Emulsion-stabilized fluorosurfactants with improved manufacturability

Abstract

The present disclosure provides methods of synthesizing fluorine-containing surfactants and fluorine-containing surfactants prepared by the disclosed methods. These fluorine-containing surfactants can be used in a variety of regimens, such as a PCR regimen.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 583,423, filed on September 18, 2023, the entire disclosure of which is incorporated herein by reference, including all figures, tables and amino acid or nucleic acid sequences. Background Technology

[0003] Traditional methods for synthesizing fluorinated surfactants, including those used in droplet digital PCR, are either difficult or limited. For example, some fluorinated surfactants used in droplet digital PCR are manufactured using hazardous and difficult-to-handle chemicals and involve the synthesis of highly moisture-sensitive acyl halide intermediates. This requires highly trained chemists and extensive preparation.

[0004] Another example includes a synthetic route in which a nucleophilic nonfluorinated polymer reacts directly with a perfluorinated polymer via activation by an alkyl ester. This method has a major limitation: only small molecules or short oligomers can be used. Using longer oligomers and polymers results in long reaction times and typically low yields and purity due to dilution reactions, phase separation, and / or decarbonylation of the perfluorinated polymer. Furthermore, removing unreacted and decarbonylated fluorinated polymers from the surfactant is complex and difficult.

[0005] Therefore, there is a need for improved fluorinated surfactants and their synthesis methods. Summary of the Invention

[0006] This disclosure provides methods for synthesizing fluorinated surfactants and fluorinated surfactants prepared by the disclosed methods. These fluorinated surfactants can be used in various protocols, such as PCR protocols. Attached Figure Description

[0007] Figure 1 Various exemplary poly(hexafluoropropylene oxide)-oligomeric (ethylene oxide) intermediates. For these structures, n can be a value between 5 and 40, preferably between 5 and 35 (inclusive), and i can be a value between 1 and 12 (inclusive).

[0008] Figure 2 Exemplary poly(hexafluoropropylene oxide)-oligomeric (ether) intermediates with different oligomeric (ether) structures. For these structures, n can be a value between 5 and 40, preferably between 5 and 35 (inclusive).

[0009] Figure 3Examples of other perfluorinated polyether polymers reacted with diamine oligo(ethylene oxide). For these structures, m and n are independently values between 1 and 40 (including decimals), and m + n = values between 5 and 40, preferably between 8 and 35, and the structure is a valid chemical structure, i can be a value between 1 and 12 (including decimals).

[0010] Figure 4 Examples of other perfluorinated polyether polymers reacted with diamine polyols. For these structures, n can be a value between 5 and 40, preferably between 5 and 35 (including decimals).

[0011] Figures 5A-5B . 1 H NMR: Spectrum of example surfactant. Two amides are shown to be present at 8.38 and 7.59 ppm. Weak signal at 6.02 ppm shows ~1% decarbonylation Figure 5A ). Figure 5B : 19 F NMR: Fluorine NMR shows low degree of decarbonylation at -146.8 and -85.6 ppm.

[0012] Figure 6 Digital PCR performed in droplets prepared using one embodiment of the surfactant of the disclosure at the indicated weight % prior to and after thermal cycling using a standard PCR protocol in HFE 7500. Droplets visually show stability and are comparable to two different control surfactants prepared using different chemical methods.

[0013] Figure 7 Digital PCR performed in droplets prepared using one embodiment of the surfactant of the disclosure at the indicated weight %. Data show genomic copy number comparable to digital PCR performed in droplets formed using two different control surfactants prepared using different chemical methods. Two different targets were quantified by digital PCR for each surfactant tested (control #1, control #2, and the surfactant of the disclosure at each indicated weight percent). Replicate tests were performed (indicated by brackets).

[0014] Figure 8 Count (number of droplets detected in the digital PCR instrument) shown by one embodiment of the surfactant of the disclosure at the indicated weight % in replicate tests of dual detection comparable to two different control surfactants.

[0015] For Figures 5-8, the surfactant has the structure:

[0016] Figure 9 . Reaction scheme for forming exemplary intermediate compounds. "n" can be an average value (including decimals) selected from 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50.

[0017] Figure 10 . Reaction scheme for forming exemplary surfactants. "n" can be an average value (including decimals) selected from 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50, and "i" can be any value between 1 to 10, 1 to 20, 1 to 30, or higher. DETAILED DESCRIPTION

[0018] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0019] In the description and claims of the application, each of the verbs "comprise" "include" "contain", and "have", and conjugates thereof, are used to indicate that elements or items listed are among the items or elements comprehended but do not exclude others.

[0020] The phrase “and / or” as used in the specification and claims should be understood to mean “one or both” of the elements so combined, that is, elements that exist together in some cases and separately in others. Multiple elements listed with “and / or” should be interpreted in the same way, that is, “one or more / one or more types” of the elements so combined. In addition to the elements specifically indicated by the “and / or” phrase, other elements may optionally be present, whether related to or unrelated to the specifically indicated elements. Thus, as a non-limiting example, when “A and / or B” is used with open-ended language (such as “comprising”), in one embodiment, it may refer only to A (optionally including elements other than B); in another embodiment, it may refer only to B (optionally including elements other than A); in yet another embodiment, it may refer to both A and B (optionally including other elements); and so on.

[0021] The word “or” as used in this specification and claims shall be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as inclusive, meaning that it includes at least one of a certain number or series of elements, but also includes more than one, and includes optional unlisted items. Terms such as “only one of…” or “exact one…” or “composed of / constituting of…” used only explicitly to indicate the opposite, refer to exactly one of several elements or a series of elements. Generally, the term “or” as used herein shall be interpreted as indicating an exclusive alternative (i.e., “one or the other but not both”) only when preceded by an exclusive term (such as “any,” “one of,” “only one of,” or “exactly one of”). “Substantially composed of…” used in claims shall be understood to have its ordinary meaning in the field of patent law.

[0022] As used herein in the specification and claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that the

[0023] It should also be understood that, regardless of whether the use of the term “about” is expressly recited in the specification for a particular numeric value or range of values, the term “about” will also be understood to encompass the recited numeric value or range of values, unless the context clearly indicates otherwise.

[0024] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively.

[0025] The term "about" or "approximately" means within an acceptable error range for the particular value as determined by one of ordinary skill in the art, which will depend on the measurement or determination being made and the limitation of the measuring system. For example, "about" can mean within 1 or more than 1 standard deviation, per the practice in the art. Alternatively, "about" can mean a range of up to 0-20%, 0-10%, 0-5% or up to 1% of a given value. Alternatively, particularly with respect to biological systems or processes, the term can mean within an order of magnitude, preferably within 5-fold and more preferably within 2-fold. Where particular values are described in the specification and claims, unless otherwise stated the term "about" means within an acceptable error range for the particular value as determined by one of ordinary skill in the art, which will depend on the measurement or determination being made and the limitation of the measuring system. In compositions containing component amounts and where the term "about" or "approximately" is used, the composition contains the stated amount of the component, which varies by 0-10% (X ± 10%) of the stated value.

[0026] In the present disclosure, ranges are used as shorthand for describing a group of values. Any value falling within the range is individually and specifically

[0027] The present disclosure provides improved methods of synthesizing fluorosurfactants, fluorosurfactants made by these methods, and compositions, methods, and uses related thereto. The disclosed methods significantly reduce sensitivity to humidity, avoid the use of toxic reagents, and allow for tuning the size and geometry of the surfactant hydrophilic portion. The fluorosurfactants of the present disclosure can be used to prepare compositions for use in various systems and protocols, such as PCR protocols. The fluorosurfactants of the present disclosure can also be referred to herein as surfactants.

[0028] Accordingly, the present disclosure provides a surfactant comprising a perfluoropolyether (PFPE) block or other alkyl ester activated perfluorinated polymer (PFPAE) block coupled through a first amide bond to a hydrophilic linker molecule (L) having at least two amine groups (e.g., 2-(2-aminoethoxy)ethanamine, 1,8-diamino-3,6-dioxaoctane (DADOO), or a polyethylene glycol having at least two amine groups), and the linker molecule (L) is coupled through a second amide bond to a hydrophilic polymer block, optionally, the hydrophilic polymer block is alkylated. In some embodiments, the hydrophilic polymer block comprises a polyethylene glycol (PEG) block, optionally, the PEG block is alkylated. The PEG block can comprise the formula -(C n H 2n O) y -H or -(C n H 2n O) y -alkyl, wherein the alkyl is C1-C 10 alkyl, n is an integer selected from 1, 2, 3, 4, 5, or 6, preferably 1, 2, 3, or 4, more preferably 2, and y is an integer selected from 2-75 or an integer selected from 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30, preferably 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25, more preferably 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20; or y is an average repeat value between 2 and 75, including decimals thereof, an average repeat value between 2 and 30, including decimals thereof, an average repeat value between 5 and 25, including decimals thereof, or an average repeat value between 8 and 20, including decimals thereof.

[0029] In various other embodiments, the PFPAE block or PFPE block comprises: a) the formula F(CF(CF3)CF2O) x CF(CF3)CO-, wherein x is an average repeat number selected from 5 to 50, or 5 to 45, including decimals thereof; or b) the formula (CF3CF2CF2(OCF(CF3)CF2) yCO-, wherein y is an average number of repetitions selected from the group consisting of 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, or 60, including fractions thereof, or y is a value between 5 and 60, or between 5 and 50, or between 5 and 40, including fractions within each of the ranges; or c) Formula CF3O(CF2CF2O) m (CF2O) n CF2CO-, wherein m and n are independently selected such that m+n = a value between 5 and 50, preferably between 8 and 40; or d) Formula CF3O(CF2CF(CF3)O) m (CF2O) n CF2CO-, wherein m and n are independently selected such that m+n = a value between 5 and 50, preferably between 8 and 40.

[0030] In various aspects and embodiments, L can comprise: a) Formula -NH(CH2CH2O) y (CH2) z NH-, wherein y is an integer selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 (preferably 1, 2, 3, 4, 5, 6, 7, 8, or 9, or more preferably 2), and z is an integer selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3, or more preferably 2); or b) Formula -NH(CH2) e (C a H b OH c (CH2) g ) d (CH2) fNH-, wherein e and f can be the same or different and are independently 0, 1, 2, 3, 4, or 5 (preferably, independently 0, 1, 2, or 3, or e and f are selected such that e + f = 0, 1, or 2); a is an integer selected from 1, 2, 3, 4, 5, or 6; b is selected from 0 or 1; c is selected from 1 or 2, wherein b + c = 2a; g is 0, 1, 2, or 3; and d is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; or c) the formula -NH((CH2) g O) m (CH2) h CHX1X2, wherein X1and X2may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH-, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or d) the formula -NH((CH2) g O) m (CH2) h CX1X2X3, wherein X1, X2, and X3may be the same or different and are -(CH2) i O(CH2) j O(CH2) kNH-, wherein g, h, i, j, k and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3); or e) the formula -NH(CH2) q O(CH2) r O(CH2) s NH-, wherein q, r and s can be the same or different and are integers selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 (preferably, q and s are independently 1, 2 or 3 and can be the same or different, r is 1, 2, 3 or 4); or f) L forms an amide bond with the PFPAE block or PFPE block to which it is coupled and forms an amide bond with the hydrophilic polymer block and is 2-(2-aminoethoxy)ethylamine, 1,8-diamino-3,6-dioxaoctane (DADOO), 1,11-diamino-3,6,9-trioxoundecane, and 3,6,9,12-tetraoxatetradecane-1,14-diamine (1,14-diamino-3,6,9,12-tetraoxatetradecane), or 4,9-dioxa-1,12-dodecanediamine (1,12-diamino-4,9-dioxadodecane). The disclosed fluorosurfactants and methods provide several advantages. For example, the disclosed methods provide a synthesis process that is not extremely sensitive to humidity, making it easier to synthesize the desired fluorosurfactant. The intermediates formed in the two-step synthesis process are significantly more stable than the acyl fluorides or chlorides used in other methods, allowing for more flexibility in the timeline and reducing the probability of contamination of the intermediates before the final product is formed. Other advantages include low levels of decarbonylation, low phase separation issues, and ease of purification. A further advantage is that the disclosed fluorosurfactants do not contain a hydrophobic linker. Thus, the disclosed fluorosurfactants have essentially two parts (fluorinated and hydrophilic) as compared to the three parts (fluorinated / hydrophobic / hydrophilic) of previously disclosed fluorosurfactants. In addition, the linker molecule (e.g., a polyether linker having at least two amine groups) can be selected so as to be proximal to the desired hydrophilic polymer. Finally, by reacting a second hydrophilic polymer with the intermediate product, the hydrophilic side can be extended, allowing for adjustment of the size ratio between the fluorinated portion and the hydrophilic portion of the surfactant.

[0031] The present disclosure provides a two-step synthesis route for preparing a fluorosurfactant from an alkyl ester activated perfluorinated polymer (PFPAE). Any PFPAE polymer can be used to synthesize the fluorosurfactants of the present disclosure. Non-limiting examples include perfluoropolyether (PFPE), perfluoroalkyl, perfluoro octanoate, perfluoro methyl octanoate, and perfluoroalkyl-alkyl ester.

[0032] The first step forms a moisture stable intermediate by reacting a PFPAE (e.g., perfluoropolyether (PFPE), perfluoroalkyl, perfluoro octanoate, perfluoro methyl octanoate, or perfluoroalkyl-alkyl ester) with a hydrophilic linker molecule (e.g., a polyethylene glycol (PEG) diamine) to form a PFPAE block-linker molecule. The PFPAE block-linker intermediate is then coupled to a hydrophilic polymer, such as PEG or alkylated PEG (e.g., methylated PEG (mPEG)), to provide the fluorosurfactant. A non-limiting example of this method is provided in Example 1, and an exemplary reaction scheme is provided in FIG. 1. Figures 9-10The method uses an excess of hydrophilic linker (e.g., PEG diamine or mPEG diamine) to limit the formation of tri-blocks having the chemical structure: PFPAE block-hydrophilic linker-PFPAE block. In various embodiments, the amount of hydrophilic linker added can be about 1.1 times to about 100 times the amount of PFPAE, including fractions thereof, e.g., about 1.5 times, 2 times, 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, 10 times, 11 times, 12 times, 13 times, 14 times, 15 times, 16 times, 17 times, 18 times, 19 times, 20 times, 21 times, 22 times, 23 times, 24 times, 25 times, 26 times, 27 times, 28 times, 29 times, 30 times, 31 times, 32 times, 33 times, 34 times, 35 times, 36 times, 37 times, 38 times, 39 times, or 40 times, or any fraction thereof, can be added to limit the formation of tri-blocks. Quality control of intermediates by NMR can also track the unintended formation of this tri-block and quantify the tri-block formed.

[0033] Accordingly, the present disclosure provides a method of making a compound comprising reacting a PFPAE with a hydrophilic linker molecule (L) comprising at least first and second amine groups (e.g., a polyethylene glycol comprising at least two amine groups or 2-(2-aminoethoxy)ethylamine, or 1,8-diamino-3,6-dioxaoctane (DADOO)), and forming an amide bond between the PFPAE and the linker molecule (L) through the first amine group to form a compound represented by the formula PFPAE block-L, where “-” represents the amide bond. In some embodiments, the linker is 2-(2-aminoethoxy)ethylamine or 1,8-diamino-3,6-dioxaoctane (DADOO). Accordingly, the present disclosure provides a method of making a compound comprising reacting a PFPAE with a linker molecule (L) comprising at least first and second amine groups, and forming an amide bond between the PFPAE and the linker molecule (L) through the first amine group to form a compound represented by the formula PFPAE block-L, where “-” represents the amide bond.

[0034] In various embodiments, the PFPAE comprises: a) the formula F(CF(CF3)CF2O) x CF(CF3)COO-alkyl, where alkyl is methyl, ethyl, propyl, butyl, or pentyl, and x is an average number of repetitions selected from 5 to 50 or 5 to 45, including fractions thereof; or b) the formula (CF3CF2CF2(OCF(CF3)CF2) yCOO-alkyl, wherein alkyl is methyl, ethyl, propyl, butyl, or pentyl, wherein y is an average number of repetitions selected from the group consisting of 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, or 60, including fractions thereof, or y is a value between 5 and 60, or between 5 and 50, or between 5 and 40, including fractions within each of these ranges; or c) the formula CF3O(CF2CF2O) m (CF2O) n CF2COO-alkyl, wherein alkyl is methyl, ethyl, propyl, butyl, or pentyl, wherein m and n are independently selected such that m+n = a value between 5 and 50, preferably between 8 and 40, including fractions. d) the formula CF3O(CF2CF(CF3)O) m (CF2O) n CF2COO-alkyl, wherein alkyl is methyl, ethyl, propyl, butyl, or pentyl, wherein m and n are independently selected such that m+n = a value between 5 and 50, preferably between 8 and 40, including fractions.

[0035] In various embodiments, L comprises a linker comprising at least two amine groups. Non-limiting examples include those having: a) the formula NH2(CH2CH2O) y (CH2) z NH2, wherein y is an integer selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 (in some cases 1, 2, 3, 4, 5, 6, 7, 8, or 9, in other cases 2), and z is an integer selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (in some cases 1, 2, or 3, in other cases 2); or b) the formula NH2(CH2) e (C a H b OH c (CH2) g ) d(CH2) f NH2, wherein e and f can be the same or different and are independently 0, 1, 2, 3, 4, or 5; a is an integer selected from 1, 2, 3, 4, 5, or 6; b is selected from 0 or 1; c is selected from 1 or 2, wherein b + c = 2a; g is an integer selected from 0, 1, 2, or 3; and d is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; or c) the formula NH2((CH2) g O) m (CH2) h CHX1X2, wherein X1and X2may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH2, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or d) the formula -NH((CH2) g O) m (CH2) h CX1X2X3, wherein X1, X2, and X3may be the same or different and are -(CH2) i O(CH2) j O(CH2) kNH2, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or e) the formula NH2(CH2) q O(CH2) r O(CH2) s NH2, wherein q, r, and s can be the same or different and are integers selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20; or f) L is 2-(2-aminoethoxy)ethanamine, 1,8-diamino-3,6-dioxaoctane (DADOO), 1,11-diamino-3,6,9-trioxoundecane, and 3,6,9,12-tetraoxatetradecane-1,14-diamine (1,14-diamino-3,6,9,12-tetraoxatetradecane), or 4,9-dioxa-1,12-dodecanediamine (1,12-diamino-4,9-dioxadodecane).

[0036] In certain embodiments, the present disclosure provides a composition comprising the disclosed surfactant and optionally an aqueous and / or non-aqueous component. The composition can comprise a discontinuous aqueous and / or lipophilic (non-aqueous) phase, and the composition can comprise one or more physiologically acceptable agents. The agents can be dissolved or suspended in the discontinuous phase. In another set of embodiments, the discontinuous aqueous and / or lipophilic phase of the droplet / emulsion can comprise one or more agents that can participate in a target chemical and / or biological reaction. Non-limiting examples of agents that can participate in a chemical and / or biological reaction (or other chemical and / or biological process) include: buffers, salts, nutrients, therapeutic agents, drugs, hormones, antibodies, analgesics, anticoagulants, anti-inflammatory compounds, antimicrobial compositions, cytokines, enzymes, reverse transcriptases, growth factors, interferons, lipids, oligonucleotide polymers, polysaccharides, polypeptides, protease inhibitors, cells, nucleic acids, RNA, DNA, vasoconstrictors or vasodilators, vitamins, minerals, stabilizing agents, and the like. In other embodiments, the discontinuous aqueous and / or lipophilic phase can comprise toxins and / or other substances to be tested, assayed, or reacted within the droplets. Thus, chemical and / or biological reactions can be carried out within the compositions disclosed herein. In some cases, polymerase chain reactions can be carried out within the compositions disclosed herein.

[0037] As used herein, "non-aqueous" is intended to define a material (e.g., a hydrophobic material or liquid), such as a fluid that is immiscible with water. That is, a liquid that forms a stable two-phase mixture when mixed with water. The non-aqueous phase is not necessarily a liquid, but can be a solid or semi-solid lipid or other non-polar substance that is not soluble in water. In some cases, the non-aqueous phase can comprise a lipophilic component (e.g., a hydrocarbon) or a fluorinated component (e.g., a fluorocarbon). The aqueous phase can be any liquid that is miscible with water; that is, any liquid that can form a stable room temperature single-phase solution when mixed with water. In some cases, the aqueous phase can comprise one or more physiologically acceptable agents and / or solvents, etc. Non-limiting examples of aqueous phase materials include (in addition to water itself) methanol, ethanol, DMF (dimethylformamide), or DMSO (dimethylsulfoxide).

[0038] The compositions or surfactants disclosed herein can form emulsions or be part of an emulsion, and these emulsions can be formed using any suitable emulsification procedure known to one of ordinary skill in the art. In this regard, it is understood that emulsions can be formed using microfluidic systems, sonication, high pressure homogenization, shaking, stirring, spray processes, membrane technology, or any other appropriate method. In one particular embodiment, microcapillary or microfluidic devices are used to form emulsions in the form of droplets. The size and stability of the droplets produced by this method can depend on, for example, the capillary tip diameter, the fluid velocity, the viscosity ratio of the continuous and discontinuous phases, and the interfacial tension of the two phases. Droplets of different sizes and volumes can be produced within a microfluidic system. These sizes and volumes can vary depending on factors such as fluid viscosity, infusion rate, and nozzle size / configuration. Droplets of different volumes can be selected depending on the particular application. For example, the volume of the droplets can be less than 1 μL (microliter), less than 0.1 μL (microliter), less than 10 nL, less than 1 nL, less than 0.1 nL, or less than 10 pL.

[0039] Examples of linker molecules suitable for use in the disclosed methods and surfactants provided herein include, but are not limited to, PEG diamines having 1 to 10 repeating units, such as (a) 2-(2-aminoethoxy)ethanamine, (b) 1,8-diamino-3,6-dioxaoctane (DADOO), (c) 1,11-diamino-3,6,9-trioxoundecane, and (d) 3,6,9,12-tetraoxatetradecane-1,14-diamine (1,14-diamino-3,6,9,12-tetraoxatetradecane), as well as other polyether diamines such as 4,9-dioxa-1,12-dodecanediamine. Alternatively, branched / starry / dendritic polyether linkers having two (2) or more amines can also be used. Non-limiting examples of such linkers include C 21 H 48 N4O8, 8-[2-(2-aminoethylethoxy)ethylethoxy]-C,C,C,C-tetraethyl-3,6,10,13- tetraoxapentadecane-1,15-diamine, CAS 172355-14-5: 8,8-bis({[2-(2-aminoethoxy)ethoxy]methyl})-3,6,10,13-tetraoxapentadecane-1,15-diamine, and CAS 5045-94-3 (tetra-aminopropoxy)methylmethane. Still other linkers can be polyol molecules containing two or more amine groups. Non-limiting examples of such polyols include: 1,6-diaminohexane-2,3,4,5-tetrol (CAS: 41111-65-3), 1,2-diaminoethane-1,2-diol (CAS: 103538-65-4), and 1,4-diaminobutane-2,3-diol (CAS: 32798-38-2).

[0040] Other exemplary linkers are: a) the formula NH2(CH2CH2O) y (CH2) z NH2, wherein y is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 (in some cases 1, 2, 3, 4, 5, 6, 7, 8, or 9, in other cases 2), and z is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (in some cases 1, 2, or 3, in other cases 2); or b) the formula NH2(CH2) e (C a H b OH c (CH2) g ) d (CH2) f NH2, wherein e and f can be the same or different and are independently 0, 1, 2, 3, 4, or 5; a is an integer selected from 1, 2, 3, 4, 5, or 6; b is selected from 0 or 1; c is selected from 1 or 2, wherein b + c = 2a; g is an integer selected from 0, 1, 2, or 3; and d is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; or c) the formula NH2((CH2) g O) m (CH2) h CHX1X2, wherein X1and X2may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH2, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; or d) the formula NH2((CH2) g O) m (CH2)h CX1X2X3, wherein X1, X2and X3may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH2, wherein g, h, i, j and k can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; or e) the formula NH2(CH2) q O(CH2) r O(CH2) s NH2, wherein q, r and s can be the same or different and are integers selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20.

[0041] The first step of reacting a PFPAE (e.g., perfluoropolyether (PFPE), perfluoroalkyl, perfluorooctanoate, perfluoromethyl octanoate, or perfluoroalkyl-alkyl ester) with a hydrophilic linker molecule (e.g., PEG diamine) can be performed using any suitable conditions to form a PFPAE block-linker molecule or PFPE block-linker molecule. For example, the reaction can be performed neat, or using a solvent or combination of solvents for one or both of the PFPAE and the hydrophilic linker molecule. Any suitable solvent known in the art can be used, including but not limited to, organic solvents; aprotic solvents, such as tetrahydrofuran (THF), acetone, acetonitrile, chloroform, dichloromethane, dimethylformamide, dimethylpropylene urea, dimethyl sulfoxide, ethyl acetate, hexamethylphosphoramide, pyridine, and sulfolane; alcohols, such as ethanol or isopropanol; hydrophobic fluids, such as oils; fluorinated solvents, such as fluorinated oils, such as HFE7500, HFE7200, and HFE7100. In some embodiments, the PFPAE (e.g., PFPE) is dissolved in a fluorinated solvent, such as HFE7500. In some embodiments, the linker molecule (e.g., PEG diamine) is dissolved in an organic solvent, such as an aprotic solvent (e.g., THF). In some embodiments, the reaction can be performed at room temperature (e.g., a temperature of about 20 °C to about 25 °C). In other cases, the reaction can be performed at a temperature lower than room temperature (e.g., about 0 °C to about 19 °C). In other cases, the reaction can be performed at a temperature higher than room temperature (e.g., about 26 °C to about 100 °C). The reaction can be performed in the presence of oxygen or under an inert atmosphere (e.g., a nitrogen atmosphere).

[0042] The intermediate formed from the first step is further reacted with a selected hydrophilic polymer to form a surfactant having a desired hydrophilic tail length. Examples of hydrophilic polymers that can be used include, but are not limited to, monodisperse and polydisperse PEG NHS-esters. Monodisperse PEG can be used to reduce batch-to-batch variation.

[0043] The second step of reacting the intermediate formed in the first step (the PFPAE block-linker molecule) with a selected hydrophilic polymer can be performed using any suitable conditions to form the surfactant with the desired length of the hydrophilic tail. For example, the reaction can be performed neat, or using a solvent or combination of solvents for one or both of the intermediate and the hydrophilic polymer. Any suitable solvent known in the art can be used, including but not limited to organic solvents; aprotic solvents, such as tetrahydrofuran (THF), acetone, acetonitrile, chloroform, dichloromethane, dimethylformamide, dimethylpropylene urea, dimethylsulfoxide, ethyl acetate, hexamethylphosphoramide, pyridine, and sulfolane; alcohols, such as ethanol or isopropanol; hydrophobic fluids, such as oils; fluorinated solvents, such as fluorinated oils, such as HFE7500, HFE7200, and HFE7100. In some embodiments, the intermediate formed from the first step (the PFPAE block-linker molecule) is dissolved in a fluorinated solvent, such as HFE7100. In some embodiments, the hydrophilic polymer is dissolved in an organic solvent, such as an aprotic solvent, such as THF. In some embodiments, the reaction can be performed at room temperature, such as a temperature of about 20 °C to about 25 °C. In other cases, the reaction can be performed at a temperature lower than room temperature, such as about 0 °C to about 19 °C. In other cases, the reaction can be performed at a temperature higher than room temperature, such as about 26 °C to about 100 °C. The reaction can be performed in the presence of oxygen or under an inert atmosphere, such as a nitrogen atmosphere.

[0044] In one embodiment, a PFPAE (such as a PFPE-methyl ester) is reacted with a PEG diamine to form an intermediate. The reaction can be performed in the presence of oxygen or under an inert atmosphere, such as a nitrogen atmosphere. One non-limiting example is provided by the reaction scheme in Figure 9 where n is an average number of repetitions between 5-50, 5-45, preferably between 5-25.

[0045] The intermediate is then reacted with a monodisperse or polydisperse functionalized hydrophilic polymer (e.g., a monodisperse or polydisperse functionalized PEG molecule or a monodisperse or polydisperse functionalized alkyl-PEG molecule, such as a monodisperse or polydisperse NHS-mPEG) to provide a polyfluorinated surfactant. The monodisperse or polydisperse hydrophilic polymer can be functionalized with an amine-reactive group (such as an N-hydroxysuccinimide or otherwise activated carboxylic acid) to facilitate linkage to the amine group on the intermediate. A monodisperse hydrophilic polymer (e.g., a monodisperse PEG polymer) is a pure compound with a precise number of units (e.g., PEG units) and a single molecular weight. In contrast, a polydisperse hydrophilic polymer (e.g., a polydisperse PEG polymer) is a mixture of polymers with an average molecular weight of, for example, 5K, 10K, etc. Hydrophilic polymer shapes include linear, branched, star-shaped, with combinations of different chain lengths. In various aspects of the disclosure, the molecular weight (or average molecular weight) of the monodisperse or polydisperse polymer (e.g., monodisperse or polydisperse PEG polymer) or alkylated polymer (e.g., alkylated PEG) is from about 500 Da to about 5000 Da, from about 500 Da to about 2500 Da, from about 500 Da to about 1000 Da, or from about 500 Da to about 750 Da. In various other aspects of the disclosure, the molecular weight (or average molecular weight) of the monodisperse or polydisperse polymer (e.g., monodisperse or polydisperse PEG polymer) or alkylated polymer (e.g., alkylated PEG) is from about 350 Da to about 5000 Da, from about 350 Da to about 2500 Da, from about 350 Da to about 1000 Da, or from about 350 Da to about 750 Da. In yet other aspects of the disclosure, the molecular weight (or average molecular weight) of the monodisperse or polydisperse polymer (e.g., monodisperse or polydisperse PEG polymer) or alkylated polymer (e.g., alkylated PEG) is from about 300 Da to about 5000 Da, from about 300 Da to about 2500 Da, from about 300 Da to about 1000 Da, or from about 300 Da to about 750 Da. In other embodiments, a monodisperse or polydisperse polymer (e.g., monodisperse or polydisperse PEG) or alkylated polymer (e.g., alkylated PEG) having from 2 to 75 repeating units (-(0-CH2-CH2)- for PEG) can be used in the methods provided herein. In some embodiments, there are 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 -(0-CH2-CH2)- repeating units.In some embodiments, there are 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 -(0-CH2-CH2)- repeat units. For polydisperse PEG or alkylated PEG, the average molecular weight of these polymers can be from about 350 Da to about 5000 Da, from about 350 Da to about 2500 Da, from about 350 Da to about 1000 Da, or from about 350 Da to about 750 Da, or can be specified as an average repeat value (also referred to as an average repeat unit) of between 2 and 75, inclusive of decimals thereof; between 2 and 30, inclusive of decimals thereof; between 5 and 25, inclusive of decimals thereof; or between 8 and 20, inclusive of decimals thereof.

[0046] As used herein, the term "alkyl" refers to a straight chain or branched saturated, aliphatic molecule having 1-10 carbon atoms. For example, C1-C10alkyl includes methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl, pentyl, isopentyl, hexyl, and stereoisomers thereof, heptyl and stereoisomers thereof, octyl and stereoisomers thereof, nonyl and stereoisomers thereof, decyl and stereoisomers thereof. Alkyl groups can include any number of carbons, for example, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7, 1-8, 1-9, 1-10, 2-3, 2-4, 2-5, 2-6, 2-7, 2-8, 2-9, 2-10, 3-4, 3-5, 3-6, 3-7, 3-8, 3-9, 3-10, 4-5, 4-6, 4-7, 4-8, 4-9, 4-10, 5-6, 5-7, 5-8, 5-9, 5-10, 6-7, 6-8, 6-9, 6-10, 7-8, 7-9, 7-10, 8-9, 8-10, 9-10, or 10 carbons. 10 Alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl, pentyl, isopentyl, hexyl, and stereoisomers thereof, heptyl and stereoisomers thereof, octyl and stereoisomers thereof, nonyl and stereoisomers thereof, decyl and stereoisomers thereof. Alkyl groups can include any number of carbons, for example, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7, 1-8, 1-9, 1-10, 2-3, 2-4, 2-5, 2-6, 2-7, 2-8, 2-9, 2-10, 3-4, 3-5, 3-6, 3-7, 3-8, 3-9, 3-10, 4-5, 4-6, 4-7, 4-8, 4-9, 4-10, 5-6, 5-7, 5-8, 5-9, 5-10, 6-7, 6-8, 6-9, 6-10, 7-8, 7-9, 7-10, 8-9, 8-10, 9-10, or 10 carbons.

[0047] Thus, various forms of monodisperse and polydisperse amine reactive polymers, such as amine reactive PEG-alkyl molecules, can be used. PEG-alkyl groups can be of the formula alkyl-(0-CH2-CH2) m wherein m is an integer between 2 and 75, inclusive of the endpoints of the range, or is any integer selected from 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30, R is an amine reactive group (such as N-hydroxysuccinimidyl or other activated carboxylic acid group), and alkyl is a C1-C10alkyl group. 10alkyl, preferably methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl, pentyl, isopentyl, and / or hexyl, more preferably methyl, ethyl, or propyl, and more preferably methyl or ethyl. In some embodiments, m is an average repeat value (also referred to as average repeat units) of between 2 and 75, inclusive of decimals thereof; between 2 and 30, inclusive of decimals thereof; between 5 and 25, inclusive of decimals thereof; or between 8 and 20, inclusive of decimals thereof.

[0048] In other embodiments, the intermediate formed from the first step is further reacted with a selected hydrophilic polymer block to form a surfactant having a desired hydrophilic tail length. The hydrophilic polymer block can include polyethylene oxide (PEO), polyethylene glycol (PEG), poly(N-isopropylacrylamide) (PNIPAM), polyvinylcaprolactam (PVCL), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), and some polyacids and polybases, as well as combinations of hydrophilic polymers. These hydrophilic polymers are functionalized so as to react with amine groups on the linker molecule (e.g., with N-hydroxysuccinimidyl esters or other activated carboxylic acid groups), and can optionally be alkylated, as described above.

[0049] In various aspects of the present disclosure, the molecular weight (or average molecular weight) of the monodisperse or polydisperse hydrophilic polymer block (e.g., monodisperse or polydisperse PEG polymer) or alkylated polymer block (e.g., alkylated PEG) is about 500 Da to about 5000 Da, about 500 Da to about 2500 Da, about 500 Da to about 1000 Da, or about 500 Da to about 750 Da. In various other aspects of the present disclosure, the molecular weight (or average molecular weight) of the monodisperse or polydisperse hydrophilic polymer block (e.g., monodisperse or polydisperse PEG polymer) or alkylated polymer block (e.g., alkylated PEG) is about 350 Da to about 5000 Da, about 350 Da to about 2500 Da, about 350 Da to about 1000 Da, or about 350 Da to about 750 Da. In yet other aspects of the present disclosure, the molecular weight (or average molecular weight) of the monodisperse or polydisperse hydrophilic polymer block (e.g., monodisperse or polydisperse PEG polymer) or alkylated polymer (e.g., alkylated PEG) is about 300 Da to about 5000 Da, about 300 Da to about 2500 Da, about 300 Da to about 1000 Da, or about 300 Da to about 750 Da. The polydisperse hydrophilic polymer block can also be specified as an average repeat value (also referred to as average repeat units) of between 2 and 75, inclusive of decimals thereof; between 2 and 30, inclusive of decimals thereof; between 5 and 25, inclusive of decimals thereof; or between 8 and 20, inclusive of decimals thereof.

[0050] The present disclosure provides the following non-limiting embodiments (subject matter that can be claimed): 1. A surfactant comprising a perfluoropolyether (PFPE) block or PFPAE block coupled to a linker molecule (L) by a first amide bond, and the linker molecule (L) is coupled to a hydrophilic polymer block by a second amide bond, optionally, the hydrophilic polymer block is alkylated.

[0051] 2. The surfactant of embodiment 1, the hydrophilic polymer block comprises a polyethylene glycol (PEG) block, optionally, the PEG block is alkylated.

[0052] 3. The surfactant of embodiment 1 or embodiment 2, wherein the PFPAE block or PFPE block comprises: a) the formula F(CF(CF3)CF2O) x CF(CF3)CO-, wherein x is an average number of repetitions selected from 5 to 50, or 5 to 45, including decimals; b) the formula (CF3CF2CF2(OCF(CF3)CF2) y CO-, wherein y is an average number of repetitions selected from 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, or 60, including decimals thereof, or y is a value between 5 and 60, or between 5 and 50, or between 5 and 40, including decimals within each of said ranges; c) the formula CF3O(CF2CF2O) m (CF2O) n CF2CO-, wherein m and n are independently selected such that m+n = a value between 5 and 50, preferably between 8 and 40, including decimals within each of said ranges; or d) the formula CF3O(CF2CF(CF3)O) m (CF2O) n CF2CO-, wherein m and n are independently selected such that m+n = a value between 5 and 50, preferably between 8 and 40, including decimals within each of said ranges.

[0053] 4. The surfactant of embodiment 2 or embodiment 3, wherein the PEG block comprises the formula -(C n H 2n O) y -H or -(C n H 2n O) y -alkyl, wherein the alkyl is C1-C 10 alkyl, n is an integer selected from 1, 2, 3, 4, 5, or 6, preferably 1, 2, 3, or 4, more preferably 2, and y is an integer selected from 2-75 or an integer selected from 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30, preferably 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25, more preferably 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20; or

[0054] y is an average repeat value between 2 and 75, inclusive of decimals thereof; between 2 and 30, inclusive of decimals thereof; between 5 and 25, inclusive of decimals thereof; or between 8 and 20, inclusive of decimals thereof.

[0055] 5. The surfactant of any one of embodiments 1-4, wherein L comprises: a) the formula -NH(CH2CH2O) y (CH2) z NH-, wherein y is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 (preferably 1, 2, 3, 4, 5, 6, 7, 8, or 9, or more preferably 2) and z is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3, or more preferably 2); or b) the formula -NH(CH2) e (C a H b OH c (CH2) g ) d (CH2) fNH-, wherein e and f can be the same or different and are independently 0, 1, 2, 3, 4, or 5 (preferably, independently 0, 1, 2, or 3, or e and f are selected such that e + f = 0, 1, or 2); a is an integer selected from 1, 2, 3, 4, 5, or 6; b is selected from 0 or 1; c is selected from 1 or 2, wherein b + c = 2a; g is 0, 1, 2, or 3; and d is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; or c) the formula -NH((CH2) g O) m (CH2) h CX1X2, wherein X1and X2may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH-, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or d) the formula -NH((CH2) g O) m (CH2) h CX1X2X3, wherein X1, X2, and X3may be the same or different and are -(CH2) i O(CH2) j O(CH2) kNH-, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or e) the formula -NH(CH2) q O(CH2) r O(CH2) s NH-, wherein q, r, and s can be the same or different and are integers selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 (preferably, q and s are independently 1, 2, or 3 and can be the same or different, and r is 1, 2, 3, or 4); or f) L forms an amide bond with the PFPAE or PFPE block to which it is coupled and with the hydrophilic polymer block, and L is 2-(2-aminoethoxy)ethylamine, 1,8-diamino-3,6-dioxaoctane (DADOO), 1,11-diamino-3,6,9-trioxoundecane, and 3,6,9,12-tetraoxatetradecane-1,14-diamine, or 4,9-dioxa-1,12-dodecanediamine.

[0056] 6. The surfactant of any of embodiments 1-5, wherein the hydrophilic polymer block is methyl or ethyl alkylated.

[0057] 7. The surfactant of any of embodiments 1-6, wherein L comprises: a) the formula -NH(CH2CH2O) y (CH2) z NH-, wherein y is an integer selected from 1, 2, 3, 4, and 5 and z is an integer selected from 1, 2, or 3, or y is 2 or 3 and z is 1, 2, or 3, or y is 2 and z is 2; or b) the formula -NH(CH2) e (C a H b OHc (CH2) g ) d (CH2) f NH-, wherein: e is 0, 1 or 2, f is 0, 1, 2 or 3, or e and f are selected such that e + f = 0, 1 or 2; a is an integer selected from 1, 2, 3, 4, 5 or 6; b is an integer selected from 0 or 1; c is an integer selected from 1 or 2, wherein b + c = 2a; g is 0, 1, 2 or 3; and d is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; or c) the formula -NH((CH2) g O) m (CH2) h CHX1X2, wherein X1and X2may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH-, wherein g, h, i, j, k and m can be the same or different; g is an integer selected from 1, 2 or 3; h is an integer selected from 1, 2 or 3; i is an integer selected from 1, 2 or 3; j is an integer selected from 1, 2 or 3; k is an integer selected from 1, 2 or 3; and m is an integer selected from 1, 2 or 3; or d) the formula -NH((CH2) g O) m (CH2) h CX1X2X3, wherein X1, X2and X3may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH-, wherein g is an integer selected from 1, 2 or 3; h is an integer selected from 1, 2 or 3; i is an integer selected from 1, 2 or 3; j is an integer selected from 1, 2 or 3; k is an integer selected from 1, 2 or 3; and m is an integer selected from 1, 2 or 3.

[0058] 8. A compound comprising a perfluoropolyether (PFPE) block or a PFPAE block coupled to a linker molecule (L) by a first amide bond, and the linker molecule (L) comprises a second amine group, wherein L comprises: a) the formula -NH(CH2CH2O) y (CH2) zNH2, wherein y is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 (preferably 1, 2, 3, 4, 5, 6, 7, 8, or 9, or more preferably 2) and z is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3, or more preferably 2); or b) the formula -NH(CH2) e (C a H b OH c (CH2) g ) d (CH2) f NH2, wherein e and f can be the same or different and are independently 0, 1, 2, 3, 4, or 5; a is an integer selected from 1, 2, 3, 4, 5, or 6; b is selected from 0 or 1; c is selected from 1 or 2, wherein b + c = 2a; g is an integer selected from 0, 1, 2, or 3; and d is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; or c) the formula -NH((CH2) g O) m (CH2) h CHX1X2, wherein X1and X2may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH2, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or d) the formula -NH((CH2) g O) m (CH2) hCX1X2X3, wherein X1, X2and X3may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH2, wherein g, h, i, j, k and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3); or e) the formula -NH(CH2) q O(CH2) r O(CH2) s NH2, wherein q, r and s can be the same or different and are an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20; or f) L forms a single amide bond with the PFPE block or the PFPAE block and L is 2-(2-aminoethoxy)ethylamine, 1,8-diamino-3,6-dioxaoctane (DADOO), 1,11-diamino-3,6,9-trioxoundecane and 3,6,9,12-tetraoxatetradecane-1,14-diamine, or 4,9-dioxa-1,12-dodecanediamine.

[0059] 9. The compound of embodiment 8, wherein the PFPAE block or the PFPE block comprises: a) the formula F(CF(CF3)CF2O) x CF(CF3)CO-, wherein x is an average number of repetitions selected from 5 to 50, or 5 to 45, including decimals; or b) the formula (CF3CF2CF2(OCF(CF3)CF2) yCO-, wherein y is an average number of repetitions selected from the group consisting of 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, or 60, including fractions thereof, or y is a value between 5 and 60, or between 5 and 50, or between 5 and 40, including fractions within each of the ranges; or c) Formula CF3O(CF2CF2O) m (CF2O) n CF2CO-, wherein m and n are independently selected such that m+n = a value between 5 and 50, preferably between 8 and 40, including fractions; d) Formula CF3O(CF2CF(CF3)O) m (CF2O) n CF2CO-, wherein m and n are independently selected such that m+n = a value between 5 and 50, preferably between 8 and 40, including fractions.

[0060] 10. The compound of embodiment 8 or embodiment 9, selected from the group consisting of:

[0061] wherein n is an average value between 5 and 50, preferably between 8 and 40, including fractions; wherein n is an average value between 5 and 50, preferably between 8 and 40, including fractions; wherein n is an average value between 5 and 50, preferably between 8 and 40, including fractions; wherein n is an average value between 5 and 50, preferably between 8 and 40, including fractions; wherein i = 1-12, and wherein n is an average value between 5 and 50, preferably between 8 and 40, including fractions; wherein n is an average value between 5 and 50, preferably between 8 and 40, including fractions;

[0062] where n is an average value between 5 and 50, preferably between 8 and 40, including decimals;

[0063] where n is an average value between 5 and 50, preferably between 8 and 40;

[0064] where n is an average value between 5 and 50, preferably between 8 and 40, including decimals; where i is a value between 1 and 12, and m and n are independently selected such that m+n = a value between 5 and 50, preferably between 8 and 40, including decimals; where i is a value between 1 and 12, and m and n are independently selected such that m+n = a value between 5 and 50, preferably between 8 and 40, including decimals; where n is a value between 5 and 40, preferably between 5 and 35, including decimals; where n is a value between 5 and 40, preferably between 5 and 35, including decimals; and where n is a value between 5 and 40, preferably between 5 and 35, including decimals.

[0065] 11. The compound of either of embodiments 8 or 9, wherein L has the formula -NH(CH2CH2O) y (CH2) z NH2, wherein y is an integer selected from 1, 2, 3, 4 and 5 and z is an integer selected from 1, 2 or 3, or y is 2 or 3 and z is 1, 2 or 3, or y is 2 and z is 2.

[0066] 12. The compound of either of embodiments 8 or 9, wherein L has the formula -NH(CH2) e (C a H b OH c (CH2) g ) d (CH2) f NH2, wherein e and f can be the same or different and are independently 1, 2 or 3; a is an integer selected from 1 or 2; b is selected from 0 or 1; c is selected from 1 or 2, wherein b+c = 2a; g is 0, 1, 2 or 3; and d is an integer selected from 1, 2, 3 or 4.

[0067] 13. The compound of either of embodiments 8 or 9, wherein L has the formula -NH((CH2)g O) m (CH2) h CHX1X2, where X1and X2may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH2, where g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, or 3; h is an integer selected from 1, 2, or 3; i is an integer selected from 1, 2, or 3; j is an integer selected from 1, 2, or 3; k is an integer selected from 1, 2, or 3; and m is an integer selected from 1, 2, or 3.

[0068] 14. The compound of either embodiment 8 or embodiment 9, wherein L has the formula -NH((CH2) g O) m (CH2) h CX1X2X3, where X1, X2, and X3may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH2, where g is an integer selected from 1, 2, or 3; h is an integer selected from 1, 2, or 3; i is an integer selected from 1, 2, or 3; j is an integer selected from 1, 2, or 3; k is an integer selected from 1, 2, or 3; and m is an integer selected from 1, 2, or 3.

[0069] 15. The compound of either embodiment 8 or embodiment 9, wherein L has the formula -NH(CH2) q O(CH2) r O(CH2) s NH2, where q is an integer selected from 1, 2, 3, or 4; r is an integer selected from 1, 2, 3, or 4; and s is an integer selected from 1, 2, 3, or 4.

[0070] 16. A composition comprising the surfactant of any one of embodiments 1-7.

[0071] 17. The composition of embodiment 16, further comprising a hydrophobic liquid, optionally, wherein the hydrophobic liquid is a fluorinated oil or a silicone oil, or a combination thereof.

[0072] 18. The composition of either embodiment 16 or embodiment 17, further comprising an aqueous liquid.

[0073] 19. The composition of embodiment 16, further comprising a fluorinated oil and an aqueous liquid.

[0074] 20. The composition of embodiment 18 or embodiment 19, wherein the aqueous liquid additionally comprises a biomolecule.

[0075] 21. The composition of embodiment 20, wherein the biomolecule comprises a nucleic acid.

[0076] 22. A method of forming aqueous droplets, comprising: providing a microfluidic device; providing an aqueous liquid to the microfluidic device; providing a fluorinated liquid to the microfluidic device; providing a surfactant of any one of embodiments 1-7; and forming aqueous droplets in the fluorinated liquid in the presence of the surfactant, the droplets comprising the surfactant, optionally, wherein the fluorinated liquid is a fluorinated oil.

[0077] 23. A composition comprising a compound of any one of embodiments 8-15.

[0078] 24. A method of forming an emulsion comprising a plurality of droplets, the method comprising: (a) providing a composition comprising a fluid immiscible or substantially immiscible with water and a surfactant of any one of embodiments 1-7; (b) providing an aqueous fluid, optionally, wherein the aqueous fluid comprises a nucleic acid or biomolecule of interest; and (c) contacting the composition with the aqueous fluid, thereby producing an emulsion of a plurality of aqueous fluid droplets dispersed in a fluid immiscible or substantially immiscible with water.

[0079] 25. The method of embodiment 24, wherein the fluid immiscible or substantially immiscible with water is an oil, optionally a fluorinated oil, a silicone oil, or a combination thereof.

[0080] 26. An emulsion comprising: a) an aqueous liquid and a surfactant of any one of embodiments 1-7, and optionally, a fluid immiscible or substantially immiscible with the aqueous liquid; or b) a fluid immiscible or substantially immiscible with water and a surfactant of any one of embodiments 1-7, and optionally, an aqueous liquid.

[0081] 27. The emulsion of embodiment 26, wherein the emulsion further comprises a biomolecule or a nucleic acid molecule.

[0082] 28. The emulsion of embodiment 26 or 27, wherein the emulsion comprises an aqueous liquid, a surfactant, and a fluid immiscible or substantially immiscible with the aqueous liquid.

[0083] 29. An emulsion comprising: (a) a plurality of droplets of an aqueous liquid dispersed in a fluid immiscible or substantially immiscible with the aqueous liquid, and (b) a surfactant as described in any one of embodiments 1-7.

[0084] 30. The emulsion of embodiment 29, wherein at least a portion of the surfactant is present at the interface between the aqueous liquid and the fluid immiscible or substantially immiscible with the aqueous liquid.

[0085] 31. The emulsion of embodiment 29 or embodiment 30, wherein one or more of the droplets comprises a biomolecule or a nucleic acid molecule.

[0086] 32. The emulsion of any one of embodiments 26-31, wherein the fluid is an oil, optionally a fluorinated oil, a silicone oil, or a combination thereof.

[0087] 33. A method of making a compound comprising reacting a PFPAE with a linker molecule (L) comprising at least a first and a second amine group, and forming an amide bond between the PFPAE and the linker molecule (L) through the first amine group, to form a compound represented by the formula PFPAE block - L, wherein “-” represents the amide bond.

[0088] 34. The method of embodiment 33, wherein the PFPAE comprises: a) the formula F(CF(CF3)CF2O) x CF(CF3)COO-alkyl, wherein alkyl is methyl, ethyl, propyl, butyl, or pentyl, and x is an average number of repetitions selected from the group consisting of 5 to 50 or 5 to 45, including decimals; or b) the formula (CF3CF2CF2(OCF(CF3)CF2) y COO-alkyl, wherein alkyl is methyl, ethyl, propyl, butyl, or pentyl, wherein y is an average number of repetitions selected from the group consisting of 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, or 60, including decimals thereof, or y is a value between 5 and 60, or between 5 and 50, or between 5 and 40, including decimals within each of said ranges; or c) the formula CF3O(CF2CF2O)m (CF2O) n CF2COO-alkyl, wherein alkyl is methyl, ethyl, propyl, butyl or pentyl, wherein m and n are independently selected such that m+n = a value between 5 and 50, preferably between 8 and 40, including decimal numbers; or d) formula CF3O(CF2CF(CF3)O) m (CF2O) n CF2COO-alkyl, wherein alkyl is methyl, ethyl, propyl, butyl or pentyl, wherein m and n are independently selected such that m+n = a value between 5 and 50, preferably between 8 and 40, including decimal numbers.

[0089] 35. The method of embodiment 33 or embodiment 34, wherein L comprises: a) formula NH2(CH2CH2O) y (CH2) z NH2, wherein y is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20, or an integer selected from 1, 2, 3, 4, 5, 6, 7, 8 or 9, or 2, and z is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, or an integer selected from 1, 2 or 3, or 2; or b) formula NH2(CH2) e (C a H b OH c (CH2) g ) d (CH2) f NH2, wherein e and f can be the same or different and are independently 0, 1, 2, 3, 4 or 5; a is an integer selected from 1, 2, 3, 4, 5 or 6; b is selected from 0 or 1; c is selected from 1 or 2, wherein b+c = 2a; g is an integer selected from 0, 1, 2 or 3; and d is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; or c) formula NH2((CH2) g O) m (CH2) h CHX1X2, wherein X1and X2may be the same or different and are -(CH2) i O(CH2) j O(CH2) kNH2, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or d) the formula NH2((CH2) g O) m (CH2) h CX1X2X3, wherein X1, X2, and X3may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH2, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or e) the formula NH2(CH2) q O(CH2) r O(CH2) s NH2, wherein q, r, and s can be the same or different and are integers selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20; or f) L is 2-(2-aminoethoxy)ethanamine, 1,8-diamino-3,6-dioxaoctane (DADOO), 1,11 -diamino-3,6,9-trioxoundecane, and 3,6,9,12-tetraoxatetradecane-1,14-diamine, or 4,9-dioxa-1,12-dodecanediamine.

[0090] 36. The method of any one of embodiments 33-35, wherein the reaction is carried out in the presence of an excess of L.

[0091] 37. The method of embodiment 36, wherein the excess L is provided in an amount from about 1.1 times to about 100 times, including fractions thereof, the amount of PFPAE, for example, about 1.5 times, 2 times, 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, 10 times, 11 times, 12 times, 13 times, 14 times, 15 times, 16 times, 17 times, 18 times, 19 times, 20 times, 21 times, 22 times, 23 times, 24 times, 25 times, 26 times, 27 times, 28 times, 29 times, 30 times, 31 times, 32 times, 33 times, 34 times, 35 times, 36 times, 37 times, 38 times, 39 times, or 40 times.

[0092] 38. The method of any one of embodiments 33-37, further comprising reacting the PFPAE block-L compound with an activated hydrophilic polymer block to form a compound having the formula PFPAE block-L-hydrophilic polymer block, wherein the hydrophilic polymer block (HPB) is monodisperse or polydisperse.

[0093] 39. The method of embodiment 38, wherein the activated hydrophilic polymer block (HPB) is a functionalized polyethylene oxide (PEO), polyethylene glycol (PEG), poly(N- isopropylacrylamide) (PNIPAM), polyvinylcaprolactam (PVCL), polyvinylpyrrolidone (PVP), or polyvinyl alcohol (PVA), or any combination thereof.

[0094] 40. The method of embodiment 38 or embodiment 39, wherein the activated hydrophilic polymer block is functionalized with a N-hydroxysuccinimidyl ester or an activated carboxyl group for reaction with an amine group on the compound having the formula PFPAE block-L.

[0095] 41. The method of embodiment 40, wherein the activated hydrophilic polymer block is optionally alkylated and functionalized with a N-hydroxysuccinimidyl ester.

[0096] 42. The method of any one of embodiments 38-41, wherein the formed compound has the formula PFPAE block-L-HPB, the HPB is a polyethylene glycol (PEG) block, optionally the PEG block is alkylated, wherein: the PFPAE block comprises the formula F(CF(CF3)CF2O) x CF(CF3)CO-, wherein x is an average number of repetitions between 5 and 50, including fractions thereof; the PEG block comprises the formula -(C n H 2n O) y -H or -(C n H 2n O) y -alkyl, wherein the alkyl is C1-C 10 alkyl, n is an integer selected from 1, 2, 3, 4, 5, or 6, preferably 1, 2, 3, or 4, more preferably 2, and y is an integer selected from 2-75 or an integer selected from 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30, preferably 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25, more preferably 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20; or y is an average number of repetitions between 2 and 75, including fractions thereof, an average number of repetitions between 2 and 30, including fractions thereof, an average number of repetitions between 5 and 25, including fractions thereof, or an average number of repetitions between 8 and 20, including fractions thereof, and L comprises: a) the formula -NH(CH2CH2O) y (CH2) z NH-, wherein y is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 (preferably 1, 2, 3, 4, 5, 6, 7, 8, or 9, or more preferably 2) and z is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3, or more preferably 2); or b) the formula -NH(CH2) e (C a Hb OH c (CH2) g ) d (CH2) f NH- wherein e and f can be the same or different and are independently 0, 1, 2, 3, 4, or 5 (preferably, independently 0, 1, 2, or 3, or e and f are selected such that e + f = 0, 1, or 2); a is an integer selected from 1, 2, 3, 4, 5, or 6; b is selected from 0 or 1; c is selected from 1 or 2, wherein b + c = 2a; g is 0, 1, 2, or 3; and d is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; or c) the formula -NH((CH2) g O) m (CH2) h CX1X2wherein X1and X2may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH- wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or d) the formula -NH((CH2) g O) m (CH2) h CX1X2X3wherein X1, X2, and X3may be the same or different and are -(CH2) i O(CH2) j O(CH2) kNH-, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or e) the formula -NH(CH2) q O(CH2) r O(CH2) s NH-, wherein q, r, and s can be the same or different and are integers selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 (preferably, q and s are independently 1, 2, or 3 and can be the same or different, and r is 1, 2, 3, or 4); or f) L forms an amide bond with the PFPAE block to which it is coupled and forms an amide bond with the hydrophilic polymer block, and L is 2-(2-aminoethoxy)ethylamine, 1,8-diamino-3,6-dioxaoctane (DADOO), 1,11-diamino-3,6,9-trioxoundecane, and 3,6,9,12-tetraoxatetradecane-1,14-diamine, or 4,9-dioxa-1,12-dodecanediamine.

[0097] 43. The method of any one of embodiments 33-42, wherein the compound represented by the formula PFPAE block-L is a compound of any one of embodiments 8-15.

[0098] 44. A method of making a compound comprising reacting a compound of any one of embodiments 8-15 with an activated hydrophilic polymer block, which is monodisperse or polydisperse.

[0099] 45. The method of embodiment 44, wherein the hydrophilic polymer block is a functionalized polyethylene oxide (PEO), polyethylene glycol (PEG), poly(N-isopropylacrylamide) (PNIPAM), polyvinylcaprolactam (PVCL), polyvinylpyrrolidone (PVP), or polyvinyl alcohol (PVA), or any combination thereof.

[0100] 46. The method of embodiment 44 or embodiment 45, wherein the hydrophilic polymer block is functionalized to react with an amine group on the linker molecule (L).

[0101] 47. The method of embodiment 46, wherein optionally the hydrophilic polymer block is alkylated and functionalized with a N-hydroxysuccinimidyl ester or an activated carboxylic acid group.

[0102] 48. The method of any one of embodiments 44-47, wherein the hydrophilic polymer block is a polyethylene glycol (PEG) block, optionally the PEG block is alkylated, wherein: the PFPAE block comprises the formula F(CF(CF3)CF2O) x CF(CF3)CO-, wherein x is an average number of repetitions between 5 and 50, including fractions thereof; the PEG block after reaction with the compound of any one of embodiments 8-15 comprises the formula -(C n H 2n O) y -H or -(C n H 2n O) y -alkyl, wherein the alkyl is C1-C 10alkyl, n is an integer selected from 1, 2, 3, 4, 5, or 6, preferably 1, 2, 3, or 4, more preferably 2, and y is an integer selected from 2-75 or an integer selected from 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30, preferably 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25, more preferably 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20; or y is an average repeat value between 2 and 75, including decimals thereof, an average repeat value between 2 and 30, including decimals thereof, an average repeat value between 5 and 25, including decimals thereof, or an average repeat value between 8 and 20, including decimals thereof, and L after reaction with the PEG block comprises: a) the formula -NH(CH2CH2O) y (CH2) z NH-, wherein y is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 (preferably 1, 2, 3, 4, 5, 6, 7, 8, or 9, or more preferably 2) and z is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3, or more preferably 2); or b) the formula -NH(CH2) e (C a H b OH c (CH2) g ) d (CH2) f NH-, wherein e and f can be the same or different and are independently 0, 1, 2, 3, 4, or 5 (preferably, independently 0, 1, 2, or 3, or e and f are selected such that e + f = 0, 1, or 2); a is an integer selected from 1, 2, 3, 4, 5, or 6; b is selected from 0 or 1; c is selected from 1 or 2, wherein b + c = 2a; g is 0, 1, 2, or 3; and d is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; or c) the formula -NH((CH2) g O) m(CH2) h CX1X2, wherein X1and X2may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH-, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or d) the formula -NH((CH2) g O) m (CH2) h CX1X2X3, wherein X1, X2, and X3may be the same or different and are -(CH2) i O(CH2) j O(CH2) k NH-, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or e) the formula -NH(CH2) q O(CH2) r O(CH2) sNH-, wherein q, r, and s can be the same or different and are an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 (preferably, q and s are independently 1, 2, or 3 and can be the same or different, and r is 1, 2, 3, or 4); or f) L forms an amide bond with the PFPAE block to which it is coupled and forms an amide bond with the hydrophilic polymer block, and L is 2-(2-aminoethoxy)ethylamine, 1,8-diamino-3,6-dioxaoctane (DADOO), 1,11-diamino-3,6,9-trioxoundecane, and 3,6,9,12-tetraoxatetradecane-1,14-diamine, or 4,9-dioxa-1,12-dodecanediamine.

[0103] 49. The surfactant of embodiment 1, wherein the hydrophilic polymer block comprises polyethylene oxide (PEO), polyethylene glycol (PEG), poly(N-isopropylacrylamide) (PNIPAM), polyvinylcaprolactam (PVCL), polyvinylpyrrolidone (PVP), or polyvinyl alcohol (PVA), or any combination thereof, and optionally, wherein the hydrophilic polymer block is monodisperse or polydisperse.

[0104] All patents, patent applications, provisional applications, and publications cited or described in this document are hereby incorporated by reference in their entirety for all purposes, to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

[0105] The following are examples illustrating the procedures for practicing the present application. These examples should not be construed as limiting. All percentages are by weight and all solvent mixtures are by volume unless otherwise indicated.

[0106] Example 1 - Fluorosurfactant synthesis scheme

[0107] This example provides an exemplary two-step method for synthesizing a fluorosurfactant.

[0108] Step 1) PFPE-ME + DADOO → PFPE-DADOO (see exemplary reaction scheme in Figure 9 )

[0109] 1) Determine the molecular weight of PFPE-ME (methyl ester functionalized polyfluoro polyether polymer) using NMR.

[0110] 2) Dissolve PFPE-ME in HFE7500 (1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2- (trifluoromethyl)hexan-3-ylethyl ether) at a ratio of 2 g PFPE : 1 mL HFE 7500 (mass: volume).

[0111] 3) Dissolve 4 equivalents of DADOO (1,8-diamino-3,6-dioxaoctane) in tetrahydrofuran (THF) in the reactor (volume half of HFE7500) using an anchor stirrer (or other configuration for mixing viscous liquids).

[0112] 4) Slowly add the PFPE solution over 30 minutes via a dropping funnel (or pump) under ambient conditions. This can also be done under inert atmosphere.

[0113] 5) React until completion is observed by FT-IR.

[0114] 6) Transfer the reaction mixture to a separatory funnel and add an equal volume of ethanol relative to HFE7500. Shake until well mixed and allow it to fully separate into two clear layers.

[0115] 7) Collect the lower layer into a weighed round bottom flask, leaving only a small amount in the separatory funnel.

[0116] 8) Rotary evaporate the collected solution, slowly warming to 40°C, 15 mbar. Rotary evaporate until weight equilibrium. Slowly warm to 55°C and rotary evaporate until weight stable.

[0117] 9) Evaluate purity (% decarbonylated, mono-functionalized compound, and bi-functionalized compound) using NMR and FT-IR, and confirm structure is as expected. LCMS can be used to detect excess DADOO. Mono-functionalized compound has the structure of PFPE-amide-linker-amine, or here PFPE-DADOO-NH2 (desired product). Bi-functionalized compound has the structure of two PFPE molecules linked to the same linker (here DADOO), i.e. PFPE-DADOO-PFPE. This is an unexpected byproduct.

[0118] Step 2) PFPE-DADOO + mPEG-NHS ester → PFPE-DADOO-PEG

[0119] Scheme - See Figure 10

[0120] 1) Dissolve PFPE-DADOO in HFE7100 (methoxy-nonafluorobutane); 1 g polymer: 2-2.5 mL solvent. Determine Mw from NMR.

[0121] 2) Dissolve 1.9 equivalents of mPEG-NHS ester in THF (anhydrous, stabilizer free) to the same volume as the HFE 7100.

[0122] 3) Slowly add the PEG to the PFPE with stirring. The solution will slowly increase in turbidity as the PEG is added, eventually decreasing in turbidity.

[0123] 4) After the PEG is added, check to see if the solution is still turbid. If so, slowly add more THF until the solution is clear and only one phase.

[0124] 5) Allow the reaction to proceed for 3 days at ambient conditions.

[0125] 6) Rotovap the solution until the mass is stable.

[0126] 7) Resolubilize the dry product in HFE 7500 at 3 mL / g of expected product. Transfer to a separatory funnel and complete the transfer using minimal additional HFE 7500.

[0127] 8) Add EtOH (ethanol) to 50% by volume relative to the HFE 7500.

[0128] 9) Cap and shake vigorously. Allow the mixture to completely separate and become clear. Collect the lower fluorinated layer.

[0129] 10) Rotovap the product until the weight is stable (40 °C, 15 mbar -> 60 °C 15 mbar).

[0130] 11) Upon cooling, a clear gel or viscous liquid is obtained depending on the PEG / PFPE length ratio. Larger PEG to PFPE ratios result in a gel-like product. In some embodiments, the final product is also a white waxy material.

[0131] Example 2 - Performance of exemplary surfactants relative to control surfactants

[0132] This example provides experimental results characterizing exemplary surfactants provided by the present disclosure. The exemplary surfactants have the following formula:

[0133] Figure 5A and 5B NMR spectra of exemplary surfactants are provided. 1 H NMR: Shows presence of two amides at 8.38 and 7.59 ppm. Weak signal at 6.02 ppm shows about 1% decarbonylation ( Figure 5A ). Figure 5B : 19F NMR: Fluorine NMR showed low degree of decarboxylation at -146.8 and -85.6 ppm.

[0134] Droplets prepared using this exemplary surfactant in HFE 7500 at different weight % solutions were visualized before and after thermal cycling using a standard PCR protocol. The droplets visually showed stability and were comparable to two different control surfactants prepared using different chemical methods (see Figure 6 ). When used in a PCR protocol, the exemplary surfactant showed comparable copy number to the two control surfactants (see Figure 7 ). The exemplary surfactant also showed comparable event number (number of droplets detected in a digital PCR instrument) to the two control surfactants at tested weight concentrations of 0.5-3 wt% (see Figure 8 ).

[0135] It is to be understood that the embodiments and implementations described herein are merely for illustrative purposes and that various modifications or changes in light thereof will be obvious to those skilled in the art and they are to be included within the purview and spirit of the application and the scope of the appended claims. Furthermore, any element or limitations of any application or implementation disclosed herein can be combined with any and / or all other elements or limitations (alone or in any combination), or any other application or implementation, disclosed herein, and all such combinations are to be included within the scope of the application, but not limited thereto.

Claims

1. A surfactant comprising a perfluoropolyether (PFPE) block or a PFPAE block coupled to a connector molecule (L) via a first amide bond, and said connector molecule (L) coupled to a hydrophilic polymer block via a second amide bond, optionally said hydrophilic polymer block being alkylated.

2. The surfactant of claim 1, wherein the hydrophilic polymer block comprises a polyethylene glycol (PEG) block, optionally, the PEG block is alkylated.

3. The surfactant of claim 1 or claim 2, wherein the PFPAE block or PFPE block comprises: a) Formula F(CF(CF3)CF2O) x CF(CF3)CO-, where x is the average number of repetitions selected from the following: 5 to 50, or 5 to 45, including decimals; b) Equation (CF3CF2CF2(OCF(CF3)CF2) y CO-, where y is the average number of repetitions selected from the following: 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60, including its decimal, or y is a value between 5 and 60, or between 5 and 50, or between 5 and 40, including the decimal in each of the said ranges; c) Formula CF3O(CF2CF2O) m (CF2O) n CF2CO-, where m and n are chosen independently such that m+n = a value between 5 and 50, preferably between 8 and 40, including decimals within each of the said range; or d) Equation CF3O(CF2CF(CF3)O) m (CF2O) n CF2CO-, where m and n are chosen independently such that m+n = a value between 5 and 50, preferably between 8 and 40, including decimals in each of the said range.

4. The surfactant of claim 3, wherein the PEG block comprises the formula -(C n H 2n O) y -H or -(C n H 2n O) y -alkyl, wherein the alkyl group is C1-C 10 Alkyl group, where n is an integer selected from 1, 2, 3, 4, 5, or 6, preferably 1, 2, 3, or 4, more preferably 2, and y is an integer selected from 2-75 or an integer selected from 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30, preferably 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25, more preferably 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20; or y is between 2 and 75, including its decimals; The range is between 2 and 30, including its decimal part; The average repeating value between 5 and 25, including its decimal; or between 8 and 20, including its decimal.

5. The surfactant of claim 4, wherein L comprises: a) Formula -NH(CH2CH2O) y (CH2) z NH-, where y is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 (preferably 1, 2, 3, 4, 5, 6, 7, 8 or 9, or more preferably 2) and z is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3, or more preferably 2); or b) Formula -NH(CH2) e (C a H b OH c (CH2) g ) d (CH2) f NH-, where e and f can be the same or different, and are independently 0, 1, 2, 3, 4, or 5 (preferably, independently 0, 1, 2, or 3, or e and f are chosen such that e + f = 0, 1, or 2); a is an integer selected from 1, 2, 3, 4, 5, or 6; b is selected from 0 or 1; c is selected from 1 or 2, where b + c = 2a; g is 0, 1, 2, or 3; and d is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; or c) Formula -NH((CH2) g O) m (CH2) h CX1X2, where X1 and X2 can be the same or different, and are -(CH2). i O(CH2) j O(CH2) k NH-, where g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); An integer of 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or d) Formula -NH((CH2) g O) m (CH2) h CX1X2X3, where X1, X2, and X3 can be the same or different, and are -(CH2). i O(CH2) j O(CH2) k NH-, where g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); An integer of 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or e) Formula -NH(CH2) q O(CH2) r O(CH2) s NH-, where q, r, and s can be the same or different, and are integers selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 (preferably, q and s are independently 1, 2, or 3 and can be the same or different, and r is 1, 2, 3, or 4); or f) L forms an amide bond with its coupled PFPAE or PFPE block and with a hydrophilic polymer block, wherein L is 2-(2-aminoethoxy)ethylamine, 1,8-diamino-3,6-dioxaoctane (DADOO), 1,11-diamino-3,6,9-trioxaundecane and 3,6,9,12-tetraoxatetradecane-1,14-diamine, or 4,9-dioxa-1,12-dodecanediamine.

6. The surfactant of claim 5, wherein the hydrophilic polymer block is alkylated with methyl or ethyl groups.

7. The surfactant of claim 3, wherein L comprises: a) Formula -NH(CH2CH2O) y (CH2) z NH-, where y is an integer selected from 1, 2, 3, 4, and 5 and z is an integer selected from 1, 2, or 3, or y is 2 or 3 and z is 1, 2, or 3, or y is 2 and z is 2; or b) Formula -NH(CH2) e (C a H b OH c (CH2) g ) d (CH2) f NH-, where: e is 0, 1, or 2; f is 0, 1, 2, or 3; or e and f are chosen such that e + f = 0, 1, or 2; a is an integer selected from 1, 2, 3, 4, 5, or 6; b is an integer selected from 0 or 1; c is an integer selected from 1 or 2, where b + c = 2a; g is 0, 1, 2, or 3; and d is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; or c) Formula -NH((CH2) g O) m (CH2) h CHX1X2, where X1 and X2 can be the same or different, and are -(CH2). i O(CH2) j O(CH2) k NH-, where g, h, i, j, k, and m may be the same or different; g is an integer selected from 1, 2, or 3; h is an integer selected from 1, 2, or 3; i is an integer selected from 1, 2, or 3; j is an integer selected from 1, 2, or 3; k is an integer selected from 1, 2, or 3; and m is an integer selected from 1, 2, or 3; or d) Formula -NH((CH2) g O) m (CH2) h CX1X2X3, where X1, X2, and X3 can be the same or different, and are -(CH2). i O(CH2) j O(CH2) k NH-, where g is an integer selected from 1, 2 or 3; h is an integer selected from 1, 2 or 3; i is an integer selected from 1, 2 or 3; j is an integer selected from 1, 2 or 3; k is an integer selected from 1, 2 or 3; and m is an integer selected from 1, 2 or 3.

8. A compound comprising a perfluoropolyether (PFPE) block or a PFPAE block coupled to a linker molecule (L) via a first amide bond, wherein the linker molecule (L) comprises a second amino group, wherein L comprises: a) Formula -NH(CH2CH2O) y (CH2) z NH2, where y is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 (preferably 1, 2, 3, 4, 5, 6, 7, 8 or 9, or more preferably 2) and z is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 (preferably 1, 2 or 3, or more preferably 2); or b) Formula -NH(CH2) e (C a H b OH c (CH2) g ) d (CH2) f NH2, where e and f can be the same or different and are independently 0, 1, 2, 3, 4 or 5; a is an integer selected from 1, 2, 3, 4, 5 or 6; b is selected from 0 or 1; c is selected from 1 or 2, where b + c = 2a; g is an integer selected from 0, 1, 2 or 3; and d is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; or c) Formula -NH((CH2) g O) m (CH2) h CHX1X2, where X1 and X2 can be the same or different, and are -(CH2). i O(CH2) j O(CH2) k NH2, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m ... An integer of 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or d) Formula -NH((CH2) g O) m (CH2) h CX1X2X3, where X1, X2, and X3 can be the same or different, and are -(CH2). i O(CH2) j O(CH2) k NH2, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m ... An integer of 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or e) Formula -NH(CH2) q O(CH2) r O(CH2) s NH2, where q, r, and s can be the same or different, and are integers selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20; or f) L forms a single amide bond with the PFPE block or PFPAE block, and L is 2-(2-aminoethoxy)ethylamine, 1,8-diamino-3,6-dioxaoctane (DADOO), 1,11-diamino-3,6,9-trioxaundecane and 3,6,9,12-tetraoxatetradecane-1,14-diamine, or 4,9-dioxa-1,12-dodecanediamine.

9. The compound of claim 8, wherein the PFPAE block or PFPE block comprises: a) Formula F(CF(CF3)CF2O) x CF(CF3)CO-, where x is the average number of repetitions selected from the following: 5 to 50, or 5 to 45, inclusive of the decimal; or b) Equation (CF3CF2CF2(OCF(CF3)CF2) y CO-, where y is the average number of repetitions selected from the following: 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60, including its decimal, or y is a value between 5 and 60, or between 5 and 50, or between 5 and 40, including the decimal in each of the stated ranges; or c) Formula CF3O(CF2CF2O) m (CF2O) n CF2CO-, where m and n are chosen independently such that m+n = a value between 5 and 50, preferably between 8 and 40, including decimals; or d) Equation CF3O(CF2CF(CF3)O) m (CF2O) n CF2CO-, where m and n are chosen independently such that m+n = a value between 5 and 50, preferably between 8 and 40, including decimals.

10. The compound of claim 8 or claim 9, wherein the compound is selected from the group consisting of: Where n is between 5 and 50, preferably an average value between 8 and 40, including decimals; Where n is between 5 and 50, preferably an average value between 8 and 40, including decimals; Where n is between 5 and 50, preferably an average value between 8 and 40, including decimals; Where n is between 5 and 50, preferably an average value between 8 and 40, including decimals; Where i = 1-12, and n is between 5 and 50, preferably an average between 8 and 40, including decimals; Where n is between 5 and 50, preferably an average value between 8 and 40, including decimals; Where n is between 5 and 50, preferably an average value between 8 and 40, including decimals; Where n is between 5 and 50, preferably an average value between 8 and 40; Where n is between 5 and 50, preferably an average value between 8 and 40, including decimals; Where i is a value between 1 and 12, and m and n are chosen independently such that m + n = is between 5 and 50, preferably between 8 and 40, including decimals; Where i is a value between 1 and 12, and m and n are chosen independently such that m + n = is between 5 and 50, preferably between 8 and 40, including decimals; Where n is between 5 and 40, preferably between 5 and 35, including decimals; Where n is between 5 and 40, preferably between 5 and 35, including decimals; and Where n is between 5 and 40, preferably between 5 and 35, including decimals.

11. The compound of claim 8 or claim 9, wherein L has the formula -NH(CH2CH2O). y (CH2) z NH2, where y is an integer selected from 1, 2, 3, 4 and 5 and z is an integer selected from 1, 2 or 3, or y is 2 or 3 and z is 1, 2 or 3, or y is 2 and z is 2.

12. The compound of claim 8 or claim 9, wherein L has the formula -NH(CH2). e (C a H b OH c (CH2) g ) d (CH2) f NH2, where e and f can be the same or different and are independently 1, 2 or 3; a is an integer selected from 1 or 2; b is selected from 0 or 1; c is selected from 1 or 2, where b + c = 2a; g is 0, 1, 2 or 3; and d is an integer selected from 1, 2, 3 or 4.

13. The compound of claim 8 or claim 9, wherein L has the formula -NH((CH2) g O) m (CH2) h CHX1X2, where X1 and X2 can be the same or different, and are -(CH2). i O(CH2) j O(CH2) k NH2, where g, h, i, j, k and m can be the same or different; g is an integer selected from 1, 2 or 3; h is an integer selected from 1, 2 or 3; i is an integer selected from 1, 2 or 3; j is an integer selected from 1, 2 or 3; k is an integer selected from 1, 2 or 3; and m is an integer selected from 1, 2 or 3.

14. The compound of claim 8 or claim 9, wherein L has the formula -NH((CH2) g O) m (CH2) h CX1X2X3, where X1, X2, and X3 can be the same or different, and are -(CH2). i O(CH2) j O(CH2) k NH2, where g is an integer selected from 1, 2 or 3; h is an integer selected from 1, 2 or 3; i is an integer selected from 1, 2 or 3; j is an integer selected from 1, 2 or 3; k is an integer selected from 1, 2 or 3; and m is an integer selected from 1, 2 or 3.

15. The compound of claim 8 or claim 9, wherein L has the formula -NH(CH2). q O(CH2) r O(CH2) s NH2, where q is an integer selected from 1, 2, 3 or 4; r is an integer selected from 1, 2, 3 or 4; and s is an integer selected from 1, 2, 3 or 4.

16. A composition comprising the surfactant as described in any one of claims 4-7.

17. The composition of claim 16, further comprising a hydrophobic liquid, optionally wherein the hydrophobic liquid is a fluorinated oil or a silicone oil, or a combination thereof.

18. A method for forming aqueous droplets, comprising: Provide microfluidic devices; Provide an aqueous liquid to the microfluidic device; Fluorinated liquid is supplied to the microfluidic device; Provide a surfactant as described in any one of claims 4-7; and In the presence of the surfactant, aqueous droplets are formed in the fluorinated liquid, the droplets containing the surfactant, optionally wherein the fluorinated liquid is a fluorinated oil.

19. A composition comprising the compound as described in any one of claims 8-15.

20. A method for forming an emulsion comprising a plurality of droplets, the method comprising: (a) providing a composition comprising a fluid immiscible or substantially immiscible with water and a surfactant as described in any one of claims 4-7; (b) providing an aqueous fluid, optionally wherein the aqueous fluid comprises a target nucleic acid or biomolecule; (c) Contacting the composition with the aqueous fluid to produce an emulsion of a plurality of aqueous fluid droplets dispersed in a fluid that is immiscible or substantially immiscible with water.

21. An emulsion comprising: a) an aqueous liquid and a surfactant as described in any one of claims 4-7, and optionally, a fluid that is immiscible or substantially immiscible with the aqueous liquid; or b) A fluid that is immiscible or substantially immiscible with water and a surfactant as described in any one of claims 4-7, and optionally, an aqueous liquid.

22. An emulsion comprising: (a) a plurality of aqueous liquid droplets dispersed in a fluid that is immiscible or substantially immiscible with an aqueous liquid, and (b) a surfactant as claimed in any one of claims 4-7.

23. A method of preparing a compound comprising reacting a PFPAE with a linker molecule (L) comprising at least first and second amino groups, and forming an amide bond between the PFPAE and the linker molecule (L) via the first amino group to form a compound represented by the formula PFPAE-L, wherein "-" represents an amide bond.

24. The method of claim 23, wherein the PFPAE comprises: a) Formula F(CF(CF3)CF2O) x CF(CF3)COO-alkyl, wherein the alkyl group is methyl, ethyl, propyl, butyl, or pentyl, and x is the average number of repetitions selected from: 5 to 50 or 5 to 45, inclusive; or b) Equation (CF3CF2CF2(OCF(CF3)CF2) y COO-alkyl, wherein the alkyl group is methyl, ethyl, propyl, butyl, or pentyl, and y is the average number of repeats selected from the following: 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60, including its decimal, or y is a value between 5 and 60, or between 5 and 50, or between 5 and 40, including the decimal in each of the stated ranges; or c) Formula CF3O(CF2CF2O) m (CF2O) n CF2COO-alkyl, wherein the alkyl group is methyl, ethyl, propyl, butyl, or pentyl, wherein m and n are independently chosen such that m+n = a value between 5 and 50, preferably between 8 and 40, including decimals; or d) Equation CF3O(CF2CF(CF3)O) m (CF2O) n CF2COO-alkyl, wherein the alkyl group is methyl, ethyl, propyl, butyl or pentyl, wherein m and n are independently chosen such that m+n = a value between 5 and 50, preferably between 8 and 40, including decimals.

25. The method of claim 24, wherein L comprises: a) Formula NH2(CH2CH2O) y (CH2) z NH2, where y is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20, or an integer selected from 1, 2, 3, 4, 5, 6, 7, 8 or 9, or 2, and z is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, or an integer selected from 1, 2 or 3, or 2; or b) Formula NH2(CH2) e (C a H b OH c (CH2) g ) d (CH2) f NH2, where e and f can be the same or different and are independently 0, 1, 2, 3, 4 or 5; a is an integer selected from 1, 2, 3, 4, 5 or 6; b is selected from 0 or 1; c is selected from 1 or 2, where b + c = 2a; g is an integer selected from 0, 1, 2 or 3; and d is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; or c) Formula NH2((CH2) g O) m (CH2) h CHX1X2, where X1 and X2 can be the same or different, and are -(CH2). i O(CH2) j O(CH2) k NH2, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m ... An integer of 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or d) Formula NH2((CH2) g O) m (CH2) h CX1X2X3, where X1, X2, and X3 can be the same or different, and are -(CH2). i O(CH2) j O(CH2) k NH2, wherein g, h, i, j, k, and m can be the same or different; g is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); h is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); i is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); j is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); k is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); and m ... An integer of 3, 4, 5, 6, 7, 8, 9, or 10 (preferably 1, 2, or 3); or e) Formula NH2(CH2) q O(CH2) r O(CH2) s NH2, where q, r, and s can be the same or different, and are integers selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20; or f)L is 2-(2-aminoethoxy)ethylamine, 1,8-diamino-3,6-dioxaoctane (DADOO), 1,11-diamino-3,6,9-trioxaundecane and 3,6,9,12-tetraoxatetradecane-1,14-diamine, or 4,9-dioxa-1,12-dodecanediamine.

26. A method for preparing a compound comprising reacting the compound as described in any one of claims 8-15 with an activated hydrophilic polymer block, said hydrophilic polymer block being monodisperse or polydisperse.

27. The method of claim 26, wherein the hydrophilic polymer block is a functionalized polyethylene oxide (PEO), polyethylene glycol (PEG), poly(N-isopropylacrylamide) (PNIPAM), polyvinylcaprolactam (PVCL), polyvinylpyrrolidone (PVP), or polyvinyl alcohol (PVA), or any combination thereof.

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