A research group in the Department of Chemical Engineering at Pennsylvania State University uses a Brookhaven ZetaPALS instrument to characterize the zeta potential of titania particles in very low pH environments. Themis Matsoukas, Associate Professor in the department, explained: “We work with titania nanoparticles at pH between 0.5 and 2. These particles are formed in highly aggregated form and the acid helps to disperse them.”
The studies are aimed at better understanding types of ceramic membrane with controlled porosity, specific permeability and catalytic activity. These have important applications in food and beverage processing, waste treatment and biotechnology, but their synthesis is poorly understood and difficult to control. Titania is of special interest as a membrane material, due to its excellent dielectric properties and interesting catalytic and photocatalytic behaviour.
“At the very low pH e.g. 0.5 at which we work, the conductivity of the solution is very high and can be up to 2500 mS/m,” Professor Matsoukas continued. “It was important for us to be able to make measurements under such conditions.” After looking at a range of competitive instruments, he and his group decided that the Brookhaven ZetaPALS was the one best suited to their needs. It can measure zeta potential in solutions of conductivity of up to 7000 mS/m, and in a wide range of pH levels.
The ZetaPALS works using a technique called Phase Analysis Light Scattering. The technique is 1,000 times more sensitive than the traditional light scattering methods used by other manufacturers and is unique to Brookhaven Instruments.
When setting up the ZetaPALS, Brookhaven representatives visited Professor Matsoukas at his lab on many occasions to offer help and advice. “I have been very happy with the support from Brookhaven,” he concluded. Preliminary results from the group’s studies have been published in the March 2000 issue of KONA.