Anti-icing surfaces based on enhanced self-propelled jumping of condensed water microdroplets

Zhang, Qiaolan; He, Min; Chen, Jing; Wang, Jianjun; Song, Yanlin; Jiang, Lei

doi:10.1039/c3cc40592c

Cited by 281 publications

(188 citation statements)

References 17 publications

Supporting

Mentioning

188

Contrasting

Order By: Relevance

“…Note that merely using the CMDSP surfaces can greatly inhibit but not fully prevent frost accumulation. [27,[103][104][105] In essence, such an energyeffective frost-free strategy based on bionic CMDSP surfaces is also suitable for other metal-based heat exchangers, such as heat pumps and refrigerators.…”

Section: Energy-saving Functional Coatingsmentioning

confidence: 99%

Recent Progress in Bionic Condensate Microdrop Self‐Propelling Surfaces

2017

Self Cite

View full text Add to dashboard Cite

interest has focused on utilizing the lowadhesivity nature of superhydrophobic surfaces for the rapid removal of condensate microdrops, as this has significance in fundamental research and technological innovation. Example applications are the enhancement of condensation heat transfer for high-efficiency thermal management and energy utilization, [20][21][22][23][24][25] energy-effective antifreezing for airconditioner heat exchangers and aircraft wings, [26][27][28] and electrostatic energy harvesting. [29] In general, condensate drops on typical flat hydrophobic surfaces are only shed off under gravity when their sizes are comparable to the capillary length (≈2.7 mm for water), [30] which creates undesirable effects such as large thermal resistance [20][21][22][23][24][25] and the freezing of subcooled drops. [26][27][28] Clearly, a great challenge is the timely removal of condensate drops at the microscale where the gravitational effect does not work. The latest research has indicated that these small-scale condensate microdrops may self-remove via mutual coalescence as long as the coalescence-released excess surface energy is larger than the interface adhesion-induced energy dissipation. [31] Much effort has been devoted to exploring the utilization of knowledge of bionic low-adhesivity superhydrophobicity to develop innovative condensate microdrop self-propelling (CMDSP) surfaces. Different from traditional superhydrophobic surfaces, which are characterized by the bouncing or rolling off of deposited millimeter-size large drops, [32,33] CMDSP surfaces support the self-removal capability of smallscale condensate microdrops. It has been reported that classical superhydrophobic lotus leaves (Figure 1a), [34][35][36][37] as well as artificial surfaces consisting of hierarchical micro-and nanostructures, [38] one-tier microstructures, [39][40][41][42][43] or nanostructures [44,45] with larger characteristic interspaces, present a low-adhesivity property to the deposited water macrodrops, but become highly adhesive to condensed microdrops (Figure 1b). This is because moisture easily penetrates the microscale valleys or cavities. Clearly, superhydrophobic surfaces with irrationally designed surface structures can enhance the solid-liquid interfacial adhesion instead of promoting the rapid removal of condensed drops. Accordingly, it is still a challenge to design and fabricate very effective low-adhesivity superhydrophobic surfaces with the self-removal ability of condensate microdrops. Recently, there has been a large breakthrough in understanding the mechanism and construction rules of bionic CMDSP surfaces, leading to the exploration of fabrication methods for the surface functionalization of widely used metal materials and the Bionic condensate microdrop self-propelling (CMDSP) surfaces are attracting increased attention as novel, low-adhesivity superhydrophobic surfaces due to their value in fundamental research and technological innovation, e.g., for enhancing heat transfer, energy-effective antifreezing, and...

show abstract

Section: Energy-saving Functional Coatingsmentioning

confidence: 99%

Recent Progress in Bionic Condensate Microdrop Self‐Propelling Surfaces

2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…Since then, researchers have studied the mechanism of charge accumulation on atomized droplets 2 , sessile droplets [3][4][5] and the hydrophobic coatings beneath them [6][7][8][9] , sometimes using a modification of Millikan's approach 5 . Recently, with the broad interest in and development of superhydrophobic surfaces 10,11 for a variety of applications including self-cleaning 12 , condensation heat transfer enhancement [13][14][15][16][17][18][19][20][21] , thermal diodes 22,23 and anti-icing [24][25][26][27] , more detailed insights on droplet interactions on these surfaces have emerged. Specifically, when two or more small droplets (E10-100 mm) coalesce, they can spontaneously jump away from a superhydrophobic surface due to the release of excess surface energy 28 , which promises enhanced system performance by passively shedding water droplets 13,15 .…”

mentioning

confidence: 99%

Electrostatic charging of jumping droplets

et al. 2013

View full text Add to dashboard Cite

With the broad interest in and development of superhydrophobic surfaces for self-cleaning, condensation heat transfer enhancement and anti-icing applications, more detailed insights on droplet interactions on these surfaces have emerged. Specifically, when two droplets coalesce, they can spontaneously jump away from a superhydrophobic surface due to the release of excess surface energy. Here we show that jumping droplets gain a net positive charge that causes them to repel each other mid-flight. We used electric fields to quantify the charge on the droplets and identified the mechanism for the charge accumulation, which is associated with the formation of the electric double layer at the droplet-surface interface. The observation of droplet charge accumulation provides insight into jumping droplet physics as well as processes involving charged liquid droplets. Furthermore, this work is a starting point for more advanced approaches for enhancing jumping droplet surface performance by using external electric fields to control droplet jumping.

show abstract

“…[11][12][13][14][15][16] This phenomenon has been termed jumping-droplet condensation and has been shown to further enhance heat transfer by up to 30% when compared to classical dropwise condensation due to a larger population of microdroplets which more efficiently transfer heat to the surface. 17 A number of works have since fabricated superhydrophobic nanostructured surfaces to achieve spontaneous droplet removal [18][19][20][21][22][23][24][25][26][27][28] for a variety of applications including self-cleaning, [29][30][31] thermal diodes, 30,32 anti-icing, [33][34][35][36] vapor chambers, 37 electrostatic energy harvesting, [38][39][40] and condensation heat transfer enhancement. [41][42][43][44][45][46][47][48][49][50][51][52] However, heat transfer enhancement can be limited by droplet return to the surface due to…”

Section: Jumping Droplet Condensation and External Electric Fieldsmentioning

confidence: 99%

A Comprehensive Model of Electric-Field-Enhanced Jumping-Droplet Condensation on Superhydrophobic Surfaces

Birbarah

Pauls

et al. 2015

Langmuir

View full text Add to dashboard Cite

Superhydrophobic micro/nanostructured surfaces for dropwise condensation have recently received significant attention due to their potential to enhance heat transfer performance by shedding positively charged water droplets via coalescence-induced droplet jumping at length scales below the capillary length, and allowing the use of external electric fields to enhance droplet removal and heat transfer, in what has been termed electric-field-enhanced (EFE) jumping-droplet condensation. However, achieving optimal EFE conditions for enhanced heat transfer requires capturing the details of transport processes that is currently lacking. While a comprehensive model has been developed for condensation on micro/nanostructured surfaces, it cannot be applied for EFE condensation due to the dynamic droplet-vapor-electric field interactions. In this work, I developed a comprehensive physical model for EFE condensation on Furthermore, the results suggest that EFE electrodes can be optimized such that the work input is minimized depending on the condensation heat flux. To analyze overall efficiency, I defined an incremental coefficient-of-performance and showed that it is very high (~10 6 ) for EFE iii condensation. I finally proposed mechanisms for condensate collection which would ensure continuous operation of the EFE system, and which can scalably be applied to industrial condensers. This work provides a comprehensive physical model of the EFE condensation process, and offers guidelines for the design of EFE systems to maximize heat transfer.iv ACKNOWLEDGMENTS

show abstract

Anti-icing surfaces based on enhanced self-propelled jumping of condensed water microdroplets

Cited by 281 publications

References 17 publications

Recent Progress in Bionic Condensate Microdrop Self‐Propelling Surfaces

Recent Progress in Bionic Condensate Microdrop Self‐Propelling Surfaces

Electrostatic charging of jumping droplets

A Comprehensive Model of Electric-Field-Enhanced Jumping-Droplet Condensation on Superhydrophobic Surfaces

Contact Info

Product

Resources

About