scholarly journals Transition Sandwich Janus Membrane of Cellulose Acetate and Polyurethane Nanofibers For Oil-Water Separation

Author(s):  
Yong Zhang ◽  
Mei Yang ◽  
Yuan Zhou ◽  
Anrong Yao ◽  
Yanting Han ◽  
...  

Abstract Through sequential electrospinning, a sandwich Janus membrane (PU-(CA/PU)-CA) was constructed with hydrophobic polyurethane (PU) nanofiber membrane as the top layer, cellulose acetate/polyurethane (CA/PU) blend nanofiber membrane as the intermediate transition layer and hydrophilic cellulose acetate (CA) nanofiber membrane as the bottom layer. The effects of membrane structure, composition and thickness on the mechanical properties, permeability and separation ability of PU-(CA/PU)-CA nanofiber membrane were studied. The results show that the transition sandwich structure PU-(CA/PU)-CA membrane has good mechanical properties, high permeability and selective separation ability, and can realize the unidirectional transmission of water and efficient oil-water separation. When the membrane thickness is 80 μm, the hydraulic permeability is 3.4×104 L/(m2 h bar), the oil-water separation efficiency reaches 99%, and the tensile strength is 95.8% higher than that of the double-layer PU-CA membrane without intermediate transition layer. The thermal stability and antifouling ability of PU-(CA/PU)-CA nanofiber membrane have also been improved, and the reusability is good. CA/PU transition interlayer improves the interfacial compatibility between CA and PU nanofiber membrane, enhances the performance of PU-(CA/PU)-CA nanofiber Janus membrane, and shows its application prospect in the field of separation and purification.

2019 ◽  
Vol 43 (17) ◽  
pp. 6712-6720 ◽  
Author(s):  
Zhibin Zhang ◽  
Hang Yu ◽  
Jiahong Guo ◽  
Zhiwei Bai ◽  
Shiping Zhang ◽  
...  

pH-Responsive smart non-woven fabrics (NWFs) possess double switchable wettability and excellent selectivity, separation efficiency and mechanical properties for recyclability.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yuanli Chen ◽  
Hui Fan ◽  
Xinlin Zha ◽  
Wenwen Wang ◽  
Yi Wu ◽  
...  

AbstractHigh efficiency and anti-pollution oil/water separation membrane has been widely explored and researched. There are a large number of hydroxyl groups on the surface of silica, which has good wettability and can be used for oil-water separation membranes. Hydrophilic silica nanostructures with different morphologies were synthesized by changing templates and contents of trimethylbenzene (TMB). Here, silica nanospheres with radical pores, hollow silica nanospheres and worm-like silica nanotubes were separately sprayed on the PVA-co-PE nanofiber membrane (PM). The abundance of hydroxyl groups and porous structures on PM surfaces enabled the absorption of silica nanospheres through hydrogen bonds. Compared with different silica nanostructures, it was found that the silica/PM exhibited excellent super-hydrophilicity in air and underwater “oil-hating” properties. The PM was mass-produced in our lab through melt-extrusion-phase-separation technique. Therefore, the obtained membranes not only have excellent underwater superoleophobicity but also have a low-cost production. The prepared silica/PM composites were used to separate n-hexane/water, silicone oil/water and peanut oil water mixtures via filtration. As a result, they all exhibited efficient separation of oil/water mixture through gravity-driven filtration.


2021 ◽  
Vol 18 (4) ◽  
pp. 887-899
Author(s):  
Yanling Tian ◽  
Jiekai Feng ◽  
Zexin Cai ◽  
Jiaqi Chao ◽  
Dawei Zhang ◽  
...  

AbstractReckless discharge of industrial wastewater and domestic sewage as well as frequent leakage of crude oil have caused serious environmental problems and posed severe threat to human survival. Various nature inspired superhy-drophobic surfaces have been successfully applied in oily water remediation. However, further improvements are still urgently needed for practical application in terms of facile synthesis process and long-term durability towards harsh environment. Herein, we propose a simple one-step dodecyl mercaptan functionalization method to fabricate Super-hydrophobic-Superoleophilic Copper Mesh (SSCM). The prepared SSCM possesses excellent water repellence and oil affinity, enabling it to successfully separate various oil-water mixtures with high separation efficiency (e.g., > 99% for hexadecane-water mixture). The SSCM retains high separating ability when hot water and strong corrosive aqueous solutions are used to simulate oil-water mixtures, indicating remarkable chemical durability of the dodecyl mercaptan functionalized copper mesh. Additionally, the efficiency can be well maintained during 50 cycles of separation, and the water repellence is even stable after storage in air for 120 days, demonstrating the reusability and long-term stability of the SSCM. Furthermore, the functionalized mesh also shows good mechanical robustness towards abrasion by sandpaper, and oil-water separation efficiency of > 96% can be obtained after 10 cycles of abrasion. The reported one-step dodecyl mercaptan functionalization could be a simple method for increasing the water repellence of copper mesh, and thereby be a great candidate for treating large-scale oily wastewater in harsh environments.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Peng Hong ◽  
Zhu Liu ◽  
Yang Gao ◽  
Yubin Chen ◽  
Mingxun Zhuang ◽  
...  

Superhydrophobic sponge as potential absorbing material for oil/water separation is attracting great attention recently. However, there are still some challenges to feasibly fabricate superhydrophobic sponge with large scale and low cost. Herein, a novel photochromic superhydrophobic melamine sponge (PDMS-SP sponge) is fabricated by facilely dip-coating and thermocuring of hydroxyl-terminated polydimethylsiloxanes mixed with photochromic spiropyran. FT-IR, EDS, and XPS results confirm the successful coating of PDMS-SP upon melamine sponge. The resultant sponge not only possesses excellent water repellency with a contact angle of 154.5° and oil-water separation efficiency with an oil absorption capacity of 48–116 folds of itself weight, but also shows photochromic phenomenon between colorless and purple when it is successively exposed to UV irradiation and visible light.


Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 775 ◽  
Author(s):  
Fei Sun ◽  
Ting-Ting Li ◽  
Haitao Ren ◽  
Qian Jiang ◽  
Hao-Kai Peng ◽  
...  

This study aims to produce polypropylene (PP)/titanium dioxide (TiO2) melt-blown membranes for oil/water separation and photocatalysis. PP and different contents of TiO2 are melt-blended to prepare master batches using a single screw extruder. The master batches are then fabricated into PP/TiO2 melt-blown membranes. The thermal properties of the master batches are analyzed using differential scanning calorimetry and thermogravimetric analysis, and their particle dispersion and melt-blown membrane morphology are evaluated by scanning electron microscopy. TiO2 loaded on melt-blown membranes is confirmed by X-ray diffraction (XRD). The oil/water separation ability of the melt-blown membranes is evaluated to examine the influence of TiO2 content. Results show that the thermal stability and photocatalytic effect of the membranes increase with TiO2 content. TiO2 shows a good dispersion in the PP membranes. After 3 wt.% TiO2 addition, crystallinity increases by 6.4%, thermal decomposition temperature increases by 25 °C compared with pure PP membranes. The resultant PP/TiO2 melt-blown membrane has a good morphology, and better hydrophobicity even in acetone solution or 6 h ultraviolet irradiation, and a high oil flux of about 15,000 L·m−2·h−1. Moreover, the membranes have stabilized oil/water separation efficiency after being repeatedly used. The proposed melt-blown membranes are suitable for mass production for separating oil from water in massively industrial dyeing wastewater.


Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 442 ◽  
Author(s):  
Mingguang Yu ◽  
Qing Wang ◽  
Wenxin Yang ◽  
Yonghang Xu ◽  
Min Zhang ◽  
...  

In this paper, we present a facile and efficient strategy for the fabrication of magnetic, durable, and superhydrophobic cotton for oil/water separation. The superhydrophobic cotton functionalized with Fe3O4 magnetic nanoparticles was prepared via the in situ coprecipitation of Fe2+/Fe3+ ions under ammonia solution on cotton fabrics using polyvinylpyrrolidone (PVP) as a coupling agent and hydrophobic treatment with tridecafluorooctyl triethoxysilane (FAS) in sequence. The as-prepared cotton demonstrated excellent superhydrophobicity with a water contact angle of 155.6° ± 1.2° and good magnetic responsiveness. Under the control of the external magnetic field, the cotton fabrics could be easily controlled to absorb the oil from water as oil absorbents, showing high oil/water separation efficiency, even in hot water. Moreover, the cotton demonstrated remarkable mechanical durable properties, being strongly friction-resistant against sandpaper and finger wipe, while maintaining its water repellency. This study developed a novel and efficient strategy for the construction of magnetic, durable, and superhydrophobic biomass-based adsorbent for oil/water separation, which can be easily scaled up for practical oil absorption.


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