Wetting Dynamics of Hydrophobic and Structured Surfaces

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Faraday Discussions

Vol 146

Wetting Dynamics of Hydrophobic and Structured Surfaces

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Published on 29 July 2010 on http://pubs.rsc.org | doi:10.1039/C005493N

Wetting Dynamics of Hydrophobic and Structured Surfaces Jefferson Hotel, Richmond, Virginia, USA 12–14 April 2010

FARADAY DISCUSSIONS Volume 146, 2010

View Online The Faraday Division of the Royal Society of Chemistry, previously the Faraday Society, founded in 1903 to promote the study of sciences lying between Chemistry, Physics and Biology.

EDITORIAL STAFF Editor Philip Earis

Published on 29 July 2010 on http://pubs.rsc.org | doi:10.1039/C005493N

Deputy editor Jane Hordern Senior Publishing editor Nicola Nugent Development editor Vibhuti Patel

Faraday Discussions documents a longestablished series of Faraday Discussion meetings which provide a unique international forum for the exchange of views and newly acquired results in developing areas of physical chemistry, biophysical chemistry and chemical physics.

ORGANISING COMMITTEE, Volume 146 Chair Dr Hugo K Christenson (University of Leeds, UK) (Co-chair) Professor Alenka Luzar (Virginia Commonwealth University, USA) (Co-chair)

Publishing assistant Kate Bandoo

Professor Bob Evans (University of Bristol, UK) Dr Jim R Henderson (University of Leeds, UK) Professor Pablo G Debenedetti (Princeton University, USA) Professor John D Weeks (University of Maryland, USA) Professor Michael L Klein (University of Pennsylvania, USA)

Publisher Niamh O’ Connor

FARADAY STANDING COMMITTEE ON CONFERENCES

Publishing editors Helen Lunn, Anna Roffey

Faraday Discussions (Print ISSN 1359-6640, Electronic ISSN 1364-5498) is published 4 times a year by the Royal Society of Chemistry, Thomas Graham House, Science Park, Milton Road, Cambridge, UK CB4 0WF. Volume 146 ISBN-13: 978 1 84973 0563 2010 annual subscription price: print+electronic £622, US $1,160; electronic only £560, US $1,045.

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Wetting Dynamics of Hydrophobic and Structured Surfaces Faraday Discussions www.rsc.org/faraday_d

Published on 29 July 2010 on http://pubs.rsc.org | doi:10.1039/C005493N

A General Discussion on Wetting Dynamics of Hydrophobic and Structured Surfaces was held at Jefferson Hotel, Richmond, Virginia, USA on 12th, 13th and 14th April 2010.

RSC Publishing is a not-for-profit publisher and a division of the Royal Society of Chemistry. Any surplus made is used to support charitable activities aimed at advancing the chemical sciences. Full details are available from www.rsc.org

CONTENTS ISSN 1359-6640; ISBN 978-1-84973-056-3 Cover See Daub et al., Faraday Discuss., 2010, 146, 67---77. Molecular picture (top): Nanoscale roughness renders hydrophilic surface more hydrophobic (left panel); Superhydrophobicity is achieved even when surface roughness is limited to nanoscale alone (right panel).

See Reyssat et al., Faraday Discuss., 2010, 146, 19---33. Macroscopic picture (bottom): Top view of the impact of a water drop hitting a superhydrophobic solid decorated with a square lattice of micropillars. Interval between successive pictures is 1 ms.

Images reproduced by permission of Professors Alenka Luzar and David Que´re´.

PREFACE 9

Preface Alenka Luzar and Hugo K. Christenson

INTRODUCTORY LECTURE 13

Exploring nanoscale hydrophobic hydration Peter J. Rossky

PAPERS AND DISCUSSIONS 19

Dynamical superhydrophobicity Mathilde Reyssat, Denis Richard, Christophe Clanet and David Que´re´

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35

Superhydrophobic surfaces by hybrid raspberry-like particles Maria D’Acunzi, Lena Mammen, Maninderjit Singh, Xu Deng, Marcel Roth, Gu¨nter K. Auernhammer, Hans-Ju¨rgen Butt and Doris Vollmer

49

Microscopic shape and contact angle measurement at a superhydrophobic surface Helmut Rathgen and Frieder Mugele

57

Transparent superhydrophobic and highly oleophobic coatings Liangliang Cao and Di Gao

67

The influence of molecular-scale roughness on the surface spreading of an aqueous nanodrop Christopher D. Daub, Jihang Wang, Shobhit Kudesia, Dusan Bratko and Alenka Luzar

79

General Discussion

103

Contact angle hysteresis: a different view and a trivial recipe for low hysteresis hydrophobic surfaces Joseph W. Krumpfer and Thomas J. McCarthy

113

Amplification of electro-osmotic flows by wall slippage: direct measurements on OTS-surfaces Marie-Charlotte Audry, Agne`s Piednoir, Pierre Joseph and Elisabeth Charlaix

125

Electrowetting and droplet impalement experiments on superhydrophobic multiscale structures F. Lapierre, P. Brunet, Y. Coffinier, V. Thomy, R. Blossey and R. Boukherroub

141

Macroscopically flat and smooth superhydrophobic surfaces: Heating induced wetting transitions up to the Leidenfrost temperature Guangming Liu and Vincent S. J. Craig

153

Drop dynamics on hydrophobic and superhydrophobic surfaces B. M. Mognetti, H. Kusumaatmaja and J. M. Yeomans

167

Dynamic mean field theory of condensation and evaporation processes for fluids in porous materials: Application to partial drying and drying J. R. Edison and P. A. Monson

185

Molecular dynamics simulations of urea---water binary droplets on flat and pillared hydrophobic surfaces Takahiro Koishi, Kenji Yasuoka, Xiao Cheng Zeng and Shigenori Fujikawa

195

General Discussion

217

First- and second-order wetting transitions at liquid---vapor interfaces K. Koga, J. O. Indekeu and B. Widom

223

Hierarchical surfaces: an in situ investigation into nano and micro scale wettability Alex H. F. Wu, K. L. Cho, Irving I. Liaw, Grainne Moran, Nigel Kirby and Robert N. Lamb

233

An experimental study of interactions between droplets and a nonwetting microfluidic capillary Geoff R. Willmott, Chiara Neto and Shaun C. Hendy

247

Hydrophobic interactions in model enclosures from small to large length scales: non-additivity in explicit and implicit solvent models Lingle Wang, Richard A. Friesner and B. J. Berne

263

Water reorientation, hydrogen-bond dynamics and 2D-IR spectroscopy next to an extended hydrophobic surface Guillaume Stirnemann, Peter J. Rossky, James T. Hynes and Damien Laage

283

General Discussion

6 | Faraday Discuss., 2010, 146

This journal is ª The Royal Society of Chemistry 2010

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299

The search for the hydrophobic force law Malte U. Hammer, Travers H. Anderson, Aviel Chaimovich, M. Scott Shell and Jacob Israelachvili

309

The effect of counterions on surfactant-hydrophobized surfaces Gilad Silbert, Jacob Klein and Susan Perkin

325

Hydrophobic forces in the wetting films of water formed on xanthate-coated gold surfaces Lei Pan and Roe-Hoan Yoon

341

Interfacial thermodynamics of confined water near molecularly rough surfaces Jeetain Mittal and Gerhard Hummer

353

Mapping hydrophobicity at the nanoscale: Applications to heterogeneous surfaces and proteins Hari Acharya, Srivathsan Vembanur, Sumanth N. Jamadagni and Shekhar Garde

367

General Discussion

CONCLUDING REMARKS 395

Concluding remarks FD 146: Answers and questions Frank H. Stillinger

ADDITIONAL INFORMATION 403 409 413

Poster titles List of participants Index of contributors

This journal is ÂŞ The Royal Society of Chemistry 2010

Faraday Discuss., 2010, 146 | 7

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Published on 14 July 2010 on http://pubs.rsc.org | doi:10.1039/C005486K

This paper is published as part of Faraday Discussions volume 146: Wetting Dynamics of Hydrophobic and Structured Surfaces Introductory Lecture Exploring nanoscale hydrophobic hydration Peter J. Rossky, Faraday Discuss., 2010 DOI: 10.1039/c005270c

Papers Contact angle hysteresis: a different view and a trivial recipe for low hysteresis hydrophobic surfaces Joseph W. Krumpfer and Thomas J. McCarthy, Faraday Discuss., 2010

Papers Dynamical superhydrophobicity Mathilde Reyssat, Denis Richard, Christophe Clanet and David Quéré, Faraday Discuss., 2010 DOI: 10.1039/c000410n

DOI: 10.1039/b925045j Amplification of electro-osmotic flows by wall slippage: direct measurements on OTS-surfaces Marie-Charlotte Audry, Agnès Piednoir, Pierre Joseph and Elisabeth Charlaix, Faraday Discuss., 2010 DOI: 10.1039/b927158a

Superhydrophobic surfaces by hybrid raspberry-like particles Maria D'Acunzi, Lena Mammen, Maninderjit Singh, Xu Deng, Marcel Roth, Günter K. Auernhammer, Hans-Jürgen Butt and Doris Vollmer, Faraday Discuss., 2010 DOI: 10.1039/b925676h Microscopic shape and contact angle measurement at a superhydrophobic surface Helmut Rathgen and Frieder Mugele, Faraday Discuss., 2010 DOI: 10.1039/b925956b

Electrowetting and droplet impalement experiments on superhydrophobic multiscale structures F. Lapierre, P. Brunet, Y. Coffinier, V. Thomy, R. Blossey and R. Boukherroub, Faraday Discuss., 2010 DOI: 10.1039/b925544c Macroscopically flat and smooth superhydrophobic surfaces: Heating induced wetting transitions up to the Leidenfrost temperature Guangming Liu and Vincent S. J. Craig, Faraday Discuss., 2010 DOI: 10.1039/b924965f

Transparent superhydrophobic and highly oleophobic coatings Liangliang Cao and Di Gao, Faraday Discuss., 2010 DOI: 10.1039/c003392h

Drop dynamics on hydrophobic and superhydrophobic surfaces B. M. Mognetti, H. Kusumaatmaja and J. M. Yeomans, Faraday Discuss., 2010

The influence of molecular-scale roughness on the

DOI: 10.1039/b926373j

surface spreading of an aqueous nanodrop Christopher D. Daub, Jihang Wang, Shobhit Kudesia, Dusan Bratko and Alenka Luzar, Faraday Discuss., 2010 DOI: 10.1039/b927061m

Dynamic mean field theory of condensation and evaporation processes for fluids in porous materials: Application to partial drying and drying J. R. Edison and P. A. Monson, Faraday Discuss., 2010

Discussion General discussion Faraday Discuss., 2010 DOI: 10.1039/c005415c

DOI: 10.1039/b925672e

View Online

Molecular dynamics simulations of urea–water binary

Discussion

droplets on flat and pillared hydrophobic surfaces Takahiro Koishi, Kenji Yasuoka, Xiao Cheng Zeng and Shigenori Fujikawa, Faraday Discuss., 2010 DOI: 10.1039/b926919c

Discussion General discussion Faraday Discuss., 2010 DOI: 10.1039/c005416j

General discussion Faraday Discuss., 2010 DOI: 10.1039/c005417h

Papers The search for the hydrophobic force law Malte U. Hammer, Travers H. Anderson, Aviel Chaimovich, M. Scott Shell and Jacob Israelachvili, Faraday Discuss., 2010

Published on 14 July 2010 on http://pubs.rsc.org | doi:10.1039/C005486K

DOI: 10.1039/b926184b The effect of counterions on surfactant-hydrophobized

Papers First- and second-order wetting transitions at liquid– vapor interfaces K. Koga, J. O. Indekeu and B. Widom, Faraday Discuss.,

surfaces Gilad Silbert, Jacob Klein and Susan Perkin, Faraday Discuss., 2010 DOI: 10.1039/b925569a

2010

Hydrophobic forces in the wetting films of water formed

DOI: 10.1039/b925671g

on xanthate-coated gold surfaces

Hierarchical surfaces: an in situ investigation into nano and micro scale wettability

Lei Pan and Roe-Hoan Yoon, Faraday Discuss., 2010 DOI: 10.1039/b926937a

Alex H. F. Wu, K. L. Cho, Irving I. Liaw, Grainne Moran,

Interfacial thermodynamics of confined water near

Nigel Kirby and Robert N. Lamb, Faraday Discuss., 2010

molecularly rough surfaces

DOI: 10.1039/b927136h

Jeetain Mittal and Gerhard Hummer, Faraday Discuss., 2010

An experimental study of interactions between droplets and a nonwetting microfluidic capillary

DOI: 10.1039/b925913a Mapping hydrophobicity at the nanoscale: Applications to

Geoff R. Willmott, Chiara Neto and Shaun C. Hendy,

heterogeneous surfaces and proteins

Faraday Discuss., 2010

Hari Acharya, Srivathsan Vembanur, Sumanth N. Jamadagni

DOI: 10.1039/b925588e

and Shekhar Garde, Faraday Discuss., 2010

Hydrophobic interactions in model enclosures from

DOI: 10.1039/b927019a

small to large length scales: non-additivity in explicit and implicit solvent models

Discussion

Lingle Wang, Richard A. Friesner and B. J. Berne, Faraday Discuss., 2010

General discussion

DOI: 10.1039/b925521b

Faraday Discuss., 2010

Water reorientation, hydrogen-bond dynamics and 2D-IR

DOI: 10.1039/c005418f

spectroscopy next to an extended hydrophobic surface Guillaume Stirnemann, Peter J. Rossky, James T. Hynes and Damien Laage, Faraday Discuss., 2010 DOI: 10.1039/b925673c

Concluding remarks Concluding remarks for FD 146: Answers and questions Frank H. Stillinger, Faraday Discuss., 2010 DOI: 10.1039/c005398h

EDITORIAL

www.rsc.org/faraday_d | Faraday Discussions

Published on 14 July 2010 on http://pubs.rsc.org | doi:10.1039/C005486K

Preface Alenka Luzar*a and Hugo K. Christenson*b DOI: 10.1039/c005486k Hydrophobic surfaces are ubiquitous in nature and in technology, and their importance has long been recognised. More recently, interest has grown in structured surfaces as a result of research into naturally occurring hydrophobic surfaces such as those of many plant leaves (the Lotus effect). It is now possible to engineer surfaces to show a range of properties related to, but not confined to, the traditional concepts of hydrophobicity. Non-wetting of a surface may thus be achieved not only by minimising the surface free energy, as with a classical hydrophobic surface like Teflon, but also via an appropriately tailored surface morphology. As a consequence, even low-energy liquids may dewet a surface and the term hydrophobicity is replaced by the more general term ‘‘lyophobicity’’. Theoretical interest in hydrophobic interactions and wetting has also been stimulated in several ways. Work on designing superhydrophobic surfaces has led to renewed interest in the theories of heterogeneous wetting due to Wenzel and Cassie–Baxter. Various surface reflectivity measurements have been interpreted as evidence for a layer (albeit thinner than the diameter of a water molecule) of depleted water density next to extended hydrophobic surfaces, and different techniques have been adopted to investigate the boundary conditions of flow next to both smooth and structured hydrophobic surfaces and the relationship to dewetting. Submicroscopic bubbles (‘‘nanobubbles’’) have been discovered on many hydrophobic surfaces in water. Besides giving rise to a long-range attractive force that has been confused with a ‘‘hydrophobic attraction’’, they have raised the question of the importance of dissolved gas for wetting and surface properties in general.

The practical importance of wetting dynamics at hydrophobic and structured surfaces is considerable. The list of applications in many industrial and biological processes includes microfluidics, electrowetting and cell motility. The capillary driven motion of fluid through structures on a surface bears tremendous importance in the emerging field of nanofluidics and sensor development. The field of electrowetting continues to rapidly expand in applications ranging from lab-on-a-chip, liquid lenses and displays, to microelectronics. Surfaces showing significant drag reduction in liquids, as well as a decrease in turbulence at high flow rates may be constructed.

This would lead to more efficient movement through liquid, e.g. of propellers, boats, ships and torpedos, etc. Surfaces engineered to be self-cleaning would reduce fouling and contamination, hence leading to longer working life. Rust-resistant surfaces, and anti-fog surfaces may be designed to prevent the growth of discrete droplets condensing from vapour. The potential applications of such surface engineering are numerous, and a common theme is greater efficiency in many industrial and domestic processes. Among more traditional areas of technology hydrophobicity is of key importance in mineral flotation, where efficient bubble attachment often requires surface modification through the use of additives. Most coal and petroleum products are hydrophobic and often render surfaces that come into contact with them hydrophobic. Because of their inherently low surface energy hydrophobic surfaces present a problem for many applications involving paints, coatings and

a Department of Chemistry, Virginia Commonwealth University, Richmond, VA, USA. E-mail: aluzar@vcu.edu b School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK. E-mail: h.k. christenson@leeds.ac.uk

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adhesives, although this is also exploited in applications such as non-stick (paint resistant) surfaces.

A Faraday Discussion is the ideal forum for making progress towards a better understanding of these phenomena, and the published Discussion volume provides an invaluable reference to the current state of the field for a wide scientific community of physical chemists, biologists, engineers, materials scientists and nanotechnologists. We decided to act on this idea and the program started to take shape in late 2006, after invaluable input from Colin Bain, Pablo Debenedetti, Bob Evans, John Finney, Jim Henderson, Mike Klein, Peter Rossky and John Weeks. We wished to focus on nonpolar surfaces, with particular emphasis on dynamics and tunable wettability, as well as to emphasise the natural extensions to superhydrophobicity and surfaces with chemical and topological heterogeneities. In the late autumn of 2007 Colin Bain, Chairman of the Faraday Standing Committee sent us the wonderful news – that our meeting was finally on the official schedule for April 2010! We are grateful to the committee members who gave their time to sort through the large number of abstracts we received for contributed papers and took part in the final decision on selecting the best and the most appropriate ones for oral presentations.

It was an innovative event. Firstly, it was only the second time a Faraday Discussion had been held outside Europe (in North America) – the first one was at the University of Notre Dame, Indiana in 1963 (on radiation chemistry). The venue was the historic Jefferson Hotel, in Richmond, Virginia, which provided what we are sure, was an unsurpassed setting for a Faraday Discussion meeting. The location and the time of the year worked together to ensure a very successful meeting at the height of spring. On reflection, it was a good idea to bring Faraday Discussions back to US soil after 47 years. This way, we could raise the profile of the meeting and attract more delegates from the US. Secondly, it marked the introduction of a Faraday Discussion Graduate Research Seminar (FD-GRS) that we organized at Virginia Commonwealth University (VCU) over the preceding weekend. The ‘‘Concluding Remarks’’ by Frank Stillinger further describe the scope and success of FD-GRS, which ended with an outing to Maymont Park (see Fig. 1).

Questionnaire responses after the completion of FD146 demonstrated that all the students (the response rate was over 90%) felt much better prepared and less

Fig. 1 Students and mentors in Maymont Park after completion of the FD-GRS. (Photograph: Alenka Luzar).

10 | Faraday Discuss., 2010, 146, 9–12

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intimidated to engage in the FD format of critical and public ‘‘dissection’’ of papers.

The published Discussion shows that graduate students posed 30% of the questions.

The meeting was a great success, and the associated graduate research seminar provides a model that we hope many other Faraday Discussion meetings will seek to copy.

The subsequent Faraday Discussion meeting was well attended, with close to 130 delegates from over 15 countries, with the majority from the US, but quite a few from as far away as New Zealand, Australia and China. The photo of all (almost) the delegates was taken in the lobby of the Jefferson Hotel, on the magnificent Grand Staircase featured in the classic movie ‘‘Gone with the Wind’’ (Fig. 2).

We succeeded in bringing together communities that might not normally interact very closely, as they deal with length scales from the nanoscopic to the macroscopic.

There was a perfect balance between experiment and theory. During the meeting we discussed recent breakthroughs in state-of-the-art techniques to control the behaviour of hydrophobic surfaces under specific conditions; e.g. thermal, optical, electrical, mechanical, chemical. Further, we discussed new developments to devise theoretical and simulation approaches to study nano-surfaces, which dominate nanoscale systems and are necessarily highly complex and heterogeneous. Two very eminent people in the field; Peter Rossky, and Frank Stillinger, delivered the introductory lecture of the Faraday Discussion Meeting and the concluding remarks, respectively. In between these there were twenty-two contributed and invited talks, all of which gave rise to interesting and lively debate. Indeed, on many occasions the discussions had to be cut short due to time constraints. The poster session was extremely well subscribed with over 70 contributions. ‘‘Flash’’ presentations gave the opportunity for all poster presenters to advertise their work using a single PowerPoint slide. Presenting research in a condensed way was a really good learning experience for young scientists. We congratulate all the

Fig. 2 FD146 delegates taken on the historic Grand Staircase of the Jefferson Hotel. (Photograph: Alenka Luzar).

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student participants who presented a rich variety of excellent work during the poster sessions.

Bob Evans, a member of the scientific committee, was standing in for his Bristol colleague and RSC-member Mike Ashfold who could not attend, and delivered an entertaining after banquet speech in his inimitable style. Bob referred to the history of previous FD meetings on related topics and gave his account of the two meetings that he attended, FD16 and FD20, both held in the freezing cold of an Oxford winter.

The loving-cup ceremony passed without incident, except for the usual difficulty in explaining its conduct to inebriated delegates. It became much clearer to them when the Brazilian ensemble ‘‘Quatro na Bossa’’ started playing ‘‘Loving Cup’’ by Rolling Stones.

The feedback that we have received on FD-146 has been very positive. Numerous personal comments from delegates speak of how they enjoyed the meeting from a scientific and organisational point of view. Especially the US delegates, for many of whom this was the first Faraday Discussion, are now sold on this format!

We expect that this Faraday Discussion and the published 146 volume will have significant impact on this exciting field in the years ahead, and we wish to thank all the contributing authors for their effort and support of our endeavour. Delegates also expressed their gratitude at being looked after so well and made to feel so welcome. This southern hospitality extended to a few ‘‘lucky’’ ones who had to prolong their stay at Jefferson because of Eyafj€allaj€ okull.

Our organisational achievements are due to many who worked tirelessly before, during and after the meetings. Firstly, we thank the entire staff of the VCU Chemistry Department, and especially Rose. Rose’s energy was unsurpassed in overcoming all the administrative obstacles to deliver fellowships to students, and honoraria to mentors and poster judges. Shirley, from the College of Humanities and Sciences helped to ensure that the social events ran smoothly. Chemistry graduate students stretched their imagination to design the T-shirt logo (Kyler), and brought the professional Brazilian ensemble to the banquet (Fernando). RSC student stewards and members of Alenka’s research group helped with the microphones, poster boards and computers, and at the registration desk. Meredith and Victor from the School of Engineering at VCU were responsible for ensuring that the FD-GRS meeting was held in a superb lecture hall with top-notch AVI technology and Victor diligently video-recorded the lectures. Mohammad could be seen tirelessly taking photos and movies during both meetings and social events. Ken Wynne had the brilliant idea of asking those with questions to queue up to overcome the shortage of microphones at FD146. We thank Fred Hawkridge, Sally Hunnicutt, and Scott Gronert for their welcoming speech at the reception for FD146, for introducing the young generation to Michael Faraday during the banquet, and for welcoming delegates in Maymont Park. Last, but not least, we are grateful to Morwenna, Anna and Helen of the RSC. We acknowledge the Chemical Physics Division of the APS and the Division of Physical Chemistry of the ACS for their endorsement of FD146. We thank the following organisations for their generous financial support of FD-GRS and FD146: National Science Foundation (CHE-1016888), US Department of Energy (DE-FG02-10ER16152), American Chemical Society (Division of Colloid and Surface Science) and VCU. Without all the support, the inaugural FD-GRS, the overwhelming student participation in FD146, and all the social activities during both meetings, that contributed to a relaxing and engaging student/mentor atmosphere, would not have been possible.

The scientific discussion and educational commitment to the course of research in this field will continue in cyberspace. During the summer months we will be preparing a dedicated webpage (www.faraday.vcu.edu) that will serve as a continuing open-access discussion forum on this topic, along with providing the introductory lectures of the mentors, memorable photos, etc. We hope to ensure that the atmosphere established at the FD-GRS and carried over to FD146 will last much longer!

Hugo Christenson (Co-Chair) Alenka Luzar (Co-Chair, Editor) 12 | Faraday Discuss., 2010, 146, 9–12

This journal is ª The Royal Society of Chemistry 2010

List of participants Mr Hari Acharya, Rensselaer Polytechnic Institute, USA Mr Travers Anderson, University of California, Santa Barbara, USA Dr Rick Angus, Hollingsworth and Vose, USA Professor Bruce Berne, Columbia University, USA Mr Jonathan Boreyko, Duke University, USA Professor Dusan Bratko, Virginia Commonwealth University, USA Mr Kennard Brunson, Virginia Commonwealth University, USA Professor Hans-Juergen Butt, Max Planck Institute for Polymer Research, Germany Mr Kyler Carroll, Virginia Commonwealth University, USA Mr Aviel Chaimovich, UCSB, USA Ms Asima Chakravorty, Virginia Commonwealth University, France Professor Elisabeth Charlaix, University of Lyon, USA Professor Chuan-Hua Chen, Duke University, Taiwan Professor Li-Jen Chen, National Taiwan University, Taiwan Dr Kuan-Hung Cho, National Taiwan University, USA Professor Chang-Hwan Choi, Stevens Institute of Technology, United Kingdom Dr Hugo Christenson, University of Leeds, USA Dr Anindarupa Chunder, Nanoscience Technology Center, USA Professor Rene Corrales, The University of Arizona, USA Professor Vincent Craig, Australian National University, Australia Dr Colin Crick, University College London, United Kingdom Mrs Maria D’Acunzi, MPI for Polymer Research, USA Dr Chris Daub, Virginia Commonwealth University, USA Dr Debnath De, Johnson Matthey ECT, USA Professor Pablo Debenedetti, Princeton University, USA Dr Stephen Donaldson, UCSB, Finland Dr Lei Dong, Aalto University, USA Professor William Ducker, Virginia Tech, USA Mr John Edison, University of Massachusetts, USA Mr Alexander Epstein, Harvard University, USA Professor Jeffery Errington, University at Buffalo, United Kingdom Professor Bob Evans, University of Bristol, USA Professor John Fenn, Virginia Commonwealth University, USA Professor Tomoko Fujiwara, University of Memphis, USA Professor Di Gao, University of Pittsburgh, USA Professor Shekhar Garde, Rensselaer Polytechnic Institute, USA Ms Morwenna Gilbert, Royal Society of Chemistry, United Kingdom Professor Nicolas Giovambattista, Brooklyn College of the City University of New York, USA Dr Jose Guadarrama, University of Navarra, Spain Ms Ludivine Guillemot, Laboratoire PMCN, France Dr Zhiguang Guo, University of Namur, Belgium Dr Murari Gupta, Virginia Commonwealth University, USA Dr Malte Hammer, University of California, Santa Barbara, USA Dr Benjamin Hatton, Harvard University, USA Professor Savvas Hatzikiriakos, University of British Columbia, Canada Ms Kristin Hecht, Karlsruhe Insitute of Technology, Germany Dr Jim Henderson, University of Leeds, United Kingdom Dr Chris Honig, Virginia Tech, USA Dr Gerhard Hummer, National Institutes of Health, USA Professor Jacob Israelachvili, University of California, Santa Barbara, USA Dr Neha Jain, New Jersey Institute of Technology, USA Dr Sumanth Jamadagni, Rensselaer Polytechnic Institute, USA Dr Lei Jiang, Institute of Chemistry, CAS, China Mr Sung Kang, Harvard University, USA Ms Anne-Marie Kietzig, University of British Columbia, Canada Professor Jacob Klein, Weizmann Institute of Science, Israel Professor Michael Klein, University of Pennsylvania, USA Dr Takahiro Koishi, University of Fukui, Japan Dr Vaibhaw Kumar, University at Buffalo, USA Dr Yongjoo Kwon, Seoul National University, South Korea Professor Robert Lamb, The University of Melbourne, Australia

Dr Florian Lapierre, BIOMEMS Group, France Professor Bruce Law, Kansas State University, USA Dr Mei Li, Shanghai Jiao Tong University, USA Dr Hui Li, University of Nebraska Lincoln, USA Dr Zuoli Li, Virginia Tech, USA Mr Fernando Luna-Vera, Virginia Commonwealth University, USA Dr Helen Lunn, Royal Society of Chemistry, United Kingdom Professor Alenka Luzar, Virginia Commonwealth University, USA Dr Valentina Marcon, Centers of Smart Interfaces - TU Darmstadt, Germany Mr Dean Mastropietro, Virginia Tech, USA Mr Sean McBride, Kansas State University, USA Professor Thomas McCarthy, University of Massachusetts Amherst, USA Dr Anatoli Milischuk, Colorado State University, USA Ms Lidiya Mischenko, Harvard University, USA Professor Jeetain Mittal, Lehigh University, USA Professor Peter Monson, University of Massachusetts, USA Ms Barbara Mooney, The University of Arizona, USA Professor Frieder Mugele, University of Twente, The Netherlands Ms Deborah Ortiz, Georgia Tech, USA Mr Sergio Pacheco Benito, University of Twente, The Netherlands Dr Lei Pan, Virginia Tech, USA Professor Mahesh Panchagnula, Tennessee Tech University, USA Dr Neelesh Patankar, Northwestern University, USA Mr Amish Patel, Rensselaer Polytechnic Institute, USA Dr Natalia Perez-Hernandez, Instituto de Investigaciones Quimicas, CSIC, Spain Dr Susan Perkin, University College London, United Kingdom Mr Daniel Peter, Lam Research AG, Austria Professor David Qu_er_e, ESPCI, France Professor Jay Rasaiah, University of Maine, USA Mr Richard Remsing, University of Maryland, USA Mr John Ritchie, Virginia Commonwealth University, USA Dr Martina Roeselova, Czech Academy of Sciences, Czech Republic Miss Anna Roffey, Royal Society of Chemistry, United Kingdom Professor Peter Rossky, The University of Texas at Austin, USA Ms Sapna Sarupria, Princeton University, USA Dr Rossen Sedev, University of South Australia, Australia Mrs Jamileh Seyed-Yazdi, Virginia Commonwealth University, USA Mr David Sherwood, Exosect Limited, United Kingdom Mr Gilad Silbert, Weizmann Institute of Science, Rehovot, Israel Dr Christos Stamboulides, University of British Columbia, Canada Dr Frank Stillinger, Princeton University, USA Mr Guillaume Stirnemann, _ Ecole Normale Sup_erieure, France Dr Vincent Thomy, BioMEMS Group IEMN, France Mrs Joanna Thorne, University of Greenwich, United Kingdom Dr Naga Rajesh Tummala, University of Oklahoma, USA Ms Robin Underwood, Purdue University, USA Mr Davide Vanzo, Universita di Bologna, Italy Dr Kripa Varanasi, MIT, USA Dr Doris Vollmer, MPI for Polymer Research, Germany Mr Michael von Domaros, Virginia Commonwealth University, USA Dr Jiandi Wan, Princeton University, USA Mr Chenyu Wang, Virginia Commonwealth University, USA Mr Jihang Wang, Virginia Commonwealth University, USA Mr Lingle Wang, Columbia University, USA Professor John Weeks, University of Maryland, USA Professor Benjamin Widom, Cornell University, USA Dr Geoff Willmott, Industrial Research Limited, New Zealand Mr Alex Wu, The University of New South Wales, Australia Professor Kenneth Wynne, Virginia Commonwealth University, USA Professor Julia Yeomans, University of Oxford, United Kingdom Dr Yoshiteru Yonetani, Japan Atomic Energy Agency, Japan Dr Soohaeng Yoo, Pacific Northwest National Laboratory, USA Professor Roe-Hoon Yoon, Virginia Tech, USA Dr Xiao Cheng Zeng, University of Nebraska Lincoln, USA Mr Wei Zhang, Virginia Commonwealth University, USA

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Published on 29 July 2010 on http://pubs.rsc.org | doi:10.1039/C005495J

Index of contributors* Acharya, H., 195, 283, 353 Anderson, T. H., 299 Angus, R., 367 Audry, M.-C., 113 Auerhammer, G. K., 35 Berne, B. J., 247, 283 Blossey, R., 125 Boreyko, J., 79, 195, 283 Boukherroub, R., 125 Bratko, D., 67, 79, 195, 283, 367 Brunet, P., 125 Butt, H.-J., 35, 79, 195, 367 Cao, L., 57 Chaimovich, A., 299, 367 Charlaix, E., 113, 195 Chen, C.-H., 79, 195, 367 Cho, K.-H., 223 Choi, C.-H., 79 Christenson, H. K., 79, 195, 367 Chunder, A., 79 Clanet, C., 19 Coffinier, Y., 125 Corrales, R., 79, 195 Craig, V. S. J., 141, 195, 283, 367 D’Acunzi, M., 35 Daub, C., 67, 79, 367 Debenedetti, P., 79, 195, 283, 367 Ducker, W., 195 Edison, J., 167 Epstein, A., 79 Errington, J., 79 Evans, B., 79, 195, 283, 367 Friesner, R. A., 247 Fujikawa, S., 185 Gao, D., 57, 79 Garde, S., 79, 353, 367 Giovambattista, N., 79, 195, 367 Hecht, K., 283 Henderson, J., 79, 283, 367 Hendy, S. C., 233 Honig, C., 195 Hummer, G., 79, 195, 283, 341, 367 Hynes, J. T., 263 Indekeu, J. O., 217 Israelachvili, J., 299, 367 Jamadagni, S. N., 79, 283, 353 Jiang, L., 79 Joseph, P., 113 Kang, S., 79, 283, 367 Kirby, N., 223

Klein, J., 79, 195, 309, 367 Koga, K., 217 Koishi, T., 185, 195 Krumpfer, J. W., 103 Kudesia, S., 67 Kusumaatmaja, H., 153 Laage, D., 263 Lamb, R., 79, 223 Lapierre, F., 125 Law, B., 79, 195, 283, 367 Liaw, I. I., 223 Liu, G., 141 Luzar, A., 67, 79, 195, 283, 367 Mammen, L., 35 McCarthy, T., 79, 103, 195, 283 Mischenko, L., 79, 195, 283, 367 Mittal, J., 341 Mognetti, B. M., 153 Monson, P., 167, 195 Mooney, B., 283 Moran, G., 223 Mugele, F., 49, 79, 195 Neto, C., 233 Pacheco Benito, S., 79, 195, 283 Pan, L., 325 Panchagnula, M., 195 Patankar, N., 79, 195 Patel, A., 79, 195, 283, 367 Perkin, S., 195, 309, 367 Peter, D., 195, 283 Piednoir, A., 113 Qu er e, D., 19, 79, 195, 283 Rathgen, H., 49 Reyssat, M., 19 Richard, D., 19 Ritchie, J., 283 Rossky, P. J., 13, 79, 263 Sarupria, S., 79, 367 Scott Shell, M., 299 Sedev, R., 195 Seyed-Yazdi, J., 79, 195, 283, 367 Sherwood, D., 195 Silbert, G., 309, 367 Singh, M., 35 Stillinger, F., 283, 395 Stirnemann, G., 79, 195, 263, 283, 367 Thomy, V., 125, 195 Vanzo, D., 367 Varanasi, K., 79 Vembanur, S., 353

This journal is ª The Royal Society of Chemistry 2010

Faraday Discuss., 2010, 146, 413–414 | 413

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Vollmer, D., 35, 79, 195, 367 Wan, J., 67, 195 Wang, J., 195, 367 Wang, L., 247 Weeks, J., 79, 195 Widom, B., 217, 283

Willmott, G., 195, 233, 283 Wu, A. H. F., 79, 195, 223, 283 Yasuoka, K., 185 Yeomans, J., 79, 153, 195 Yoon, R.-H., 325, 367 Zeng, X. C., 185

Published on 29 July 2010 on http://pubs.rsc.org | doi:10.1039/C005495J

* The page numbers in bold type indicate papers submitted for discussions.

414 | Faraday Discuss., 2010, 146, 413–414

This journal is ª The Royal Society of Chemistry 2010

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Faraday Discussions 146

Published on 29 July 2010 on http://pubs.rsc.org | doi:10.1039/C005494C

This volume focuses on a number of highly topical and controversial issues related to wetting and dewetting at hydrophobic surfaces.

The current interest in superhydrophobic surfaces has led to a conceptual widening of the term “hydrophobicity”. Non-wetting of a surface may be achieved not only by minimising the surface free energy, but also via an appropriately tailored surface morphology.

As a consequence, even low-energy liquids may dewet a surface and hydrophobicity becomes a more general “lyophobicity”. Wetting dynamics at both smooth and structured surfaces is involved in a range of surface phenomena, including contact angle hysteresis, adhesion, surface forces, self-cleaning and the boundary conditions for fluid flow.

This very active area of current research has major cross-disciplinary implications, and a number of theoretical, modelling and experimental results are in urgent need of clarification and resolution if we are to understand better the properties and behaviour of extended and structured hydrophobic and lyophobic surfaces.

In this volume the topics covered include:  Superhydrophobic Surfaces  Dynamic Transitions  Liquid-vapour Interfaces and Nanobubbles  Heterogeneous Surfaces

Faraday Discussions Faraday Discussions documents a long-established series of Faraday Discussion meetings which provide a unique international forum for the exchange of views and newly acquired results in developing areas of physical chemistry, biophysical chemistry and chemical physics.

The papers presented are published in the Faraday Discussion volume together with a record of the discussion contributions made at the meeting. Faraday Discussions therefore provide an important record of current international knowledge and views in the field concerned.

Vol 146 ISBN 978-1-84973-056-3

9 781849 730563

www.rsc.org/books