Surface Ion Imprinting Research Articles

Surface ion imprinting-mediated carbon nanofiber-grafted highly porous polymeric beads: Synthesis and application towards selective removal of aqueous Pb(II)

Novel Pb(II) ion-imprinted and carbon nanofibers (CNFs)-grafted highly porous (∼475m2/g) polymeric beads (∼0.5mm) were prepared by the surface ion imprinting technique. The allylthiourea precursor-based polymeric beads were synthesized by suspension polymerization, in which CNFs were in-situ mixed during the polymerization reaction before the curing step. The prepared ion-imprinted and CNF-grafted polymeric (CNF-IIP) beads were used for the efficient and selective removal of Pb(II) ions from aqueous solution by adsorption. The adsorption capacity of the CNF-IIPs for Pb(II) ions was determined to be ∼47mg/g. The material exhibited high selectivity for Pb(II) in the presence of the Ni(II), Zn(II) and Cd(II) competitive ions, with the selectivity coefficients for the Pb(II)/Ni(II), Pb(II)/Zn(II) and Pb(II)/Cd(II) in binary systems determined to be ∼48, 28 and 14, respectively. The synthesized CNF-IIP adsorbents were easily regenerated by acid treatment and used in five adsorption/regeneration cycles. The method described in this study can be applied for the development of the similar CNF-IIPs for the selective removal of various toxic metal ions present in industrial effluents.

Preparation of hybrid organic-inorganic mesoporous silicas applied to mercury removal from aqueous media: Influence of the synthesis route on adsorption capacity and efficiency

New hybrid organic-inorganic mesoporous silicas were prepared by employing three different synthesis routes and mercury adsorption studies were done in aqueous media using the batch technique. The organic ligands employed for the functionalization were derivatives of 2-mercaptopyrimidine or 2-mercaptothiazoline, and the synthesis pathways used were post-synthesis, post-synthesis with surface ion-imprinting and co-condensation with ion-imprinting. The incorporation of functional groups and the presence of ordered mesopores in the organosilicas was confirmed by XRD, TEM and SEM, nitrogen adsorption-desorption isotherms, 13C MAS-NMR, 29Si MAS-NMR, elemental and thermogravimetric analysis. The highest adsorption capacity and selectivity observed was for the material functionalized with 2-mercaptothiazoline ligand by means the co-condensation with ion-imprinting route (1.03mmolg−1 at pH 6). The prepared material could be potential sorbent for the extraction of this heavy metal from environmental and drinking waters.

Synthesis, adsorption kinetics and thermodynamics of ureido-functionalized Pb(ii) surface imprinted polymers for selective removal of Pb(ii) in wastewater

A surface ion imprinting technique was utilized to synthesize a novel ureido-functionalized Pb(ii)-imprinted polymer where the Pb(ii) ion, γ-ureidopropyltrimethoxysilane, AIBN and EGDMA were used as the template ion, functional monomer, initiator and cross-linking agent. ​

Preparation and properties of ion-imprinted hollow particles for the selective adsorption of silver ions.

Four kinds of silver ion-imprinted particles (Ag-IIPs) with different morphologies were prepared by the surface ion-imprinting technology (SIIT) and were used for the selective removal and concentration of silver ions from wastewater. The favorable adsorptivity and selectivity of Ag-IIPs for Ag(+) were confirmed by a series of adsorption experiments at a suitable pH value. The adsorption mechanism was elucidated by analyzing the adsorption isotherms, adsorption thermodynamics, and adsorption kinetics systematically. The Ag(+) adsorption onto the Ag-IIPs was well-described by the Langmuir isotherm model, and it was likely to be a monolayer chemical adsorption. This conclusion was also confirmed by the thermodynamic parameters. Moreover, the adsorption kinetics indicated that the adsorption rate would be controlled jointly by the intraparticle diffusion and the inner surface adsorption process, and the latter process was generally associated with the formation and breaking of chemical bonds. Finally, the effects of different morphologies of the Ag-IIPs for Ag(+) adsorption were also investigated. In aqueous solution, the adsorptivity of the Ag(+) ion-imprinting single-hole hollow particles (Ag-IISHPs) for Ag(+) was highest (80.5 mg g(-1)) because of a specific morphology that features a single hole in the shell. In an oil-water mixture, Ag(+) in the water phase could be adsorbed efficiently by the Ag(+) ion-imprinting Janus hollow particles (Ag-IIJHPs), with emulsifiability originating from the Janus structure.

Magnetic Pb(II) Ion-Imprinted Polymer Prepared by Surface Imprinting Technique and its Adsorption Properties

A novel magnetic Pb(II) ion-imprinted polymer was prepared via surface ion-imprinting technique by using magnetic Fe3O4@SiO2 microspheres as supporter, Pb(II) as template ion, methacrylic acid and salicylaldoxime as monomers, and ethylene glycol dimethacrylate as crosslinker. The product was characterized by FT-IR, VSM, XRD, and SEM. The adsorption experiments showed that the imprinted polymer was employed successfully in comparison with non-imprinted polymer. When the temperature was in a range of 277 K to 291 K the maximum adsorption was about 81.83 mg/g with an optimal pH 6.0. Its relative selectivity coefficient values of Pb(II)/Cu(II), Pb(II)/Zn(II), and Pb(II)/Cd(II) were 2.60, 6.38, and 7.89 times greater than the ones of the magnetic non-imprinted polymer. The Langmuir adsorption model was more favorable for M-IIP than Freundlich or Temkin adsorption models. The Scatchard analysis suggested that M-IIP was processed with two kinds of binding sites with different affinity. Thermodynamic experiment showed that the adsorption was a spontaneous and endothermic process for Pb(II). The mechanism for Pb(II) adsorption on the imprinted polymer was also investigated.

A novel lead ion‐imprinted chelating nanofiber: Preparation, characterization, and performance evaluation

ABSTRACTA novel Pb(II) ion‐imprinted chelating nanofibers (nIIP), synthesized by combining electrospinning with surface ion imprinting technique, was reported in this study. nIIP was characterized with Fourier transmission infrared spectrometry and scanning electron microscopy, respectively. The performance of nIIP for Pb(II) sorption was conducted through a batch adsorption experiments. Experimental data showed that adsorption capacity of nIIP was much higher than that of non‐ion imprinted chelating acrylic microfibers (mNIP) derived from commercial available acrylic microfibers, and adsorption behaviors agreed well with pseudo‐second‐order kinetic and Langmuir isotherm model. The values of Gibbs free energy change derived from experimental data suggested that the adsorption Pb(II) on nIIP is spontaneous and favorable at high temperature. In addition, nIIP had the highest selectivity among three tested fibrous adsorbents for Pb(II) from binary metal solution, the selectivity coefficients for Pb(II) from binary metal solution of Pb(II)/Cu(II), Pb(II)/Ni(II), and Pb(II)/Cd(II) onto nIIP were 47, 101, and 162, respectively. Besides, a forty adsorption/desorption cycles revealed that nIIP was a promising recyclable adsorbent. In conclusion, the novel nIIP is a highly effective adsorbent for enrichment and separation of Pb(II) in the presence of competitive ions in aqueous solution, and it is potential to be applied for recovering metals from heavy metal polluted industrial wastewater such as Pb(II)/Cd(II), Pb(II)/Ni(II), and Pb(II)/Cu(II) polluted wastewater. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41507.

Synthesis and Adsorption Behavior of Surface Cu(II) Ion-Imprinted Poly(allylamine)-Silica Gel Material

The Cu(II) ion-imprinted poly(allylamine)-silica material (IIP-PAA/SiO2) was synthesized by surface ion imprinting technique. The effects of main imprinting conditions on its adsorption properties were examined. The results showed that there were a large number of cavities distributed in the thin imprinted PAA layers of IIP-PAA/SiO2, which contributed to improving the affinity and selectivity of the imprinted material. Scatchard analysis showed that there were two kinds of binding sites on its surface and the dissociation constants were 0.056 mmol · L−1 and 0.84 mmol · L−1, respectively. The adsorption results showed that IIP-PAA/SiO2 had excellent recognition ability for Cu(II). Additionally, it had also excellent reusability.

Electropolymerized surface ion imprinting films on a gold nanoparticles/single-wall carbon nanotube nanohybrids modified glassy carbon electrode for electrochemical detection of trace mercury(II) in water

Electrochemical detection of Hg(II) using a electropolymerized ion imprinting poly(2-mercaptobenzothiazole) films at the surface of gold nanoparticles/single-walled carbon nanotube nanohybrids modified glassy carbon electrode (PMBT/AuNPs/SWCNTs/GCE) is described for the first time. The Hg(II)-imprinted PMBT/AuNPs/SWCNTs/GCE sensor exhibits larger binding to functionalized capacity, larger affinity, faster binding kinetics and higher selectivity to template Hg(II). The differential pulse anodic stripping voltammetry (DPASV) response of the Hg(II)-imprinted PMBT/AuNPs/SWCNTs/GCE sensor to Hg(II) is ca. 3.7- and 10.5-fold higher than that at the non-imprinted PMBT/AuNPs/SWCNTs/GCE and the imprinted PMBT/AuNPs/GCE, respectively, and the detection limit for Hg(II) is 0.08nM (S/N=3, which is well below the guideline value given by the World Health Organization) and a sensitivity of 0.749μAnM−1 was obtained. Excellent wide linear range (0.4–96.0nM) and good repeatability (relative standard deviation of 2.6%) were obtained for Hg(II). The interference experiments show that Ag(I), Pb(II), Cd(II), Zn(II) and Cu(II) had little or no influence on the Hg(II) signal. These values, particularly the high sensitivity and excellent selectivity in contrast to the values reported previously in the area of electrochemical Hg(II) detection, demonstrate the analytical performance of the Hg(II)-imprinted PMBT/AuNPs/SWCNTs/GCE toward Hg(II) is superior to the existing electrodes and could be used for efficient determination of Hg(II) in natural water samples.

Stripping voltammetric detection of mercury(II) based on a surface ion imprinting strategy in electropolymerized microporous poly(2-mercaptobenzothiazole) films modified glassy carbon electrode

This work reports a surface ion imprinting strategy in electropolymerized microporous poly(2-mercaptobenzothiazole) (MPMBT) films at the surface of glassy carbon electrode (GCE) for the electrochemical detection of Hg(II). The Hg(II)-imprinted MPMBT/GCE exhibits larger binding to functionalized capacity, faster binding kinetics and higher selectivity to template Hg(II) due to their high ratio of surface-imprinted sites, larger surface-to-volume ratios, the complete removal of Hg(II) templates and larger affinity to Hg(II). The square wave anodic stripping voltammetry (SW ASV) response of the Hg(II)-imprinted MPMBT/GCE to Hg(II) is ca. 3.0 and 5.9 times larger than that at the direct imprinted poly(2-mercaptobenzothiazole) modified GCE and non-imprinted MPMBT/GCE sensor, respectively; and the detection limit for Hg(II) is 0.1 nM (which is well below the guideline value given by the World Health Organization). Excellent wide linear range (1.0–160.0 nM) and good repeatability (relative standard deviation of 2.5%) were obtained for Hg(II). The interference experiments showed that mercury signal was not interfered in the presence of Pb(II), Cd(II), Zn(II), Cu(II) and Ag(I), respectively. These values, particularly the high sensitivity and excellent selectivity compared favorably with previously reported methods in the area of electrochemical Hg(II) detection, demonstrate the feasibility of using the prepared Hg(II)-imprinted MPMBT/GCE for efficient determination of Hg(II) in aqueous environmental samples.

Synthesis, Characterization, Evaluation of Potassium Tertatitanium Whisker Surface Ni(II) Ion-Imprinted Polymers and Selective Adsorption of Nickel

Ni(II) ion-imprinted polymers(Ni(II)-IIPs) was synthesis by the method of surface ion-imprinting in combination with sol-gel process, and prepared by the Ni(II) as template ion, Chitosan(CTS) as functional monomer, γ-Glycidoxypropyl trimethoxysilane (KH560) as linking agent, potassium tertatitanium whisker as carrier. After removing Ni(II) ion from the polymer, Ni(II)-IIPs capable of selectively rebinding Ni(II) ion were obtained. The prepared material was characterized by using the infrared spectra (IR) and scanning electron microscopy (SEM). A batch of adsorption experiments were performed to evaluate its adsorption behavior of Ni(II) using inductively coupled plasma atomic emission spectrometry (ICP-AES). The effect of solution pH, sorbent amount on the extraction of Ni(II) from aqueous solutions were studied. The maximum adsorption capacity of Ni(II) on polymer beads was about 33.1 mg•g−1. The Ni(II)-IIPs have a greater affinity for Ni(II) with respect to Cd(II), Co(II), Cu(II), Hg(II), Mg(II), Mn(II), Zn(II) and Pb(II) ions. Ni(II)-IIPs enabled the selective extraction of Ni(II) from a complex matrix. The prepared functional polymer was shown to be promising for selective pre-separation and enrichment of trace Ni(II) in environmental samples.

A New Sr(II) Ion-Imprinted Polymer Grafted onto Potassium Titanate Whiskers: Synthesis and Adsorption Performance for the Selective Separation of Strontium Ions

Surface ion-imprinting technology was applied to prepare a new Sr(II) ion-imprinted polymer [Sr(II)-IP] by grafting chitosan-Sr(II) onto potassium titanate whiskers. The imprinting mechanism of the prepared polymer was examined, using infrared spectroscopy (IR), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The effects of pH and contact time were examined, together with the adsorption capacity and selectivity of the imprinted polymer. The adsorption isotherms could be fitted by the Langmuir model, with the dimensionless separation factor RL indicated favourable adsorption. In addition, the kinetic data were fitted more closely by the pseudosecond- order kinetic model rather than the pseudo-first-order model. The values of the Gibbs' free energy (ΔG0), standard entropy (ΔS0) and standard enthalpy (ΔH0) calculated from the adsorption data suggested that the adsorption of Sr(II) onto Sr(II)-IP was a spontaneous and endothermic process. The relative selectivity coefficients of Sr(II)-IP f...

MARKET REPORT: Membrane Separation

In order to effectively extract lithium from salt lake brine, a novel magnetic graphene oxide-based lithium ion-imprinted polymer (IIP-GO/Fe3O4@C) was developed by combining magnetic separation technology with surface ion imprinting technology. GO/Fe3O4@C, which is composed of graphene oxide (GO) and Fe3O4@C, was modified by silane coupling agent KH570 and then grafted with methacrylic acid (MAA). The IIP-GO/Fe3O4@C achieved excellent Li+ separation performance, including an adsorption capacity of 31.24 mg/g, good regeneration performance (91% of the initial value after six adsorption–desorption cycles), a moderate equilibrium time of about 2 h, and relatively high selectivity against Na+, K+, and Mg2+ of 14.31, 12.05, and 10.9, respectively. These excellent properties are due to the synergistic effect between the construction of adsorption sites brought by the high specific surface area (225.8 m2/g) of GO/Fe3O4@C skeleton and the particular recognition of Li+ by 2-hydroxymethyl-12-crown ether-4. Therefore, IIP-GO/Fe3O4@C can be used as a prominent candidate for extracting lithium from salt lake brine.

On the chemical potential necessary for the destruction of the latent image

Novel Pb(II) ion-imprinted and carbon nanofibers (CNFs)-grafted highly porous (∼475 m2/g) polymeric beads (∼0.5 mm) were prepared by the surface ion imprinting technique. The allylthiourea precursor-based polymeric beads were synthesized by suspension polymerization, in which CNFs were in-situ mixed during the polymerization reaction before the curing step. The prepared ion-imprinted and CNF-grafted polymeric (CNF-IIP) beads were used for the efficient and selective removal of Pb(II) ions from aqueous solution by adsorption. The adsorption capacity of the CNF-IIPs for Pb(II) ions was determined to be ∼47 mg/g. The material exhibited high selectivity for Pb(II) in the presence of the Ni(II), Zn(II) and Cd(II) competitive ions, with the selectivity coefficients for the Pb(II)/Ni(II), Pb(II)/Zn(II) and Pb(II)/Cd(II) in binary systems determined to be ∼48, 28 and 14, respectively. The synthesized CNF-IIP adsorbents were easily regenerated by acid treatment and used in five adsorption/regeneration cycles. The method described in this study can be applied for the development of the similar CNF-IIPs for the selective removal of various toxic metal ions present in industrial effluents.