John Pettibone (Fed)

Dr. Pettibone’s interests are in reactions occurring on and within particles and uses spectroscopic, spectrometric, light scattering and other developed tools (e.g., assays) to investigate their effects on the chemical and physical changes that occur. His current efforts are focused on developing analytical tools and control materials to support identified measurement needs to detect and quantify secondary micro and nanoplastic (MNP) formation and transformation. The development of new methods, material development, and improved understanding are accomplished through active collaborations involving diverse NIST staff expertise across groups and through collaborations with external partners.

Current areas of research include:

1. Identifying size-dependent spectral fingerprints for pristine and weathered MNP particles. Using a combination of high-resolution optical photothermal infrared (OPTIR) microscopy, traditional IR microscopy, and micro-Raman tools, we focus on elucidating particle-specific spectral features from both dimension change and chemical transformation. The goal for the project is to support the development of standardized methods that can be broadly used by industrial and research institutions for improved identification and quantification of sub 10 μm particles, which represents a persistent analytical challenge limiting assessments of material stability and fate. 
2. Isolation and separation methods of secondary MNPs from complex matrices. Using a diverse set of instrumentation, efforts are targeting the development of methods to determine the particle size distribution and total mass distribution of particles present in different media identified as critical for assessing exposure. PSD uncertainties are evaluated with hyphenated asymmetric flow field-flow fractionation (AF4) coupled to light scattering, optical detectors, and mass detectors along with microscopy, aerosol methods, particle imaging capabilities. These measurement methods are being coupled with efforts in the (Microplastic and Nanoplastic Metrology | NIST) group to improve mass accuracy of MNP in diverse matrices. 

The Nanomaterials Research Group is always searching for motivated, creative researchers to contribute to new research directions, applications of methods to emerging problems, and maximizing the cutting-edge facilities to solve persistent challenges in fields of reaction and interfacial chemistry, material design, and structural metrology. Opportunities can be found on the NRC Research Associateship Program page or by directly contacting Dr. Pettibone.

 Selected Publications

 D Liberda-Matyja et al., Spectroscopically evaluating composition and crystallinity in pristine and UV-exposed PET films using polarization dependent Optical Photothermal Infrared Microscopy, Analytical Chemistry, 2026 (Accepted)

TP Forbes et al., Rapid chemical screening of microplastics and nanoplastics by thermal desorption and pyrolysis mass spectrometry with unsupervised fuzzy clustering, Analytical Chemistry, 2023, 12373. https://pubs.acs.org/doi/10.1021/acs.analchem.3c01897

K Duelge et al., Improved accuracy for calibrated mass distribution measurements of bimetallic nanoparticles, Journal of Aerosol Science, 2022, 106031. https://www.sciencedirect.com/science/article/pii/S0021850222000726

F Zhang, AJ Allen, AC Johnston-Peck, J Liu, JM Pettibone, Transformation of engineered nanomaterials through the prism of silver sulfidation, Nanoscale Advances, 2019, 1, 241-253.

J. M. Pettibone and J. Liu, In Situ Methods for Monitoring Silver Nanoparticle Sulfidation in Simulated Waters. Environ. Sci. Technol., 2016, 50, 11145-11153. http://dx.doi.org/10.1021/acs.est.6b03023

J. Gigault, J. M. Pettibone, C. Schmitt and V. A. Hackley, Rational strategy for characterization of nanoscale particles by asymmetric-flow field flow fractionation: A tutorial. Anal. Chim. Acta, 2014, 809, 9-24. http://dx.doi.org/10.1016/j.aca.2013.11.021

J. M. Pettibone, J. Gigault and V. A. Hackley, Discriminating the States of Matter in Metallic Nanoparticle Transformations: What Are We Missing? ACS Nano, 2013, 7, 2491-2499. http://dx.doi.org/10.1021/nn3058517

J. M. Pettibone and J. W. Hudgens, Gold Cluster Formation with Phosphine Ligands: Etching as a Size-Selective Synthetic Pathway for Small Clusters? ACS Nano, 2011, 5, 2989-3002. http://dx.doi.org/10.1021/nn200053b

NRC postdoctoral fellowship, 2009