Particle size is a geometric characteristic that is usually assigned to material objects with sizes ranging from nanometers to millimeters. There is a wide variety of real systems that contain particles within this size range. These systems are generally polydisperse, meaning that the particles in a particular sample vary in size. Therefore, in order to adequately characterize such systems, it is not sufficient to simply determine a single particle size. We must instead determine the system’s particle size...
Zeta potential is a parameter characterizing electrochemical equilibrium at interfaces. It depends on the properties of both the surface and the surrounding liquid. It plays an important role in the theory of aggregative stability, also known as DLVO theo
Non-polar liquids such as toluene, hexane, dodecane, etc, are important for many novel products like electronic paper, batteries, and fuel cells. Dispersions prepared on their basis depend on ionic composition, which can be characterized with conductivity
Propagation of a longitudinal stress wave through a visco-elastic media creates dissipation of mechanical energy, similarly to a shear stress wave. The rate of dissipation depends on two parameters: bulk viscosity and longitudinal viscosity. For Newtonian
Electroacoustic effects are result of coupling between acoustic and electric fields. Debye realized 70 years ago that in the presence of longitudinal sound wave, any differences in the effective mass or friction coefficient between anions and cations woul
Acoustic theory for heterogeneous system should yield a relationship between some measured macroscopic acoustic properties, such as sound speed, attenuation, acoustic impedance, angular dependence of the scattered sound, etc., and some microscopic charact
There are several developed applications with results published in the papers presented below. This includes: characterization of electric properties of chromatographic resins for proper control of their interactions with proteins, particle size and evolution of micelles, particle size of cells, electric charges (valency) of proteins, proteins adsorption.
Acoustics can characterize particle size and zeta potential in ceramic slurries with no dilution. There are several paper published on this subject and listed below. There is also possibility to characterize mixtures of different oxides, such as alumina and zirconia, see Chapter 8 in the book by Dukhin and Goetz. This can answer question regarding aggregation between particles of different nature.
There are two papers published on subject of applicability of ultrasound for characterizing CMP slurries, see below. There are also 2 newsletters, # 1 and # 13 on the same subject. Acoustics provides accurate particle size that agrees well with independent data. It can monitor presence of 1% large particles on the background of small nano-particles. Electroacoustics yields very precise value of zeta potential. These measurements can be done with no dilution, which opens possibility for continuous on-line...
Both ultrasound based methods, Acoustics and Electroacoustics, can be used for monitoring effects of the plastisizer on the properties of cement slurry, as proved in the papers listed below. With no dilution. Elimination of dilution is critical for accurate measurement of the cement zeta potential Cement slurry could be affect very strongly by dilution. Zeta potential probe offers zeta potential measurement with precision 0.1 mV.
Applications of Acoustics and Electroacoustics for characterizing mineral dispersions are described in the papers listed below. Titration option of the DTI instruments is suitable for determining optimum dose of surfactant for stabilizing clay and mineral dispersions.
Electroacoustics could be used at the extremely high ionic strength above 1 M, as well as for non-polar liquids with conductivity below 10-10 S/m. This method yields not only zeta potential at these extreme conditions, but also electric surface charge and even size of ions in non-polar liquids.
Propagation of ultrasound through a porous body creates motion of liquid inside of the pores relative to the solid matrix. This, in turn, causes relative motion of ions that are located in the diffuse layer and on the pores surfaces. This shows us as an electric current. This current is similar to the Streaming Current, with the difference that it oscillates in time. It is called Streaming Vibration Current. There have been 3 papers already published reporting experimental observation of this effect. The first...
Acoustics makes possible measurement of Particle size of the emulsion and microemulsion droplets with no dilution, which is critical for these systems. Papers presented below indicate very good agreement between this method and independent data. Combination of Acoustics and Electroacoustics could reveal peculiar mechanisms controlling emulsion stability, such as ion exchange in water-in-oil emulsion.