SOME RESEARCH OPPORTUNITIES AND CHALLENGES

The geoscience community has been working on nanoparticulate materials for many decades and has made remarkable progress towards understanding the bulk structures of finely crystalline silicate clays and oxyhydroxide, oxide, and hydroxide minerals. More recently, the application of spectroscopic methods has revealed a great deal about 

Synthesis of materials suitable for qantification of size-related phenomena. In 

Characterization of naturally occurring and synthetic nanoparticles in order to determine the variation in bulk and surface structure and properties with particle size. 

Self-organization of nanoparticles. Study of the ordering of small crystals to form 

Clusters in the environment and early crystal growth. Molecules with sizes that are intermediate between aqueous ions (few and nanoparticles ( -13-15 are probably abundant and important in many natural environments. However, they are relatively unstudied because of the challenges associated with their characterization. Recent work by Purer (1993), Luther (1999) and others (see Casey et al. this volume) amplifies suggestions made in earlier studies that large clusters may account for much of what is measured as dissolved ions in certain environments. 

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