What is the difference between pesticide microemulsion and emulsion in water?

On the difference between water-in-water emulsion and microemulsion

Emulsion in water (EW) is a kind of pesticide preparation formed by dispersing the crude drug liquid insoluble in water or the liquid obtained by dissolving crude drug in water-insoluble organic solvent in water, and its appearance is opaque.

Main components:

Active ingredients:1%-60%; Emulsifier 3%~ 10%, and the rest is supplemented with water to 100%.

Technical key: focus on solving the appearance stability and chemical stability of the preparation

Advantages:

1), compared with EC:

Water replaces a large number of organic solvents, saving organic solvents.

Reduce the toxicity of pesticide preparations.

Safe for people and the environment

High flash point, not easy to burn

Reduce residues on crops.

The amount of emulsifier is equivalent to EC, but a lot of organic solvents are saved.

The efficacy is equivalent to or slightly better than that of emulsifiable concentrate (preparation with the same content).

2) Compared with microemulsion:

Emulsion in water uses much less emulsifier than microemulsion (generally 15%-20%) and has low cost.

The effective pesticide content of the processed emulsion in water is 40%-60% higher than that of microemulsion.

Microemulsion (ME) is a dispersion system in which one or more liquids are uniformly dispersed in another immiscible liquid in the form of droplets. When the dispersion particle size of the dispersion reaches 0.00 1-0. 1 μm, the emulsion becomes a transparent or translucent homogeneous liquid.

Composition: It is an optically transparent or translucent thermodynamically stable dispersion system formed spontaneously by matrix water, pesticide active ingredients and oil under the action of surfactant or cosurfactant (emulsifier, dispersant, antifreeze and stabilizer).

Advantages:

1), fine droplets, promoting infiltration into plant tissues.

2) It has good stability and belongs to a stable system in thermodynamics.

3) High transfer efficiency (caused by high surfactant concentration)

4) good safety

5) Good economy

Main disadvantages: 1), the processed pesticide active ingredients must be stable in water; 2) The added surface activity is high, usually exceeding the dosage in EC (sometimes as high as 30%, which is 4~5 times of the dosage in EC), and the cost is high; 3) It is often necessary to add cosurfactants, and the dosage is also large; 4), the content is generally low (usually lower than 10%, rarely higher than 20%); 5) There are few kinds and quantities of emulsifiers.