surfactants1

Article by: Perry Romanowski

If you haven’t done so yet, you might want to review part 1 of this surfactant series to learn what surfactants are and when you might use them.

There are thousands of different types of surfactants and it can be difficult to know which to use for any specific application. This task is made easier by knowing how surfactants are classified.

Types of surfactants

Surfactants can be grouped by the charge characteristic of their polar (hydrophilic) head groups. The four groups include

Anionic
Cationic
Amphoteric
Non-Ionic

We’ll discuss each of these next.

Anionic Surfactants

Anionic surfactants are those that have a negative charge on their polar head group. They include groups like carboxylic acids, sulfates, sulfonic acids, and phosphoric acid derivatives, of which the first three are most important in cosmetics. They are most useful for applications that require good cleansing and foam.

Carboxylic acid anionic surfactants like stearic acid are useful for creating stick products like deodorants and antiperspirants. The salt version (sodium stearate) makes an excellent soap.

Sulfates are the next most commonly used anionics. They include synthetic detergents like sodium lauryl sulfate (SLS), ammonium lauryl sulfate (ALS), or their ethoxylated companions, sodium laureth sulfate (SLES). They are excellent foamers, cleansing agents, and are relatively inexpensive. The drawback is that they can be irritating and some consumers find them troubling. In fact, sulfates are some of the most highly vilified cosmetic raw materials but we’ll save that discussion for another time.

Sulfonic acid surfactants are generally more mild than sulfates. They include Taurates (derived from taurine), Isethionates (derived from isethionic acid), Olefin sulfonates, and Sulfosuccinates. The reason they are not used more often is that they are more expensive to produce and do not provide a significant enough benefit over Sulfates.

Cationic Surfactants

Cationic surfactants are those that have a positive charge on their polar head group. They are most useful for conditioning cosmetics. They include chemical classes such as Amines, Alkylimidazolines, Alkoxylated Amines, and Quaternized Ammonium Compounds (or Quats).

By far the most significant cationic surfactants used in cosmetics are Quats. These are nitrogen-containing compounds that acquire a positive charge when dispersed in solution. This positive charge makes them electrostatically attracted to the negative (damaged) sites on hair and skin protein which makes them resist rinse-off. Quats like Cetrimonium chloride and Stearalkonium Chloride provide the basis for numerous hair conditioners.

The biggest challenge of working with cationics is that they are not typically compatible with anionic surfactants. This means it is difficult to produce products that simultaneously clean and condition using only surfactants. Cationic surfactants can also be irritating so this must be considered when formulating cosmetics with them.

Amphoteric surfactants

Some surfactants have the potential to have both positive and negative charges depending on the environment they are placed. This characteristic is termed “zwitterionic” and surfactants of this type are called amphoterics. Examples include Sodium Lauriminodipropionate and Disodium Lauroamphodiacetate.

Amphoterics are primarily used in cosmetics as secondary surfactants. They can help boost foam, improve conditioning and even reduce irritation. They are also used for baby shampoos and other cleansing products that require mildness. The drawbacks are that they do not have good cleansing properties and don’t function well as emulsifiers.

Non ionic Surfactants

The last class of surfactants we’ll cover are the ones that contain no specific charge. These are termed non-ionic surfactants and are used most often as emulsifiers, conditioning ingredients, and solubilizing agents. There is no other type of surfactant that is used more frequently than nonionic surfactants. The primary nonionics used for cosmetics include alcohols, alkanolamides, esters, and amine oxides.

Alcohols such as Cetyl or Stearyl alcohol are used in creams and lotions to provide body and feel to the formulas. They also help stabilize the emulsions and can reduce irritation. Amine oxides like Cocamidopropylamine oxide are used to boost foam in cleansing products. A number of esters are used to provide conditioning, slip and shine to biological surfaces. Polysorbate esters are also excellent solubilizing ingredients for fragrances and other botanical oils.

Surfactants and Cosmetic Chemists

Most of your formulating time will be spent working with different levels of surfactants and trying to pick out just the right one for your application. This brief overview provides all the basics that you need to know to get started (and to impress Marketing people with your knowledge), but it is only the start. You need to work with surfactants, talk with your surfactant suppliers and experiment with different blends. Only then will you get a better understanding of these molecules and what you can do with them.

For further reading see the surfactant chapters in the following industry books
Beginning Cosmetic Chemistry 3rd Edition

Harry’s Cosmeticology

Chemistry And Manufacture Of Cosmetics Ingredients 2 Book Set

Do you have more questions about surfactants? Leave a comment below.

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77 comments

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  3. Maria

    how can you make a shampoo that has a clear appearance?

  4. Mohammed Islam

    Why surfactants are bad for skins?

    1. Perry Romanowski

      They are not bad for skin. Some can be irritating if left on too long but most are not a problem.

  5. Mai

    How we can avoid cranking in emulsion

    1. Perry Romanowski

      I’d suggest you post your comments in our forum.

  6. Meg

    Hi Perry,

    I have emulsion that already have anionic emulsifier sodium hydroxide/stearic acid. My boss has asked me to add behentrimonium chloride (I know it’s cationic emulsifier). Which one will be more stable emulsion with or without behentrimonium chloride?

    1. Perry Romanowski

      Combining an anionic and cationic surfactant typically leads to an unstable formula. So without Behentrimonium Chloride will be more stable.

      1. Chris

        Hi Perry,
        why is this the case?
        Thanks

        1. Perry Romanowski

          Positive and negative materials will combine to form a salt which is usually not soluble in water.

  7. mohammad

    which the best surfactant used for oxidant cream hydrogen peroxide 6%?

  8. anteneh

    tell me best thickener for liquid detergent

    1. Perry Romanowski

      That depends on the composition of your liquid detergent.

  9. Yannick Pace

    Hi, I am currently trying to find out why surfactants are so stable at low pHs while normal soap is not and can anything be done to make a soap solution stable at a pH of say 4.
    I’m new to this site so my apologies if I have not posted this in the right place.
    Thanks,
    Yan

  10. salman

    what is the difference between SLS,SLES and TEXAPON

    1. Perry Romanowski

      They have different molecular structures.

  11. Maureen

    Thank u Perry…..u re indid a genious……I appreciate ur sharing this info…..its been helpful.

  12. Onuoha Uchechi

    Thanks very much for the wealth of information on Surfactants. I want to make a formula for Liquid bathing soap that contains scrubs. Help me with formula.
    Thanks and best regards

    1. Umoren umoren

      So educative and informative.

  13. joanne

    Hello, i’m trying to make a cleanser for my face this is my first time, and i don’t know what to use for surfactants; can you guide me of what to use? thank you,more love to you. Joanne.

    1. Perry Romanowski

      See a product that you want to emulate and use the surfactants that they use.

  14. tayyabanaeem

    i have problem in making foam for shampoo which is not maximum

  15. C.S.Rajagopalan

    Dear Sir

    I am working on the same preparation like Aveeno Moisturizing lotion. One of the ingredient they use cationic surfactant Distearyl dimonium chloride. In India it is getting not available now a days and can you suggest an alternate and the best cationic surfactant cum emulsifier equivalent to Distearyldimonium chloride to carry over the same formulation.

  16. henry

    wat surfactant can I use in cream to ensure that it doesn’t separate. I hv stearic acid cetyl alcohol wax jelly and oil pls wats missing

    1. Perry Romanowski

      I would need more information than that. It depends on what oils you use and the HLB values. Also you need to neutralize the Stearic Acid with something like TEA to get it to emulsify properly.

  17. Kartik

    Hi…
    Iam manufacturers of cationic bitumen emulsion…for road construction..
    Pl. suggest me surfactant to the make emulsion thicker by physical appearance.
    Because iam already using a surfactant to make the emulsion thick.
    But I dnt the surfactant…
    Pl. tell me the appropriate surfactant.

    1. Perry Romanowski

      I would need more specific information about your formula to give a good answer.

  18. Samira

    What is the secondary surfactant?

    1. Perry Romanowski

      It’s a surfactant used at a lower level than the primary surfactant. It helps boost foam, increase viscosity, and reduce irritation.

  19. MARK

    Hello Perry,

    I have noticed there are some companies who use surfactants other than nonionic surfactants in skin care emulsions. For example, Aveeno uses Distearyldimonium Chloride, AVON uses SODIUM LAURYL SULFATE in some of their products. Would you recommend using it as stability wise? Also, what other benefits could there be if we use either cationic or anionic surfactants in skin care products?

    Best,

    Mark

  20. welde

    what kind of surfactant should i use to avoid greasy nature of my hair cosmetics.10q…

    1. Perry Romanowski

      Sodium Lauryl Sulfate would work.

  21. Eric

    Hi,
    I have been working on body lotion. I use Potassium Hydroxide as part of the ingredients. Without it the lotion does not form and separate to water phase and oil phase. When I put it in sweet is produce when the product is applied to the skin. Can you give me an alternative procedure or formula to avoid the use of KOH and still have the product formed?

  22. Samuel

    I am trying to formulate an acid-in-diesel emulsion. Someone recommended a cationic surfactant called CTAB to me. Is there anyone that has experience with this? I just want to be sure that CTAB is applicable in this case. Thank you.

  23. mina

    HI Can anyone help me? I am full time chemist at hair and skin care products lab. Sometime I have to make shampoo and body wash and I have chances to use surfactants raw materials. However, my skin is really sensitive to those materials and I feel like getting itch by them. Do you recommend any methods to protect my skin from itch?
    Thank you
    Mina

    1. Perry Romanowski

      Perhaps you can wear gloves while formulating.

  24. shweta

    Can anyone help me, I am looking for an agent (cationic / amphoteric surfactant) which can complex with anionic surfactants (lignosulfonates); and de-complex in an alkaline medium (pH 12-14). Slower the decomplexing, the better. is this possible? if yes where should is start.

    Thanks
    Shweta

  25. Joseph

    I have some questions to ask.
    1) Can i combine both SLES and SLS in liquid detergent for home care purpose?

    2) Can you help me with a very good formulation for a liquid detergent for car washing?

    Thank you.

    1. Perry Romanowski

      1. Yes

      2. I don’t have a formulation for liquid car washing detergent. But a 10% SLS / SLES solution would be a good start.

  26. Avinash

    Can you please suggest the process/ additives to make anionic and cationic polymers compatible with each other ?

    1. Perry Romanowski

      They generally are compatible. You just need to use a low enough amount of one and a high enough amount of the other. I would suggest you post this question in our cosmetic science forum

  27. Victor Galadimawa

    Hi guys,
    Please I would like to know what non-ionic surfactants are commonly available in Nigeria if any one has knowledge of that.I currently use sodium lauryl sulphate (SLS),or sodium laureth sulphate SLES for a cleaner i concoct and am looking for a surfactant that does not foam but is effective.thanks

    1. Perry Romanowski

      Those surfactants are effective but they are anionic. You could try adding a defoamer like an oil or a silicon. I don’t know what is available in Nigeria.

  28. Amit

    Hi,
    Dear sir,
    You really have great knowledge and more important is that you share what you have , Salute to you,
    I am doing my formulation for hand wash can you guide me The materials used are SLES(28%):- 26%, CAPB:- 6%, CDEA:- 2%, Glycerine:-1.5% ,
    Citric acid, Methyl paraben . propyl paraben , Phenoxy ethanol, Perfume , Nacl
    But the foaming is not too good , and even Nacl is going in very high level for viscosity, can you give me some solutions

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  30. janeysatfield

    Thanks for the valuable info very much. This website has made my “cosmetic life” a lot easier.

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  32. Rajdeep

    Why non-ionic are most useful than cationic and anionic surfactant?

    1. Perry Romanowski

      Nonionics are best for solubilizing oils and often they are more gentle than anionics or cationics.

  33. AJIBADE Agboola

    @Perry
    Many thanks for your timely response.
    I believe that is the cause. I will adjust the pH as you have said.
    Regards

  34. AJIBADE Agboola

    @Perry!!!
    Many thanks for your reaponse.
    LABSA stands for Lauryl alkyl benzene sulfonic acid I guess it is one of the cheapest anionic surfactanct in the market.

    1. Perry

      I believe cocamide DEA will increase the pH so you’ll probably have to adjust your pH to get a clear solution. Try citric acid, HCl or Phosphoric acid.

  35. AJIBADE Agboola

    I recently came across a very economical dishwashing liquid detergent formulation but whenever I add cocoDEA to the solution of LABSA,NaOH and water, the solution turns cloudy. Below is the fomulation:
    LABSA-7.3%
    NaOH-1.0%
    CocoDEA-2.3%
    Water: 88….%
    NaCl-0.88%
    Kindly advice on what might have been making the solution milky or cloudy on the addition of cocoDEA

    1. Perry

      What does LABSA stand for?

      1. Mridula Tyagi

        LABSA STANDS FOR LINEAR ALKYL BENZENE SULFONIC ACID

  36. Atul

    Hi, i am trying to make my own shaving cream to start up my own business, i want to use shea butter as the moisturizer and coconut oil as it is very good for the skin but what surfactant should i use?
    Please can you help me on this.

  37. AJIBADE Agboola

    Many thanks for your explicit description of surfactants. Very informative!!!!
    Yea, U????? use to have problem in dissolving SLES in water. Its dissolution is somehow tedious. Can you describe how well I can dissolve it with ease?
    Again, between between coco DEA and Cocamido PB, which is better surfactant and anti-irritant?
    Again, many thanks for time

    1. Perry

      You can heat up your water and that will make SLES go into solution faster.

      Cocamidopropyl Betain is preferred.

  38. Taiwo

    My shampoo has too much foam and it did not give me clear appearance. What is that that i did wrong or that i did not add to it.

    1. Perry

      This depends on what kind of shampoo you are trying to make. If you have too much foam you have probably added too much surfactant or not enough conditioning ingredients. Try adding some propylene glycol or Glycerin and that may reduce the foam.

  39. Rosie

    Hi I am trying to make a tanning foam, I already sell my own cosmetics and tanning solutions, and am desperate to find the right formulation to make a tanning foam!! Any help will be very much appreciated!!

    Thank you xx

    Rosie xx

    1. Perry

      Hello Rosie – I’m not sure what you need. I would suggest you post your question in the cosmetic science forum. You will get more responses.

  40. Perry

    @Alireza – There are a number of other factors that would affect your surfactant choice.

    1. Desired performance
    2. Cost
    3. Stability
    4. Availability of supply

    The importance of each of these is what you have to decide for yourself when formulating.

  41. alireza

    i know that required HLB is the most important thing that determines which kind of non-ionic surfactants are suitable for which reason, but is there any features which have to be taken into consideration in choosing an appropriate surfactants? this question arises from the fact that there are several non-ionic surfactant with similiar HLB. in this condition which surfactants are more preffered?

  42. Nishani

    I would like to get more pictures to disacribe surfactants

  43. grace

    What is better to use in dishwashing liquid, SLS, SLES oe Texapon? tHanks

    1. Mridula Tyagi

      SLES is very good as it provide good cleaning & foaming even in hard water. SLS is good only for foaming but not for cleaning.

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