Undergraduate Engineering Program In Nanomaterials, Macromolecules And Interfaces

A coursework sequence for chemical engineering undergraduates is offered by the Colloids, Polymers and Surfaces (CPS) Program at Carnegie Mellon University to provide education about technology applications in nanomaterials, macromolecules and interfaces. This program has developed and improved over the last 30 years for two main reasons: continued interest from industry to hire graduates with this background and the sustained expertise and commitment of faculty in these research areas. The coursework includes the physical chemistry of colloids and polymers coupled with an intensive lab experience that covers classical physical characterization methods. The lab experience also includes exposure to examples of relevant products and processes used in industry. Recently, the program was expanded to a minor in Colloids, Polymers and Surfaces (CPS) and is available to all engineering majors in the college of engineering at Carnegie Mellon. A short review of the program content will be presented. Assessment of the program will include input from employers and graduates of the program. This paper describes how a novel program to enhance undergraduate education in engineering developed because of an alliance that was formed between industry and the research university. History of the Program An elective undergraduate four course sequence in Colloids, Polymers and Surfaces (CPS) was initiated for chemical engineering students in 1978 at Carnegie Mellon University. It followed logically from the introduction of a graduate program in 1972 that granted a Master of Science degree on these topics. In 2003, the coursework sequence was offered to all engineering undergraduates at Carnegie Mellon, with the purpose of providing these topics to an increasing audience of students interested in engineering applications of nanomaterials and macromolecules. This paper describes how the development of a Master’s program resulted in a minor for engineering undergraduates that is relevant to industrial technology. The CPS graduate program developed because the late Dr. Howard Gerhart, then vice president for R&D at PPG Industries and later adjunct professor of chemical engineering at Carnegie Mellon University, took the lead in approaching Carnegie Mellon with specifics of his company’s needs in basic training and continuing education for technical employees. His requirements fit well with existing planning by the polymer research group of the chemistry department to launch a graduate curriculum in polymers and by the chemical engineering department to introduce colloid and surface science as a focus for graduate study. The result was a new interdisciplinary graduate program titled “Colloids, Polymers and Surfaces”, beginning with lecture courses in 1972 and hands-on laboratory training added in 1974. On the academic side it was a cooperative effort under the direction of Professor D. Fennell Evans, employing personnel and physical resources of both the chemistry and chemical engineering departments. Input of R&D supervisors from eight local industries came from the Advisory Board, who participated in major policy decisions and periodic reviews, and encouraged qualified employees P ge 13303.2 to take advantage of this unique educational opportunity, with tuition underwritten entirely or in part by the employer. Program Content and Philosophy The rationale for combining the three areas of colloid, polymer and surface science in a single curriculum addresses problems not of traditional industries alone but of emerging high technologies in medical, biological and interfacial science. Surface chemistry deals with interactions at boundaries where two phases meet. Equilibrium states as well as kinetic events at such interfaces depend upon the phenomena of surface tension, adsorption and desorption, condensation and evaporation, and the like. Colloid chemistry deals with materials dispersed in a continuous medium in units of size from 10 to 10 cm (10 Å to 10 Å). Colloidal units in dispersions may be single particles containing many molecules (as condensed solids or liquids), or aggregates of many molecules in thermodynamic equilibrium (as micellar surfactants) or the subunits may actually be joined by covalent bonds (as macromolecules or polymers of natural or synthetic origin). What colloidal systems have in common, and what links them to surface chemistry, are the peculiar properties that follow from the presence of a material boundary or discontinuity of submicroscopic scale, and the relatively enormous extent of that boundary, i.e. the high ratio of surface to mass that prevails when matter is finely subdivided. Some of the interesting properties of colloidal dispersions are enhanced physical and chemical reactivity, scattering of light, hydrodynamic properties, osmotic and electrical phenomena. Polymer physical chemistry, a historical offshoot of colloid chemistry, employs many of the same methods of experimentation that are useful for colloids in general. There is certain cohesion in the common intellectual framework of thermodynamics and statistical mechanics, useful in attacking most problems confronting researchers in colloids, polymers and surfaces. Exclusion of any one of the three areas removes at the same time a substantial zone of overlap wherein lie some of today’s most exciting and difficult challenges. The educational focus of CPS core courses is first to teach theoretical chemical and physical concepts that account for the properties of macromolecules and nanoparticles, including the critical role of surface phenomena. This is accomplished with two physical chemistry lecture courses, one covering colloids and surfaces and the other macromolecules followed by two lab courses in characterization techniques. The Physical Chemistry of Colloids and Surfaces lecture course includes topics such as thermodynamics of surfaces; adsorption at gas, liquid, and solid interfaces; capillarity; wetting, spreading, lubrication and adhesion; properties of monolayers and thin films; preparation and characterization of colloids; colloidal stability, flocculation kinetics, micelles/association colloids, electrokinetic phenomena and emulsions. 1,2 The Physical Chemistry of Macromolecules lecture course covers methods for synthesis, processing and testing of polymers P ge 13303.3 that are currently used in industry including topics such as physical, chemical and mechanical properties, their relationship to chain structure and molecular weight, glass transition temperature, rubber elasticity and polymer rheology. 3, 4 Applications of the theoretical principles covered in lecture courses to the characterization and manipulation of complex systems, which confront industry in everyday production, development and trouble-shooting, are the tools which students gain from this experience. The requirement of a full year of laboratory training is not meant to turn out accomplished technicians but to reinforce, extend and make tangible the theory which has been learned. It has the further practical value of showing students what can be learned from the appropriate design and choice of investigational tools with full appreciation of both the power and the limitations of available modern methods. CPS Laboratory Experience Students describe the CPS laboratory exercises as “hands-on-theory”, a union of theoretical framework and experimental technique. Each experiment is designed to explore aspects of the principles covered in the lecture courses. Colloids, polymers, and surfaces are evaluated and characterized using state-of-the-art instruments. The initial set of classical experiments was developed over 30 years ago by the late Emerita Professor Ethel Casassa and Rosemary Frollini to complement topics covered in the physical chemistry courses; these continue to serve the program well and have been adapted over the years to involve new equipment, new techniques, and current applications. Experiments are added to the curriculum with the acquisition of instruments which reflect current and expanded research expertise by the faculty. Presently, two semesters of laboratory courses are offered to undergraduates: Experimental Colloid and Surface Science and Experimental Polymer Science. A brief description of the experiments comprising each follows. Experimental Colloid and Surface Science Experiments • Surface Tension Determinations by the Dipping Ring Method Pure liquids, solutions, and liquid-liquid interfaces are studied. Topics include surface free energy, surface excess, intermolecular forces, and the influence of solutes on surface tension. • Contact Angle Determination by the Sessile Drop Method Equilibrium contact angle of liquids and critical surface tension of wetting of polymer surfaces are related to adhesion, detergency, surface energy, spreading, and non-ideal surfaces. • Critical Micelle Concentration of a Surfactant Solution P ge 13303.4 Abrupt changes in physical properties of a solution series are used to determine the critical micelle concentration of an ionic surfactant. Experimental methods include dye solubilization, conductance, surface tension, and foaming behavior. • Surface Area of a Powder by Gas Adsorption Specific surface area of a fine powder is determined by measuring the low temperature adsorption of nitrogen at the gas-solid interface and then constructing a Brunauer, Emmett, & Teller (BET) isotherm. • Surface Area of a Porous Solid by Adsorption from Solution Equilibrium concentrations of a series of acidic solutions are measured by computerassisted titration and used to construct a Langmuir isotherm. Topics include solution equilibrium, monolayer formation, chemisorption, and effects of temperature, adsorbent size and structure. • Adsorptive Bubble Separation A bubble fractionation column produces a concentration gradient due to differences in surface activities of the solution components. After concentrations of samples from along