Nanosheet-Biomolecular Hybrid Films Synthesis, Structure, and Controlled Release

Brown University, Providence RI

Investigators

Abstract

Two-dimensional materials are a broad class of atomically thin, sheet-like solids with novel properties. These two-dimensional materials, or “nanosheets”, can be stacked together in various configurations to make macroscopic materials with internal layered structures. Such macroscopic layered materials find use in emerging technologies that include textile barrier layers for personal protective equipment, coatings to stabilize or protect surfaces, drug delivery patches and implantable biomaterials. This project seeks to enhance the functions of these layered materials by incorporating biologically active molecules to make hybrids. A major focus is to measure and predict the rates at which those imbedded biomolecules are released, and become active and functional on the outer surfaces and nearby fluid phases. This controlled release can be used to create long-lifetime antibacterial and antiviral coatings for surfaces, textile layers that release insect repellants, or biomaterials that provide timed delivery of drugs. The research will identify methods for controlling the release rate and thus controlling the active lifetime of these devices by manipulating the methods of synthesis and processing. The research team will also be engaged in activities that motivate and prepare underrepresented groups for studies and careers in engineering and science. The principal investigators will collaborate with societies promoting engineering career choices and advancement for women, Hispanics, and Native Americans and will host a Rhode Island Science Day event featuring tours, demonstrations and hands-on activities for upper elementary and middle school tribal youth in the state to introduce and promote opportunities in science and engineering. This project will create, characterize and apply a new set of hetero-structured layered materials with active biomolecular species intercalated in the van der Waals gaps between stacked two-dimensional nanosheets. These frontier hybrids combine the novel properties of atomically-thin nanosheets with the targeted, chemically specific functions of biomolecules. The project will pursue the hypothesis that molecular release kinetics are governed by internal transport processes involving molecular diffusion through nanochannels. Nanochannel transport phenomena are poorly understood, as are the implications for the timing, location, and direction of molecular release from films or macroscopic layered monoliths. The research plan has three Objectives: (1) to synthesize and characterize a panel of hybrid layered materials; (2) to measure biomolecular release kinetics and elucidate release mechanisms to identify design strategies for control; and (3) to demonstrate multifunctional 2D hybrid devices and characterize their dynamic expression of biochemical surface activity in case studies focused on antibacterial and antiviral function. Scientific outputs from this project will include a suite of new hybrid materials with information on their structures and properties, the first quantitative models for release rate prediction and control, and values of nanochannel diffusion coefficients for a range of molecules obtained by model-based extraction from molecular release rate data. The investigator team will also engage in educational outreach to motivate and prepare students from underrepresented groups for studies and careers in science and engineering. 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.