Already in 2014, between 15 and 51 trillion pieces of microplastics (weighing ~ 93,000 and 236,000 metric tons) are estimated to be present in the world’s oceans. Nanoplastics, while its impact is still unknown, are thought to be more of a risk to environmental and human health since its small size allows them to cross cellular membranes. While both FTIR and Raman spectroscopy are used to identify microplastics, FTIR is generally considered to be an easier and preferred technique for particles greater than about 10 microns in size. For particles smaller than ~10 microns, Raman spectroscopy is used for its higher spatial resolution despite its many weaknesses: background fluorescence signal, low signal, and potential damage to particles from the use of laser excitation. While the presence of nanoplastics is certain, the extent of its concentration is uncertain due to the lack of analytical techniques for nanoplastics. IR PiFM (infrared photo-induced force microscopy) is well suited for analyzing nanoplastics for various reasons: (1) its capability to categorize both size, micro-structure, and chemical identity for particles down to about 5 nm in size; (2) its capability to identify both organic and inorganic nanoparticles; (3) its capability to selectively analyze surface modifications or “see through” the surface layers of biological contaminants to identify underlying nanoparticle; (4) its excellent sensitivity without any concern for fluorescence interference; (5) its non-contact and non-damaging measurement capabilities; and (6) simple sample preparation. In this presentation, we will present the IR PiFM analysis of a sample that consists of four different nanoparticles: PTFE, PMMA, PS, and gold nanoparticles. In addition, examples that display the other capabilities described above will be shared.

Chemical, size, and structure analysis of micro and nanoplastics via IR PiFM

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.