TY - JOUR

T1 - Steering radical pathways and molecular pre-organization enables efficient polymerization of polyvinyl alcohol in the ferric chloride-assisted heat/peroxydisulfate system

AU - Wu, Jianying

AU - Dai, Yinhao

AU - Liu, Fuqiang

AU - Gao, Chenyang

AU - Dong, Hongyu

AU - Pozdnyakov, Ivan

AU - Guan, Xiaohong

N1 - This work was supported by the National Natural Science Foundation of China (No. 22436001 and 22025601). The authors thank the Multifunctional Platform for Innovation (004) of East China Normal University for providing SEM analysis.

PY - 2026/12/15

Y1 - 2026/12/15

N2 - The heat-activated peroxydisulfate (PDS) system exhibits significant potential for removing polyvinyl alcohol (PVA) through polymerization in water treatment. However, excessive chain scission severely limits intermolecular crosslinking and oxidant utilization efficiency during the polymerization process. Herein, we demonstrated that introducing ferric chloride (FeCl3) into the heat/PDS system dramatically enhanced PVA polymerization, achieving 22.2- and 11.5-fold improvements in TOC removal and PDS utilization efficiency, respectively. Mechanistic investigations revealed a dual-regulation mechanism involving Fe(III)-induced intermolecular pre-organization of PVA chains and a shift in the dominant radicals from sulfate radicals (SO4•⁻) to chlorine radicals (Cl•). Fe(III)-mediated pre-organization shortened intermolecular distances, creating a favorable conformation for subsequent crosslinking, while Cl• preferentially abstracted hydrogen atoms from PVA rather than cleaving the carbon backbone, thereby suppressing chain scission and promoting polymer growth. As a result, insoluble Fe-coordinated polymeric aggregates with porous, amorphous, and thermally stable characteristics were formed. Furthermore, the system was effective for treating real desizing wastewater containing PVA and exhibited broad applicability to hydroxylated aromatic compounds. Overall, this study provides a feasible strategy for enhancing PVA polymerization in the heat/PDS system by suppressing chain scission and promoting intermolecular crosslinking, offering new insights into improving oxidant utilization and selective polymerization in advanced oxidation processes.

AB - The heat-activated peroxydisulfate (PDS) system exhibits significant potential for removing polyvinyl alcohol (PVA) through polymerization in water treatment. However, excessive chain scission severely limits intermolecular crosslinking and oxidant utilization efficiency during the polymerization process. Herein, we demonstrated that introducing ferric chloride (FeCl3) into the heat/PDS system dramatically enhanced PVA polymerization, achieving 22.2- and 11.5-fold improvements in TOC removal and PDS utilization efficiency, respectively. Mechanistic investigations revealed a dual-regulation mechanism involving Fe(III)-induced intermolecular pre-organization of PVA chains and a shift in the dominant radicals from sulfate radicals (SO4•⁻) to chlorine radicals (Cl•). Fe(III)-mediated pre-organization shortened intermolecular distances, creating a favorable conformation for subsequent crosslinking, while Cl• preferentially abstracted hydrogen atoms from PVA rather than cleaving the carbon backbone, thereby suppressing chain scission and promoting polymer growth. As a result, insoluble Fe-coordinated polymeric aggregates with porous, amorphous, and thermally stable characteristics were formed. Furthermore, the system was effective for treating real desizing wastewater containing PVA and exhibited broad applicability to hydroxylated aromatic compounds. Overall, this study provides a feasible strategy for enhancing PVA polymerization in the heat/PDS system by suppressing chain scission and promoting intermolecular crosslinking, offering new insights into improving oxidant utilization and selective polymerization in advanced oxidation processes.

KW - Chlorine radical

KW - Peroxydisulfate

KW - Polymerization

KW - Polyvinyl alcohol

KW - Thermal activation

UR - https://www.scopus.com/pages/publications/105041285405

UR - https://www.mendeley.com/catalogue/ea361000-002c-3147-83bf-10c02b02f7be/

U2 - 10.1016/j.apcatb.2026.127106

DO - 10.1016/j.apcatb.2026.127106

M3 - Article

VL - 399

JO - Applied Catalysis B: Environmental

JF - Applied Catalysis B: Environmental

SN - 0926-3373

M1 - 127106

ER -