A novel Fe3+-stabilized magnetic polydopamine composite for enhanced selective adsorption and separation of Methylene blue from complex wastewater

Magnetic nanoadsorbents for micropollutant removal in real water treatment: a review

“…In another study, a Fe 3+ -stabilized magnetic polydopamine composite (specific surface area=32.7 m 2 g –1 and total pore volume =0.1943 cm 3 g –1 ) demonstrated excellent adsorption capability for methylene blue in single adsorbate aqueous solutions (maximum adsorption capacity=608.8 mg g –1 ) for pH ranging 3–10 and at 45 °C (Chen et al 2020 ). Encouragingly, the nanocomposite could selectively capture methylene blue from mixed dye aqueous systems (methylene blue/methyl orange, methylene blue/carmine, and methylene blue/Rhodamine B) and complex aqueous solutions having ionic strengths as high as 0.5 mol L –1 sodium chloride as well (Chen et al 2020 ). The enhanced and selective adsorption of methylene blue occurred as a result of the synergistic effects of multiple mechanisms (Chen et al 2020 ).…”

“…Encouragingly, the nanocomposite could selectively capture methylene blue from mixed dye aqueous systems (methylene blue/methyl orange, methylene blue/carmine, and methylene blue/Rhodamine B) and complex aqueous solutions having ionic strengths as high as 0.5 mol L –1 sodium chloride as well (Chen et al 2020 ). The enhanced and selective adsorption of methylene blue occurred as a result of the synergistic effects of multiple mechanisms (Chen et al 2020 ). In the case of the methylene blue/methyl orange mixed dye system, the faster and selective uptake of methylene blue was attributed to the strong electrostatic interactions between the negatively charged adsorbent and the cationic methylene blue molecules (Chen et al 2020 ).…”

“…The enhanced and selective adsorption of methylene blue occurred as a result of the synergistic effects of multiple mechanisms (Chen et al 2020 ). In the case of the methylene blue/methyl orange mixed dye system, the faster and selective uptake of methylene blue was attributed to the strong electrostatic interactions between the negatively charged adsorbent and the cationic methylene blue molecules (Chen et al 2020 ). In the case of methylene blue/Rhodamine B, the poor adsorption of Rhodamine B was set on account of mainly steric hindrance generated by the longer lateral alkyl chain connected to the N + center, which in turn considerably weakened π–π stacking interactions and electrostatic attractions between Fe 3 O 4 /polydopamine-Fe 3+ and the Rhodamine B molecules (Chen et al 2020 ).…”

“…In the case of the methylene blue/methyl orange mixed dye system, the faster and selective uptake of methylene blue was attributed to the strong electrostatic interactions between the negatively charged adsorbent and the cationic methylene blue molecules (Chen et al 2020 ). In the case of methylene blue/Rhodamine B, the poor adsorption of Rhodamine B was set on account of mainly steric hindrance generated by the longer lateral alkyl chain connected to the N + center, which in turn considerably weakened π–π stacking interactions and electrostatic attractions between Fe 3 O 4 /polydopamine-Fe 3+ and the Rhodamine B molecules (Chen et al 2020 ). Besides maintaining a four-cycle adsorption–desorption adsorptive efficiency greater than 80% of its initial uptake performance for methylene blue in simulated textile effluent, the nanocomposite could yield a superior adsorption performance than commercial powder-activated carbon in column adsorption setup (Chen et al 2020 ).…”

An Application of Polydopamine-dip Coating as a Gentle Surface Modification Process for Cryogel Disks

“…For example, it has been applied to prepare functional membranes (Fang et al, 2016;Li et al, 2009Li et al, , 2012, magnetic nanoparticles (Wang et al, 2013), organic frameworks (Chen and Chen, 2017), carbon nanotubes (Yin et al, 2015), open tubular columns for capillary electrochromatography (Chen et al, 2012;Liang et al, 2014;Xiao et al, 2015;Zeng et al, 2010), capillaries for capillary electrophoresis (Zhang and Yang, 2019), aerogel sorbents (Tang et al, 2019;Zhan et al, 2019), composite of graphene hybridized PDA-kaolin (He et al, 2019), magnetic sub-micro spheres (Pan et al, 2019), ultrathin nanofiltration membranes (Wu et al, 2019), and etc. Some of the prepared materials are seen to have a potential (as adsorbent) in adsorption of some chemicals such as heavy metals (Mu et al, 2020;Wang et al, 2020), dyes (An et al, 2020;Chen et al, 2020), and bisphenol A (Sun et al, 2020).…”