A facile ion imprinted synthesis of selective biosorbent for Cu²⁺ via microfluidic technology

Abstract

BACKGROUND Heavy metal pollution has become one of the most serious environmental problems. Novel approaches are needed for removal of heavy metal from water. Copper, a familiar heavy metal, has attracted much attention for its remarkable toxic domino offect at elevated concentrations. RESULTS A novel ion imprinted approach combined with microfluidic technology was explored. Cu2+ was taken as ionic template and chitosan was used as carrier material. Chemical crosslinking was applied in the formation of imprinted sign. A selective biosorbent of ion‐imprinted microspheres (IIMS) with uniform size, regular shape and high performance for Cu2+ had been prepared. The SEM, FTIR, EDS, XPS were employed to detect their distinct features. IIMS showed much higher adsorption capacity (qm=81.97 mg g−1) than those non‐imprinted chitosan microspheres (CSMS). The adsorption isotherm fitted the Langmuir equation while thermodynamic adsorption results were considered strong proof of an adsorption exothermal process. IIMS exhibited excellent selectivity for Cu2+ when competitive metal ions and Cu2+ co‐existed together, which profited from the specific spaces of Cu2+ template left after crosslinking and desorption. Results confirmed that chemical adsorption was dominant and amino played an important role in adsorption process. CONCLUSION IIMS showed high adsorption capacity and excellent selectivity for Cu2+. Combining microfluidic technology with an ion‐imprinted method proved to be a promising process for preparing selective materials. © 2017 Society of Chemical Industry

Selective heavy metal removal and water purification by microfluidically-generated chitosan microspheres: Characteristics, modeling and application

“…Xu et al [18] prepared monodispersed CS microspheres using in-house built microfluidic chips, which showed an adsorption capacity of 52 mg g -1 , according to the non-holonomic system used to study the Cu uptake process. Zhu et al [21] introduced a multi-step microfluidic synthesis procedure using an imprinted method to obtain CS microspheres, exhibiting enhanced Cu adsorption capacity (81 mg g -1 ), improving the capacity found (42 mg g -1 ) in their previous works using conventionally prepared CS microspheres [22]. Again, the same non-holonomic system could not fully describe the adsorption process.…”

Selective removal of tungstate anions from aqueous solutions by surface anion‐imprinted ceramic membranes

“…After elution of W(VI) template, the imprinted cavities and specific binding sites for W(VI) are formed in the IIP‐PEI/CM (see Scheme ). However, this imprinting behavior does not occur in the process of the preparation of NIP‐PEI/CM …”

“…Recognition cavities are generated in IIPs, complementary to the template ions in shape, size and function . Some IIPs have been prepared, and its performances were investigated . While, IIPs obtained by traditional synthesis methods may lead to deficiencies of slow rebinding kinetics and a residue of the template that arises from the deeply buried binding sites in the polymer matrix .…”

A New Ion-Imprinted Chitosan-Based Membrane with an Azo-Derivative Ligand for the Efficient Removal of Pd(II)

“…Recently, a noteworthy research interest has been addressed to ion imprinting for palladium recognition [ 32 , 33 ]. More generally, various works in the field of metal-imprinted chitosan membranes for the purification of wastewaters have appeared in the literature very recently, proving the appeal towards these innovative and low cost systems [ 34 , 35 , 36 , 37 ].…”