Delivery of Herbicidal Actives From Highly Charged Microcapsules

1 . A method for forming a herbicidal composition, the method comprising:

(a) preparing an emulsion including a continuous phase that is polar or non-polar, and a dispersed phase comprising droplets including (i) a polar herbicidal active ingredient when the continuous phase is non-polar or (ii) a non-polar herbicidal active ingredient when the continuous phase is polar; and

(b) adding a silica precursor to the emulsion such that the silica precursor can be emulsion templated on the droplets to form hollow silica-based particles that encapsulate the herbicidal active ingredient,

wherein the silica precursor has the general formula (I):

R 1 x—Si—(OR 2 ) y   (I)

wherein R 1 is selected from substituted and unsubstituted alkyl, substituted and unsubstituted aryl, alcohols, amines, amides, aldehydes, acids, esters, and functional groups having an unsaturated carbon-carbon bond, R 2 is an alkyl group, x+y=4, and y=1, 2 or 3.

2 . The method of claim 1 wherein:

the herbicidal active ingredient is selected from the group consisting of glyphosate, glyphosate salts, and mixtures thereof.

3 . The method of claim 1 wherein:

the herbicidal active ingredient is associated with a shell of the particles,

the herbicidal active ingredient is a glyphosate salt, and

the glyphosate salt is released on leaves, stems, flowers and/or roots of a plant due to dissolution of the glyphosate salt by contact of water vapor from transpiration of the plant.

4 . The method of claim 1 wherein:

step (a) comprises adding a surfactant selected from cationic, anionic, nonionic and amphoteric surfactants to a first material comprising the continuous phase and a second material comprising the dispersed phase to form the emulsion, and

the surfactant enhances the activity of the herbicidal active ingredient.

5 . The method of claim 1 wherein:

a shell of the particles degrades due to a pH change due to the contact of water vapor from transpiration of the plant.

6 . The method of claim 1 further comprising:

(c) coating the shell with a polymer associated with the herbicidal active ingredient, and

wherein the herbicidal active ingredient is released on leaves, stems, flowers and/or roots of a plant due to dissolution of the polymer by contact of water vapor from transpiration of the plant.

7 . The method of claim 1 wherein:

the herbicidal active ingredient is non-selective.

8 . The method of claim 1 wherein:

the herbicidal active ingredient is selective for monocot species.

9 . The method of claim 1 wherein:

the herbicidal active ingredient is selective for dicot species.

10 . The method of claim 1 wherein:

R 1 is phenyl.

11 . The method of claim 1 wherein:

R 1 is C 12—C 24 alkyl.

12 . The method of claim 1 wherein:

R 1 is substituted or unsubstituted acrylic acid.

13 . The method of claim 1 wherein:

R 1 is polyethylene glycol.

14 . The method of claim 1 wherein:

R 1 is alkylamine.

15 . The method of claim 1 wherein:

R 1 is alkyl carboxylate.

16 . The method of claim 1 wherein:

R 1 is alkyl quaternary amine.

17 . The method of claim 1 further comprising:

adding a cationic agent to the emulsion.

18 . The method of claim 17 wherein the cationic agent comprises a cationic polymer.

19 . A method for increasing the bioactivity of a herbicide, the method comprising:

encapsulating the herbicide in a sol-gel microcapsule wherein the herbicide is in the salt form such that the herbicide is released on leaves, stems, flowers and/or roots of a plant due to dissolution of the salt by contact of water vapor from transpiration of the plant.

20 . A method for increasing the bioactivity of a herbicide, the method comprising:

encapsulating the herbicide and a surfactant in a sol-gel microcapsule wherein the surfactant enhances the activity of the herbicide.