Researchers Develop Thermoresponsive Graft Polymer for Nanoparticle and Dye Removal

Strategic Insights -

A recent study by researchers from the Vietnam Academy of Science and Technology has led to the development of a thermoresponsive graft polymer for removing metal oxide nanoparticles and anionic dyes from wastewater. The research demonstrated the effectiveness of the polymer in removing up to 95% of iron concentrations and 84% of methyl orange from wastewater, while also showing potential for the removal of other contaminants.

Key Takeaways:

  • The researchers prepared a thermoresponsive graft polymer, Chitosan-poly(N-isopropylacrylamide) (CS-PNIPAM), using mercaptoacetic acid (MAA) and chitosan (CS) for the removal of metal oxide nanoparticles and organic dyes.
  • The CS-PNIPAM graft polymer with 10% chitosan showed a lower critical solution temperature (LCST) of 38.3 oC and a grafting yield of 88.5%, making it an ideal candidate for further studies.
  • The zeta potential of the polymers changed from nearly 5 mV for PNIPAM to -23 mV for PNI-COOH and 51 mV for CS-PNIPAM, indicating the potential of CS-PNIPAM for flocculation.
  • The flocculation experiments showed high removal efficacy for all three metal oxide particles, with a quantitative measurement of iron concentration presenting a removal percentage of about 95% after 30 min of exposure at 50 oC.
  • The flocculation efficiency was pH-dependent, with significant lower efficiency at pH 9, indicating the presence of chitosan in the polymer structure.
  • The organic dye flocculation showed that CS-PNIPAM graft polymer is effective on methyl orange (MO, 84% removal) but not methylene blue (MB, 20% removal), due to the highly positive charge of the polymer.

Statistics:

  • 95% removal of iron concentration after 30 min of exposure at 50 oC.
  • 84% removal of methyl orange (MO) from wastewater.
  • 20% removal of methylene blue (MB) from wastewater.

Sources:

  • NewsRx. Investigators at Vietnam Academy of Science and Technology Report Findings in Nanoparticles [Flocculation of Metal Oxide Nanoparticles and Anionic Dyes Using Chitosan - Poly (N-isopropylacrylamide) Graft Polymer]. News of Science. August 3, 2025; p 1445.
  • Journal of Polymer Research, 2025;32(7). Journal of Polymer Research can be contacted at: Springer, Van Godewijckstraat 30, 3311 Gz Dordrecht, Netherlands. (Springer - www.springer.com; Journal of Polymer Research - www.springerlink.com/content/1022-9760/)