On rainy days, some raindrops run down the surface of umbrellas, but others stay in place. What's the reason for these types of differences? What properties should be studied and improved? Static wetting of solids has been mainly dealt with in colloid and interface science, and dynamic wetting of solids in fluid mechanics and mechanical engineering. This course will cover science that bridges the gap between those two in order to "control static and dynamic wetting on solid surfaces". This is an "interactive" course. For the first 12 classes, students will learn the science of wetting, and then everyone will create and present research proposals on wetting control. Students will deepen their understanding of the "wetting of solid surfaces" through relevant debate.
The purpose of this course is for students to gain an understanding of the effect the structure of solid surfaces and their size and layers, the ratio of size and change of chemical composition and their distributions, etc. have on the wetting of solid surfaces, such that students can build a foundation for controlling these factors to produce desired properties. Students will learn the skills for applying knowledge from surface chemistry and interfacial chemistry related to solids.
By the end of this course, students will be able to :
1) Understand fundamentals of surface wettability.
2) Acquire the knowledge on the technologies on surface wettability control and its evaluation.
3) Apply the fundamental knowledge on wettability to the design of various surface functional materials.
wettability, contact angle, sliding angle, surface energy, Young's equation
|✔ Specialist skills||Intercultural skills||✔ Communication skills||✔ Critical thinking skills||✔ Practical and/or problem-solving skills|
The course contents will be provided in 12 classes, then students should give presentation on the research proposal about the topics on surface wettability. The presentation, questions to other presenters, and final version of the proposal (within 10 sheets) are evaluated for grading.
|Course schedule||Required learning|
|Class 1||Introduction-fundamentals of solid surface: course outline, definition of surface, difference between static and dynamic wettability||Outline of the class is presented.|
|Class 2||Fundamentals of solid surface: ideal surface, well-defined surface, real surface, surface relaxation, surface reconstruction, surface roughness, adsorption equilibrium||Classification of the solid surface structure is presented.|
|Class 3||Various solid surface: inorganic materials, organic materials, good solvent, poor solvent, LTT structure, self-assembled monolayer||Surface characteristics on various solids are explained.|
|Class 4||Surface energy I: thermodynamics on wetting, Young-Dupre equation, contact angle, Gorofalco-Good equation||The origin and characteristics of surface energy are presented.|
|Class 5||Surface energy II: Berthelot theory, Fowkes theory, surface energy measurement||The origin and characteristics of surface energy are presented.|
|Class 6||Surface energy III: Laplacian pressure, Kelvin equation, capillary length, line tension, effect of surface roughness||Effect of surface roughness on the wettability of solid surface is presented.|
|Class 7||Dynamic wettability I: limit of static wettability, Furmidge equation, contact angle hysteresis and sliding angle||Difference between static wettability and dynamic one is explained.|
|Class 8||Dynamic wettability II: pinning, sliding mode, particle image velocimetry||Evaluation of dynamic wettability and the factors that affect the property are explained.|
|Class 9||Dynamic wettability III: sliding and evaporation, effects of surface energy distribution and its morphology||Effect of surface energy distribution on the dynamic wettability is presented.|
|Class 10||Wettability control by external fields: electric field, magnetic field, wind blowing||Explain the effects of mechanisms other than gravity such as electric fields, magnetic fields, and wind on the dynamic behavior of water drops.|
|Class 11||Functional materials using wettability I: superhydrophobic surface, anti-snow adhesion||Recent study on superhydrophobic surface is presented.|
|Class 12||Functional materials using wettability II: photoinduced superhydrophilicity of TiO2 photocatalyst||Recent study on superhydrophilic surface is presented.|
|Class 13||Research proposal presentation by students1: surface structure and chemistry design||Preparation of presentation and resume. Discussion on the presented topics.|
|Class 14||Research proposal presentation by students2: applying external field||Preparation of presentation and resume. Discussion on the presented topics.|
|Class 15||Research proposal presentation by students3: evaluation and analysis||Preparation of presentation and resume. Discussion on the presented topics.|
No text book. Original materials will be presented by the instructor.
Akira Nakajima "Kotaihyoumen no Nure Seigyo" Uchida Rokakuho Press. Tokyo Japan
Research proposal: presentation 30%, questions to other presenters 30%, final term paper (within 10 sheets) 40%.
Fundamental understanding of thermodynamics (undergraduate level), English competency for understanding English lecture