NER: Nanophase Calcite

University Of North Carolina At Chapel Hill, Chapel Hill NC

Investigators

Abstract

This proposal was received in response to Nanoscale Science and Engineering initiative, NSF 04-043, category NER. The objective of this NER research is to develop biomimetic materials synthesis strategies to produce nanophase calcite structures. In particular, calcite nanorods and nanotubes will be synthesized and their structural, mechanical, and optical properties evaluated. The approach is to use a combination of spatial confinement and chemical templating techniques to synthesize calcite nanorods and nanotubes. These two strategies combine molecular scale structural control with nanometer/micron scale morphological control. Polycarbonate track-etched (PCTE) templates consisting of nanometer scale pores will be used to nucleate and grow calcite nanorods. Nanorods of differing size and crystal structure will be synthesized through tuning of the pore diameter and surface treatment of the template. Overall nanorod morphology and crystal structure will be analyzed with combined AFM/SEM, TEM, and optical microscopy (fluorescence). Nanotubes and nanorods will also be used as cylindrical templates for growth of calcite nanotubes. If successful, the projects outlined here will bridge a gap between the recent advancements in understanding biomineralization processes at the molecular scale, and nanometer scale materials synthesis. From a materials science perspective, biominerals are advanced composite materials. Their complex structures are amazingly well designed for optimal mechanical performance as well as optical and magnetic functions. This work will lend insight into multi-scalar biomineralization processes as well as suggest new avenues for materials synthesis. The particular potential of nanophase calcite materials lies in areas as diverse as tissue engineering, non-linear optics, and labeling for advanced biological imaging. This project will also inform the scientific content of several ongoing outreach and educational activities that the PI is engaged in. These include a nanoscience First Year Seminar Course as well as science education research on middle, high school and undergraduate concepts of scale and scaling.