Functionalized β-cyclodextrin with polyethyleneimine-coated Fe3O4 as a recyclable demulsifier for the efficient treatment of oily wastewater

Preparation of Hydrophobic Octadecylphosphonic Acid-Coated Magnetite Nanoparticles for the Demulsification of n-Hexane-in-Water Nanoemulsions

“…The result is consistent with an earlier report [3,34]. As was reported, the R O of Fe 3 O 4 @PEI@β-CD and Fe 3 O 4 @OA was reduced from 96.8% to 95.3%, and there were no obvious differences as the pH of the emulsion increased from 4 to 10, respectively [3,34]. The effect of NaCl or CaCl 2 with a concentration (C salt ) of 0.30 g•L −1 on the R O of sample S2 in the nanoemulsion at pH = 6.9 and 25 • C is shown in Figure 11.…”

“…This indicates that the pH value of nanoemulsion had a minor effect on the demulsification efficiency in the studied range. The result is consistent with an earlier report [3,34]. As was reported, the R O of Fe 3 O 4 @PEI@β-CD and Fe 3 O 4 @OA was reduced from 96.8% to 95.3%, and there were no obvious differences as the pH of the emulsion increased from 4 to 10, respectively [3,34].…”

“…Recently, the magnetite oil-water separation technique has received extensive attention, as it offers rapid and efficient separation, recyclability, simple operation, low cost, and no secondary pollution [1][2][3][4]23,[26][27][28][29][30]. Magnetite Fe 3 O 4 nanoparticles, which are functionalized by organic and/or inorganic substrates, are used to demulsify oil-in-water or water-in-oil emulsions [1][2][3]26,27,[31][32][33][34][35][36]. The functionalized magnetite nanoparticles can impart magnetite property to the dispersed oil droplets [3,4,23], which are coagulated rapidly and isolated from the continuous water phase under the application of an external magnetite field [3,4,23,29].…”

“…XRD Analysis The XRD patterns of the prepared magnetite nanoparticles are shown in Figure 5. All the samples exhibited peaks at 2θ of 18.4 • , 30.4 • , 35.5 • , 43.3 • , 53.7 • , 57.4 • , and 62.8 • , which correspond to the (111), (220), (311), (400), (422), (511), and (440) diffraction planes, respectively, of the cubic spinel structure of Fe 3 O 4[3,33,34,45,46]. The XRD peak positions and intensities of Fe 3 O 4 @ODPA samples were similar to those of Fe 3 O 4 , indicating that the crystal structure of the magnetite particles were effectively retained after ODPA coating[2,3,44,45,47].…”

Fluorinated polyether-coated Fe3O4-functionalized oxidized carbon nanotubes as a recyclable demulsifier for crude oil emulsion treatment

“…Moreover, the recovery experiments showed that PEI-coated Fe 3 O 4 could be reused up to ten times, thus showing good reusability. Yan et al 18 synthesized a magnetic nanodemulsifier Fe 3 O 4 @PEI@β-CD with high interfacial activity using polyethyleneimine (PEI), β-cyclodextrin (β-CD), and Fe 3 O 4 . Results showed that under acidic, neutral and alkaline conditions, when the dosage of Fe 3 O 4 @PEI@β-CD was 200 mg L −1 , the temperature was 45 °C, and the sedimentation time was 30 min, the demulsification rate was greater than 95%.…”