Electrospray on superhydrophobic nozzles treated with argon and oxygen plasma

The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could—subject to satisfactory resolution of technical and scientific problems identified herein—have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seed-particle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud–albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100×100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action.

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“…The ideas, engineering requirements and some climate impacts associated with MCB have been significantly explored by more recent studies [3–11]. …”

Section: Introductionmentioning

confidence: 99%

Marine cloud brightening

Latham

Bower

Choularton

et al. 2012

Phil. Trans. R. Soc. A.

161

164

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“…Generation and manipulation of tiny liquid droplets (down to micro‐ or nanoliter scale) and fine bubbles have attracted an ever increasing amount of interest because of the broad applications, such as liquid transportation, inkjet printing, high‐resolution three‐dimensional (3D) printing, cell engineering, micro‐reactor, bio‐analysis, bio‐sensing, energy production, chemical engineering, and environmental remediation . Signicant efforts have been devoted from scientific and industrial communities to produce smaller droplets by reducing the nozzle size or through assistance of special driving mechanisms (e. g., mechanical‐, electrical‐, and thermal‐driven equipments) in the past . However, the traditional nozzles and dispensing methods still face many limitations.…”

Section: Introductionmentioning

confidence: 99%

“…In nature, the surfaces of many plants and animals show various special wettabilities. [11][12][13][14][15][16][17][18][19][20] Lotus leaf has great water repellence and ultralow adhesion to water droplets, allowing rain droplets and dewdrops to easily roll on its surface and take contaminations away (called "self-cleaning effect"). [21,22] Such superhydrophobicity is ascribed to the hierarchical rough papillae and the hydrophobic wax crystal layer covering on the lotus leaf.…”

Section: Introductionmentioning

confidence: 99%

Reducing Adhesion for Dispensing Tiny Water/Oil Droplets and Gas Bubbles by Femtosecond Laser‐Treated Needle Nozzles: Superhydrophobicity, Superoleophobicity, and Superaerophobicity

et al. 2018

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Three‐level microstructures were formed on the stainless‐steel surfaces by simple femtosecond laser ablation. The structured surfaces exhibit superhydrophilicity in air and superoleophobicity/superaerophobicity in water. After further stearic acid modification, the surfaces turned to superhydrophobicity and underwater superoleophilicity/superaerophilicity. Through this technique, the nozzle of a needle is transformed to possess superwettabilities. When the nozzles were used to release liquid and gas, the sizes of the dispensed water and oil droplets and air bubbles were dramatically reduced. Particularly, we demonstrate that the underwater superaerophobic nozzle could dispense air bubbles in nanoliter volume without the need of reducing the nozzle diameter. The liquid retention at the opening of the needle was also effectively prevented. Therefore, the reduced droplet/bubble size and retention allow us to achieve a dramatically enhanced volume accuracy and resolution during manipulation and transport of aqueous solutions and gases. The femtosecond laser‐induced superwetting nozzles can be used in high‐resolution liquid transport, inkjet printing, 3D printing, pipettes, medical devices, cell engineering, biological detection, microchemical reactor, and reducing industrial gas emission.

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“…These water‐in‐oil droplet systems drastically increase throughput rates as each nanoliter droplet functions as a separate reaction vessel. Despite progress, development of compact low‐cost tools capable of contamination‐free nanoliter droplet manipulation remains elusive, and current approaches are based on bulky mechanical‐, thermal, electrical, and pyroelectrodynamics‐driven systems. These latter designs may experience contamination stemming from liquid residue adhering to the surfaces of tips or nozzles .…”

Section: Introductionmentioning

confidence: 99%

Superamphiphobic Bionic Proboscis for Contamination‐Free Manipulation of Nano and Core–Shell Droplets

Wong

Liu

Tricoli

2017

Small

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Manipulation of nanoliter droplets is a key step for many emerging technologies including ultracompact microfluidics devices, 3D and flexible electronic printing. Despite progress, contamination-free generation and release of nanoliter droplets by compact low-cost devices remains elusive. In the present study, inspired by butterflies' minute manipulation of fluids, the authors have engineered a superamphiphobic bionic proboscis (SAP) layout that surpasses synthetic and natural designs. The authors demonstrate the scalable fabrication of SAPs with tunable inner diameters down to 50 µm by the rapid gas-phase nanotexturing of the outer and inner surfaces of readily available hypodermic needles. Optimized SAPs achieve contamination-free manipulation of water and oil droplets down to a liquid surface tension of 26.56 mN m and a volume of 10 nL. The unique potential of this layout is showcased by the rapid and carefully controlled in-air synthesis of core-shell droplets with well-controlled compositions. These findings provide a new low-cost tool for high-precision manipulation of nanoliter droplets, offering a powerful alternative to established thermal- and electrodynamic-based devices.

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Electrospray on superhydrophobic nozzles treated with argon and oxygen plasma

Cited by 43 publications

References 19 publications

Marine cloud brightening

Marine cloud brightening

Reducing Adhesion for Dispensing Tiny Water/Oil Droplets and Gas Bubbles by Femtosecond Laser‐Treated Needle Nozzles: Superhydrophobicity, Superoleophobicity, and Superaerophobicity

Superamphiphobic Bionic Proboscis for Contamination‐Free Manipulation of Nano and Core–Shell Droplets

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