Highly regenerable alkali-resistant magnetic nanoparticles inspired by mussels for rapid selective dye removal offer high-efficiency environmental remediation

Abstract

Most recently, polydopamine (PDA) and its hybrid nanomaterials have been developed as promising adsorbents to remove organic dyes. However, PDA based adsorbents are typically lack of recyclability, alkali resistant and selective adsorption. Herein, novel PDA based magnetic nanoparticles are fabricated for the first time via the simultaneous incorporation of PDA and poly(ethylenimine) (PEI) on Fe3O4 nanoparticles simply in one step to overcome almost all disadvantages of "traditional" PDA adsorbents. The constructed PDA based magnetic nanoparticles have ultrathin shell layer (only about 3 nm, much thinner than that of other PDA adsorbents), and can withstand strong alkaline solutions (0.1 M NaOH, pH=13), exhibiting excellent alkali resistance. Remarkably, the nanoparticles show superior performance in smart and fast selective removal (>95%, just in five minutes) of anionic dyes from dye mixtures and can maintain their high efficiency (>90%) even after 10 cycles, indicating the unprecedented selective adsorption capacity and desirable recyclability. The adsorption process follows pseudo-second order reaction kinetics, as well as Langmuir isotherm, indicating that anionic dyes are monolayer adsorbed on the hybrid by electrostatic interaction. In particular, the readily regeneration of the novel composite nanoparticles can be accomplished only within several minutes, demonstrating excellent regeneration ability. Our work can provide new insights into utilizing mussel-inspired materials for environmental remediation and creating advanced magnetic materials for various promising applications.

CuSO4/H2O2‐Induced Rapid Deposition of Polydopamine Coatings with High Uniformity and Enhanced Stability

“…One issue is the low formation rate of PDAcoatings,which generally requires atime range of ten hours up to af ew days. [14] In these cases,p ost-functionalization and applications are limited for PDAc oatings and their coated materials.T herefore,i ts till remains at remendous challenge to develop facile strategies for the rapid construction of PDAc oatings with high uniformity and improved stability. [12] Thedeposition rate of PDAcan be improved to some extent by these methods.H owever,t ypical PDAc oatings are uneven, and there are large PDAa ggregates on the coated materials,which influence or even obstruct their applications in smooth surfaces.…”

Preparation of silver nanoparticle functionalized polyamide fibers with antimicrobial activity and electrical conductivity

“…The absorption band at 2901 cm −1 belonged to the antisymmetric and symmetric stretching vibrations of CH 2 in PDA . Additionally, it has revealed that PDA was unstable in alkaline condition . To further confirm the successful deposition of PDA on PA6 fibers, PA6/PDA fibers were washed with alkaline eluent (pH = 13) for 2 h at room temperature.…”

“…It was demonstrated that PDA coatings are unstable in some media, such as acidic or alkaline aqueous solutions and polar organic solvents, which to some degree limits further functionalization or applications of PDA‐modified materials. Considering the solution environment in the subsequent silver plating procedure, the chemical stability of PDA coatings in three different solvents including deionized water, ethanol and alkaline solution (pH = 13) was investigated, and the results were compared for the rapid modification method using DA/CuSO 4 /H 2 O 2 for 30 min and the traditional modification method using DA for 24 h. Figure shows the relationship between UV/Vis absorbance at 420 nm, which is the characteristic peak of PDA, with washing time for different solvents.…”

Self‐assembly of alginate/polyethyleneimine multilayer onto magnetic microspheres as an effective adsorbent for removal of anionic dyes

“…As the magnetic cores encapsulated in the PEI‐modified magnetic adsorbents reported by the references were usually prepared by co‐precipitation and susceptible to acid corrosion, the saturation magnetization values of these magnetic adsorbents might be reduced greatly under acidic conditions, which led to difficulty in magnetic separation. Therefore, the magnetic cores (MN magnetic microspheres) used in this study was obtained by a solvothermal reduction process, which had much larger particle sizes and saturation magnetization values than that of Fe 3 O 4 nanoparticles prepared by co‐precipitation, and showed better tolerance to low pH value.…”