The City College of New York
Phone: (212) 650-6701
Surface engineering, templated crystallization, biosensors, surfactant facilitated wetting of hydrophobic surfaces.
ALEXANDER COUZIS, the Herbert G. Kayser Professor and chairman of the chemical engineering department at The City College of New York, has a BS in chemical engineering from the National Technical University, Athens, Greece and MS and PhD degrees in chemical engineering from The University of Michigan.
The technological, environmental and biological importance of adsorption of organic material from solution onto a solid surface cannot be overestimated. The impact of such phenomena on our everyday lives is obvious in areas such as food science and packaging, detergency, the extraction of petroleum resources, lubrication, the use of paints, inks, adhesives and protective coatings, magnetic recording media, optics, microelectronics, delayed drug release and artificial organs in medicine. Each of these applications, and many more that involve the stability of colloidal dispersions, modification of solid surfaces for the control of wetting and lubrication, would be difficult, if not impossible, in the absence of the effect of adsorbed polymers, surfactants and stabilizers at the solid-liquid interface. The presence of these materials on the solid-liquid interface can alter significantly phenomena related to wetting, adhesion, lubrication, friction, wear and corrosion adhesion and wetting studies, and therefore it is vital to have a complete and thorough understanding of their formation process. The main research of this program focus is the study of adsorption phenomena occurring at the interface of a polymer or surfactant solution and a solid substrate. Furthermore, we are interested in characterization of these thin organic films and their response to ambient changes, which would indicate their applicability for use as sensors. Additionally, the ability of some polymers or surfactants to form well-ordered domains (self-assembled monolayers) on the solid-liquid interface under certain conditions can lead to the development of optically or electronically active materials or to the realization of engineered surfaces properties with direct application in the areas of templated crystallization, controlled wetting and sensors devices.
Three projects are under way:
Templated Crystallization (in collaboration with Prof. Maldarelli): The objective is to design solid surface nano templates for the heterogeneous crystallization as seeds of one form of a crystalline material that can exist in several polymorphic forms. These polymorph-specific seeds are then used to control the selective crystallization in a bulk industrial crystallizer. The approach employs self-assembled silane or organosulfur monolayers that bond to solid supports to functionalize surfaces with chemical moieties. The moieties are selected so that the surface mimics a crystalline face of the desired polymorph. This face nucleates on the surface, and the mature crystal of the desired polymorph grows.
Engineering of Molecularly Thin Organic Layers for Water andOrganic Vapor Barriers: We investigate the use of self-assembled monolayers for organic and water vapor barrier applications. We focus on understanding the relationship between vapor permeability and structure of the molecular film. The final benefit will be the development of novel membrane materials that can be used in the fabrication of devices such as implanted medical devices like miniature blood analyzers, super-efficient filtering devices (such as needed in dialysis equipment), pollution-control devices and specific chemical sensors.
Surfactant Facilitated Wetting of Hydrophobic Surfaces (in collaboration with Prof. Maldarelli): The objectives of this project are to develop and validate a mechanism to explain the observed enhancement in the wetting of water on hydrophobic surfaces by the use of siloxane surfactants and to use this mechanism to further develop surfactant wetting systems capable of facilitating water wetting on non-polar surfaces.