Enhancing the fixation performance of cerium oxide (simulated uranium) aerosol by acrylic acid graft modified polyvinyl alcohol

Addressing the issue of uranium radioactive aerosol sedimentation during a nuclear emergency is critically important. In this study, polyvinyl alcohol (PVA) was used as the base material, and acrylic acid (AA) monomers were introduced through chemical grafting modification. Graft copolymers (PVA-g-PAA) were synthesized via solution polymerization with PVA to AA mass ratios of 1∶0, 1∶0.25, 1∶0.5, 1∶0.75, and 1∶1. The structure of the grafted polymers was characterized using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, X-ray photoelectron spectroscopy, and X-ray diffraction, confirming the successful grafting of AA onto the PVA chains. Scanning electron microscopy (SEM) revealed changes in the microscopic morphology. The grafted polymers were evaluated for thermal properties, grafting efficiency, contact angle, surface tension, and viscosity. Sedimentation fixation experiments were then performed to assess the aerosol capture and fixation performance of the polymers on cerium oxide aerosols, which serve as a uranium aerosol simulant. SEM images of freeze-dried samples showed that the grafted polymer formed a denser and more porous network structure. The grafted polymer also exhibited enhanced thermal stability. At a PVA/AA ratio of 1∶0.75, the grafting rate reached 18.3%. After grafting AA, the polymer solution's surface tension decreased by 2.84 mN/m, the contact angle dropped by 28.73°, and viscosity increased by 20.7 mPa·s. Additionally, after film formation, the elongation at break improved by 224.91%. Sedimentation fixation tests demonstrated that the PVA-g-PAA graft polymer effectively captured and fixed cerium oxide aerosols, achieving a sedimentation fixation rate of 84.68% within 35 min. The study also clarifies the mechanism behind aerosol fixation, offering technical support for the sedimentation fixation of uranium radioactive aerosols.