Light and X-ray scattering from the early growth stages of zeolite A - Part I

In situ dynamic light scattering and small angle X-ray scattering from clea r homogenous solutions which synthesise zeolite A, is reported for the part icle size range from nano- to micrometres. Clearly defined "particle scatte ring'' was only observed at sizes 80 nm radius of gyration. Between this an d 2 mu m the growth kinetics showed an activation energy of 75 kJ mol(-1) f rom a fresh preparation and 71 kJ mol(-1) from an aged preparation. Scatter ing signatures from the processes in the size range below 80 nm have been r ecorded and observation of the phenomena as a function of temperature has b een used to distinguish some salient features. The early growth processes a re consistent with rather close scattering contrast between the mother liqu or and aluminosilicate zeolite embryos, their subsequent transformation to ca. 8 nm precursor particles and their growth after reaching a size from ab out 80 nm to micrometer size zeolite A crystals.