Calcium carbonate nanoparticles are widely used in various composite materials across industrial sectors. However, previously synthesized calcite nanoparticles have typically been rhombohedral with an aspect ratio of ~1. This study investigates the microscopic evolutions of particle morphologies during the formation of calcite rhombohedral nanoparticles. By better understanding these changes, methods involving the addition of Ca(OH)₂ and Mg(OH)₂ have been developed to produce high-aspect-ratio 1D chain-like particles. Controlling the primary particle morphology significantly enhances solid-liquid separation in slurries after liquid-phase synthesis and improves the mechanical properties when these particles are used as fillers in composite materials.

The flexible metal-organic frameworks (MOFs), which are a new type of porous material, exhibit unique adsorption behavior, and are expected to have a wide range of applications. However, to overcome the issue of low handling performance of flexible MOFs, it is necessary to establish a molding process. Although it is predicted that the flexible MOF particles and their aggregate structure should strongly affect the molding process, the effect on the particularly unique adsorption behavior is still unknown. In this study, the effect of the aggregate structure of flexible MOF particles on the uniaxial compression process was investigated experimentally and numerically. It was demonstrated that hollow-structured aggregates maintained the best adsorption properties. In addition, numerical analysis revealed that the force applied to the particles was reduced in hollow-structured aggregates. These would be useful results for the practical application of flexible MOF particles.

Cerium oxide nanoparticles were synthesized using the Forced Thin-Film Type Reactor (FTFR). The precipitation solution was changed from aqueous sodium hydroxide to ammonia solutions. By adjusting the mixing ratio of trivalent and tetravalent cerium ions in the solutions and varying the cerium ion concentration, the shape of the particles varied from spherical to truncated octahedron and irregular shape to cuboidal to truncated octahedral. It was estimated that the change in particle shape could be attributed to the difference in the concentration of dissolved oxygen and hydroxide ion in each solution.

Nanoemulsions have been employed as one of the methods for nano-dispersing poorly water-soluble drugs in mucus. However, most liquid suspension such as the emulsions is washed by the clearance effect on the mucus surface. This study examined the spontaneous emulsification formulation using porous polymer microparticles with mucosal adhesion as the technology for drug permeation enhancement. The nanoemulsion formation expected in this technology could be realized using medium-chain fatty acid triglyceride as the oil component. Moreover, the spontaneous emulsification and the diffusion of the nanoemulsion in mucus proceeded smoothly by using porous particles composed of anionic polymers that have little interaction with mucus components, because mucus is composed of anionic polymer, mucin. It was anticipated that the fine emulsions prepared by this method would enhance drug transport in mucus.

Flowability of wet granules is an important indicator for design and control of manufacturing processes. In this study, we aimed to develop a method to evaluate the flowability with simple equipment and operation. We measured the stirring torque under constant normal stress and the resistance force acting on the plate penetrating into the granules layer. The stirring operation did not properly measure the flowability of strongly cohesive wet granules because voids around the stirring impeller were generated. The penetration operation was able to evaluate the flowability over a wide range of water content conditions by two different indices. Furthermore, the theory of bearing capacity was applied to the penetration tests.