Branched amino acid surfactants
The present disclosure provides derivatives of amino acids that have branched alkyl structures and surface-active properties. The amino acid can be naturally-occurring or synthetic, or they may be obtained via a ring-opening reaction of a lactam, such as caprolactam. The amino acid may be functionalized to form a compound that is surface-active and have advantageous surfactant characteristics. The compounds of the present disclosure have low critical micelle concentrations (CMC) as well as superior ability to lower the surface tension of a liquid.
1. A compound of the following formula:
wherein R 1 is selected from the group consisting of hydrogen, an oxygen atom, and a substituted or unsubstituted C 1 -C 6 alkyl, wherein the C 1 -C 6 alkyl comprises a group selected from the group consisting of carboxylates, hydroxyls, sulfonyls, or sulfonates;
n is an integer from 2 to 5;
R 2 is C 5 or C 6 alkyl;
R 3 is C 3 or C 4 alkyl;
the terminal nitrogen is optionally further substituted with R 4 , wherein R 4 chosen from hydrogen, an oxygen atom, and a substituted or unsubstituted C 1 -C 6 alkyl, wherein the substituted C 1 -C 6 alkyl comprises a group selected from the group consisting of carboxylates, hydroxyls, sulfonyls, or sulfonates;
and if R 4 is present then the compound comprises a counterion selected from the group consisting of chloride, bromide, iodide, and 4-methylbenzenesulfonate.
2. The compound of claim 1 , wherein the compound is 6-((2-butyloctyl)oxy)-N,N,N-trimethyl-6-oxohexan-1-aminium iodide, having the following formula:
3. The compound of claim 2 , having a critical micelle concentration (CMC) of about 21.30 mmol in water.
4. The compound of claim 1 , wherein the compound is 6-((2-butyloctyl)oxy)-N,N-dimethyl-6-oxohexan-1-aminium 4-methylbenzenesulfonate, having the following formula:
5. The compound of claim 4 , having a critical micelle concentration (CMC) of about 0.97 mmol in water.
6. The compound of claim 4 , having a surface tension in water equal to or less than 30 mN/m at a surface age of 100 ms or greater.
7. The compound of claim 1 , wherein the compound is 6-((2-butyl octyl)oxy)-N,N-dim ethyl-6-oxohexan-1-aminium chloride, having the following formula:
8. The compound of claim 7 , having a critical micelle concentration (CMC) of about 27.47 mmol in water.
9. The compound of claim 1 , wherein the compound is 4-((6-((2-butyloctyl)oxy)-6-oxohexyl)dimethylammonio)butane-1-sulfonate, having the following formula:
10. The compound of claim 9 , having a critical micelle concentration (CMC) of about 0.54 mmol in water.
11. The compound of claim 9 , having a surface tension in water equal to or less than 36 mN/m at a surface age of 100 ms or greater.
12. The compound of claim 1 , wherein the compound is 2-butyloctyl6-(dimethylamino)hexanoate N-oxide, having the following formula:
13. The compound of claim 12 , having a critical micelle concentration (CMC) of about 0.29 mmol in water.
14. The compound of claim 12 , having a surface tension in water equal to or less than 30 mN/m at a surface age of 1,000 ms or greater.
15. A compound of the following formula:
wherein le is selected from the group consisting of an oxygen atom, and a substituted or unsubstituted C 1 -C 6 alkyl, wherein the substituted C 1 -C 6 alkyl comprises a group selected from the group consisting of carboxylates, hydroxyls, sulfonyls, or sulfonates;
n is an integer from 2 to 5;
R 2 is C 5 -C 12 alkyl;
R 3 is C 3 -C 10 alkyl;
the terminal nitrogen is optionally further substituted with R 4 , wherein R 4 chosen from an oxygen atom, and a substituted or unsubstituted C 1 -C 6 alkyl, wherein the substituted C 1 -C 6 alkyl comprises a group selected from the group consisting of carboxylates, hydroxyls, sulfonyls, or sulfonates;
and if R 4 is present then the compound comprises a counterion selected from the group consisting of chloride, bromide and iodide.
16. A liquid composition comprising:
a medium; and
a surfactant of the following formula:
wherein R 1 is selected from the group consisting of hydrogen, an oxygen atom, and a substituted or unsubstituted C 1 -C 6 alkyl, wherein the substituted C 1 -C 6 alkyl comprises a group selected from the group consisting of carboxylates, hydroxyls, sulfonyls, or sulfonates;
n is an integer from 2 to 5;
R 2 is C 5 or C 6 alkyl;
R 3 is C 3 or C 4 alkyl;
the terminal nitrogen is optionally further substituted with R 4 , wherein R 4 chosen from hydrogen, an oxygen atom, and a substituted or unsubstituted C 1 -C 6 alkyl, wherein the substituted C 1 -C 6 alkyl comprises a group selected from the group consisting of carboxylates, hydroxyls, sulfonyls, or sulfonates;
and if R 4 is present then the compound comprises a counterion selected from the group consisting of chloride, bromide, iodide, and 4-methylbenzenesulfonate.
17. The composition of claim 16 , wherein the medium is water.
18. A liquid composition comprising:
a medium; and
a surfactant of the following formula:
wherein le is selected from the group consisting of an oxygen atom, and a substituted or unsubstituted C 1 -C 6 alkyl, wherein the substituted C 1 -C 6 alkyl comprises a group selected from the group consisting of carboxylates, hydroxyls, sulfonyls, or sulfonates;
n is an integer from 2 to 5;
R 2 is C 5 or C 6 alkyl;
R 3 is C 3 or C 4 alkyl;
the terminal nitrogen is optionally further substituted with R 4 , wherein R 4 chosen from an oxygen atom, and a substituted or unsubstituted C 1 -C 6 alkyl, wherein the substituted C 1 -C 6 alkyl comprises a group selected from the group consisting of carboxylates, hydroxyls, sulfonyls, or sulfonates;
and if R 4 is present then the compound comprises a counterion selected from the group consisting of chloride, bromide and iodide.
19. The composition of claim 18 , wherein the medium is water.