New insights into the effects of isomeric chlorine substitution on microstructures and enrichment capacities of functionalized polystyrene nanospheres

The substitution position of functional group is potential to affect the microstructure and adsorption performance of functionalized polystyrene (PS) nanospheres, yet to be explored. In this study, a series of hyper-crosslinked PS nanospheres with isomeric chlorine substitution have been prepared by emulsion polymerization and Friedel-Crafts reaction. The detailed characterizations indicated that the substitution position of chlorine greatly influenced the pore volume and specific surface area of constructed PS nanospheres, and the hyper-crosslinked ortho-Cl-functionalized nanospheres (o-xClFNs) possessed the highest specific surface area and largest pore volume, followed by para- and meta-Cl-functionalized nanospheres (p-xClFNs and m-xClFNs). Besides, these PS nanospheres were fabricated as even solid phase microextraction (SPME) coatings to study their extraction performance for substituted benzenes, chlorobenzenes, polychlorinated biphenyls (PCBs) and polybrominated biphenyls (PBBs). The experimental results showed that the p-xClFNs possessed the most outstanding extraction efficiencies for halogenated organic pollutants, and it was combined with gas chromatography-mass spectrometry (GC–MS) to develop a highly sensitive method, realizing the precise quantifications of trace PCBs and PBBs in environmental water. Our work provided invaluable insights on the choice of functional monomer to construct high-performance adsorbent, also demonstrated the important function of PS on the enrichments of organic pollutants.