Excellence in Research: Synthesis and Evaluation of Amino Acid-Appended Macromolecules Designed Towards Enhanced Water Purification via Lead Chelation

The use of lead in construction and industrial processes has contributed to widespread heavy metal contamination of water sources and increased occurrences of biological lead intoxication, which is detrimental to human health and development. Conventional remediation approaches include the use of adsorbents such as activated charcoal; however, the long-term effectiveness remains unknown.

To address this public health risk, this project will synthesize innovative, efficient, and biocompatible macromolecules that effectively encapsulate the heavy metal and purify lead-contaminated water upon extraction from aqueous environments. The investigator's long-term goal is to build a viable and competitive polymer research program at Prairie View A&M University.

Through this program, graduate and undergraduate students will learn how to conduct application- and hypothesis-driven investigations in the polymer chemistry field. The following objectives will be pursued to satisfy the overall goals of the project: (1) understand how polymer architecture and branching impact metal chelating affinity; (2) explore how solubility parameters affect the chelation efficiency of the nanomaterials; and 3) engage undergraduate and graduate students in high-impact and intensive polymer chemistry research environments.

Collaborators at Texas A&M University, Tulane University, and the State University of New York at Stony Brook will aid in specialized characterization of the nanomaterials, extending the potential for transformative impact.

The overarching goal of this project is to investigate the effectiveness of amino acid-functionalized macromolecules towards sequestering lead ions to promote water purification. Biocompatible, polymeric materials with both linear and branched architectures will be generated with adequate functionality to comprehensively probe the structure-property relationship underlying metal-chelating activity.

To enable sufficient complexation of lead ions, hyperbranched and dendrimeric polyesters and linear polycarbonates will be outfitted with n-acetylcysteine via thiol-yne click addition to generate numerous vicinal thioether binding pockets covering the polymer surface or backbone. Novel insights into binding capability will be obtained, and vicinal thioethers and water-soluble polymers will be produced.

The efficacy of the materials will provide data that can inform future efforts to prevent and treat lead contamination.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.