Bifunctional Demulsifier of ODTS Modified Magnetite/Reduced Graphene Oxide Nanocomposites for Oil–water Separation

Abstract

A bifunctional demulsifier of ODTS modified magnetite/reduced graphene oxide (MRGO@ODTS) was synthesized and demonstrated to demulsify effectively both water‐in‐oil (W/O) and oil‐in‐water (O/W) emulsions, benefitting from its surfactant property. The demulsifier was fully characterized with TEM, XRD, FTIR, TGA, and magnetometer instruments, which confirmed the evenly Fe3O4 nanoparticle modified RGO sheet structure of MRGO@ODTS demulsifier. The demulsification efficiency can reach 96.8 ± 2.9 % for W/O emulsion and 97.9 ± 2.1 % for O/W emulsion with 25 g L−1 and 75 g L−1 demulsifier, respectively. Another important feature of MRGO@ODTS is responsive to magnetic field, and consequently reusable. The recyclability tests of MRGO@ODTS show there is no obvious decline of demulsification efficiency within ten cycles. The demusification ability of MRGO@ODTS is more effective for W/O emulsions than that for O/W emulsions. The possible demulsification mechanism was also proposed. The bifunctional demulsifier may find great potential in oil‐water separation in industry.

Magnetically recoverable magnetite-reduced graphene oxide as a demulsifier for surfactant stabilized crude oil-in-water emulsion

“…In this study, Tween 60 was selected and used as a surfactant to stabilize the crude O/W emulsion. The involvement of Tween solution in the preparation of O/W emulsion is similar to those in reported literature [15,27,49]. Fig 8 shows the crude O/W emulsions were stable for 7 days.…”

“…Thus far, M-rGO nanocomposites have been widely used for electrochemical application and the removal of dyes and heavy metals from wastewater, but the study of M-rGO nanocomposites as demulsifier in oil-water separation is scarce. In 2016, Ma et al [27] had synthesized ODTS modified M-rGO nanocomposites (MRGO@ODTS) to demulsify both water-in-oil (W/O) and oil-in-water (O/W) emulsions. Ma et al [27] achieved demulsification efficiency of 83.8 ± 4.1% and 52.0 ± 2.8% when 0.05 g M-rGO@ODTS were added to both W/O and O/W emulsions, respectively.…”

“…In 2016, Ma et al [27] had synthesized ODTS modified M-rGO nanocomposites (MRGO@ODTS) to demulsify both water-in-oil (W/O) and oil-in-water (O/W) emulsions. Ma et al [27] achieved demulsification efficiency of 83.8 ± 4.1% and 52.0 ± 2.8% when 0.05 g M-rGO@ODTS were added to both W/O and O/W emulsions, respectively. In this study, M-rGO nanocomposites are synthesized without any surface modification and used to treat highly stable crude O/W emulsion.…”

Nanoscale Silica Coated Graphene Oxide and Its Demulsifying Performance in Water-in-oil and Oil-in-water Emulsions

“…In W/O emulsion, the sheets of GO@SiO 2 can be stabilized at the oil-water interface with more hydrophobic areas facing to oil phase (Fig. 14k) (Ma et al 2016). When the demulsi er migrate to the oil-water interface, the demulsi er will destroy the protective lm by strong adsorption with asphaltene and resin through π-π or n-π interactions (Liu et al 2015b).…”

Optimization and characterization of magnetite–reduced graphene oxide nanocomposites for demulsification of crude oil in water emulsion

“…Graphene-like materials, such as reduced graphene oxide (rGO), were used in this work and mixed with magnetite nanoparticles to form magnetite nanocomposites. 11,12 The purpose of adding magnetite nanoparticles to rGO sheets is to prevent the restacking of rGO sheets and restrict the agglomeration of Fe 3 O 4 nanoparticles. Loading magnetite nanoparticles on graphene sheets can enhance the adsorption capacity due to the spacing effect of graphene sheets and magnetite nanoparticles.…”