New Research in PNAS from Prof. Henry He's Team Introduces PFAS-defined liquid crystal monomers (PFAS-LCMs)
Exciting new research in PNAS from Prof. Yuhe (Henry) He's team at SKLMEH introduces PFAS-defined liquid crystal monomers (PFAS-LCMs) — an overlooked class of organofluorine contaminants at the intersection of two research fields!
What are PFAS-LCMs? Liquid crystal monomers (LCMs) that contain an OECD-qualifying fully fluorinated methyl or methylene carbon are, by definition, also PFAS. Yet they have largely fallen between the cracks—studied in LCM frameworks (e.g., molecular structure design, environmental persistency, bioaccumulation, and toxicity) without recognizing their PFAS identity, and missed by PFAS-targeted screening.
Why does this matter? Structure-based screening of two inventories identified 228 nonredundant PFAS-LCM structures. These compounds have been detected in marine mammals (including brain tissues of Chinese White Dolphins and Finless porpoises), household dust globally, and e-waste worker serum—with evidence of placental transfer and biological effects.
A critical gap: While legacy PFAS burdens are declining thanks to regulatory phase-outs (as shown by Sun et al.), PFAS-LCMs may follow distinct source profiles and temporal trends tied to electronics production and disposal. Their omission from both LCM- and PFAS-focused monitoring leaves part of the organofluorine chemical space unresolved.
The call to action: We need structure-resolved environmental monitoring, EOF mass-balance analysis, and studies on transformation, bioaccumulation, and toxicity. PFAS-LCMs should serve as an entry point for systematic investigation of the wider LCM chemical space across the electronics lifecycle.
All authors are from our SKLMEH. Prof. Yuhe (Henry) He (SEE, CityUHK) is the corresponding author of the paper. Ms. Xu Li and Ms. Huixian Li are Prof. He's PhD students. Prof. Qi Wang (SES, EdUHK), Prof. Xuneng Tong (SEE, CityUHK), and Prof. Kenneth Leung (Chem, CityUHK) are co-authors of this paper.
Read the full letter: www.pnas.org/doi/10.1073/pnas.2625255123