Development of Polymeric Membranes for Oil/Water Separation

In this work, the treatment of oily wastewater was investigated using developed cellulose acetate (CA) membranes blended with Nylon 66. Membrane characterization and permeation results in terms of oil rejection and flux were compared with a commercial CA membrane. The solution casting method was used to fabricate membranes composed of CA and Nylon 66. Scanning Electron Microscopy (SEM) analysis was done to examine the surface morphology of the membrane as well as the influence of solvent on the overall structure of the developed membranes. Mechanical and thermal properties of developed blended membranes and a commercial membrane were examined by thermogravimetric analysis (TGA) and universal (tensile) testing machine (UTM). Membrane characterizations revealed that the thermal and mechanical properties of the fabricated blended membranes better than those of the commercial membrane. Membrane fluxes and rejection of oil as a function of Nylon 66 compositions and transmembrane pressure were measured. Experimental results revealed that the synthetic membrane (composed of 2% Nylon 66 and Dimethyl Sulfoxide (DMSO) as a solvent) gave a permeate flux of 33 L/m2h and an oil rejection of around 90%, whereas the commercial membrane showed a permeate flux of 22 L/m2h and an oil rejection of 70%.

Download Full-text

Micro/Nanoscale Structured Superhydrophilic and Underwater Superoleophobic Hybrid-Coated Mesh for High-Efficiency Oil/Water Separation

Polymers ◽

10.3390/polym12061378 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1378

Author(s):

Teng Yuan ◽

Jian Yin ◽

Yingling Liu ◽

Weiping Tu ◽

Zhuohong Yang

Keyword(s):

Contact Angle ◽

Surface Topography ◽

Cross Linking ◽

Permeate Flux ◽

Stainless Steel Mesh ◽

Water Separation ◽

Nano Sio2 ◽

Binary Structure ◽

Oil Water Separation ◽

Oil Water

A novel micro/nanoscale rough structured superhydrophilic hybrid-coated mesh that shows underwater superoleophobic behavior is fabricated by spray casting or dipping nanoparticle–polymer suspensions on stainless steel mesh substrates. Water droplets can spread over the mesh completely; meanwhile, oil droplets can roll off the mesh at low tilt angles without any penetration. Besides overcoming the oil-fouling problem of many superhydrophilic coatings, this superhydrophilic and underwater superoleophobic mesh can be used to separate oil and water. The simple method used here to prepare the organic–inorganic hybrid coatings successfully produced controllable micro-nano binary roughness and also achieved a rough topography of micro-nano binary structure by controlling the content of inorganic particles. The mechanism of oil–water separation by the superhydrophilic and superoleophobic membrane is rationalized by considering capillary mechanics. Tetraethyl orathosilicate (TEOS) as a base was used to prepare the nano-SiO2 solution as a nano-dopant through a sol-gel process, while polyvinyl alcohol (PVA) was used as the film binder and glutaraldehyde as the cross-linking agent; the mixture was dip-coated on the surface of 300-mesh stainless steel mesh to form superhydrophilic and underwater superoleophobic film. Properties of nano-SiO2 represented by infrared spectroscopy and surface topography of the film observed under scanning electron microscope (SEM) indicated that the film surface had a coarse micro–nano binary structure; the effect of nano-SiO2 doping amount on the film’s surface topography and the effect of such surface topography on hydrophilicity of the film were studied; contact angle of water on such surface was tested as 0° by the surface contact angle tester and spread quickly; the underwater contact angle to oil was 158°, showing superhydrophilic and underwater superoleophobic properties. The effect of the dosing amount of cross-linking agent to the waterproof swelling property and the permeate flux of the film were studied; the oil–water separation effect of the film to oil–water suspension and oil–water emulsion was studied too, and in both cases the separation efficiency reached 99%, which finally reduced the oil content to be lower than 50 mg/L. The effect of filtration times to permeate flux was studied, and it was found that the more hydrophilic the film was, the stronger the stain resistance would be, and the permeate flux would gradually decrease along with the increase of filtration times.

Download Full-text

Application of a triblock copolymer additive modified polyvinylidene fluoride membrane for effective oil/water separation

Royal Society Open Science ◽

10.1098/rsos.171979 ◽

2018 ◽

Vol 5 (5) ◽

pp. 171979 ◽

Cited By ~ 4

Author(s):

S. S. Shen ◽

K. P. Liu ◽

J. J. Yang ◽

Y. Li ◽

R. B. Bai ◽

...

Keyword(s):

Polyvinylidene Fluoride ◽

Triblock Copolymer ◽

Oily Wastewater ◽

The Novel ◽

Permeate Flux ◽

Cleaning Efficiency ◽

Water Separation ◽

Water Emulsion ◽

Oil Water Separation ◽

Oil Water

A hollow fibre membrane was fabricated by blending polyvinylidene fluoride (PVDF) with a triblock copolymer additive polymer that has both hydrophilic and oleophobic surface properties. The novel membrane was characterized and examined for oil/water separation under various system conditions, including different cross-flow rate, feed temperature, trans-membrane pressure, and its rejection and cleaning efficiency, etc. By applying the membrane into the filtration of synthesized oil/water emulsion, the membrane constantly achieved an oil rejection rate of above 99%, with a relatively constant permeate flux varied in the range of 68.9–59.0 l m −2 h −1 . More importantly, the fouling of the used membrane can be easily removed by simple water flushing. The membrane also demonstrated a wide adaptability for different types of real oily wastewater, even at very high feed oil concentration (approx. 115 000 mg l −1 in terms of chemical oxygen demand (COM)). Hence, the novel triblock copolymer additive-modified PVDF membrane can have a great prospect in the continuing effort to expand the engineering application of polymeric membranes for oily wastewater treatment.

Download Full-text

Development of Janus Cellulose Acetate Fiber (CA) Membranes for Highly Efficient Oil–Water Separation

Materials ◽

10.3390/ma14205916 ◽

2021 ◽

Vol 14 (20) ◽

pp. 5916

Author(s):

Xiaotian Yu ◽

Xian Zhang ◽

Yajie Xing ◽

Hongjing Zhang ◽

Wuwei Jiang ◽

...

Keyword(s):

Cellulose Acetate ◽

Water Mixture ◽

Permeate Flux ◽

Fiber Membrane ◽

Water Separation ◽

Water Emulsion ◽

X Ray ◽

Centrifugal Spinning ◽

Oil Water Separation ◽

Oil Water

A new type of Janus cellulose acetate (CA) fiber membrane was used to separate oil–water emulsions, which was prepared with plasma gas phase grafting by polymerizing octamethylcyclotetrasiloxane (D4) onto a CA fiber membrane prepared by centrifugal spinning. The Janus–CA fiber membrane was described in terms of chemical structure using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) analysis, energy dispersive X-ray spectroscopy (EDX) analysis and morphology by field emission scanning electron microscopy (FESEM). In this contribution, we examine the influence of spinning solution concentration, spinning speed and nozzle aperture on the centrifugal spinning process and the fiber morphology. Superhydrophobic/hydrophilic Janus–CA fiber membrane was used to separate water and 1,2-dibromoethane mixture and Toluene-in-water emulsion. Unidirectional water transfer Janus–CA fiber membrane was used to separate n-hexane and water mixture. The separation for the first-time interception rate was about 98.81%, 98.76% and 98.73%, respectively. Experimental results revealed that the Janus cellulose acetate (CA) fiber membrane gave a permeate flux of about 43.32, 331.72 and 275.27 L/(m2·h), respectively. The novel Janus–CA fiber membrane can potentially be used for sustainable W/O emulsion separation. We believe that this is a facile strategy for construction of filtration materials for practical oil–water separation.

Download Full-text

Enhancing Mechanical and Thermal Properties of Polyurethane Rubber Reinforced with Polyethylene Glycol-g-Graphene Oxide

Advances in Polymer Technology ◽

10.1155/2019/2318347 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11

Author(s):

Li Wang ◽

Wen Fu ◽

Wenlong Peng ◽

Haotuo Xiao ◽

Shenglin Li ◽

...

Keyword(s):

Hydrogen Bond ◽

Graphene Oxide ◽

Polyethylene Glycol ◽

Thermogravimetric Analysis ◽

Testing Machine ◽

Mechanical And Thermal Properties ◽

Tensile Testing Machine ◽

Hydrogen Bond Interactions ◽

Lower Temperature ◽

Strength And Toughness

This paper attempted to achieve the purpose of increasing the tensile strength and toughness of polyurethane rubber (PUR) simultaneously by introducing polyethylene glycol (PEG) onto the surface of graphene oxide (GO) to introduce hydrogen bond interactions into the PUR-GO system. GO was grafted with PEG and added to PUR by mechanical blending. The polyethylene glycol-g-graphene oxide (MGO) was characterized by infrared spectroscopy, Raman spectroscopy, X-ray diffraction, and thermogravimetric analysis. The PUR/MGO composites were tested by tensile testing machine, thermogravimetric analysis, dynamic thermal analysis, and scanning electron microscopy. The results demonstrated that PEG was successfully grafted onto the surface of GO and the grafting rate was about 37%. The grated PEG did not affect the crystalline structure of GO. The addition of MGO could improve the thermal stability of PUR vulcanizate. After the addition of GO, the glass transition temperature (Tg) of vulcanizate was shifted to higher temperature. However, the Tg of vulcanizate reinforced by MGO was shifted to lower temperature. The strength and toughness of vulcanizate were significantly improved by adding MGO. The reason was that the hydrogen bond interactions between MGO and PUR were destroyed and the hidden length was released during the strain process. A lot of energy was consumed, and thus the strength and toughness of PUR vulcanizate were improved.

Download Full-text

Influence of Operational Parameters on Oil-Water Separation Efficiency of Titanium Oxide Modified Alpha-Alumina Microfiltration Membrane

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.512-515.1655 ◽

2012 ◽

Vol 512-515 ◽

pp. 1655-1658

Author(s):

Jian Er Zhou ◽

Xue Bing Hu ◽

Yong Qing Wang ◽

Xiao Zhen Zhang ◽

Jin Tian Pan

Keyword(s):

Separation Efficiency ◽

Transmembrane Pressure ◽

Operational Parameters ◽

Water Separation ◽

Microfiltration Membrane ◽

Oil Water Separation ◽

Crossflow Velocity ◽

Oil Water ◽

Alpha Alumina ◽

Feed Temperature

During oil-water separation process, the influence of the operational parameters such as transmembrane pressure, crossflow velocity and feed temperature on the oil-water separation efficiency of TiO2 modified α-alumina microfiltration membrane was studied. The results show that the permeation flux of the membrane is 371.68 L•m-2•h-1 and the oil content in the permeation is 9.63 mg•L-1 when the TMP is 0.15 MPa, the crossflow velocity is 5.89 m•s-1 and the feed temperature is 30°C.

Download Full-text