Structure‐Oriented Metal‐Organic Framework Activation via Proximal Oligoalkyl Quaternary Ammonium Grafting Enhances Long‐Chain PFAS Sorption

) for long-chain PFAS and derivatives, outperforming alkylated/quaternized analogs by up to 13.3-fold. Density functional theory (DFT) calculations reveal that electronic redistribution induced by oligoalkyl segments enhances the electrostatic potential at adjacent ammonium centers, enabling chain-length-dependent selectivity with sorption coefficients ranging from 2.3 to 4.9. Our work highlights the critical role of surface chemistry modulation in Zr-MOFs and advances structure-oriented design of high-performance sorbents for long-chain PFAS and derivatives.