Novel apparatus for the in situ study of hydrothermal crystallizations using time-resolved neutron diffraction

Abstract
The design and use of a pressure cell for the in situ study of hydrothermal crystallizations using time-resolved neutron diffraction are described. This novel apparatus allows the kinetics and mechanism of the crystallization of complex inorganic solids, such as zeolites and other microporous materials, to be investigated under laboratory conditions. Reactions can be studied over a wide range of temperatures (25–250 °C) under conditions of autogenous pressure (1–22 bar). The use of the cell is demonstrated by a study of the hydrothermal crystallization of the zeolite sodium hydroxosodalite with time-of-flight neutron diffraction data collected using the Polaris diffractometer of the United Kingdom’s pulsed spallation neutron source, ISIS.