Abstract:
Introduction:
Environmental pollution, especially of water resources with heavy metal ions, is of great concern. The removal of heavy metal ions from wastewater remains a challenge for scientific research. Polymer-based microsphere adsorbents are promising due to their design flexibility and chemical tunability, but classical synthesis methods often lack control over the morphology, porosity and wettability. In the current work, we introduce a new method for facile synthesis of polymer microspheres, namely Pickering emulsion polymerization technology (PemPTech) and utilize them as adsorbents for Cu(II) ion extraction and recovery from water.
Methods:
Polymer microspheres were synthesized by polymerization of w/o Pickering emulsions stabilized by surface functionalized silica nanoparticles with thiol groups. The water phase comprised of water and water soluble monomers, such as vinyl imidazole and methacrylic acid with varying amounts of ligands, crosslinkers or porogens. A homologous series of microspheres were prepared by systematically varying these components. Structural and morphological characterization was performed using FTIR and SEM, and the adsorption and desorption capacities of Cu(II) were evaluated via UV–vis spectrophotometry.
Results:
In this work, we highlight the versatility of the PemPTech. For example, by adjusting the chemical composition in terms of the relative ratio of the ligands, vinyl imidazole to methacrylic acid, we were able to fine tune the adsorption capacity of the adsorbent. The adsorbtion capacities were comparable or exceeding those of similar adsorbents obtained via alternative methods. Kinetic adsorbtion studies were performed, and isotherm profile were established for each adsorbent, indicating a good performance. The adsorbents were also tested for other divalent heavy metal ions.
Conclusions:
PEmPTech enables precise compositional and morphological tuning of polymer microspheres, offering a green and scalable route to high-performance adsorbents. This study provides critical insight into the design parameters governing metal ion uptake, laying the groundwork for applications in water purification and environmental remediation.
