DDBAC (Didecyldimethylammonium Chloride), a quaternary ammonium compound (QAC), is widely used as a disinfectant, surfactant, and biocide due to its strong antimicrobial activity and surface-active properties.
1. Key Properties of DDBAC
(1) Chemical Structure
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Chemical Name: Didecyldimethylammonium Chloride
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CAS No.: 7173-51-5
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Molecular Formula: C₂₂H₄₈ClN
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Appearance: Colorless to pale yellow viscous liquid
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Solubility:
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Soluble in water (forms a clear solution)
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Soluble in organic solvents (ethanol, isopropanol)
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(2) Antimicrobial Activity
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Broad-spectrum efficacy: Effective against bacteria (Gram+ & Gram-), fungi, algae, and viruses (enveloped types).
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Mechanism: Disrupts microbial cell membranes, causing leakage and death.
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pH Stability: Works best in neutral to slightly alkaline (pH 6-9) conditions.
(3) Surface-Active Properties
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Cationic surfactant: Positively charged, adsorbs onto negatively charged surfaces (e.g., bacteria, skin, fabrics).
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Foaming & Wetting Agent: Used in cleaning formulations for better surface contact.
(4) Stability & Compatibility
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Thermal Stability: Stable up to ~50°C; higher temps may degrade it.
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Chemical Compatibility:
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Works well with nonionic surfactants (e.g., alcohol ethoxylates).
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Avoid mixing with anionic surfactants (e.g., SDS) → precipitation.
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2. Major Uses of DDBAC
(1) Disinfection & Sanitization
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Hospital & Healthcare: Surface disinfectant (against MRSA, E. coli, SARS-CoV-2).
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Food Industry: Sanitizer for equipment & processing areas.
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Household Cleaners: All-purpose disinfectant sprays & wipes.
(2) Water Treatment
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Cooling Towers & Pools: Controls biofilm, algae, and Legionella.
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Oilfield Water Systems: Prevents microbial-induced corrosion (MIC).
(3) Industrial & Agricultural Applications
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Textile & Paper Mills: Antimicrobial treatment for fabrics and pulp.
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Agriculture: Livestock sanitizer, seed treatment, and antifungal agent.
(4) Personal Care & Cosmetics
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Preservative: Extends shelf life of shampoos, conditioners, and wet wipes.
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Antidandruff Agent: Used in anti-fungal hair care products.
(5) Other Uses
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Wood Preservation: Protects against mold and termites.
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Oilfield Chemicals: Biocide in drilling fluids.
3. Advantages Over Other QACs
| Property | DDBAC | BAC (Benzalkonium Chloride) | DDAC (Didecyl Dimethyl Ammonium Chloride) |
|---|---|---|---|
| Antimicrobial Spectrum | Broad (Gram+, Gram-, fungi) | Narrower (mainly Gram+) | Similar to DDBAC |
| Foaming | Moderate | High | Low |
| Hard Water Tolerance | Good | Poor | Excellent |
| Skin Irritation | Low | Moderate | Low |
4. Safety & Environmental Considerations
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Toxicity:
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Low acute toxicity (LD50 oral, rat: ~300 mg/kg).
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Skin/eye irritant at high concentrations.
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Environmental Impact:
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Biodegradable (but persistent in high doses).
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Toxic to aquatic life (use controlled release in water treatment).
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Regulatory Status:
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EPA-approved for disinfectants.
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EU REACH-compliant (with usage limits).
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5. Recommended Concentrations
| Application | Working Concentration |
|---|---|
| Surface Disinfection | 0.1–0.5% (1000–5000 ppm) |
| Water Treatment | 5–50 ppm (depends on biofilm load) |
| Preservative (Cosmetics) | 0.05–0.2% |
Conclusion
DDBAC is a versatile, effective, and widely used biocide with applications in disinfection, water treatment, agriculture, and personal care. Its broad-spectrum antimicrobial activity, surfactant properties, and moderate toxicity make it a preferred choice over other QACs in many industries.