The demands on preparing, processing, and characterizing novel materials and structures and the need for full exploration of the parameter space has led to the development of a plethora of multi-variant approaches. Some of these methods are based on decorating surfaces with a position-dependent and gradually varying chemistry. In these so-called "gradient surfaces", the gradient in surface energy is responsible for a position-bound variation in physical properties, most notably the wettability. In my presentation, I will discuss details pertaining to several projects currently under way, which will demonstrate that surfaces with well-defined characteristics can be prepared by engineering novel soft-materials and controlling their assembly on surfaces. Specifically, I will talk about forming molecular and macromolecular gradients with tailorable surface properties; I will also outline novel means of measuring their physico-chemical characteristics. I will document that very good control over the chemistry and physical properties of the gradients on the substrate can be achieved. I will demonstrate that the gradient-based technology allows for preparation of substrates covered with surface anchored polymers with a gradual variation of polymer grafting density, molecular weight, and composition. I will also discuss how these gradient structures can be utilized as soft material scaffolds that govern the spatial distribution of nano-sized object (such as nanoparticles or proteins).
Chemical Engineering Department
North Carolina State University
Riddick Labs, PO Box 7905
Raleigh, NC 27695-7905 USA
Phone: 919-515-2069 Fax: 919-515-3465