US-20260126356-A1 - SELECTIVE LIQUID TRANSPORT SYSTEM AND PROCESS

US20260126356A1US 20260126356 A1US20260126356 A1US 20260126356A1US-20260126356-A1

Abstract

A methods and systems for separating and analyzing liquid samples wherein a liquid mixture having at least one transport liquid and at least one non-transport liquid is applied to a selective liquid-transport surface. The selective liquid-transport surface is on a substrate and defined by a liquid-repellant background surface on the substrate. The selective liquid-transport area is coated with a substance having a higher affinity with the transport liquid than the non-transport liquid. Additionally, there are methods of preparing the systems for use in separation and analyzing liquid samples.

Inventors

Yu Mao
Mengfan Zhu

Assignees

The Board of Regents for the Oklahoma Agricultural and Mechanical Colleges

Dates

Publication Date: 20260507
Application Date: 20221103

Claims (20)

1 . A selective liquid-transport device for separating a liquid mixture having at least one transport liquid and at least one non-transport liquid, the selective liquid-transport device comprising: a substrate; a liquid-repellant background surface on the substrate; and at least one transport-surface area defined by the liquid-repellant background, wherein the transport-surface area has a liquid-mixture introduction area, a transport-liquid track, and a transport-liquid receiving area; and wherein the liquid-repellant background is a liquid-impermeable barrier surrounding the transport-surface area so as to prevent flowing of both the transport liquid and the non-transport liquid from inside the transport-surface area to outside the transport-surface area; and wherein the transport-surface area is coated with a substance such that the liquid-mixture introduction area and at least a portion of the transport-liquid track adjacent to the liquid-mixture introduction area have a higher affinity with the transport liquid than the non-transport liquid such that the transport liquid selectively flows from the liquid-mixture introduction area through the transport-liquid track to the transport-liquid receiving area and the non-transport liquid selectively remains in the liquid-mixture introduction area.
2 . The selective liquid-transport device of claim 1 , wherein the transport surface is coated with a hydrophilic material.
3 . The selective liquid-transport device of claim 1 , wherein the transport surface is coated with a hydrophobic material.
4 . The selective liquid-transport device of claim 3 , wherein the hydrophobic material is a siloxane.
5 . The selective liquid-transport device of claim 1 , wherein the liquid-repellant background is coated with an omniphobic substance.
6 . The selective liquid-transport device of claim 5 , wherein the omniphobic substance is poly(1H,1H,2H,2H-heptadecafluorodecyl acrylate).
7 . A method for separating and analyzing liquid samples, the method comprising: obtaining a liquid mixture having at least one transport liquid and at least one non-transport liquid; placing a droplet of the liquid mixture onto an introduction area of a transport-surface area, wherein the transport-surface area has the introduction area, a transport-liquid track and a receiving area, and wherein the transport-surface area is coated with a substance having a higher affinity with the transport liquid than the non-transport liquid such that the transport liquid selectively flows from the introduction area through the transport-liquid track to the receiving area and the non-transport liquid selectively remains in the introduction area; allowing a sufficient amount of time for the transport liquid to flow across the transport-liquid track and into the receiving area of the selective liquid-transport surface so that the transport liquid collects in the receiving area; and subsequent to the step of allowing sufficient amount of time, analyzing at least one of (i) the transport liquid collected in the receiving area, and (ii) the non-transport liquid in the introduction area for one or more property.
8 . The method of claim 7 , wherein the transport-surface area is defined on a substrate by a liquid-repellant background surrounding the transport-surface area, and wherein the liquid-repellant background is a liquid-impermeable barrier so as to prevent flowing of both the transport liquid and the non-transport liquid from inside the transport-surface area to outside the transport-surface area.
9 . The method of claim 8 , wherein the collected transport liquid or non-transport liquid is analyzed by infrared spectroscopy.
10 . The method of claim 8 , wherein the one or more property is related to a compound dissolved in the collected transport liquid.
11 . The method of any of claim 8 , wherein the transport surface is coated with a hydrophilic material.
12 . The method of claim 8 , wherein the transport surface is coated with a hydrophobic material.
13 . The method of claim 12 , wherein the hydrophobic material is a siloxane.
14 . The method of claim 8 , wherein the liquid-repellant background is coated with an omniphobic substance.
15 . The method of claim 14 , wherein the omniphobic substance is poly(1H,1H,2H,2H-heptadecafluorodecyl acrylate).
16 . A method for producing a selective liquid-transport device having at least one transport-surface area comprising an introduction area, a transport-liquid track, and a transport-liquid receiving area, the method comprising: selecting a contiguous geometric shape for the transport-surface area such that the introduction area is in fluid flow communication with the transport-liquid track, and the transport-liquid track is in fluid flow communication with the transport-liquid receiving area; preparing a stamp in the geometric shape of the transport-surface area wherein the stamp includes a substance having a higher affinity with a transport liquid than a non-transport liquid; placing the stamp in contact with a substrate such that at least a portion of the substance is transferred to the substrate to produce a coating on the substrate in the geometric shape of the stamp; creating a liquid-repellant background area on the substrate surface such that the liquid-repellant background surrounds the transport-surface area, and wherein the liquid-repellant background is a liquid-impermeable barrier so as to prevent flowing of both the transport liquid and the non-transport liquid from inside the transport-surface area to outside the transport-surface area; and removing the stamp from the substrate.
17 - 20 . (canceled)
21 . The method of claim 16 , wherein the liquid-repellant background is coated with an omniphobic substance.
22 . The method of claim 21 , wherein the omniphobic substance is deposited onto the substrate surface by vapor deposition.
23 . The method of claim 22 , wherein the omniphobic substance is poly(1H,1H,2H,2H-heptadecafluorodecyl acrylate).

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of U.S. Provisional Application 63/276,241 filed Nov. 5, 2021, which is hereby incorporated by reference. FIELD The present invention relates generally to systems and methods to separate two immiscible phases of microliter droplets using open surfaces, such as, for example, may be used for diagnostics where processing of the samples involves liquid-liquid phase separation. BACKGROUND Miniature, cost-effective devices for sample separation have long been desired for medical diagnostics as well as analysis in areas such as process control and environmental monitoring. Traditional sample separation methods such as centrifugation, solvent extraction, and liquid-liquid phase separation require complex instrumentation and processing. Such traditional separation methods inflate the cost of diagnostics. Accordingly, cost-effective methods involving smaller samples are desirable. SUMMARY The methods, systems and apparatuses herein cover the use of a fast, disposable, inexpensive way to prepare a sample which requires separation from a first liquid. The sample may be a second liquid. Typically, the first liquid and second liquid will be mixed, combined or blended but will be immiscible. Alternatively, the sample may be dissolved, suspended or mixed in the first liquid and the second liquid. Generally, in this disclosure the first liquid will be referred to as the non-transport liquid and the second liquid will be referred to as the transport liquid. For example, the system or apparatus can be a selective liquid-transport device for separating a liquid mixture having at least one transport liquid and at least one non-transport liquid. The selective liquid-transport device comprises a substrate. Defined on the substrate is a transport surface having a mixing area (also called the liquid-liquid mixture introduction area), a transport-liquid track, and a transport-liquid receiving area. Additionally, the device comprises a liquid-repellant background surface defined on the substrate. Each of the mixing area, the transport-liquid track, and the transport-liquid receiving area are coated with a substance having a higher affinity with the transport liquid than the non-transport liquid. The liquid-repellant background area is coated with an omniphobic substance having a low affinity with both the transport liquid and the non-transport liquid. The selective liquid-transport device has a length and a width which are longer and wider than the transport surface. The mixing area has a width of wm and a length of lm (although in some cases the mixing area can be round with a radius of rm, or oval), the transport-liquid track has a length of l and a width of w, and the transport-liquid receiving area has a width of wr and a length of lr (although in some cases the receiving area can be round with a radius of rr, or oval). Additionally, there can be multiple transport surfaces defined on the substrate. For example, a method under this disclosure can be a method for producing a selective liquid-transport surface comprising a transport surface having a mixing area, a liquid-transport track, and a transport-liquid receiving area, the method comprising: a. selecting a contiguous geometric shape for a mixing area, a transport-liquid track communicated with the mixing area, and a transport-liquid receiving area communicated with the transport-liquid track;b. cutting a microcontact polydimethylsiloxane (PDMS) stamp in the geometric shape of the mixing area, transport-liquid track and transport-liquid receiving area;c. placing the cut PDMS stamp into tight contact with a substrate;d. forming an adsorbed siloxane surface on the substrate matching the contiguous geometric shape with the PDMS stamp;e. creating a liquid-repellant background area on the substrate surface; andf. removing the PDMS stamp from the substrate so as to expose the adsorbed siloxane surface having the contiguous shape of the mixing area, the transport-liquid track, and the transport-liquid receiving area. For example, the substrate is comprised of at least one of silicon, glass, metal, plastic, or paper. In the method, the creating step can comprise depositing an omniphobic substance onto the portion of the substrate surface that is not in tight contact with the PDMS stamp. The omniphobic substance can be deposited onto the substrate surface by vapor deposition. For example, the omniphobic substance can be poly(1H,1H,2H,2H-heptadecafluorodecyl acrylate). In the method, the vapor deposition can occur by: i. vacuuming an initiated chemical vapor deposition reactor to a first predetermined pressure;ii. vaporizing a monomeric 1H,1H,2H,2H-heptadecafluorodecyl acrylate and an initiator tert-butyl peroxide at first and second temperatures respectively;iii. injecting the vaporized 1H,1H,2H,2H-heptadecafluorodecyl acrylate and tert-butyl peroxide into the reactor at first and second flow rates respectively