Final Report Summary - CAPS (Capillary suspensions: a novel route for versatile, cost efficient and environmentally friendly material design)
The mechanical properties of a suspension can be dramatically altered by adding a small amount of a secondary fluid that is immiscible with the bulk phase. The substantial changes in the strength of these capillary suspensions arise due to the capillary force inducing a percolating particle network. This transition is similar to the difference between a dry sand pile and a sandcastle with the addition of water, but occurs at a much smaller scale and at lower particle fractions. Using confocal microscopy, we can observe the 3D particle network and observe how the network microstructure relates to the material strength. These microscopic images show us that a sample-spanning network can be build both when the secondary fluid preferentially wets the particles and even when the contact angle is greater than 90°.
Suspensions are ubiquitous; a wide variety of materials including coatings and adhesives, emerging materials for nanotechnology products, as well as everyday food products are processed or delivered as suspensions. We can therefore use this capillary suspension concept to create smart, tunable fluids, stabilize mixtures that would otherwise phase separate, significantly reduce the amount organic or polymeric additives, and the strong particle network can be used as a precursor for the manufacturing of cost-efficient porous ceramics and foams with unprecedented properties. This stabilization and increase in strength has also been demonstrated using water based cocoa suspensions. The natural cocoa butter in the particles can be used to build a particle network and thicken the suspension to create a low fat chocolate spread.
Suspensions are ubiquitous; a wide variety of materials including coatings and adhesives, emerging materials for nanotechnology products, as well as everyday food products are processed or delivered as suspensions. We can therefore use this capillary suspension concept to create smart, tunable fluids, stabilize mixtures that would otherwise phase separate, significantly reduce the amount organic or polymeric additives, and the strong particle network can be used as a precursor for the manufacturing of cost-efficient porous ceramics and foams with unprecedented properties. This stabilization and increase in strength has also been demonstrated using water based cocoa suspensions. The natural cocoa butter in the particles can be used to build a particle network and thicken the suspension to create a low fat chocolate spread.