University USA
In the Department of Chemical Engineering, work is focused on the modification of surface properties for inorganics (glass, silicon, metals, etc.), polymers, nanoparticles, fibres, composites, etc. On the academic side, interest is to connect macroscopic interfacial events with molecular details of structure and composition about a surface.
On the industrial side, developed novel coating methods for metals, semiconductors, polymers, and other materials that produce:
Extremely thin barriers against corrosion;
Nanometre thick self-assembling films that retard biofouling;
A method whereby a surface reaction produces the driving force to allow drops to move on surfaces in a self-propelled manner;
Nanometre-thick non-fouling coatings with selective adsorption characteristics as needed in a waveguide-based biosensor;
A new strategy for immobilizing DNA to surface for generating of gene chips with enhance properties;
Magnetic nanoparticles with tailored surfaces that then serve as separation agents for proteins, water purification agents, etc.;
Methods that allow high-density polymer brushes to be grown from surface.
The approach is one based primarily on self-assembly, so the use of containers whereby materials could be dunked into them is one approach, but the approach of spraying or wiping on a solution, waiting, and them removing it as a way to allow surface coatings to form would certainly work.
For some systems, there is the concern that the solutions used for generating a film may become limited in their shelf life when overly exposed to moisture. This will depend on the surface and applications whether such a limitation would apply. In general, liquid delivery is the best and a spray or wipe would be among the best ways to apply the coatings they develop to surfaces. For some applications, there could be a need to say use wipe A, a short wait, and then follow by wipe B, again depending on particulars of a system/application.
Using a variety of techniques for surface modification and coating the researchers develop polymer films with barrier and ultra-barrier properties or with selective permeability to permanent gases, vapours and light. Further aims of their development work are the incorporation of functional components into composite films for technical applications (adsorbents, indicators, regulators right through to polymeric electronic elements).
The surface energy of high surface area, highly conducting carbon nanotube systems can be tuned by electronic doping to control surface properties. This charge injection can be either by doping with relatively small amounts of donors or acceptors or by electrochemical doping. It has been experimentally demonstrated that nanotube sheets and fibres (charged either capacitively by double-layer charge injection or by dopant intercalation) undergo order of magnitude increases in electrical conductivity.
Technologies being utilized include surface modification of polymer systems, switchable polymer surfaces (that either change their properties in response to contaminants or that can be switched on/off to clean a surface, such as a polymer brush), and incorporation of active compounds into polymer surfaces to affect the behaviour of other entities when they contact the surface. Modifying the surfaces of inorganic (oxide) particles by the grafting on of polymer systems could also have some application to how waste particles interact with their environment.
There is also research looking at the immobilization of radioactive and toxic waste in cements, glasses and ceramics that may provide unique opportunities to combine organic and inorganic skills in this area.
Anticipated Benefits:
Self-cleaning textiles, coatings and paints for effective decontamination of protective clothing or containment systems;
Highly responsive tunable and fully reversible sensors for hydrogen or other, molecular analytes which can be easily incorporated into composite coatings.
