Dispersant NNO is the same naphthalene sulfonate formaldehyde chemistry as the SNF water reducer used in concrete. It disperses cement particles, so it can be used as a cement dispersant. In practice, cement and concrete producers usually buy SNF grades, whose data sheets give cement and concrete test results; NNO is chosen where a dispersant grade or a low-formaldehyde grade is wanted.
How It Works in Cement
The molecules adsorb on cement grains and give them a negative charge, so they repel each other and release trapped water. The paste flows more at the same water content, or needs less water for the same flow.
NNO or SNF?
| Need | Usual choice |
|---|---|
| Concrete water reducer with concrete test data | SNF grades (SNF-5 to SNF-20) |
| Low free formaldehyde and naphthalene | NNO High-Purity grade |
| Gypsum and wallboard slurries | NNO High-Purity or SNF powder grades, by trial |
| Mixed use with dyes or pigments in the same plant | NNO Grade A or B |
Starting Ranges
The High-Purity TDS gives these supplier-recommended starting trial ranges: 2–5% of total dry solids for pigments and dyestuffs, 0.3–0.8% of dry gypsum for wallboard, and 0.5–1.2% of cementitious material for concrete. Confirm by trials.
What to Test
- Cement paste fluidity at fixed water.
- Concrete or mortar slump at mixing and after the time you need.
- Setting time and air content.
- Strength at the ages in your specification.
SNF grades for concrete: SNF product page. NNO grades: Dispersant NNO product page.
Frequently Asked Questions
Can Dispersant NNO be used in cement?
Yes, it disperses cement particles. For concrete, SNF grades with concrete test data are usually chosen; NNO High-Purity suits low-formaldehyde needs.
What dose of NNO is used in cement?
The High-Purity TDS gives a starting range of 0.5–1.2% of cementitious material. Confirm by trial mixes.
Is NNO the same as SNF?
Same chemistry, different specifications: NNO for dye dispersion, SNF for cement fluidity.
