Dodecyl Trimethyl Ammonium Chloride (DTAC) is a cationic surfactant widely used in various industrial, cosmetic, and research applications.
1. Basic Information
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Chemical Formula: C₁₅H₃₄N⁺Cl⁻
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IUPAC Name: Dodecyltrimethylazanium chloride
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CAS No.: 112-00-5
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Molecular Weight: 263.89 g/mol
2. Structure & Properties
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Structure: Consists of a 12-carbon alkyl chain (dodecyl) attached to a trimethylammonium head group, with chloride as the counterion.
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Appearance: Colorless to pale yellow transparent liquid or white crystalline solid (depending on concentration).
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Solubility: Soluble in water and polar organic solvents (e.g., ethanol); forms clear solutions.
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Active Content: Common commercial forms:
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30–35% aqueous solution (liquid)
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≥99% powder/crystalline solid
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3. Key Characteristics
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Surfactant Class: Cationic (positively charged head group in aqueous solutions).
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Critical Micelle Concentration (CMC): ~15–20 mM (≈4–5 g/L) in water at 25°C.
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Surface Activity: Reduces surface tension, forms micelles, and binds strongly to negatively charged surfaces.
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Biocidal Activity: Exhibits antimicrobial properties against bacteria, fungi, and algae.
4. Applications
| Field | Uses |
|---|---|
| Personal Care | Hair conditioners, cream rinses (anti-static, softening agent). |
| Household & Industrial Cleaners | Fabric softeners, sanitizers, surface disinfectants. |
| Biotechnology/Research | Cell lysis buffer component, protein purification, DNA extraction. |
| Oil & Gas | Emulsifier, corrosion inhibitor, biocidal additive in drilling fluids. |
| Textile/Leather | Softening agent, dyeing auxiliary, antistatic treatment. |
| Agriculture | Adjuvant for pesticides, fungicidal formulations. |
| Water Treatment | Algicide, flocculant aid. |
5. Safety & Handling
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Toxicity: Moderate acute toxicity (oral LD₅₀ ~250–500 mg/kg in rats).
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Irritation: Can cause skin/eye irritation; use gloves and goggles.
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Environmental Impact: Biodegradable under aerobic conditions, but toxic to aquatic life at high concentrations.
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Incompatibilities: Avoid strong oxidizers and anionic surfactants (can form insoluble complexes).
6. Storage & Stability
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Store in sealed containers (HDPE/glass) at 5–30°C, protected from light.
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Aqueous solutions are stable at pH 4–8; avoid extreme pH or prolonged heating (>60°C).
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Solid form is hygroscopic; keep dry.
7. Related Compounds
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Longer-chain analogs:
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Cetyltrimethylammonium chloride (CTAC): C16 chain, used in hair conditioners.
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Stearyltrimethylammonium chloride (STAC): C18 chain, fabric softener base.
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Bromide version: DTAB (dodecyltrimethylammonium bromide), often used in research.
Summary
DTAC is a versatile cationic surfactant valued for its softening, antimicrobial, and surface-modifying properties. Its applications span from daily-use cosmetics to specialized industrial processes, though proper handling and environmental precautions are necessary due to its inherent toxicity and ionic nature.