Cement dispersants are admixtures that keep cement particles apart so concrete or mortar flows with less water. Three products with similar names are often confused here: Dispersant MF, SMF and SNF. This page explains which one is a cement dispersant and how to choose.
MF, SMF and SNF: Which Is Which
| Name | Chemistry | Main use |
|---|---|---|
| Dispersant MF | Methylnaphthalene sulfonate formaldehyde condensate | Dye dispersant; its TDS also lists use as a water reducer |
| SMF | Sulfonated melamine formaldehyde | Concrete superplasticizer, often for precast and light-coloured concrete |
| SNF (PNS) | Naphthalene sulfonate formaldehyde condensate | The most widely used naphthalene-based concrete superplasticizer |
Dispersant MF is a methylnaphthalene sulfonate formaldehyde condensate. Despite the letters, “MF” here has nothing to do with melamine formaldehyde; the melamine-based concrete superplasticizer is SMF (sulfonated melamine formaldehyde).
How a Cement Dispersant Works
The anionic polymer adsorbs on cement grains and gives them a negative charge. The grains repel each other, release trapped water, and the paste flows more at the same water content.
Which to Choose for Concrete
- For general concrete and precast: SNF grades, whose data sheets include concrete test results. See the SNF product page.
- For light-coloured or early-strength precast: SMF. See SMF for concrete.
- Dispersant MF is mainly a dye dispersant. If you test it in cement, compare it with SNF in the same mixes.
What to Test
- Cement paste or mortar flow at fixed water.
- Concrete slump at mixing and after the time you need.
- Air content and setting time.
- Strength at the ages in your specification.
Frequently Asked Questions
What is a cement dispersant?
An admixture that disperses cement particles so concrete or mortar needs less water for the same flow; SNF, SMF, PCE and lignosulfonate are common examples.
Is MF dispersant the same as melamine formaldehyde?
No. Dispersant MF is methylnaphthalene-based. The melamine-based concrete superplasticizer is SMF.
Which dispersant is used in concrete admixtures?
Mainly SNF, SMF and PCE as high-range water reducers, and lignosulfonate as a normal-range water reducer.
