Christopher Biedermann - University of Maryland:...
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Christopher Biedermann [email protected] SDU, Electrical Engineer Surfactants serve as a major part of commercial cleaning products. Through their hydrophilic and hydrophobic head and tail, surfactants bond with water and oil components to effectively creating a uniform solution. During an internship with Procter & Gamble, I worked with select surfactants to understand and model the stability of P&G’s Pantene and Head&Shoulders products. Determine surfactant hydrolysis rates at various temperatures and pH: Surfactants: • SLS (sodium lauryl sulfate) • SLE3S (sodium laureth-3 sulfate) • SLE1S (sodium laureth-1 sulfate) Surface Active Agent that cleans, builds viscosity, adds structure to shampoo, etc. A surfactant contains a water-soluble head group and an oil-soluble tail. All anionic surfactants (sulfates) hydrolyze (decompose) with time, high temperature, low pH Surfactant Micelle •Decomposition of a surfactant molecule in the presence of water, time, and high temperature •During hydrolysis, the system becomes more acidic with time which facilitates additional hydrolysis Acid Fatty alcohol SLS SLE1S SLE3S As SLS, SLE3S, and SLE1S hydrolyze, the system becomes more acidic as shown above. Demonstration of Decreasing pH due to Hydrolysis 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 p H Time Elapsed (hours) 7 pH (no caustic) 100C (10% active) SLS SLE3S SLE1S H, Time, pH H, Time, pH Add NaOH Fatty Alcohol Acid Surfactant 0 50 100 150 200 250 300 350 400 0 1 2 3 4 5 N a O H A d d e d ( g ) Time Elapsed (hours) pH 4 (caustic) SLE1S (10% active) 100C 90C 75C Temperature Comparison 0 5 10 15 20 25 30 35 40 45 50 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 N a O H A d d e d ( g ) Time Elapsed (hours) SLS 29% active, 75C pH 4 pH 5 pH Comparison: 1 pH unit 0 5 10 15 20 25 30 35 40 45 50 0 1 2 3 4 5 6 7 8 9 10 11 12 13 N a O H A d d e d ( g ) Time Elapsed (hours) pH 5 (caustic) 75C SLS SLE3S SLE1S Surfactant Comparison
Transcript of Christopher Biedermann - University of Maryland:...
Christopher Biedermann [email protected]
SDU, Electrical Engineer
Surfactants serve as a major part of commercial cleaning products. Through their hydrophilic and hydrophobic head and tail, surfactants bond with water and oil components to effectively creating a uniform solution. During an internship with Procter & Gamble, I worked with select surfactants to understand and model the stability of P&G’s Pantene and Head&Shoulders products.
Determine surfactant hydrolysis rates at various temperatures and pH: Surfactants: • SLS (sodium lauryl sulfate) • SLE3S (sodium laureth-3 sulfate) • SLE1S (sodium laureth-1 sulfate)
Surface Active Agent that cleans, builds viscosity, adds structure to shampoo, etc. A surfactant contains a water-soluble head group and an oil-soluble tail. All anionic surfactants (sulfates) hydrolyze (decompose) with time, high temperature, low pH
Surfactant Micelle
•Decomposition of a surfactant molecule in the presence of water, time, and high temperature •During hydrolysis, the system becomes more acidic with time which facilitates additional hydrolysis
Acid Fatty alcohol
SLS
SLE1S
SLE3S
As SLS, SLE3S, and SLE1S hydrolyze, the system becomes more acidic as shown above.
Demonstration of Decreasing pH due to Hydrolysis
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p
H
Time Elapsed (hours)
7 pH (no caustic) 100C (10% active)
SLS
SLE3S
SLE1S
H, Time, pH H, Time, pH
Add NaOH
Fatty Alcohol
Acid
Surfactant
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Time Elapsed (hours)
pH 4 (caustic) SLE1S (10% active)
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75C
Temperature Comparison
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0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
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SLS 29% active, 75C
pH 4
pH 5
pH Comparison: 1 pH unit
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Time Elapsed (hours)
pH 5 (caustic) 75C
SLS
SLE3S
SLE1S
Surfactant Comparison
