Covalently bonded polyamidoamine functionalized silica used as a Pb(II) scavenger from aqueous solution

Ebelegi, Augustus Newton; Ayawei, Nimibofa; Wankasi, Donbebe; Dikio, Ezekiel Dixon; Diagboya, Paul N.; Mtunzi, Fanyana M.

doi:10.1016/j.jece.2019.103214

Cited by 21 publications

(29 citation statements)

References 42 publications

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“…BET surface area was 16.9 m 2 /g with a pore width of 17.4 nm which is larger than that for some previously reported silica-based adsorbents [34]. is large pore width would have facilitated the fast uptake of large adsorbate molecules from aqueous solutions by means of pore-filling mechanisms [33]. e FTIR spectra of the unmodified silica and G-3 PAMAM SGA adsorbents are shown in Figure 2(a).…”

Section: Characterization Resultsmentioning

confidence: 75%

Generation-3 Polyamidoamine Dendrimer-Silica Composite: Preparation and Cd(II) Removal Capacity

Ebelegi

Ayawei

Inengite

et al. 2020

Journal of Chemistry

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Generation-3 polyamidoamine (PAMAM) dendrimer was implanted on silica to produce a very good adsorbent (G-3 PAMAM-SGA). The composite was characterized and used for the removal of Cd(II) ions from aqueous solution. Kinetic data fit the Lagergren pseudo-second-order model and also follow the intraparticle diffusion kinetic model to an extent, which is an indication that the sorption process is controlled by both mechanisms: intraparticle/film layer and adsorption inside the pores/crevices of the composite. Equilibrium sorption data of Cd(II) on G-3 PAMAM-SGA fit the Freundlich isotherm (R2 = 0.9993) which is indicative of multilayered adsorption that occurred on heterogeneous surfaces. The ΔG° values for all temperatures studied were negative, which indicated a spontaneous and feasible process. The result implies that G-3 PAMAM-SGA is a promising adsorbent for microscale scavenging of Cd(II) ions in aqueous solutions.

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Section: Characterization Resultsmentioning

confidence: 75%

Generation-3 Polyamidoamine Dendrimer-Silica Composite: Preparation and Cd(II) Removal Capacity

Ebelegi

Ayawei

Inengite

et al. 2020

Journal of Chemistry

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“…The initial 10% weight loss at ≈120 °C was attributed to removal of surface-adsorbed water and ethanol molecules and those locked up within the mesopores . The extra 8% weight loss starting at ≈276 °C was attributed to dissociation of some covalently bonded functional moieties , such as OH, CO, NH, and COOH, while the final 10.5% weight loss recorded starting at ≈530 °C was associated with the complete removal of the OH, CO, NH, and COOH groups as well as the possible partial dissociations of the Si–O–Si and CC linkages. In total, at the TGA temperature of ≈850 °C, weight loss of ≈21% was reported for the mPSBA adsorbent.…”

Section: Resultsmentioning

confidence: 99%

“…The G-5 PAMAM dendrimers with succinic acid terminals have been synthesized to facilitate coupling reaction between the SBA-15-NH 2 functional groups and the PAMAM-COOH terminals. The G-5 PAMAM dendrimers preparation has been reported earlier . Briefly, 3.1 g of succinic anhydride and ≈3.7 mL of G-5 PAMAM dendrimers were dissolved in separate 50 mL volumes of DMSO; these were then transferred into a round-bottom flask which was refluxed at 80 °C for 12 h, followed by dialysis with ultrapure water over 3 d (water was replaced every 6 h).…”

Section: Methodsmentioning

confidence: 99%

“…The pH of the pure, intermediate, and functionalized materials in water and 1.0 M KCl were determined, as well as the pH at point zero charge (pHpzc). The solid addition method was used to determine the pH PZC . The materials were instrumentally characterized with a Fourier transform infrared (FTIR) spectrometer (Thermo Scientific Nicolet iS50 FT-IR), a thermogravimetric analyzer (TGA) (Perkin- Elmer TGA 4000, PerkinElmer Instruments, Waltham, MA), and a scanning electron microscope (SEM) (Zeiss Auriga Field Emission) and by X-ray powder diffraction (XRD) (D8 Advance Bruker AXS, Germany).…”

Section: Methodsmentioning

confidence: 99%

“…In this study, we further explore this technique by using poly(amidoamine) (PAMAM) dendrimers as a functional active material to enhance the adsorption properties of pristine SBA-15. The PAMAM dendrimers are units of repetitive amide and amine functional groups, which make it a potential candidate to enhance most contaminant adsorption processes. , Another functional component that may be useful in advanced materials is the addition of magnetic nanomaterials to enhance both the adsorption process as well as the separation process of the adsorbent from water after the adsorption process. , In this light, Fe oxide magnetic nanoparticles were synthesized and incorporated into the PAMAM-tailored SBA-15.…”

Section: Introductionmentioning

confidence: 99%

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Metals and Antibiotics as Aqueous Sequestration Targets for Magnetic Polyamidoamine-Grafted SBA-15

et al. 2021

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In this study, a magnetic generation-5 polyamidoamine (G-5 PAMAM) dendrimer-functionalized SBA-15 (mPSBA) composite was synthesized by coupling amine-functionalized silica (SBA-15-NH 2 ) and amine-functionalized magnetic nanoparticles (MNP-NH 2 ) with the G-5 PAMAM, before characterization and aqueous sorption of As(III), Cd(II), tetracycline, and ciprofloxacin using the composite. The mPSBA characterization data exhibited the typical Si−O−Si infrared peaks from the SBA-15 backbone in addition to the acquired characteristic infrared Fe−O and amide-I/II peaks from the MNP and G-5 PAMAM dendrimers, respectively. Postsorption infrared spectra showing shifts for the amide-linked groups indicated the likely points of contaminant attachment on the composite. Its thermal stability was lower than that of SBA-15 but higher than that of SBA-15-NH, while the XRD diffractograms of the backbone SBA-15-NH and MNP were unchanged in the final composite. The mPSBA composite was a better As(III) and Cd(II) adsorbent than SBA-15 by ≈400 and 140%, respectively, with rapid uptake in the first 60 min and equilibrium achieved at 120 min. Sorption was enhanced with increasing pH (until pHpzc) and initial contaminant concentration. The process was spontaneous and endothermic; thus, increasing ambient temperature enhanced Cd(II) sorption. The sorption data fitted better to the homogeneous fractal pseudo-second-order (FPSO) kinetics model and the Brouers−Sotolongo fractal adsorption isotherm models, indicating complex sorption interactions and pore-filling/contaminant trapping within mPSBA. Further experiments using mPSBA for the uptake of tetracycline and ciprofloxacin showed 679% and 325% higher sorption, respectively, compared with that for SBA-15-NH. In addition to the added advantage of easy removal from solution/treated water after the adsorption process, mPSBA sorption capacities for these studied contaminants [As(III): 23.3 mg/g; Cd(II): 74.5 mg/g; tetracycline: 38.4 mg/g; ciprofloxacin: 23.0 mg/g] are better than those of several advanced adsorbents reported in the literature.

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Application of eco‐friendly multifunctional porous graphene oxide for adsorptive sequestration of chromium in aqueous solution

Nkutha

Diagboya

Mtunzi

et al. 2020

Water Environment Research

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Graphene oxide (GO) was functionalized using two silanes ((3‐aminopropyl)‐triethoxysilane and (3‐mercaptopropyl)‐triethoxysilane) to obtain, separately, the eco‐friendly amine‐functionalized GO (GONH) and thiol‐functionalized GO (GOSH). Both silanes were also used together to obtain the amine–thiol dual‐functionalized GO (GOSN). Various physicochemical characterizations were obtained including spectra from using Fourier‐transform infrared (FTIR) spectrometer, thermogravimetric analyzer, and X‐ray diffractometer. The adsorbents were used for a comparative study of Cr adsorption from aqueous solution. The obtained data were fitted to pseudo‐first order (PFO) and pseudo‐second order (PSO) models, the homogeneous fractal pseudo‐second order (FPSO), and the Weber–Morris intraparticle diffusion (IPD) kinetics models. Model parameters of the Langmuir and Freundlich adsorption isotherm models, as well as the thermodynamics, were calculated. Characterization results showed successful functionalizations. The GONH, GOSH, and GOSN exhibited alkaline, acidic, and neutral pH, respectively, in water. Amine and thiol functional groups were observed in the new adsorbents, as well as reduced orderliness. The adsorbents had higher density per unit weight and better thermal stability than pristine GO. Equilibrium Cr adsorption was attained within 60 min for all adsorbents. The PSO and FPSO described the rate data better. The Cr adsorption decreased as solution pH increased; optimum adsorption was recorded at pH 2. Equilibrium adsorption data fitted the Langmuir adsorption isotherm model for the GONH, while it fitted the Freundlich for both GOSH and GOSN. The adsorption process was theoretically exothermic process that was spontaneous processes. The Cr adsorption capacities of these adsorbents are 114, 89.6, and 173 mg/g for GONH, GOSH, and GOSN, respectively, and these were better than several reported graphene‐based adsorbents and suggest the potential of these adsorbents for water treatment.Practitioner points Graphene oxide was mono and dual‐functionalized with amine and thiol groups for Cr adsorption. The adsorption capacities of these adsorbents were better than several earlier reported. These adsorbents may be used for real contaminated water treatment.

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Covalently bonded polyamidoamine functionalized silica used as a Pb(II) scavenger from aqueous solution

Cited by 21 publications

References 42 publications

Generation-3 Polyamidoamine Dendrimer-Silica Composite: Preparation and Cd(II) Removal Capacity

Generation-3 Polyamidoamine Dendrimer-Silica Composite: Preparation and Cd(II) Removal Capacity

Metals and Antibiotics as Aqueous Sequestration Targets for Magnetic Polyamidoamine-Grafted SBA-15

Application of eco‐friendly multifunctional porous graphene oxide for adsorptive sequestration of chromium in aqueous solution

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