Rational design of a dissolution-repolymerization strategy for the accurate quantification of polyvinyl alcohol based nano-/micro-plastics contents.

Synthetic polyvinyl alcohol (PVA) plastic exhibits complex heterogeneity in form and degrees of polymerization, which complicates the accurate quantification of its total contents. Herein, we achieved efficient determination of the total contents of PVA-based micro-/nano-plastics (MNPs) via a novel dissolution-repolymerization strategy. Briefly, PVA MNPs were dynamically dissolved under mild conditions (80°C) via CPBA-assisted hydrogen-bond disruption rather than high-temperature physical melting. Subsequently, the generated chains were repolymerized into size-tunable spherical nanoparticles (denoted as Tb-CPBA@PVA) with superior photoluminescence property through an anti-solvent precipitation method. In this process, CPBA acted as a cosolvent to facilitate PVA dissolution and as an auxiliary ligand to sensitize terbium ions (Tb3+). Detailed characterization confirmed that both the size and emission intensity of repolymerized PVA composite showed a direct correlation with PVA contents. By separately establishing quantitative relationships between spectral intensity, particle size, and PVA contents, a hyperbolic correction strategy was constructed to enable more accurate PVA quantification. This strategy achieved satisfactory detection limits as low as 0.22 mg/mL and 0.085 mg/mL for size analysis and fluorescent probing, respectively. Validated in real environmental samples, this robust approach serves as a reliable tool for PVA content determination. This work pioneers a rapid and accurate quantification strategy for total PVA-based plastic content, highlighting significant potential for plastic environmental safety assessment studies.