Cosmetic Daily Care

As the development and application of surfactant go deeper, its applicable range enlarges. At present, surfactant has become the main element in washing supplies, and in the meantime, it plays an important role in cosmetics in many ways. For example, it functions as emulsification, dispersion, solubilization, foaming and cleaning.

1)Emulsification

Non-water soluble substances presented as being emulsified evenly in water is called emulsification. Emulsifier is majorly applied to produce cream and lotion, among which the powder vanishing cream and neutral cold cream seen commonly are 0/W milk sap that can be emulsified by anionic emulsified delspray soap because it is easier to extract the milk sap with less oil by means of the emulsification of soap; also, the gelling of soap will promote its viscosity. As for cold cream with more oil whose emulsification is w/O, it is suitable to use natural lanolin with large sokage and big viscosity. Currently, non-ion emulsification is the most widely used due to non-ion type is safe and low in thrill. The famous Sorbitol Fatty Acid Ester of Loss Water( span) and its ethylene oxide adduct(tween) is the excellent composite non-ion emulsification, among which span is olephylic and tween is hydrophilic so that when both of them is mixed to be applied to O/W emulsion, the milk sap will be formed with good stability and high affinity for skin.

2)Solubilization

Solubilization means that the solubility of slightly soluble or insoluble substances is increasing. When surfactant is added into water, the surface tension of water will drop dramatically and then micella of molecule aggregates of surfactant is formed so the concentration of surfactant at that time is called CMC. When the concentration of surfactant reaches the CMC, micella can absorb solid particles or oil to the side of lipophilic group, thus raising the solubility of sightly soluble substances or insoluble substances.

The solubilizer is primarily used to make astringent, hair oil, hair tonic. The surfactant working as solubilization possesses high hydrophily with HLB>15, such as Etocas(90), fatty alcohol-polyoxyethylene ether, fatty alcohol polyoxyethylene monooxypropylene ether, Polyoxyethylene dehydrated sorbitol fatty acid ester and polyglyceryl fatty acid ester.

Oily ingredients in cosmetics such as spices, oils and fat soluble vitamin has different formations for solubilization owing to their structures and polarities, thus suitable surfactant should be chosen to have solubilizer. For instance, if the objects in cosmetics are about to have solubilization such as spices, oil and medicament, alkyl polyethenoxy ether can be picked up. Despite alkyl polyethenoxy ether( belong to OP and TX) is strong in solubilization, it is rarely used because of its incitement to eyes. In addition, amphoteric ramification of castor can dissolve spices, oil and plant oil as well as it does no harm to eyes, so it suits for making cosmetics like non-irritating shampoo.

3)Dispersion

The phenomenon that insoluble substances become particles and disperse evenly in the water is called dispersion. The disperse system of cosmetics include powder, solvent and dispersant. The powder can be divided as inorganic pigment (such as talc, mica, titanium dioxide and conductex) and organic pigment (such as phthalocyanine blue), aiming to improve the tone of cosmetics so as to cover the bottom color, accompanied with good sense of use and sunscreen effect. Solvent is classified into water and non-water system. As the medium, dispersion is not only hydrophilic (applicable to water system) but lipophilic (applicable to non-water system). Therefore, the system has various compound modes.

Much surfactant used as dispersion is emulsification and dispersion like fatty alcohol polyoxyethylene ether, desiccant sorbitol fatty acid ester, aliphatic ester of fatty alcohol-polyoxyethylene ether, alkyl ether carboxylate and alkane sulfonate that are good performance. Only when liquid can wet the surface of powder well can powder disperse fully in liquid. Thus, when we choose the surfactant, the first thing comes to us is the powder surface and disperse medium HLB. Generally, hydrophilic surface active agent is majorly used when it comes to lipophilic powder in water matrix system.

4)Cleansing action

Shampoo, body wash and mildy wash occupies in personal belongings for cleaning. The mildness for skin is the first one to be taken into consideration for the time being besides the functions of leaning, foaming and wetting, which requires that surfactant should not damage epidermal cells, not react with the protein in skin, not permeate or go less into the skin, keeping the oil of skin and skin in normal condition.

Anionic surfactant has a long history in cleanliness, which has incomparable dirt-removing power. Lauryl sodium sulfate is a common material in cleaning cosmetics because it does good in cleaning the skin. Amphoteric surfactant tetrahydroglyoxaline, coconut oil amidopropyl betaine and amino acids are mild surfactant for cleaning, all of which are indispensable parts of high-end cleansing products, hair care shampoos and baby shampoos.

5)The functions about softness and anti-static electricity

Cationic surfactant is the main amendment in hair conditioning products including hair conditioner and moisturizer on account of its excellent softness and anti-static electricity. The cationic surfactant that is the most commonly used is monoalkyl and dialkyl quaternary ammonium salts, that is C16-18 monoalkyl ammonium salts, bisC16-18 alkyl quaternary ammonium salts and alkyl benzyl quaternary ammonium salts. Asymmetric beef tallow, octyl dimethyl quaternary ammonium salt and 3-cetyl methyl ammonium salt are beneficial to dry combing, wet combing and viscosity removal of hair. Recently, quaternaries derived from the wool delspray that attracts people’s attention has small thrill but combine the characteristics of water retention, wetness and cationic surfactant, giving a unique touch of hair wetness and softness.

6)Wetting and osmosis

Being cosmetics, they should be equipped with not only the effect of cosmetology but comfort, all of which can not live without the wetting of surfactant. And biological surfactant has made remarkable achievement in this respect. Phospholipid is the significant component in biological cells, having crucial impact on cell metabolism and osmosis and adjustment of cell membrane. Sophorose biosurfactant has peculiar affinity to skin, making the skin being soft and wet. Biochemical active substances, vitamin derivatives, zymin, EGF, DFGF, collagen protein, elastin, ceramide and hyaluronic acid produced by corresponding biochemical synthesis can be used in cosmetics and they can permeate the skin, take part in the supersession of skin and cell tissue and change their structures, gaining the effects of crease-resist, senility and whitening.