ChE 385M Surface Phenomena Spring 2013 Course Description: The effects due to the presence of interfaces become important at the micron length scale and smaller, and they often have macroscopic consequences. These surface phenomena have become increasingly important as the size of engineering systems and processes continue to shrink, as for example for microelectronics, labs-on-achip, nanomanufacturing, and polymer processing. It is also important for many biological systems such as how geckos stick to walls and cell motion. This course will focus on phenomena derived from the presence of a surface or interface between two or more phases, particularly those involving surface tension, van der Waals forces and electrical double layers, and to a much lesser extent steric, solvation and Brownian forces. Several of these surface phenomena will be described and discussed qualitatively and quantitatively. The specific goals of the course are to:
Introduce van der Waals interactions and their consequences Introduce the concept of surface energy/tension and its applications Introduce the phenomena of electrical double layers. Study and analyze the static and dynamic consequences of these forces Develop some skill at modeling such interfacial processes.
To achieve these goals the following specific topics will be studied: • Molecular origin of surface energy • Thermodynamics of interfaces • Some effects of surfactants • Surface-tension driven flows • Poisson-Boltzmann Equation • Electrophoresis
• Van der Waals forces • Electrical double-layer forces • Interfacial stress balance • Linear stability theory • Electroosmosis • Suspension & emulsion stability
Class Meeting: TTh 11:00am-12:30pm, CPE 2.216 Instructor: Dr. Roger Bonnecaze
[email protected]
CPE 5.454 Office Phone: 471-1497 Office Hours: F 1:30-3:00pm & by appointment.
Teaching Asst.: Akhilesh Jain
[email protected]
CPE 5.472 Office Phone: 471-5082 Office Hours: M 3-4:30pm (CPE 4.446) & by appointment.
Prerequisites: 1) Graduate standing or instructor's permission. 2) Undergraduate courses similar in content to ChE 353, M 427K
Evaluation Method:
Homework Mid-Term Exams Project TOTAL
20% 50% 30% 100%
NOTE: This class may only be taken for a grade; no Pass/Fail. However, anyone is welcome to attend the lectures. Critical Dates: Last Day to ADD/DROP a course without approvals: January 17 Last Day to DROP a course without academic penalty: January 30 Mid Term Take-Home Exam 1: Given Tues., Mar. 5--Due Fri., Mar. 8 Mid Term Take-Home Exam 2: Given Thur., May 2--Due Mon., May 6 Project Proposal: February 28 Project Two-Page Extended Project Abstract: April 16 Final Project Report: May 2 Project Presentations: April 25, April 30 and May 2 Homework Policy: Problem sets will be assigned on every 10-14 days. Please complete the problem sets on time because the lectures and homework builds on previous homework. To discourage tardiness, homework will be counted 20% less for each day it is late. Homework may be handed in late without penalty only if prior arrangements have been made with the TA or instructor and there are extenuating circumstances. Also, homework should be neatly presented and only one side of each sheet of paper should be used. Exam Policy: Two mid-term, take-home exams will be administered by the honor system during the semester. You will receive the exam on the dates noted above. The exam is to be completed under some specified conditions on time and materials on your honor and returned to the grader or me within about three to four days. Project: Students will work in teams of two to devise and solve an illustrative problem in surface phenomena. The problem should be comparable in scope and difficulty to the more challenging homework problems given in this course. The projects are subject to my approval, which is based on a proposed problem (a typed one page problem statement with figures as necessary). The milestones are listed in the critical dates above and the final report should incorporate my comments and our discussions based on the problem proposal and a two-page extended abstract of the project. In addition one student from each group will give a 10 minute presentation to the class sometime toward the end of the course.
References: Unfortunately, there is no single comprehensive text for this course. The skills and information required to complete the problem sets and exams are for the most part contained in the lectures, but additional references and perspectives are always useful, so the below is a list of useful advanced texts on interfacial phenomena, fluid mechanics and applied mathematics. An Introduction to Interfaces and Colloids: The Bridge to Nanoscience, J. C. Berg Fundamentals of Interfacial Engineering, R.J. Stokes & D.F. Evans Intermolecular & Surface Forces, J. Israelachvili Physical Chemistry of Surfaces, A.W. Adamson & A.P. Gast Physicochemical Hydrodynamics, R.F. Probstein Interfacial Transport Processes and Rheology, D.A. Edwards, H. Brenner & D.T. Wasan Capillarity and Wetting Phenomena, P.G. de Gennes, F. Brochard-Wyart & D. Quere Lecture Outline: The course is composed of the following 30 lectures: 1. Course introduction 2. Dipole interactions 3. van der Waals interactions between surfaces 4. Electrical double-layer – Poisson-Boltzmann equation 5. Steric / Solvation / Hydrophobic Forces 6. Brownian motion 7. DLVO theory for colloidal stabilization 8. Electro-osmosis / Electrophoresis 9-10. Surface energy, surfactants 11. Interfacial stress balance 12. Asymptotic theories of the shapes of sessile and spinning drops 13-14. General theory for shape of sessile and pendant drops 15. Lateral capillary forces 16. Kelvin equation 17. Nucleation 18-19. Modeling and stability of thin films 20. Rayleigh or capillary instability 21. Capillary waves 22. Marangoni or surface-tension driven flow 23-24. Rayleigh-Benard instability 25. Electrowetting 26. Moving contact lines, contact angle hysteresis 27. Marangoni stabilization 28-30. Student presentations
