A study of structural memory effects in synthetic hydrotalcites using environmental SEM

The 'memory' effect in synthetic hydrotalcite was demonstrated using d(001) and d(002) peaks in X-ray diffraction (XRD) patterns. These peaks were present in the hydrotalcite before it was calcined and after it was reformed but not in the thermally activated hydrotalcite. SEM images were taken of the hydrotalcite to show the layering and size of the crystals. Environmental SEM (ESEM) images were taken of the thermally activated hydrotalcite, and then manipulation of temperature and pressure allowed water to condense on the sample. The ESEM images show that the layered structure is reforming following exposure to water.