Green Surfactants Workshop
Church & Dwight Co.
Princeton, New Jersey
New York, New York
The goal of this new program is to gain a fundamental understanding of the surface and colloidal properties of surfactants derived from non-petroleum sources. Details of the program are being formulated now and will shortly be made available by Professor Somasundaran with some preliminary industrial inputs.
The Science Behind Printing Ink - A Lot More Than You Think
Sun Chemical Corporation
Carlstadt, New Jersey
This seminar will seek to connect printing science with associated physical chemistry of surfaces and colloids. A basic overview of printing processes, printing inks and the wide variety of chemistries possible will be presented. Five specific real world examples of the challenges involving surface and colloid science in this field will be discussed as case studies. Topics of relevance will include particle size analysis, rheology, energy curable materials, pigment surface chemistry, and dynamic aspects of printing.
Title: Advanced Techniques for Investigating Adsorption
DESCRIPTION OF THE WORKSHOP
Adsorptions of surface-active agents including polymers and biomolecules at solid/liquid interfaces have applications in a wide variety of industries. In these applications, the conformation & orientation of the adsorbed species alone can influence the interfacial properties dramatically. Various in-situ and ex-situ characterization techniques have been developed to probe the structure and composition of the adsorbed layer and the corresponding bulk structures on a molecular level. Techniques for examining practical complex systems are of particular interest in this regard. The aim of this workshop is to examine leading edge techniques for characterizing adsorbed layers as well as bulk structures and for studying mechanism of their formation including dynamics involved.
Dr. Greg Haugstad
Nanoscopic Characterization of Organic Films”
Prof. Robert Thomas
Scattering Methods for Investigating Thin Organic Films”
ABSTRACTS OF PRESENTATIONS
Nanoscale Characterization of Organic Films
Analytical techniques to study nanoscale structures and properties in organic materials are overviewed. Emphasis is on scanning and nanomechanical probes (imaging, local measurements); cryo electron microscopy and X-ray scattering are also discussed. Various scanning probe microscopy (SPM) methods are sensitive to mechanical response and tribology (friction/wear/lubrication), as well as chemical, electrostatic, and near-field optical properties. Tribological response relates not only to local mechanical compliance but also to intrinsic looseness, in turn a function of local order. Force-distance measurements, as performed with SPM-based nanomechanical tests or the JKR (surface-forces-like) apparatus, quantify local material parameters like modulus and surface energy. Three-dimensional SPM scanning procedures enable lateral mapping of the distance dependence of probe-sample interaction. Appropriate data reduction produces a “spectroscopic line shape” of probe-sample adhesion, for example, reflecting variations in local chemical and mechanical properties.
Scattering Methods for Investigating
Thin Organic Films
Until recently there have been no experimental techniques for probing the structure of air/liquid and solid/liquid interfaces and consequently they are poorly understood. These interfaces are particularly important in technology (colloids, detergents, biological systems, etc.). The use of the reflection and scattering of radiation for the investigation of surfaces will be assessed, where radiation is taken to include light, x-rays and neutrons. Special emphasis will be given to the relative strengths of the various techniques, i.e. small angle scattering, grazing incidence scattering, specular reflection, ellipsometry, and to the situations where each is most effective. The second half of the talk will be devoted to the range of experiments that can be done using neutron specular reflection and their relation to results from other techniques. Examples of single surfactants at air/liquid and solid/liquid interfaces and of more complex systems (mixtures, etc.) will be given.
Dr. GREG HAUGSTAD
Senior Research Associate and Director
IT Characterization Facility, University of Minnesota
Greg Haugstad graduated summa cum laude with a B.A. in physics from Gustavus Adolphus College. After a research fellowship at 3M studying electromagnetic absorption in “stealth”composites, he began his Ph.D. research in physics at the University of Minnesota investigating the electronic properties of metal semiconductor interfaces. The primary analytical tool was photoelectron spectroscopy. His postdoctoral fellowship was also at Minnesota in the Center for Interfacial Engineering (NSF ERC), in collaboration with member-company DuPont. The collaboration employed scanning probe microscopy (SPM) to examine interfacial systems in photographic media (including fluid environments). Greg is the director of the Characterization Facility at the University of Minnesota. His principal activity has been in the SPM and ion beam analysis laboratories to study nanoscale structures and properties focusing on polymeric materials.
Dr. ROBERT THOMAS
Physical & Theoretical Chemistry Laboratory
Department of Chemistry, Oxford University
Dr. Robert Thomas got his degree in Chemistry from Oxford University. He is now a lecturer in the Physical and Theoretical Chemistry Department. Most of his work has been devoted to using scattering methods (neutrons and x-rays) to study surfaces and interfacial systems. The principal work has been the development of neutron reflection as an experimental tool for studying wet interfaces, which he started to develop about 20 years ago. He is now applying it to a range of different systems. Neutron reflection facilities used in the work are the spallation source at ISIS (in UK), the high flux beam reactor at Grenoble, and occasionally neutron sources in the U.S.A. He has collaboration with industrial groups (Unilever, Kodak (U.K. and U.S.A.)) and with groups in other universities. He was made a Fellow of the Royal society in 1998.
Title: Polymeric Surfactants at Interfaces:
Structure, Methodology and Applications
DESCRIPTION OF THE WORKSHOP
Polymers such as cellulose, acrylates, acrylamides and pyrollidones are currently being modified for special performance in commercial applications. In this regard, hydrophobically modified polymers are finding increasing use in the manufacture of consumer products and in industrial operations. While their performance is certainly dependent upon the nature and degree of functionalization and the backbone, the relationship between structural modifications and performance is yet to be fully understood. This workshop is aimed towards discussing current applications in various fields and principles involved and identifying new research and development opportunities in the design of novel polymeric surfactants and their new applications.
Speakers and Discussion Leaders
• Prof. Ian D. Robb, North East Wales Institute
• Prof. Gerard Riess, Ecole Nationale Superieure de Chimie de Mulhouse
• Dr. Berislav Markovic, IAB Chair
• Dr. Paul Thau, PaCar Tech
• Dr. Phil Cummins, International Specialty Products
ABSTRACTS OF PRESENTATIONS
Polymeric Surfactants at Interfaces: Structure & Methodology
• Prof. Ian Robb
This lecture will cover the basic issues governing the behavior of polymeric surfactants in solution and in colloidal systems. Polymeric surfactants serve all the same functions as "normal" surfactants, the main difference being their greater molecular mass and higher order structural conformation. Certain classes of polymeric surfactants can associate in solution to give micelles. These micelles can solubilise materials such as drugs or associate to give large changes in viscosity, that can be used for suspending colloidal particles. Polymeric surfactants adsorb at surfaces, either of solids to give enhanced colloidal stability, or of liquids to control foaming or emulsion stability. The different molecular masses of polymeric surfactants mean that competitive adsorption affects other components in a formulation. Polymeric surfactants are subject to the same changes in solution properties as "normal” surfactants with changing solution conditions such as temperature and electrolyte. They also undergo complex conformational changes. Materials can be designed either to be impervious to these changes or to take advantage of them for triggered reactions.
Properties and Applications of Polymeric Surfactants
• Prof. Gerard Riess
Polymeric surfactants are gaining increasing importance and their interest arises mainly from their low CMC values and their low diffusion coefficients as compared to classical low molecular weight surfactants. Two categories of polymeric surfactants were examined: ", T and T functionalized oligomers, block and graft copolymers having hydrophobic and hydrophilic sequences. The dicarboxy terminated oligomers, with a hydrophobic block of polyester, PMMA or PS and styrenic, acrylic and malonic block copolymers were prepared and used as emulsion stabilizers, dispersing agents for pigments and in the preparation of styrenic and acrylic latexes, micro-latexes and microgels. The main advantage of the "hairy latexes" thus obtained in the presence of block copolymer surfactants is that the thickness of the PEO or PAA fringe on the latex surface can be adjusted as a function of the molecular characteristics (molecular weight, composition, structure) of the block copolymer. The applications of such surface modified latexes will be illustrated in controlled agglomeration processes of latex, in film formation of acrylic polymers, in the preparation of polymer particles with microvoids which are useful as organic white pigments and for controlled release of biomaterials. Further applications, such as the preparation of "solid emulsions" (dispersion of liquids in a polymeric matrix) will be outlined.
Prof. Ian Robb
Center for Water Soluble Polymers
North East Wales Institute
Dr. Robb studied for his PhD in Sydney, on the topic of emulsion polymerization and surfactant monolayers. In 1967 he joined Unilever Research, Port Sunlight, England, where he was involved in a wide range of industrial and academic projects including issues such as polymers surfactant interactions, adsorption of polymers, precipitation, colloidal materials and rheology. In 1995 he joined the Center for Water Soluble Polymers where he continued work on polymers, surfactants and their behavior in colloidal systems. He is currently Chairman of the Colloid and Interface Science, a sub-division of the Royal Society and Chemistry.
Prof. Gerard Riess
Ecole Nationale Superieure de Chimie deMulhouse
Professor Gerard Riess received his Chemical Engineering degree in 1954, his Dr-Ing. in Polymer Chemistry from the University of Strasbourg in 1957 and his Dr-es-Sciences in 1980. In 1959 he joined the Ecole Nationale Superieure de Chimie, and from 1968 to 1997 he has been full Prof. and head of Dept. at the University of Haute Alsace. Since then Dr. Riess has been a Professor Emeritus in Polymer Science. His academic research interest and his industrial experience as a consultant are in the areas of polymer synthesis, block and graft copolymers, polymer blends and colloidal systems. He is co-editor of 4 leading polymer journals, the author of over 230 scientific publications, 12 book chapters, and 45 patents. In 1993 he was promoted as Exceptional Class Professor, the highest rank in the French Universities and 1995 he received the Grand European Prize for Innovation. Professor G. Riess is an advisor to the French Law Court and a member of many Chemical Societies.