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US-12625134-B2 - Complex liquid crystal droplets

US12625134B2US 12625134 B2US12625134 B2US 12625134B2US-12625134-B2

Abstract

Articles (e.g., a colloid) and methods for providing complex colloids comprising a hydrocarbon phase (e.g., a hydrocarbon phase comprising a liquid crystal) and a fluorocarbon phase are generally described. In some embodiments, the hydrocarbon phase and the fluorocarbon phase are distinct.

Inventors

  • Timothy Manning Swager
  • Cassandra Zentner
  • Alberto Concellon Allueva

Assignees

  • MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Dates

Publication Date
20260512
Application Date
20200824

Claims (20)

  1. 1 . An article, comprising: an aqueous phase; a mesogenic surfactant; a droplet, wherein the droplet comprises a hydrocarbon phase, second phase immiscible with the hydrocarbon phase such that an interface is formed between the hydrocarbon phase and the second phase, wherein the article comprises a second interface formed between the hydrocarbon phase and the aqueous phase, wherein the hydrocarbon phase comprises a liquid crystal, and wherein the mesogenic surfactant anchors the liquid crystal to the second interface thereby directing orientation of the molecules of the liquid crystal within the droplet.
  2. 2 . The article of claim 1 , wherein the second phase comprises a fluorocarbon phase, and wherein the hydrocarbon phase and the second phase have a relative interfacial tension of at least 3 mN/m.
  3. 3 . The article of claim 1 , wherein the liquid crystal is smetically ordered.
  4. 4 . The article of claim 1 , wherein the liquid crystal is cholesterically ordered.
  5. 5 . The article of claim 1 , wherein the second phase is a fluorocarbon phase comprising a hydrofluoroether.
  6. 6 . The article of claim 1 , wherein the droplet comprises a Janus droplet.
  7. 7 . The article of claim 1 , wherein the droplet comprises a plurality of Janus droplets.
  8. 8 . The article of claim 1 , wherein the hydrocarbon phase and the second phase form a Janus droplet.
  9. 9 . The article of claim 1 , wherein the hydrocarbon phase and the second phase form an asymmetric Janus droplet.
  10. 10 . The article of claim 1 , wherein the mesogenic surfactant is a nonionic surfactant.
  11. 11 . The article of claim 1 , further comprising an emulsifying agent.
  12. 12 . The article of claim 1 , wherein the second phase comprises a fluorocarbon phase, and wherein the aqueous phase, the hydrocarbon phase, and/or the second phase have a relative interfacial tension of at least 4 mN/m and at most 8 mN/m.
  13. 13 . The article of claim 1 , wherein the liquid crystal comprises at least one point defect.
  14. 14 . The article of claim 1 , wherein the droplet further comprises a plurality of functional groups dispersed uniformly over a surface at a first temperature such that the plurality of functional groups localizes into one of more clusters by a phase transition of the liquid crystal within the droplet.
  15. 15 . The article of claim 1 , wherein molecules of the liquid crystal align perpendicularly to the aqueous phase.
  16. 16 . The article of claim 1 , wherein molecules of the liquid crystal align parallel to the aqueous phase.
  17. 17 . An article, comprising: an aqueous phase; a nonionic surfactant; a droplet, wherein the droplet comprises a hydrocarbon phase, second phase immiscible with the hydrocarbon phase such that an interface is formed between the hydrocarbon phase and the second phase, wherein the article comprises a second interface formed between the hydrocarbon phase and the aqueous phase, wherein the hydrocarbon phase comprises a liquid crystal, and wherein the nonionic surfactant anchors the liquid crystal to the second interface thereby directing orientation of the molecules of the liquid crystal within the droplet, and wherein the nonionic surfactant comprises Formula (I): wherein designates connection from an intervening chemical species.
  18. 18 . A method for preparing the article of claim 17 , comprising: providing an aqueous phase, a hydrocarbon phase, and a fluorocarbon phase, wherein the hydrocarbon phase comprises a liquid crystal; providing a non-ionic surfactant, wherein the nonionic surfactant comprises Formula (I): wherein, designates connection from an intervening chemical species; emulsifying the aqueous phase, the hydrocarbon phase, the fluorocarbon phase with an emulsifying agent; and evaporating the emulsifying agent to prepare a colloid.
  19. 19 . The method of claim 18 , comprising applying a stimulus to change the position of the hydrocarbon phase and the fluorocarbon phase.
  20. 20 . The article of claim 19 , wherein the stimulus is light.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 62/925,756, filed Oct. 24, 2019, and entitled “COMPLEX LIQUID CRYSTAL DROPLETS,” which is incorporated herein by reference in its entirety for all purposes. This Application is also a continuation-in-part of U.S. application Ser. No. 16/201,961 filed Nov. 27, 2018, entitled “SYSTEMS INCLUDING JANUS DROPLETS,” which is a continuation-in-part of U.S. application Ser. No. 16/113,520 filed Aug. 27, 2018, entitled “SYSTEMS INCLUDING JANUS DROPLETS,” which is a continuation of U.S. application Ser. No. 15/269,543, filed Sep. 19, 2016, entitled “SYSTEMS INCLUDING JANUS DROPLETS,” and this application is a continuation-in-part of U.S. application Ser. No. 14/929,117, filed Oct. 30, 2015, entitled “COMPOSITIONS AND METHODS FOR FORMING EMULSIONS,” which claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application Ser. No. 62/073,896, filed Oct. 31, 2014, each of which is incorporated herein by reference in their entirety. GOVERNMENT SUPPORT This invention was made with government support under N00014-18-1-2878 awarded by the Office of Naval Research. The government has certain rights in this invention. FIELD OF THE INVENTION The present invention generally relates to systems and methods including Janus droplets. Articles and methods for providing colloids comprising liquid crystals are also generally described. BACKGROUND Emulsification is a powerful age-old technique for mixing and dispersing immiscible components within a continuous liquid phase. Consequently, emulsions are central components of medicine, food, and performance materials. Complex emulsions, including multiple emulsions and Janus droplets, are of increasing importance in pharmaceuticals and medical diagnostics, in the fabrication of microdroplets and capsules for food, in chemical separations, for cosmetics, for dynamic optics, and chemical separations. However, quantitative detections of analytes with high sensitivity and selectivity using Janus droplets have yet to be realized. Accordingly, improved systems and methods are needed. SUMMARY OF THE INVENTION The present invention provides systems and methods including Janus droplets. In one aspect, an article comprising a colloid is described. The article may comprise an aqueous phase, a surfactant disposed within the aqueous phase, and a droplet surrounded by the aqueous phase, wherein the droplet comprises a hydrocarbon phase and fluorocarbon phase, and wherein the hydrocarbon phase comprises a liquid crystal. In one aspect, a method for preparing a colloid is described, the method comprising suspending a droplet comprising a hydrocarbon phase and a fluorocarbon phase in an aqueous phase, wherein the hydrocarbon phase comprises a liquid crystal, dissolving a non-ionic surfactant in the aqueous phase, emulsifying the aqueous phase, the hydrocarbon phase, the fluorocarbon phase with an emulsifying agent, and evaporating the emulsifying agent. In another aspect, emulsions are provided. In some embodiments, the emulsion comprises an outer phase, a plurality of droplets dispersed within the outer phase, wherein the plurality of droplets comprise two or more components, wherein the two or more components are substantially miscible at a first temperature, and wherein the two or more components are substantially immiscible at a second temperature. In another aspect, methods for forming an emulsion are provided. In some embodiments, the method comprises adjusting the temperature of a fluid to a first temperature, wherein the fluid comprises a first phase and a second phase substantially immiscible in the first phase, wherein the second phase comprises two or more components that are substantially miscible with each other, emulsifying the fluid, and adjusting the temperature of the fluid to a second temperature, such that the two or more components become substantially immiscible. In another aspect, systems are provided. In some embodiments, the system comprises a plurality of Janus droplets associated with binding moieties to an analyte, the binding moiety and analyte selected such that when the analyte binds to the binding moiety at least a portion of the plurality of Janus droplets are changed in orientation sufficient to change electromagnetic radiation interacting with the plurality of Janus droplets in a detectable manner. In some embodiments, the system comprises a plurality of Janus droplets associated with a plurality of binding moieties to an analyte and a detector positioned relative to the plurality of Janus droplets such that when sufficient numbers of the binding moieties bind to analyte at least a portion of the plurality of Janus droplets are changed in orientation sufficient to change electromagnetic radiation interacting with the Janus droplets in a manner determinable by the detector. In certain embodiments, a hydrocarbon phase and/or a fluorocarb