Capillary foams, methods of making thereof, and uses thereof including for mitigation of oil spills
Methods of making various capillary foams are provided. The foams can include liquid foams having a plurality of particles connected by a network of a secondary fluid at the interface between the discontinuous and continuous phase. The foams can also include solid foams where the continuous phases (bulk fluid) is removed to produce the solid foam having high overall porosities and low densities. Densities as low as 0.3 g cm −3 and porosities as high as 95% or higher can be achieved. The secondary fluid can be polymerized to further strengthen the solid foam. Methods and devices are also provided for oil recovery from water using a capillary foam. The methods can include forming a capillary foam wherein the oil is the secondary fluid, and wherein the foam can transport the oil to the surface of the water.
1. A liquid foam comprising
a continuous liquid phase comprising a bulk fluid,
a discontinuous phase comprising a gas, wherein the discontinuous phase is dispersed within the continuous phase to form a plurality of bubbles having an interface between the continuous phase and the discontinuous phase,
a secondary fluid and a plurality of particles adsorbed at the interface between the continuous phase and the discontinuous phase,
wherein the particles form networks connected by capillary or pendular bridges of the secondary fluid that span the space between bubbles.
2. The liquid foam according to claim 1 , wherein the bulk fluid is selected from the group consisting of water and other aqueous solutions, a C1-C5 alcohol, a C1-C5 glycol, a C1-C5 aminoalcohol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, dimethyl sulfone, sulfolane, and a mixture thereof.
3. The liquid foam according to claim 1 , wherein the secondary fluid is selected from the group consisting of trimethylolpropane trimethacrylate (TMPTMA), diisonyl phthalate (DINP), paraffin, and a combination thereof.
4. The liquid foam according to claim 1 , wherein the secondary fluid is selected from the group consisting of substituted and unsubstituted C12-C50 linear, branched, or cyclic alkanes; substituted and unsubstituted phenyl; and a combination thereof.
5. The liquid foam according to claim 1 , wherein the secondary fluid comprises a photopolymerizable monomer, a cross-linkable monomer, or a combination thereof.
6. The liquid foam according to claim 1 , wherein the secondary fluid is present in an amount from about 0.5 percent by weight to about 5 percent by weight based upon an entire weight of the bulk fluid.
7. The liquid foam according to claim 1 , wherein the gas is selected from the group consisting of air, oxygen, nitrogen, carbon dioxide, helium, neon, argon, and a combination thereof.
8. The liquid foam according to claim 1 , wherein the bubbles in the plurality of bubbles have an average diameter of about 10 μm to about 1000 μm.
9. The liquid foam according to claim 1 , wherein the liquid foam is stable for a period of time from about 1 day to about 14 days.
10. The liquid foam according to claim 1 , wherein the particles have an affinity for the interface between the secondary fluid and the gas that can be characterized by a contact angle from about 60° to about 120°.
11. The liquid foam according to claim 1 , wherein the particles have an affinity for the interface between the secondary fluid and the bulk fluid that can be characterized by a contact angle from about 60° to about 120°.
12. The liquid foam according to claim 1 , wherein the secondary fluid has an effective spreading coefficient in the liquid foam from about 5 mN m-1 to about 100 mN m-1.
13. The liquid foam according to claim 1 , wherein the particles are present at a concentration from about 0.1 wt % to about 10 wt based upon an entire weight of the foam.
14. The liquid foam according to claim 1 , wherein the particles are selected from the group consisting of polymer particles, metal particles, metal oxide particles, silica particles, and combinations thereof.
15. The liquid foam according to claim 1 , wherein the particles comprise polymers selected from the group consisting of homo- and co-polymers prepared from vinyl or acrylic monomers, homo- and co-polymers prepared from olefinic monomers, homo- and co-polymers prepared from functional polyaddition or condensation, copolymers thereof, and blends thereof.
16. The liquid foam according to claim 1 , wherein the particles comprise polymers selected from the group consisting of cellulose, chitin, starches and other polysaccharides, and derivatives thereof.
17. The liquid foam according to claim 1 , wherein the particles have an average diameter from about 50 nm to about 1000 nm.