Fabrication and manipulation of non-wetting surfaces and drops: From super liquid-repellency and the Leidenfrost effect to liquid marbles Dissertation zur Erlangung des Grades „Doktor der Naturwissenschaften” im Promotionsfach Chemie Fachbereich Chemie, Pharmazie und Geowissenschaften der Johannes Gutenberg-Universität in Mainz Maxime Paven geboren in Brest, Frankreich Mainz, November 2016 Die vorliegende Arbeit wurde von Oktober 2013 bis November 2016 unter der Betreuung von [n.a. in online version] am Max-Planck-Institut für Polymerforschung in Mainz angefertigt. Tag der Prüfung: 14. Dezember 2016 Dekan: [n.a. in online version] 1. Berichterstatter: [n.a. in online version] 2. Berichterstatter: [n.a. in online version] Table of content Table of content 1 Introduction ........................................................................................... 13 1.1 Conceptual similarities and differences in super liquid-repellency, the Leidenfrost effect and liquid marbles ........................................... 16 1.2 Super liquid-repellency ........................................................................ 21 1.2.1 Wetting of smooth and rigid surfaces ...................................................... 21 1.2.2 Contact angle hysteresis ......................................................................... 22 1.2.3 Wetting of rough surfaces: The Wenzel and Cassie-Baxter states .......... 23 1.2.4 Superhydrophobic surfaces .................................................................... 26 1.2.5 How drops move on superhydrophobic surfaces ..................................... 27 1.2.6 Superamphiphobic surfaces .................................................................... 30 1.2.7 Design parameters of super liquid-repellent surfaces .............................. 33 1.2.8 Fabrication of super liquid-repellent surfaces .......................................... 35 1.2.9 Challenges and opportunities of super liquid-repellent surfaces .............. 39 1.3 The Leidenfrost effect .......................................................................... 45 1.3.1 Features of boiling and the lifetime of drops ............................................ 46 1.3.2 Lateral and vertical movement of drops and objects exploiting the Leidenfrost phenomenon ........................................................................ 48 1.3.3 Challenges and opportunities in drop and object manipulation using transition and film boiling ........................................................................ 51 1.4 Liquid marbles ...................................................................................... 53 1.4.1 Manipulation and application of liquid marbles ........................................ 56 1.4.2 Challenges and opportunities of liquid marbles ....................................... 60 1.5 Aim of the thesis ................................................................................... 62 1.6 References ............................................................................................ 64 2 Optimization of superamphiphobic layers based on candle soot ..... 71 2.1 Abstract ................................................................................................. 71 2.2 Introduction ........................................................................................... 72 2.3 Materials and methods ......................................................................... 73 2.4 Results ................................................................................................... 76 2.4.1 Deposited soot mass .............................................................................. 76 2.4.2 Network structure for different sooting times ........................................... 79 2.4.3 Analyzing soot composition by Raman spectroscopy .............................. 80 5 Table of content 2.4.4 Thickness of porous silica ....................................................................... 81 2.4.5 Porosity of the layer ................................................................................ 83 2.4.6 Contact angle and roll-off angles ............................................................ 84 2.5 Conclusions .......................................................................................... 85 2.6 Acknowledgments ................................................................................ 86 2.7 References ............................................................................................ 86 3 Mech. properties of highly porous super liquid-repellent surfaces .. 88 3.1 Abstract ................................................................................................. 88 3.2 Introduction .......................................................................................... 89 3.3 Results and discussion ........................................................................ 91 3.3.1 Wetting properties .................................................................................. 92 3.3.2 Finger and pencil scratching ................................................................... 93 3.3.3 Morphology ............................................................................................. 95 3.3.4 Nanoscale mechanical test using the atomic force microscope .............. 98 3.3.5 Microscale mechanical tests using colloidal probe .................................. 99 3.3.6 Microscale mechanical tests using nanoindentation ............................. 105 3.4 Conclusion .......................................................................................... 106 3.5 Experimental section .......................................................................... 106 3.6 Acknowledgments .............................................................................. 111 3.7 References .......................................................................................... 111 4 Spontaneous jumping and long-lasting bouncing of hydrogel drops from a superheated surface ............................................................... 114 4.1 Abstract ............................................................................................... 114 4.2 Introduction ........................................................................................ 115 4.3 Results ................................................................................................ 117 4.3.1 Preparation and characterization of millimetric hydrogel drops ............. 117 4.3.2 Determining the modulus of soft hydrogel drops ................................... 118 4.3.3 Heat-induced jumping and bouncing of 30 kPa hydrogels .................... 120 4.3.4 Effect of elastic modulus on jumping and bouncing .............................. 122 4.3.5 Jumping mechanism ............................................................................. 125 4.3.6 Observation of the contact time ............................................................ 127 4.4 Discussion .......................................................................................... 129 4.5 Methods ............................................................................................... 132 4.6 Acknowledgements ............................................................................ 134 6 Table of content 4.7 Further supporting information ......................................................... 135 4.8 References .......................................................................................... 135 5 Light-driven delivery and release of materials using liquid marbles138 5.1 Abstract ............................................................................................... 139 5.2 Introduction ......................................................................................... 139 5.3 Results and discussion ...................................................................... 141 5.4 Conclusions ........................................................................................ 155 5.5 Experimental section .......................................................................... 155 5.6 Acknowledgment ................................................................................ 158 5.7 References .......................................................................................... 158 5.8 Further supporting information ......................................................... 161 6 Conclusion .......................................................................................... 164 7 Appendix ............................................................................................. 166 7.1 Supplement information to chapter 1.2.9: Brief overview of contact mechanics to analyse force-sensitive measurements ..................... 166 8 List of publication ............................................................................... 170 8.1 Original paper ..................................................................................... 170 8.2 Books................................................................................................... 171 8.3 Patent applications ............................................................................. 171 9 Acknowledgment ................................................................................ 172 10 Curriculum Vitae ................................................................................. 173 10.1 Conference contributions .................................................................