Co-reporter:Hongya Geng, Bowen Yao, Jiajia Zhou, Kai Liu, Guoying Bai, Wenbo Li, Yanlin Song, Gaoquan Shi, Masao Doi, and Jianjun Wang
Journal of the American Chemical Society September 13, 2017 Volume 139(Issue 36) pp:12517-12517
Publication Date(Web):August 25, 2017
DOI:10.1021/jacs.7b05490
The properties and functions of graphene oxide (GO)-based materials strongly depend on the lateral size and size distribution of GO nanosheets; therefore, GO and its derivatives with narrow size distributions are highly desired. Here we report the size fractionation of GO nanosheets by controlled directional freezing of GO aqueous dispersions. GO nanosheets with a narrow size distribution can be obtained by controlling the growth rate of the freezing front. This interesting phenomenon can be explained by the adsorption of GO nanosheets on the ice crystal surface in combination with the stratification of GO nanosheets at the ice growth front. Such a convenient size fractionation approach will be essential for practical applications of chemically modified graphene, including GO, reduced GO, and their assemblies or composites.
Co-reporter:Shuwang Wu, Linhai Li, Han Xue, Kai Liu, Qingrui Fan, Guoying Bai, and Jianjun Wang
ACS Nano October 24, 2017 Volume 11(Issue 10) pp:9898-9898
Publication Date(Web):August 24, 2017
DOI:10.1021/acsnano.7b03821
Ice templates have been widely utilized for the preparation of porous materials due to the obvious advantages, such as environmentally benign and applicable to a wide range of materials. However, it remains a challenge to have controlled pore size as well as dimension of the prepared porous materials with the conventional ice template, since it often employs the kinetically not-stable growing ice crystals as the template. For example, there is no report so far for the preparation of 2D metal meshes with tunable pore size based on the ice template, although facile and eco-friendly prepared metal meshes are highly desirable for wearable electronics. Here, we report the preparation of 2D silver meshes with tunable mesh size employing recrystallized ice crystals as templates. Ice recrystallization is a kinetically stable process; therefore, the grain size of recrystallized ice crystals can be easily tuned, e.g., by adding different salts and changing the annealing temperature. Consequently, the size and line width of silver meshes obtained after freeze-drying can be easily adjusted, which in turn varied the conductivity of the obtained 2D silver film. Moreover, the silver meshes are transparent and display stable conductivity after the repeated stretching and bending. It can be envisioned that this approach for the preparation of 2D conducting films is of practical importance for wearable electronics. Moreover, this study provides a generic approach for the fabrication of 2D meshes with a controllable pore size.Keywords: ice recrystallization; ice templates; silver meshes; size controllable; wearable electronics;
Co-reporter:Zhenqi Liu;Zhiyuan He;Jianyong Lv;Yuankai Jin;Shuwang Wu;Guangming Liu;Feng Zhou
RSC Advances (2011-Present) 2017 vol. 7(Issue 2) pp:840-844
Publication Date(Web):2017/01/03
DOI:10.1039/C6RA24847K
Ice propagation is an essential step when freezing happens on hydrated surfaces. In this work, we choose polyelectrolyte brushes (PB), whose hydration ability can be controlled by simply exchanging the counterions, to demonstrate the distinct ice propagation mechanism on differently hydrated surfaces.
Co-reporter:Zhichao Zhu, Junfeng Xiang, Jianjun Wang, and Dong Qiu
Langmuir 2017 Volume 33(Issue 1) pp:
Publication Date(Web):December 6, 2016
DOI:10.1021/acs.langmuir.6b03374
Tuning ice formation is of great importance in biological systems and some technological applications. Many synthetic polymers have been shown to affect ice formation, in particular, polyvinyl alcohol (PVA). However, the experimental observations of the effect of PVA on ice formation are still conflicting. Here, we introduced colloidal silica (CS) as the model liquid/solid interface and studied the effect of PVA on ice formation in detail. The results showed that either PVA or CS promoted ice formation, whereas the mixture of these two (CS–PVA) prevented ice formation (antifreezing). Using quantitative analysis based on classical nucleation theory, we revealed that the main contribution came from the kinetic factor J0 rather than the energy barrier factor Γ. Combined with the PVA adsorption behavior on CS particles, it is strongly suggested that the adsorption of PVA at the interface has significantly reduced ice nucleation, which thus may provide new ideas for developing antifreezing agents.
Co-reporter:Guoying Bai, Dong Gao, Jianjun Wang
Carbon 2017 Volume 124(Volume 124) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.carbon.2017.08.074
Carbonaceous particles, as one of the main sources of atmospheric aerosols, have great influence on the climate change, such as ice formation, precipitation and polar ice melting. Because sulphur-containing emissions can significantly affect the chemical compositions and properties of carbonaceous particles through various aging processes, it is critical to investigate the influence of sulphur-doped carbon materials on ice formation. Here, we synthesized a sulphur-doped carbon nanomaterial–sulphur-doped oxidized quasi-carbon nitride quantum dots (S-OCNQDs), and investigated the influence of chemical structure on ice growth and recrystallization. The experimental results show that the S-OCNQDs can inhibit ice growth/recrystallization. In addition, we found that forming more hydrogen-bonds with ice contributes to enhancing the efficiency of ice growth/recrystallization inhibition and that heteroatom-doping is a promising way to regulate the ice growth/recrystallization. This work correlates the specific chemical structures of carbon nanomaterials with their performance in inhibiting ice growth/recrystallization through their density of hydrogen-bonds formed with ice. It is instructive for understanding the effect of sulphur-doping on ice formation as well as the design of efficient anti-icing materials.Download high-res image (507KB)Download full-size image
Co-reporter:Dr. Hongya Geng;Dr. Xing Liu;Dr. Guosheng Shi;Dr. Guoying Bai; Ji Ma; Jingbo Chen;Dr. Zhuangyuan Wu; Yanlin Song; Haiping Fang; Jianjun Wang
Angewandte Chemie International Edition 2017 Volume 56(Issue 4) pp:997-1001
Publication Date(Web):2017/01/19
DOI:10.1002/anie.201609230
AbstractWe show graphene oxide (GO) greatly suppresses the growth and recrystallization of ice crystals, and ice crystals display a hexagonal shape in the GO dispersion. Preferred adsorption of GO on the ice crystal surface in liquid water leads to curved ice crystal surface. Therefore, the growth of ice crystal is suppressed owing to the Gibbs–Thompson effect, that is, the curved surface lowers the freezing temperature. Molecular dynamics simulation analysis reveals that oxidized groups on the basal plane of GO form more hydrogen bonds with ice in comparison with liquid water because of the honeycomb hexagonal scaffold of graphene, giving a molecular-level mechanism for controlling ice formation. Application of GO for cryopreservation shows that addition of only 0.01 wt % of GO to a culture medium greatly increases the motility (from 24.3 % to 71.3 %) of horse sperms. This work reports the control of growth of ice with GO, and opens a new avenue for the application of 2D materials.
Co-reporter:Yuankai Jin;Zhiyuan He;Qian Guo; Jianjun Wang
Angewandte Chemie 2017 Volume 129(Issue 38) pp:11594-11597
Publication Date(Web):2017/09/11
DOI:10.1002/ange.201705190
AbstractIce propagation is of great importance to the accumulation of ice/frost on solid surfaces. However, no investigation has been reported on the tuning of ice propagation through a simple coating process. Herein, we study the ice propagation behavior on polyelectrolyte multilayer (PEM) surfaces coated with the layer-by-layer (LBL) deposition approach. We discover that ice propagation is strongly dependent on the amount of water in the outermost layer of PEMs, that is, the ice propagation rate increases with the amount of water in the outermost layer. The ice propagation rate can be tuned by up to three orders of magnitude by changing the polyelectrolyte pairs, counterions of the outermost polymer layer, or the salt concentration during the preparation of PEMs. Because the simple, versatile, and inexpensive LBL deposition approach is generally applicable to almost all available surfaces, the PEM coatings can tune ice propagation on a wide range of substrates.
Co-reporter:Jianyong Lv;Xi Yao;Yongmei Zheng;Lei Jiang
Advanced Materials 2017 Volume 29(Issue 45) pp:
Publication Date(Web):2017/12/01
DOI:10.1002/adma.201703032
AbstractVarious organogel materials with either a liquid or solid surface layer have recently been designed and prepared. These surface materials can substantially reduce the adhesion of foreign deposits such as water, blood, paint, ice, and so on; therefore, they exhibit great potential for the easy removal of foreign deposits. Here, a brief discussion about the mechanism of organogel materials in reducing adhesion is given; then, examples of liquid organogels for fighting against varieties of complex fluidic deposits are presented, and efforts in preventing the depletion of liquid are discussed. Finally, applications of antiadhesion organogels with multifunctionality, and the strategy of replacing liquids with solids are presented.
Co-reporter:Guoying Bai;Zhiping Song;Hongya Geng;Dong Gao;Kai Liu;Shuwang Wu;Wei Rao;Liangqia Guo
Advanced Materials 2017 Volume 29(Issue 28) pp:
Publication Date(Web):2017/07/01
DOI:10.1002/adma.201606843
Antifreeze proteins (AFPs), a type of high-efficiency but expensive and often unstable biological antifreeze, have stimulated substantial interest in the search for synthetic mimics. However, only a few reported AFP mimics display thermal hysteresis, and general criteria for the design of AFP mimics remain unknown. Herein, oxidized quasi-carbon nitride quantum dots (OQCNs) are synthesized through an up-scalable bottom-up approach. They exhibit thermal-hysteresis activity, an ice-crystal shaping effect, and activity on ice-recrystallization inhibition. In the cryopreservation of sheep red blood cells, OQCNs improve cell recovery to more than twice that obtained by using a commercial cryoprotectant (hydroxyethyl starch) without the addition of any organic solvents. It is shown experimentally that OQCNs preferably bind onto the ice-crystal surface, which leads to the inhibition of ice-crystal growth due to the Kelvin effect. Further analysis reveals that the match of the distance between two neighboring tertiary N atoms on OQCNs with the repeated spacing of O atoms along the c-axis on the primary prism plane of ice lattice is critical for OQCNs to bind preferentially on ice crystals. Here, the application of graphitic carbon nitride derivatives for cryopreservation is reported for the first time.
Co-reporter:Huige Yang;Chao Ma;Kaiyong Li;Kai Liu;Mark Loznik;Rosalie Teeuwen;Jan C. M. van Hest;Xin Zhou;Andreas Herrmann
Advanced Materials 2016 Volume 28( Issue 25) pp:5008-5012
Publication Date(Web):
DOI:10.1002/adma.201600496
Co-reporter:Zhiyuan He;Zhenqi Liu;Guangming Liu;Wen Jun Xie;Zuowei Wang;Yi Qin Gao
Science Advances 2016 Volume 2(Issue 6) pp:e1600345
Publication Date(Web):03 Jun 2016
DOI:10.1126/sciadv.1600345
This work is the first to show that the ion specificity in tuning HIN on ionic surfaces follows the Hofmeister series.
Co-reporter:Yaling Wang;Xi Yao;Jing Chen;Zhiyuan He;Jie Liu;Qunyang Li
Science China Materials 2015 Volume 58( Issue 7) pp:559-565
Publication Date(Web):2015 July
DOI:10.1007/s40843-015-0069-7
A durable organogel anti-icing material via swelling cross-linked poly(dimethylsiloxane) with liquid paraffin is reported. The surface of the organogel is covered by a thin released layer of paraffin due to the osmotic pressure, which acts as a lubricant and reduces the ice adhesion greatly. Results show that the ice adhesion on the surface of the organogel is as small as 1.7±1.2 kPa (at −30°C) and the low ice adhesion remains even when the temperature is lowered to −70°C. The surface with lubricating liquid paraffin layer exhibits excellent durability, as it shows an ultralow ice adhesion after 35 cycles of icing/deicing and 100 days of exposure in ambient environment.本论文报道了一种通过液体石蜡溶胀聚二甲基硅氧烷制备的持久耐用的油凝胶除冰涂层. 由于油凝胶表面被一层渗透压驱动的石蜡缓释层覆盖, 这层缓释层可作为润滑层, 大大降低油凝胶表面的冰粘附强度. 实验结果显示, 油凝胶表面是一种具有超低冰粘附的防结冰材料, 在−30°C测试温度条件下的冰粘附强度是1.7 ± 1.2 kPa, 且温度降低到−70°C时, 其冰粘附强度不高于10 kPa. 在连续100天的使用期间, 经过35次的结冰/除冰循环操作, 具有润滑层的油凝胶表面仍然保持了持久的低粘附特性. 较低的冰粘附和较宽的低温适用窗口, 以及持久的耐用性, 使其在依靠重力或风力的低粘附被动除冰领域具有很大的潜力和实际应用价值.
Co-reporter:Dr. Xi Yao;Shuwang Wu;Dr. Lie Chen;Dr. Jie Ju;Dr. Zhong Gu; Mingjie Liu; Jianjun Wang; Lei Jiang
Angewandte Chemie International Edition 2015 Volume 54( Issue 31) pp:8975-8979
Publication Date(Web):
DOI:10.1002/anie.201503031
Abstract
Solid deposition, such as the formation of ice on outdoor facilities, the deposition of scale in water reservoirs, the sedimentation of fat, oil, and grease (FOG) in sewer systems, and the precipitation of wax in petroleum pipelines, cause a serious waste of resources and irreversible environmental pollution. Inspired by fish and pitcher plants, we present a self-replenishable organogel material which shows ultra-low adhesion to solidified paraffin wax and crude oil by absorption of low-molar-mass oil from its crude-oil environment. Adhesion of wax on the organogel surface was over 500 times lower than adhesion to conventional material surfaces and the wax was found to slide off under the force of gravity. This design concept of a gel with decreased adhesion to wax and oil can be extended to deal with other solid deposition problems.
Co-reporter:Dr. Xi Yao;Shuwang Wu;Dr. Lie Chen;Dr. Jie Ju;Dr. Zhong Gu; Mingjie Liu; Jianjun Wang; Lei Jiang
Angewandte Chemie 2015 Volume 127( Issue 31) pp:9103-9107
Publication Date(Web):
DOI:10.1002/ange.201503031
Abstract
Solid deposition, such as the formation of ice on outdoor facilities, the deposition of scale in water reservoirs, the sedimentation of fat, oil, and grease (FOG) in sewer systems, and the precipitation of wax in petroleum pipelines, cause a serious waste of resources and irreversible environmental pollution. Inspired by fish and pitcher plants, we present a self-replenishable organogel material which shows ultra-low adhesion to solidified paraffin wax and crude oil by absorption of low-molar-mass oil from its crude-oil environment. Adhesion of wax on the organogel surface was over 500 times lower than adhesion to conventional material surfaces and the wax was found to slide off under the force of gravity. This design concept of a gel with decreased adhesion to wax and oil can be extended to deal with other solid deposition problems.
Co-reporter:Xi Yao;Jie Ju;Shuai Yang;Lei Jiang
Advanced Materials 2014 Volume 26( Issue 12) pp:1895-1900
Publication Date(Web):
DOI:10.1002/adma.201304798
Co-reporter:Renmei Dou, Jing Chen, Yifan Zhang, Xupeng Wang, Dapeng Cui, Yanlin Song, Lei Jiang, and Jianjun Wang
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 10) pp:6998
Publication Date(Web):May 14, 2014
DOI:10.1021/am501252u
In this paper, an anti-icing coating with an aqueous lubricating layer is reported. This anti-icing coating can be directly applied to various substrates, and the ice adhesion strength on the coated surfaces can be lowered greatly as compared to uncoated substrates. We demonstrate for the first time that the formed ice on this anti-icing coating can be blown off by a wind action in the wind tunnel with a controlled temperature and wind velocity. Moreover, the low ice adhesion of the anti-icing coating can be maintained even when the temperature is lowered to -53 oC. The robustness and durability of the anti-icing coating are proved by the icing/de-icing experiments. The results show that the anti-icing coating with an aqueous lubricating layer is of great promise for practical applications.Keywords: anti-icing coating; aqueous lubricating layer; hydrophilic component; low ice adhesion; robustness and durability;
Co-reporter:Jianyong Lv, Yanlin Song, Lei Jiang, and Jianjun Wang
ACS Nano 2014 Volume 8(Issue 4) pp:3152
Publication Date(Web):March 4, 2014
DOI:10.1021/nn406522n
Undesired ice accumulation leads to severe economic issues and, in some cases, loss of lives. Although research on anti-icing has been carried out for decades, environmentally harmless, economical, and efficient strategies for anti-icing remain to be developed. Recent researches have provided new insights into the icing phenomenon and shed light on some promising bio-inspired anti-icing strategies. The present review critically categorizes and discusses recent developments. Effectively trapping air in surface textures of superhydrophobic surfaces weakens the interaction of the surfaces with liquid water, which enables timely removal of impacting and condensed water droplets before freezing occurs. When ice already forms, ice adhesion can be significantly reduced if liquid is trapped in surface textures as a lubricating layer. As such, ice could be shed off by an action of wind or its gravity. In addition, bio-inspired anti-icing strategies via trapping or introducing other media, such as phase change materials and antifreeze proteins, are discussed.Keywords: anti-icing; bio-inspired; coalescence induced self-removal; condensed microdroplet; deicing; ice adhesion; lubricating layer; rebound; superhydrophobic; wettability
Co-reporter:Yifan Zhang, Renmei Dou, Huige Yang, Jianjun Wang, Yanlin Song
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2014 Volume 445() pp:92-96
Publication Date(Web):20 March 2014
DOI:10.1016/j.colsurfa.2014.01.022
•A surface-mediated buckling process via thermal annealing for fabricating morphology-controllable particles was reported.•Dimple-like particles and back-rest chair-like particles were obtained, and the indentation depth of these particles could be tuned.•Water adhesion-tunable films were built by the morphology-controllable particles.Here, we report a surface-mediated buckling process via thermal annealing for fabricating morphology-controllable particles. We obtained both dimple-like particles and backrest chair-like particles, and the indentation depth of these particles could be tuned. Furthermore, we successfully utilized the core/shell particles to build water adhesion-tunable films. These films could potentially be used as transfer-printing materials.
Co-reporter:Huige Yang, Meng Su, Kaiyong Li, Lei Jiang, Yanlin Song, Masao Doi, and Jianjun Wang
Langmuir 2014 Volume 30(Issue 31) pp:9436-9441
Publication Date(Web):2017-2-22
DOI:10.1021/la502659e
Though patterned ultrathin polymer films (<100 nm) are of great importance in the fields of sensors and nanoelectronic devices, the fabrication of patterned ultrathin polymer films remains a great challenge. Herein, patterned ultrathin polymer films are fabricated facilely on hydrophobic substrates with different hydrophilic outline patterns by the pinning of three-phase contact lines of polymer solution on the hydrophilic outlines. This method is universal for most of the water-soluble polymers, and poly(vinyl alcohol) (PVA) has been selected as a model polymer due to its biocompatibility and good film-forming property. The results indicate that the morphologies of ultrathin polymer films can be precisely adjusted by the size of the hydrophilic outline pattern. Specifically, patterned hydrophilic outlines with sizes of 100, 60, and 40 μm lead to the formation of concave-shaped ultrathin PVA films, whereas uniform ultrathin PVA films are formed on 20 and 10 μm patterned substrates. The controllabilities of morphologies can be interpreted through the influences of the slip length and coffee ring effect. Theoretical analysis shows that when the size of the hydrophilic outline patterns is smaller than a critical value, the coffee ring effect disappears and uniform patterned ultrathin polymer films can be formed for all polymer concentrations. These results provide an effective methodology for the fabrication of patterned ultrathin polymer films and enhance the understanding of the coffee ring effect.
Co-reporter:Qiaolan Zhang, Min He, Jing Chen, Jianjun Wang, Yanlin Song and Lei Jiang
Chemical Communications 2013 vol. 49(Issue 40) pp:4516-4518
Publication Date(Web):02 Apr 2013
DOI:10.1039/C3CC40592C
A spontaneous and controllable removal of condensed microdroplets at high supersaturation via self-propelled jumping is achieved by introducing a designed micropore array on a nanostructured superhydrophobic surface. The fabricated surface was demonstrated to delay the ice formation for 1 hour at −15 °C with a supersaturation of 6.97.
Co-reporter:Jing Chen, Renmei Dou, Dapeng Cui, Qiaolan Zhang, Yifan Zhang, Fujian Xu, Xin Zhou, Jianjun Wang, Yanlin Song, and Lei Jiang
ACS Applied Materials & Interfaces 2013 Volume 5(Issue 10) pp:4026
Publication Date(Web):May 3, 2013
DOI:10.1021/am401004t
A robust prototypical anti-icing coating with a self-lubricating liquid water layer (SLWL) is fabricated via grafting cross-linked hygroscopic polymers inside the micropores of silicon wafer surfaces. The ice adhesion on the surface with SLWL is 1 order of magnitude lower than that on the superhydrophobic surfaces and the ice formed atop of it can be blown off by an action of strong breeze. The surface with self-lubricating liquid water layer exhibits excellent capability of self-healing and abrasion resistance. The SLWL surface should also find applications in antifogging and self-cleaning by rainfall, in addition to anti-icing and antifrosting.Keywords: anti-icing surface; hygroscopic polymer; ice adhesion; micropore arrayed silicon wafer; self-lubricating liquid water layer;
Co-reporter:Yifan Zhang, Teng Lu, Xiping Zeng, Haijun Zhou, Hongxia Guo, Elmar Bonaccurso, Hans-Juergen Butt, Jianjun Wang, Yanlin Song and Lei Jiang
Soft Matter 2013 vol. 9(Issue 9) pp:2589-2592
Publication Date(Web):10 Jan 2013
DOI:10.1039/C2SM27582A
In this paper we report a surface-mediated growth process for oriented anisotropic particles with tunable morphologies. The morphology of the anisotropic particles can be tuned and the generality of this process is checked. This process also provides a new avenue for constructing ensembles of anisotropic particles.
Co-reporter:Yang Feng, Guangming Chen and Jianjun Wang
RSC Advances 2013 vol. 3(Issue 31) pp:12631-12634
Publication Date(Web):20 Jun 2013
DOI:10.1039/C3RA41484A
A convenient quantitative study of a mesophase of syndiotactic polystyrene induced by isothermal annealing was carried out via FT-IR spectroscopy. The absorptivity ratio of mesophase to amorphous phase was found to be independent of annealing time, and varied with annealing temperature. The fraction of mesophase firstly increased with annealing time, then tended to reach a plateau.
Co-reporter:Qiaolan Zhang, Min He, Xiping Zeng, Kaiyong Li, Dapeng Cui, Jing Chen, Jianjun Wang, Yanlin Song and Lei Jiang
Soft Matter 2012 vol. 8(Issue 32) pp:8285-8288
Publication Date(Web):06 Jul 2012
DOI:10.1039/C2SM26206A
A series of surfaces with the similar morphology but different surface free energy were fabricated to achieve surfaces with distinct condensation modes. It was found that the freezing of condensed water formed via filmwise condensation occurred much more quickly and at a higher temperature than that of condensed water formed via dropwise condensation.
Co-reporter:Min He, Xin Zhou, Xiping Zeng, Dapeng Cui, Qiaolan Zhang, Jing Chen, Huiling Li, Jianjun Wang, Zexian Cao, Yanlin Song and Lei Jiang
Soft Matter 2012 vol. 8(Issue 25) pp:6680-6683
Publication Date(Web):25 May 2012
DOI:10.1039/C2SM25828E
Hierarchically structured porous aluminum surfaces for the high efficient removal of condensed water microdroplets are prepared via simply immersing aluminum sheets in hot water followed by modification with a low surface energy chemical. A correlation between the work of adhesion with the self-removal of condensed water microdroplets is established.
Co-reporter:Kaiyong Li, Shun Xu, Wenxiong Shi, Min He, Huiling Li, Shuzhou Li, Xin Zhou, Jianjun Wang, and Yanlin Song
Langmuir 2012 Volume 28(Issue 29) pp:10749-10754
Publication Date(Web):June 28, 2012
DOI:10.1021/la3014915
Understanding the role played by solid surfaces in ice nucleation is a significant step toward designing anti-icing surfaces. However, the uncontrollable impurities in water and surface heterogeneities remain a great challenge for elucidating the effects of surfaces on ice nucleation. Via a designed process of evaporation, condensation, and subsequent ice formation in a closed cell, we investigate the ice nucleation of ensembles of condensed water microdroplets on flat, solid surfaces with completely different wettabilities. The water microdroplets formed on flat, solid surfaces by an evaporation and condensation process exclude the uncontrollable impurities in water, and the effects of surface heterogeneities can be minimized through studying the freezing of ensembles of separate and independent water microdroplets. It is found that the normalized surface ice nucleation rate on a hydrophilic surface is about 1 order of magnitude lower than that on a hydrophobic surface. This is ascribed to the difference in the viscosity of interfacial water and the surface roughness.
Co-reporter:Min He, Jianjun Wang, Huiling Li and Yanlin Song
Soft Matter 2011 vol. 7(Issue 8) pp:3993-4000
Publication Date(Web):03 Mar 2011
DOI:10.1039/C0SM01504K
Retarding and preventing ice/frost formation has an increasing importance because of the significant energy and safety concerns nowadays. In this paper, super-hydrophobic surfaces with ZnO nanorod arrays were fabricated. These surfaces were super-hydrophobic not only to sessile macro-droplets at room temperature but also to condensed micro-droplets at temperatures below the freezing point. The effects of these ZnO surfaces towards ice/frost formation were investigated. The results show that the time of condensed droplets maintaining the liquid state (t) increases with the decrease of the growth time (tZnO) of ZnO nanorods which determines the surface wettability, clearly indicating the retardation of ice/frost formation. An explanation is proposed based on classic nucleation theory and the heat transfer between condensed droplets and super-hydrophobic surfaces. These results make clear that superhydrophobicity to condensed micro-droplets at temperatures below the freezing point is desirable for effectively retarding ice/frost formation. In addition, they are significant for understanding the effect of superhydrophobicity at surface temperatures lower than the equilibrium freezing point on retarding and preventing ice/frost formation and will be beneficial for the design of effective anti-ice/frost materials.
Co-reporter:Xiping Zeng, Min He, Huiling Li, Jianjun Wang, Yanlin Song, and Lei Jiang
Langmuir 2011 Volume 27(Issue 24) pp:14995-14998
Publication Date(Web):November 13, 2011
DOI:10.1021/la2036136
Adhesion of droplets to solid surfaces at low temperatures is crucial for antifogging and antifreezing, etc. So far, most reports on adhesion measurements have been carried out in air–liquid–solid systems, but it remains difficult to precisely investigate the adhesion at low temperatures due to the uncontrollable condensation. On the basis of the liquid–liquid–solid system, a new method to measure the adhesion of water droplets at low temperatures was developed and employed. Moreover, the reported method could be viable in other liquid–liquid–solid systems with wider temperature window; thus, it will find applications in broad fields such as crude oil recovery, ore-dressing, and transfer printing.
Co-reporter:Qiaolan Zhang, Min He, Jing Chen, Jianjun Wang, Yanlin Song and Lei Jiang
Chemical Communications 2013 - vol. 49(Issue 40) pp:NaN4518-4518
Publication Date(Web):2013/04/02
DOI:10.1039/C3CC40592C
A spontaneous and controllable removal of condensed microdroplets at high supersaturation via self-propelled jumping is achieved by introducing a designed micropore array on a nanostructured superhydrophobic surface. The fabricated surface was demonstrated to delay the ice formation for 1 hour at −15 °C with a supersaturation of 6.97.
