ASTM D8300-19

3.1 The electrical conductivity of silica is related to both the adsorbed water and the hydroxyl groups on the surface of the precipitated, hydrated silica. Since the electrical conductivity of distilled or de-ionized water is very low, high electrical conductivity values are associated with ionic sources due to impurities.

3.2 A specific quantity of the silica sample is boiled in distilled or deionized water. After cooling to room temperature, the suspension is diluted to 4 % mass per volume (m/V) and its temperature is adjusted to 20°C with a thermostat. The electrical conductivity is measured using a conductivity meter and a conductivity cell.

1.1 This test method is used to determine the electrical conductivity of silica and the electrical conductivity is suitable for characterizing rubber-grade silicas.

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, health, and environmental 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.