Dr. Valerie Bradford

Who am I? P&G Career: Tech development & formulation At P&G for 6 years Emerging Technologies (Cincinnati) -Nanotechnology, Hair care, surfactants Gillette R&D (Boston) -Blade Edge Technology -Integrated Chemistry- Formulation Expertise: Skin and Hair Science, Surface Modification, Surfactancy, Material development, Molecular Biology/ Biotechnology, Organic Synthesis Personal: BS Chemistry –Univ. of Delaware PhD Org. Chem- UT Austin Eli Lilly (medicinal chemist), molecular biologist Married to Lafe (10 yrs!) Craft beer geek

Topics Rules of consumer product formulation Technical questions & contradictions Surfactants Tide Skin & hair science 2-in-1 shampoo/body wash Febreze

Rules of consumer product chemistry Opposites attract Hydrophobic/hydrophilic - Haters gonna hate! Know your biology The consumer is always right! (even if not scientifically supported) +=

Technical questions & contradictions Defining the question is 90% of solving the problem Contradictions Two benefits that seem at odds Toilet paper that is strong and soft Body wash that cleans and conditions your skin

Tide How could you clean clothes without leaving them hard and rough? Requirements: Good wetting agent Fair detergent Not affected by hard water Solution: Synthetic surfactants

And Surfactants Are a Key Component in Many Consumer Products

Detergency: The ability of a surface active agent to enhance the cleaning power of a liquid. General Steps in Cleaning: 1.Removal of the soil from the surface 2.Suspension of the soil to prevent redeposition 3. Fabric, teeth, skin, hair, hard surfaces, etc 2. Sebum, stains, grease, biofilms, polymers, etc 1. Surfactants, Polymers, Solvents, Water, etc Components of Cleaning: Cleaning

Surfactants Natural sources Synthetic Fight Club IVORY SoapDetergent

In Order to Formulate Surfactants, We Must First Understand Them… HydrophilicHydrophobic

Surfactant Structure CH 3 -CH "Tail" Group Hydrophobic - Water Hating Lipophilic - Oil Loving - 3 SO 3 O(CH 2 CH 2 O) x H COO - N + R "Head" Group Hydrophilic - Water Loving Lipophobic - Oil Hating So if you put surfactants in water what happens?

Monolayer at Air-Water Interface Saturated Dispersed in Additional Surfactant Bulk Water Surfactants Aggregate to Form Micelles Head groups outside A Surfactant micelle Hydrophobic Pocket CMC = Critical Micelle Concentration = Concentration at which micelles begin to form = max concentration of monomers What is a Critical Micelle Concentration ?

CMC values depend on… Solubility surfactant : the more soluble the surfactant the higher the CMC (shorter C-chain = less hydrophobic= more soluble) Ability to pack in micelles : the higher the packing, the lower the CMC Function of eletrostatic repulsion (more repulsion = less packing = higher CMC) Function of sterical hindrance (more sterical hindrance = less packing = higher CMC)

Cleaning Formulations So is a low CMC always best? No! Higher CMC’s = more monomers = higher kinetics Lower CMC’s = better soil solubilization and foam stabilization Finding the right balance – balance depends on cleaning condition (Dawn requires higher kinetics vs Tide) While the soils, surfactant systems and substrates may vary, the “underlying mechanisms” are similar. However the formulation may be different for different surfaces and soils and applications!

Water hardness Back to the technical contradiction… Water contains salts of all kinds Hardness is from Ca+2 and Mg+2 (gpg- grains per gallon) Traditional soaps form insoluble salts with divalent cations Tacky Bad for skin (dry) Buildup in machines Stiff clothes Bug food!

HE vs non-HE Tide Top loader washer = gallons Front loader washer = gallons

Perception = Reality If you don’t see foam, is it cleaning? In formulating, the consumer is boss! If they want bubbles, they get bubbles even if that means more surfactant is needed than necessary to clean

Skin biology Most skin issues (lines, wrinkles, dryness) derive from increased water loss You can’t put moisture in skin, you can only prevent it from coming out too fast! How can you prevent water loss through the skin?

Common Skin Ingredients Humectants Occlusives Strengthen the barrier (thicker, stronger mortar) Increase the moisture from the inside Panthenol Glycerine Niacinamide Ceramide

Hair Biology Healthy Hair Damaged Hair Is it harder or easier to clean damaged hair?

Common Hair Ingredients Silicones help reduce combing and inter-strand friction by sealing off cuticle edges Silicones are very hydrophobic Which one works better on damaged hair?

Skin/Hair Science How can you clean and leave something behind at the same time?

Coacervation On dilution the counter ions can be released → increase in entropy Charge components are allowed to interact  Phase Separation and Enhanced Deposition => co-deposition of actives – skin conditioning/softness Solution of Anionic Surfactant and Cationic Active Dilution Coacervate Formation +++ Anionic SurfactantCationic PolymerComplex

Where is coacervation used? Anywhere you don’t want an ingredient to go down the drain

Febreze How can you get rid of bad odors and replace them with good ones?

Beta-Cyclodextran Hydrophobic interior acts as a trap for hydrophobic molecules H2OH2O