Research topics

Characterization of nano particle slurries

We have developed a novel characterization method for nano particles slurries. Our developed device can be measured the osmotic pressure of nano particles slurry and evaluate the nano particles dispersion state quantitatively. It is a simple, easy, and cost-effective method. It has already demonstrated that the osmotic pressure of nano particles slurry had a good connection to the nano particles dispersion state. Besides it was shown that the homogeneity of the microstructure of nano composites could be well predicted from the osmotic pressure of nano particles slurry.

Evaluation of particles dispersion state in slurries

The final goal of this research is to predict the product quality only from the slurry characterization and to optimize the slurry preparation condition without trial and error. Normally it is very difficult to evaluate the particles dispersion state for dense slurry, because the particle(aggregate) size cannot be measured by conventional particle size analyzer such as laser diffraction method. Thus, we developed the hydrostatic pressure measurement device called “HYSTAP” and established the novel evaluation technique of particle dispersion state and particle packing ability of slurry. “HYSTAP” has been already on sale and we have measured the hydrostatic pressure of various slurries. Considering its principle, the limit of its application such as materials, solvents, maximum particle concentration etc. does not exist. Currently we are trying to investigate how to evaluate the multi-component slurries such as slurries for Li-ion battery. We are also studying about crack formation during drying of green body, where we are trying to clarify what kind of slurry can derive the crack formation in green body.

Chemical-free floccuation by DC

Recently a novel technique which can make dispersed particles in water flocculate without chemicals is desired on a field of material recycling. Thus, we have developed the chemical-free flocculation technique and device by using DC electric field. The particles in water can be flocculated by applying DC electric field because the electric double layer around the particle can be temporally deformed, resulting in reduce of electrostatic repulsive force between particles. We are trying to develop a continuous flocculation device utilizing the combination of flocculation effect due to DC electric field and boycott effect.

Novel osmotic pump

We have been developing a novel osmotic pump in which the concentrated layer of fine particles generates osmotic pressure and sucks up water from a reservoir. The great difference between our developed osmotic pump and conventional ones is the duration time. Our developed osmotic pump can suck up water much longer time because particles in the concentrated layer have “mass”, which can keep the particles in the concentrated layer against the upward flow created by the sucked water. We are investigating the optimal slurry conditions and device specifications to maximize the flux of sucked water.

Novel characterization method of particles’ wettability

We have developed a novel characterization method and device of particles’ wettability. In our developed device, a particles bed in a closed cell is immersed in liquid, allowing the liquid to penetrate into the particles bed. The internal pressure of the cell increases with liquid penetration, thus, wettability (contact angle) can be determined by the analysis of the pressure change. For this method, the particles amount needed can be minimized, less than 1.0 cc. Besides this is the only device which can determine not only contact angle (equilibrium value) but also advance contact angle in a short time.