What is ISO 21822 - Iso-electric point of ceramic powder about?
ISO 21822 is an international standard on fine ceramics that covers the measurement of the iso-electric point of ceramic powder.
ISO 21822 specifies the test method to determine the iso-electric point of fine ceramic powders, which is measured in the state of suspension.
Who is ISO 21822 - Iso-electric point of ceramic powder for?
ISO 21822 on the iso-electric point of ceramic powder is useful for:
- Fine ceramics manufacturers
Why should you use ISO 21822 - Iso-electric point of ceramic powder?
The isoelectric point (IEP) is a key material property for the aqueous-based processing of advanced ceramic powders. The isoelectric point characterizes the acid-base behavior of the powder surface, which in turn influences powder dispersion and chemical interactions at the powder surfaces.
According to general colloid chemistry principles, an electrostatically stabilized dispersion system typically loses stability when the magnitude of the zeta potential decreases. As a result, there will be some region surrounding the condition of zero potential (i.e. the iso-electric point) for which the system is not particularly stable. Within this unstable region, the particles may agglomerate, thereby increasing the particle size. Determining the pH conditions where the zeta potential becomes zero (the iso-electric point) is, therefore, important for zeta potential analysers.
ISO 21822 walks us through the test method for the determination of the iso-electric point of fine ceramic powders which is measured in the state of suspension. International standards for IEP determination are generally lacking, ISO 21822 overcomes this by providing a comprehensive overview of the determination of isoelectric point.