scholarly journals Stabilization of Pickering Emulsions by Hairy Nanoparticles Bearing Polyanions

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 816 ◽  
Author(s):  
Ying Zhang ◽  
Kaimin Chen ◽  
Lan Cao ◽  
Kai Li ◽  
Qiaoling Wang ◽  
...  

Pickering emulsions are increasingly applied in drug delivery, oil–water separation, composite materials preparation, and other fields. However, systematic studies on the stabilization of Pickering emulsions to satisfy the growing application demands in multiple fields with long-term conservation are rare. Compared to conventional solid nanoparticles, polyanion-modified hairy nanoparticles are more stable in practical environments and are investigated in this study. Poly (sodium p-styrenesulfonate) was grafted to a polystyrene (PS) core via a photoemulsion polymerization. A hairy nanoparticle bearing polyanions called poly (sodium p-styrenesulfonate) brush (PS@PSS) was synthesized. The size and uniformity of the Pickering emulsions stabilized by PS@PSS were investigated via a polarizing microscope. The stability of Pickering emulsions were optimized by adjusting critical factors like ultrasonic power and time, standing time, oil phases, salt concentration, and water:oil ratio. Results indicated that the Pickering emulsions could be stabilized by PS@PSS nanoparticles, which showed remarkable and adjustable partial wetting properties. It was found that the optimized conditions were ultrasonic power of 150 W, ultrasonic time of 3 min, salt concentration of 0.1 mM, oil phase of hexadecane, and water:oil ratio of 1:1. The formation and stability of Pickering emulsion are closely related to the hairy poly (sodium p-styrenesulfonate) brush layer on the nanoparticle surface.

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.


Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 978
Author(s):  
Yi Zhang ◽  
Yang Gan ◽  
Liwen Zhang ◽  
Deyuan Zhang ◽  
Huawei Chen

Unidirectional liquid spreading without energy input is of significant interest for the broad applications in diverse fields such as water harvesting, drop transfer, oil–water separation and microfluidic devices. However, the controllability of liquid motion and the simplification of manufacturing process remain challenges. Inspired by the peristome of Nepenthes alata, a surface-tension-confined (STC) channel with biomimetic microcavities was fabricated facilely through UV exposure photolithography and partial plasma treatment. Perfect asymmetric liquid spreading was achieved by combination of microcavities and hydrophobic boundary, and the stability of pinning effect was demonstrated. The influences of structural features of microcavities on both liquid spreading and liquid pinning were investigated and the underlying mechanism was revealed. We also demonstrated the spontaneous unidirectional transport of liquid in 3D space and on tilting slope. In addition, through changing pits arrangement and wettability pattern, complex liquid motion paths and microreactors were realized. This work will open a new way for liquid manipulation and lab-on-chip applications.


Author(s):  
Balraj K. Tudu ◽  
Aditya Kumar ◽  
Bharat Bhushan

Superoleophobicity is of interest for practical applications such as liquid repellency, self-cleaning, stain resistance, anti-bacterial properties and oil–water separation. In this work, the superoleophobic coating on cotton fabric was applied by simple immersion in TiO 2 nanoparticles, perfluorodecyltriethoxysilane and tertraethylorthosilicate solution. Its anti-wetting properties, surface morphology and functionality were characterized. The coated cotton fabric shows superoleophobicity with oil (surface tension more than 27 mN m −1 ) contact angle of 152° and tilt angle of 6°. Furthermore, the superoleophobic cotton fabric was demonstrated to exhibit self-cleaning, stain resistance, mechanical durability, chemical stability, thermal stability, anti-bacterial properties and oil–water separation capabilities. This article is part of the theme issue ‘Bioinspired materials and surfaces for green science and technology (part 2)’.


RSC Advances ◽  
2020 ◽  
Vol 10 (14) ◽  
pp. 8008-8015 ◽  
Author(s):  
Xuewei Ruan ◽  
Tiancheng Xu ◽  
Dingjiang Chen ◽  
Ziwen Ruan ◽  
Haitu Hu

Although various filtration materials with (super)wetting properties have been fabricated for effective oil/water separation, eco-friendly and low-cost materials are still highly desired.


2020 ◽  
Vol 4 (4) ◽  
pp. 1-7
Author(s):  
Zhang D

The basic properties of alkali‒surfactant‒polymer (ASP) flooding produced water and effect of oil displacing agent on the stability of flooding produced water were obtained, through measuring and analysing water quality, oil content-settling time relationship and oil displacing agent-oil droplet size relationship of Zhong-106, Zhong-312, Zhong-417, Nan 4-8 and Bei 2-7 flooding produced water from Daqing Oilfield. The addition of ternary oil displacement agent to ASP flooding produced water greatly increases the difficulty of oil-water separation, and higher the concentration, worse the separation effect after standing. The effects of alkali, surfactant, and polymer on oil-water stability in simulated ASP flooding produced water were studied respectively. The ASP flooding produced water after 48 hours of settling formed a trace amount of nano-oil droplets, also accompanied by the accumulation and separation of a part of the oil droplets.


2021 ◽  
Vol 3 (6) ◽  
pp. 65-68
Author(s):  
Fu Fang ◽  
◽  
Chengzhen Wu ◽  
Pengfei Shi ◽  
Yilin Ning ◽  
...  

In recent years, more and more researches and reports on nanofluids have been made, and hybrid nanofluids as new fluids have gradually entered the field of vision. Hybrid nanofluids have many excellent properties at the same time. Because the stability of hybrid nanofluids has an important influence on the thermal properties and flow heat transfer properties of the solution, the stability of nanoparticles suspended in the base liquid has become an important direction of research. The stability of graphene oxide-Al2O3 hybrid nanofluids was studied with ultrasonic time, dispersant and ultrasonic power as variables. The experimental results show that when the ratio of graphene oxide: Nano-Al2O3: dispersant is 1:1:1, ultrasonic time is 2 h and ultrasonic power is 300 w, the stability of graphene oxide- Al2O3 hybrid nanofluid solution is the best.


2018 ◽  
Vol 334 ◽  
pp. 394-401 ◽  
Author(s):  
Haiyan Zhu ◽  
Doudou Li ◽  
Mingjuan Cai ◽  
Xinquan Yu ◽  
Youfa Zhang

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