FTIR and TGA analysis of ZrO₂ particles collected from the slurry before and after light irradiation as well as the microstructure investigation of photocured bodies using FE-SEM. Compared to the ultraviolet light-responsive interparticle photo-cross-linkable ZrO₂ slurries, the designed nIR-responsive slurry found to possess large curing depth which enabled the shaping of complex structured ZrO₂ green bodies through a simple photocuring process in a mold.

In this study, we investigated milling characteristics of sulfide solid electrolytes (SEs) for all-sold-state lithium ion batteries (ASSLIBs). Subsequently, we employed the milled SEs as guest particles for dry coating of cathode active material (AM), and examined the influence of SE size distribution on ASSLIB performance. Our finding revealed that SE particles have unique milling characteristics, in which coalescence of milled fine particles occurs simultaneously with size reduction by milling. The dry coating experiments confirmed that the use of milled SEs (guest particles) resulted in more uniform coating of the AM (host particles) with SE, leading to significant improvement in the performance of ASSLIB (630% increase in capacity as compared to unmilled SEs). However, when SEs were excessively milled, the SE coating layer exhibited non-uniform morphology, resulting in lower battery performance (15% decrease in capacity). Consequently, our results highlighted that there is an optimal milling condition for SE guest particle for the dry coating.