Preparation of a thermosensitive surface imprinted polymer based on palygorskite for removal of copper (II) from environment aqueous solution

ABSTRACT

In this study, a new thermosensitive surface imprinted polymer based on palygorskite was successfully synthesised by a surface imprinting technique and used as an intelligent selective recognition adsorbent for the adsorption of Cu(II) ions from aqueous solution. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) measurements results demonstrated that Cu(II)-imprinted polymer was successfully synthesised. The separation and preconcentration characteristics of Cu(II)-imprinted polymer for Cu(II) were researched by batch and column procedures. optimal intelligent recognition temperature for adsorption is 35°C and intelligent identification and elution of Cu(II) can be achieved by adjusting the temperature. The maximum static adsorption capacity of the ion-imprinted and non-imprinted sorbents for Cu(II) was 35.55 and 9.78 mg g⁻¹, respectively. The relative selectivity factor values (a_r) of Cu(II)/Zn(II), Cu(II)/Ni(II), Cu(II)/Co(II) and Cu(II)/Pb(II) were 111.48, 85.37, 98.31 and 73.85 respectively, which were all greater than 1. The Cu(II)-imprinted polymer offered fast kinetics for the adsorption and desorption of Cu(II). Under the optimised conditions (pH-5, temperature-35°C, shaking time-15 min), a detection limit of 0.21 μg L⁻¹ with a relative standard deviation (RSD) of 2.5% for Cu(II) was obtained. Based on Cu(II)-imprinted polymer packed columns, a highly selective pre-concentration method for Cu(II) was established. The accuracy of the method has been certified using national reference materials (GBW 08301). This method has also been successfully used for the determination of Cu (II) in locally collected water samples.

KEYWORDS:

• Surface imprinted
• palygorskite
• thermosensitive
• solid-phase extraction
• Cu(II)

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Northwest Minzu University’s Double First-class and Characteristic Development Guide Special Funds-Chemistry Key Disciplines in Gansu Province [No. 11080316], The Fundamental Research Funds for the Central Universities, Northwest Minzu University [No.31920200002], The National Natural Science Foundation of China [No. 21968032], The innovative team building project of Northwest Minzu University [Nos. 1110130139 and 1110130141] and The Natural Science Foundation of Gansu Province [Nos. 20JR10RA127 and 18JR3RA374].