Development of New Thio-Functionalized Resins for the Study of Confinement of High Solubility Nanoparticles: An Alternative to Reduce the Future Ecological Impact

The rapid advance of nanotechnology has led to the proliferation of a wide range of water-soluble nanomaterials and therefore, a profound impact on the environment, underscoring the need to devise effective methods for isolating and confining these nanomaterials. This study presents the development of a highly effective system capable of removing and storing gold nanoparticles in solution using modified resins with different linking groups, such as tris(2-aminoethyl) amine, 3-mercaptopropionic acid, 11-mercaptoundecanoic acid, and L-cysteine. The catalytic properties of the resins functionalized with the thiol group containing gold nanoparticles were evaluated, using the reduction of the nitro compounds (3,5-dinitrosalicylic acid, 4-nitroguaiacol and 4-nitroaniline) as model reaction. Solid-phase organic synthesis was employed to prepare the modified resins and their interaction with gold nanoparticles was characterized using infrared spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy-energy dispersive spectroscopy, and X-ray photoelectron spectroscopy. The removal capacity of the resins was evaluated using ultraviolet-visible optical emission spectroscopy and inductively coupled plasma techniques. Ultraviolet-visible technique was suitable to assess the catalytic properties of the functionalized resins containing gold nanoparticles. It was determined that the functionalized resins showed remarkable capacity for complex gold nanoparticles, removing them from the solution. The most significant removal was with 11-mercaptoundecanoic acid.

Keywords:
solid-phase; resins; remotion of AuNPs; catalysis