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Crystallization in gels: Application to mineralogic, biomineralogic and environmental problems

THURSDAY JANUARY 30 - 4 PM

Lourdes Fernández Díaz
Dept. Crystallography & Mineralogy, Universidad Complutense de Madrid

ABSTRACT: Gels are three-dimensional networks of interconnected porosity filled with a solution. In gel matrices, convection and advection are mostly suppressed and transport of aqueous species takes place by diffusion through the gel porous network, leading to the development of compositional and supersaturation gradients and eventually to the formation of crystals. Due to the compartmentalization of the solution into small cavities together to the specific characteristics of mass transfer through them, nucleation in gels is highly reduced. This low nucleation density has historically promoted the use of gels as platforms for the growth of large crystals of sparingly soluble salts. Since the 90’s of the last century the application of a fundamental approach to the study of the crystallization in gel phenomenon has provided results that shed light on a variety of mineralogical problems, including metastable crystallization, solvent mediated phase transformations and mineral replacement processes, crystallization in solid solution-aqueous solution systems and the sorption of inorganic pollutants by surface precipitation of solid solution crystals, the development of zoning patterns, etc.  More recently, the understanding that biominerals form in gelatinous environments and are composites whose mineral component entraps a gel-like network of fibrils is driving the use of in gels to mimic biomineralization processes. In this talk a detailed summary of these applications is presented.

BIO:  Lourdes Fernández Díaz is based at the Complutense University of Madrid (UCM), where she also graduated in Geology and obtained her doctorate degree. After a postdoctoral position at the Department of Earth Sciences at the University of Cambridge, she joined the Department of Crystallography and Mineralogy of the UCM as lecturer in 1990 and as full professor in 2007. She has also been a member of the Board of Directors of the Spanish Society of Mineralogy (2007-2010), a member of the Management Commission of the Geosciences Institute (2011) and director of the Department of Geomaterials (2011-2013) at UCM. Her research interests span many fields in Earth Science, including the mineralogy, crystallization mechanisms and transformations of calcium carbonate polymorphs, trace metal uptake in such polymorphs as well as mimicking biomineralization processes.

 

Crystallization in gels