Polydopamine-assisted grafting of chitosan on porous poly (L-lactic acid) electrospun membranes for adsorption of heavy metal ions

Int J Biol Macromol. 2021 Jan 15:167:1479-1490. doi: 10.1016/j.ijbiomac.2020.11.101. Epub 2020 Nov 19.

Abstract

In this study, a versatile method for the manufacturing of chitosan-grafted porous poly (L-lactic acid) (P-PLLA) nanofibrous membrane by using polydopamine (PDA) as an intermediate layer has been developed. P-PLLA fibres were electrospun and collected as nano/micro fibrous membranes. Highly porous fibres could serve as a substrate for chitosan to adsorb heavy metal ions. Moreover, PDA was used to modify P-PLLA surface to increase the coating uniformity and stability of chitosan. Due to the very high surface area of P-PLLA membranes and abundant amine groups of both PDA and chitosan, the fabricated membranes were utilized as adsorbent for removal of copper (Cu2+) ions from the wastewater. The adsorption capability of Cu2+ ions was examined with respect to the PDA polymerization times, pH, initial metal ion concentration and time. Finally, the equilibrium adsorption data of chitosan-grafted membranes fitted well with the Langmuir isotherm with the maximum adsorption capacity of 270.27 mg/g.

Keywords: Chitosan; Electrospinning; Grafting; PLLA; Polydopamine.

MeSH terms

  • Adsorption
  • Chitosan / chemistry*
  • Copper / chemistry
  • Hydrogen-Ion Concentration
  • Indoles / chemistry*
  • Ions / chemistry
  • Kinetics
  • Metals, Heavy / chemistry*
  • Microscopy, Electron, Scanning
  • Models, Statistical
  • Nanofibers / chemistry*
  • Nanofibers / ultrastructure
  • Polyesters / chemistry*
  • Polymers / chemistry*
  • Porosity
  • Spectrophotometry
  • Spectroscopy, Fourier Transform Infrared
  • Surface Properties
  • Wastewater / analysis
  • Water Pollutants, Chemical / analysis
  • Water Purification / methods*
  • X-Ray Diffraction

Substances

  • Indoles
  • Ions
  • Metals, Heavy
  • Polyesters
  • Polymers
  • Waste Water
  • Water Pollutants, Chemical
  • polydopamine
  • poly(lactide)
  • Copper
  • Chitosan