(604h) Collagen-Based Dispersions and Associated Applications

Collagen is a biodegradable polymeric fibrous protein found in all animals. In a series of steps, the collagen molecule assembles into a fiber that has the appearance of a rope. The material is insoluble in water, but can retain many times its own mass in water near its charged surface. The ability to unravel the fiber thus maximizing the surface area is the key physical property that leads to numerous environmental and biotechnological applications. With regard to environmental applications, when added to sludge or any material with suspended solids, a collagen dispersion causes agglomeration, the formation of large flocs, and settling, all at a very rapid rate. The material has proven to be effective in the rapid agglomeration of fine solids in all types of sludge: industrial, water treatment, waste water, and inert suspensions. Kaolin based suspensions were used as a standard in the settling experiments, bench scale and pilot scale.

Collagen dispersions may also be used in other environmental applications such as, as an aid to filtration, separation of pollutants (including metals and soluble organic molecules) from aqueous streams, selective fractionation of molecules, and oil droplet stabilization. Moreover, because treated collagen can hold hundreds of times its mass in water, the nanofibrils have application in water purification (with minimal energy consumption) and in water siphoning. All of these applications are based on the affinity of the activated surface of collagen, carrying positive charges, for the negative end of the polar water molecule. Further processing of the dispersions yields products suitable for biotechnological applications. When the collagen dispersion is frozen and then freeze dried, the resulting material retains the overall dimensions of the original frozen material. However, over 99% of the volume is empty and the structure of the protein is a spongy organic aerogel with controllable pore size, good mechanical properties and a density of one thousandth of water. This solid material can be crosslinked to anchor the shape, pore size and morphology.