WK91814 - New Guide for for Measuring the Stability of Concentrated Colloidal Dispersions of Nanoparticles Under Gravity Sedimentation Using Static Multiple Light Scattering (SMLS) | ASTM
Work Item
ASTM WK91814
New Guide for for Measuring the Stability of Concentrated Colloidal Dispersions of Nanoparticles Under Gravity Sedimentation Using Static Multiple Light Scattering (SMLS)
1. Scope
1.1 Concentrated colloidal dispersions/emulsions/formulations, such as vaccines and flavor emulsions for beverages, to name only two, must remain stable, well-dispersed, from the time they're prepared until they’re put to use for their particular application. Static Multiple Light Scattering (SMLS) technology can be used to measure the sedimentation or creamimg rates of particles, droplets, or bubbles, and their particle size distribution from 10 to 1,000 nanometres in these highly concentrated dispersions. This technology can very rapidly measure these rates, in minutes, rather than the hours or days it could take by visual observation. The detailed procedure for making these measurements is given in Section 5. along with the formulae and parameters.
1.2 Units - The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of international Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Keywords
stability,; stability, dispersion,
Rationale
Colloidal dispersions, emulsions, formulations are used throughout many industries as such ingredients as vaccines and flavorings in drinks, to name only two. These dispersions must remain stable and not separate from the liquid they’re dispersed in by flocculation, which would render them ineffective and possibly dangerous. An automated technology, Static Multiple Light Scattering, can be used to measure the rate of settling or creaming from agglomeration, which is much faster than simply observation over long periods of time. This technology can also calculate and report the size distribution of the suspended particles. It can also measure much higher concentrations of particles than Dynamic Light Scattering and Laser Diffraction are capable of. There currently are no ASTM standards for this technology. This guide is proposed to fill that void.
