OCTOBER 2014 • Vol. 20 No. 8
New York Society of Cosmetic Chemists
www.nyscc.org
The Greening of Emulsions
… by Joseph Albanese
Let’s Start with a Joke
V
egetarian: “I’m not a vegetarian because I think eating meat is unhealthy for me. It’s because raising cattle is bad for the planet. Cow flatulence adds to the ozone layer and the clearing of land for the raising of cattle means fewer green plants producing oxygen through photosynthesis. What are you doing to help the environment?” Ron White: “Personally, I'm eating the cows as fast as I can. BUT I’M ONLY ONE MAN!”
Now Let’s Get Serious! As a cosmetic chemist developing a new emulsion is there anything that you can do to help save the environment? Might I suggest that in your daily work you keep in mind the Twelve Principles of Green Chemistry?1 See Figure 1. For this brief article, let’s limit the discussion by focusing on Principle No. 6, which calls us to “Design for Energy Efficiency – Minimize the energy requirements of chemical processes and conduct synthetic methods at ambient temperature and pressure if possible.” An early pioneer in this area is Dr. T. Joseph Lin who published his initial work on Low Energy Emulsification (LEE) in 1978,2 long before the EPA came out with their Twelve Principles (see Figure 2). Dr. Lin’s research taught that stable emulsions could be prepared successfully even if all of the external phase is not at elevated temperature. In the case of an oil-in-water (O/W) emulsion, the LEE procedure calls for only a portion of the external water phase (β phase) to be heated before combining it with the hot internal oil phase. This emulsion concentrate is then diluted to the desired concentration with the remaining ambient temperature water (α phase) to cool down the emulsion. The rate of cooling has a profound effect on particle size of the internal phase and overall acceptability of the final emulsion. In his more recent publication,3 a delightful and educational treatise, Dr. Lin explains, in story-telling fashion, that by carefully controlling processing variables (pV) and component variables (cV also known as ingredients) LEE optimizes the desired properties (Zp) of your emulsion. In short, LEE requires less energy input to create stable emulsions, thus it saves money, reduces processing time, increases plant capacity, and reduces the carbon footprint of your plant without having to reformulate or invest in new equipment. Dr. Lin also stresses the “less is more” philosophy. Namely, too much of a good thing can be detrimental to achieving your goals. Later, we will advance this pioneering research of Dr. Lin’s to show how you can include specific types of polymers into your formula that will enable you to create emulsions quickly, with little to no surfactant emulsifiers and requiring less energy input, but first, let’s take a step back in time. (Continued on page 4)
N Y S C C
N O V E M B E R
C H A P T E R
M E E T I N G
N o v e m b e r 5 t h • T h e Te r r a c e a t B i a g i o ’ s , P a r a m u s , N J