Massachusetts Institute of Technology

Sushant Anand

Kripa K Varanasi

J David Smith

Srinivas Prasad Bengaluru Subramanyam

Konrad Rykaczewski

Seyed Reza Mahmoudi

Ingrid Fuller Guha

Konrad Rykaczewksi

In certain embodiments, the invention is directed to apparatus comprising a liquid-impregnated surface, said surface comprising an impregnating liquid and a matrix of solid features spaced sufficiently close to stably contain the impregnating liquid therebetween or therewithin, and methods thereof. In some embodiments, one or both of the following holds: (i) 0<ϕ≤0.25, where ϕ is a representative fraction of the projected surface area of the liquid-impregnated surface corresponding to non-submerged solid at equilibrium; and (ii) S<0, where Sis spreading coefficient, defined as γ−γ−γ, where γ is the interfacial tension between the two phases designated by subscripts w, a, and o, where w is water, a is air, and o is the impregnating liquid.

Apparatus and methods employing liquid-impregnated surfaces

Methods described herein provide a way to reduce or eliminate drag and adhesion of a substance flowing over a surface by creating a vapor cushion via evaporation of a phase-changing material of or on the surface or encapsulated within textures of the surface. The vapor cushion causes the flowing substance to be suspended over the surface, greatly reducing friction, drag, and adhesion between the flowing substance and the surface. The temperature of the flowing substance is above the sublimation point and/or melting point of the phase-changing material. The phase-changing material undergoes a phase change (evaporation or sublimation) upon contact with the flowing substance due to local heat transfer from the flowing substance to the material, generating a vapor cushion between the solid or liquid material and the flowing substance.

Articles and methods for levitating liquids on surfaces, and devices incorporating the same

In certain embodiments, the invention is directed to apparatus comprising a liquid-impregnated surface, said surface comprising an impregnating liquid and a matrix of solid features spaced sufficiently close to stably contain the impregnating liquid therebetween or therewithin, and methods thereof. In some embodiments, one or both of the following holds: (i) 0&#x3c;&#x3d5;&#x2264;0.25, where &#x3d5; is a representative fraction of the projected surface area of the liquid-impregnated surface corresponding to non-submerged solid at equilibrium; and (ii) S&#x3c;0, where Sis spreading coefficient, defined as &#x3b3;&#x2212;&#x3b3;&#x2212;&#x3b3;, where &#x3b3; is the interfacial tension between the two phases designated by subscripts w, a, and o, where w is water, a is air, and o is the impregnating liquid.

Nanoscale emulsions can be made by means of condensing a liquid vapor onto another liquid. The precise size, chemical composition, and density of emulsions may be controlled through varying the experimental parameters, such as surfactant concentration, time of condensation, humidity, and temperature.

Growing community of inventors

Somerville, MA, United States of America

Sushant Anand