Physical Chemistry of Colloids and Surfaces
Spring 200

Tu, Th 6:30-7:50 p.m.  DH 1102, Prof. Jim Schneider

bullet Announcements
bullet Homework Assignments
bullet Handouts
bullet MathCad Examples
bullet Course Overview
bullet General Information
bullet Grading Policies
bullet Course Outline
bullet Colloidal Links


5/1:  Here are the solutions to the practice problems and a review of the material covered for the final exam.  Please send me an email if you'd like to stop by and ask questions so I'm sure to be available.

4/25:  The final exam will be Thursday, May 2nd in class.  It will be closed-book and closed-note.  The exam will focus on the last part of the course, but keep in mind that you will need to understand many aspects of the earlier material to solve problems such as electrokinetics.  Here are some practice problems for the final; we'll discuss the solutions in class Tuesday night.  The equation sheet to be supplied with the final is here.

4/13:  There is a small correction to Homework #7.  The negative sign in the first equation should be switched to a positive sign.  Please download a new copy of the homework set.

4/9:  Lecture for Thursday, April 11th is canceled.  To make up for the cancellation, we'll have a shorter lecture on Thursday, April 18th, the night before carnival.  Thanks for your understanding.

4/1:  Here is the answer key for Midterm II.

3/25:  Here is a copy of Ray's overheads used during last week's lecture on the Derjaguin approximation and the Hamaker constant.

3/16:  The second midterm is Thursday March 21st in class.  Again, it will be closed-note and closed-book.  Here is the equation sheet you'll get with the exam and a practice exam to help you review.

3/1:  You may skip the last problem on the latest homework set.  Also, I included a sketch of aluminosilicate structure in the handouts section.

2/28:  I'll return Midterm I in class tonight.  A solution to the exam is posted in the handouts section.

2/26:  The linearized BET equation will give a linear plot for 0.05 > x > 0.35.  I've included a supplemental lecture on BET in the "handouts" section of the website.

2/26:  I've added a section to the website for handouts, etc. that have been passed out in class.

2/18:  Just to clarify, the exam tomorrow night will be closed-book and closed-note.  That means all you need to bring is a pencil, eraser, and calculator.  Necessary equations will be provided (see below).

2/13:  Here is an equation sheet you will be given along with the exam Tuesday.

2/13:  Here is a practice exam and a solution to help you study for Midterm I.

2/13:  The first midterm exam will be on Tuesday, February 19th from 6:30-9:00 p.m. in class (DH 1102).  The exam will be closed-book and cover all lecture material through Thursday, February 21st, and Sections 1.1-1.2, 1.5-1.6, and 2.1-2.4 in the textbook.  Numerical problems on the exam will only cover material from the first two homework sets.

1/30:  For problem 3 on HW #1, the answer is very sensitive to the viscosity chosen.  Please use a value of 0.0089 g/cm-s (0.89 cp) for problem 3.

1/18:  A summary of some colloidal definitions is here.

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Homework Assignments

HW#1 (1/22, due 1/31)            HW#1 solutions
HW#2 (1/31, due 2/12)            HW#2 solutions
HW#3 (2/12, due 2/19)            HW#3 solutions
HW#4 (2/21, due 3/5)              HW#4 solutions
HW#5 (3/5, due 3/14)              HW#5 solutions
HW#6 (3/26, due 4/9)              HW#6 solutions
HW#7 (4/9, due 4/18)              HW#7 solutions
HW#8 (4/18, due 4/30)            HW#8 solutions

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Brownian motion lectures
Gibbs dividing plane
Common applications of surfactants
Dynamic surface tension
BET surface area presentation
Exam I answer key
Isomorphic substitution in aluminosilicates
Monte Carlo simulation of electric double-layer

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MathCad Examples

Grahame equation

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Course Overview

So what is a colloid anyway?  And what does this have to do with a surface?

        A colloid is a two-phase system consisting of microscopic particles dispersed in a continuous fluid phase.  The particles are so tiny that thermal energy prevents them from settling, and in many ways they appear homogeneous.  Milk, latex paint, liquid soap, aerosols, and even beer are examples of colloids.  Under some conditions, the particles can be forced to aggregate and precipitate, such as when milk curdles with the addition of an acid.  As you might imagine, the aggregation or dispersion of colloidal particles is largely determined by attractive or repulsive forces felt between the surfaces of the particles.  Because colloidal particles have high surface-to-volume ratios, many other colloidal properties have their roots in inter-surface forces as well.  Broader definitions of colloids include any systems with a high surface-to-volume ratio, encompassing foams, vapor bubbles, and particles dispersed in a solid phase.  Colloids find widespread industrial application, including oil recovery, separations, paints, adhesives, biotechnology, food processing, and many more.

        In this course, we provide an introduction to colloid and surface science, with an overview of theoretical treatments of colloidal processes, experimental methods, and industrial applications.  Topics include flocculation, colloidal forces, surfactancy, adsorption, adhesion, wetting, and electrokinetic phenomena.  The course is intended for juniors, seniors, and graduate students in engineering, chemistry, physics, materials science, and biological sciences.  

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General Information

Instructor Teaching Assistant
Prof. Jim Schneider Min Luo
DH 3102A DH A109
268-4394 268-3984
Office Hours
5:00-6:30 p.m. Tu, Th
Office Hours
12:30-1:30 M, W


Required text:   The Colloidal Domain, Evans and Wennerstrom (1999), Wiley-VCH

On reserve in E&S Library:   
        Physical Chemistry of Surfaces, Adamson and Gast (1997), Wiley
        Intermolecular and Surface Forces, Israelachvili (1992), Academic Press
        Principles of Colloid and Interface Science, Hiemenz and Rajagopalan (1997), Marcel Dekker

Prerequisites:    A basic familiarity with undergraduate physical chemistry and/or chemical thermodynamics.  Contact instructor if you have questions.

For those considering the CPS option:  This is the first in a sequence of four required courses for the CPS option.  To receive the option, you will need to take Colloids Lab and Physical Chemistry of Macromolecules next fall and Polymers Lab next spring.

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Grading Policies

Grading components:  Your final grade will be a weighted average of the following:

                                    Midterm I  25% (In class, Tuesday Feb. 19th)
                                    Midterm II 25%  (In class, Thursday Mar. 21st)
                                    Final Exam 25% (In class, Thursday May 2nd)
                                    Homework 25%

Exams:  Exams are closed-book.  A sheet of equations to be included with the exam will be distributed for your review one week before the exam.  You should bring a small calculator to perform simple math calculations.  Only exams missed as a result of a documented illness or emergency can be retaken.  Interviews, plant trips, etc. must be scheduled around the exam dates.

Homework: Homework is due at the beginning of class on the assigned date.   Homework submitted after this deadline will be scored for feedback purposes, but will receive no credit. 

Regrading:  All requests for re-grading must be submitted in writing within one week of receipt of the graded homework or exam.  The written request must clearly identify the disputed work and justify the request for additional credit.  A randomly chosen fraction of homework and exams will be photocopied to verify that the homework or exam was not altered after grading.


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Course Outline


Topic Lecture Reading Assignment
     Examples of colloidal systems
1-2 Introduction
Transport of colloidal particles
     Brownian motion
     Flocculation and colloidal stability
3-5 Sec. 1.4-1.6
Surface energy
     Surface tension vs. surface energy
     Curved interfaces, Laplace equation
     Measuring surface energy
     Wetting and adhesion
6-8 Sec. 2.1-2.3
     Surfactant properties
     Adsorption of soluble surfactants
     Surface isotherms of insoluble surfactants
9-11 Sec. 2.4-2.6
Molecular-level interactions
     Van der Waals interactions
     Electrostatic interactions
12-14 Sec. 3.1-3.8
Self-assembled colloids
     The critical micelle concentration
     Surfactant microstructures
     Thermodynamics of self-assembly
15-18 Sec. 1.1-1.3
Sec. 4.1-4.3
Colloidal forces
     Colloidal forces and colloid stability
     Electrostatic double-layer forces
     Van der Waals forces
     Polymer-induced forces
     Hydrodynamic forces
     Measuring colloidal forces
19-22 Sec. 5.1-5.7
Colloidal stability
     DLVO theory and stability
     Aggregation kinetics
23-24 Sec. 8.1-8.3
     The zeta potential
     The streaming potential
25-26 Sec. 8.4
Colloids in biology and medicine
     Liposomal drug delivery
     DNA and protein separation
27-28 handouts

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Colloidal Links

bullet Center for Complex Fluids Engineering at CMU
bullet ACS Colloid and Surface Science Symposium at CMU last summer
bullet Digital Instruments, major supplier of AFM instrumentation

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