Dual chelation-dispersion antiscaling strategy via β-cyclodextrin star polymers with precisely controlled branching and molecular weights

This study presents a green scale inhibitor design paradigm through the precision synthesis of β-cyclodextrin-grafted poly (tert-butyl acrylate) (P t BA) star polymers via atom transfer radical polymerization (ATRP), followed by hydrolysis to yield poly (acrylic acid) (β-CD-PAA). Structural characterization by FTIR 1 H NMR and GPC confirmed well-defined architectures with tunable PAA arm lengths ( Mₙ = 12–58 kDa, Đ = 1.05–1.15). The star topology demonstrated exceptional dual functionality: (1) Scale inhibition – achieving 86.36 % CaCO 3 inhibition at 55 mg/L and 96.87 % CaSO 4 inhibition at 6 mg/L, outperforming linear polyacrylic acid by 15–32 % efficiency; (2) Scale dissolution – maintaining excellent conductivity recovery via colloidal stabilization. Systematic evaluation revealed robust performance across harsh conditions (pH 4–12, 60–90 °C). Multiscale characterizations (i.e., SEM, XRD) unveiled a dual mechanism: multidentate Ca 2+ chelation and 3D steric hindrance that distorted crystal nuclei and promoted metastable vaterite formation. This work establishes star-shaped polysaccharide derivatives as next-generation scale inhibitors, offering a sustainable alternative to phosphorus-based inhibitors while advancing molecular-level understanding of topology-dependent scaling control.