Abstract X-ray diffraction (XRD) has been a useful tool to study minerals, compounds and materials for the past century. Nanosciences discovered new phenomena and properties in matter with nanometric dimensions. Several instruments of solid state analysis (like XRD) were applied to the study of nanometric systems. Our article reviews some studies conducted especially in Latin America where XRD played a key role in the analysis of nanometric materials.

Resumen La difracción de rayos x (DRX) es una herramienta que se ha utilizado durante el último siglo para el estudio de minerales, compuestos y materiales. Las nanociencias descubrieron que, en dimensiones nanométricas, materiales antes conocidos muestran nuevos fenómenos y propiedades. Esto llevó a que se aplicaran técnicas de caracterización en estado sólido tradicionales, como la DRX a sistemas nanométricos. En este trabajo recopilamos casos publicados principalmente en América Latina en los que la DRX ayudó a resolver problemas en la escala nano.

Crystals of Mg/Al layered double hydroxide were synthesized by alkaline precipitation and treated in an aqueous solution of glutamic acid. The glutamate ions were not intercalated into the interlayer space, but were detected in the material by Fourier transform infrared spectroscopy, suggesting that only the external surfaces of crystals were modified with glutamate ions. The resulting hybrid material was tested as a support for immobilization of the enzyme laccase (Myceliophthora thermophila). The immobilized enzyme preparation was characterized by electronic paramagnetic resonance spectroscopy and by assays of catalytic activity. The activity of the immobilized laccase was 97% of the activity in the free enzyme. Layered double hydroxide is a suitable support for use in remediation of soil studies.