When the temperature is low enough, the dye and the acid molecules are in close proximity, allowing transfer of hydrogen atoms between the molecules and leaving the dye in its coloured form.
As temperature increases, the solvent melts, and the molecules move away from each other; with hydrogen transfer no longer occurring, the dye changes to a colourless form. Photochromic polishes use light-sensitive compounds which experience a structural change when exposed to sunlight.
Examples of compounds used include spiropyrans and spirooxazines. The structural change on the absorption of UV light changes the absorption of the compound, causing its colour to change. UV light can also be a problem for nail polishes — over time exposure to sunlight can cause the colour of the polish to fade. To avoid this, additives such as benzophenone-1 are added into the mixture. These additives absorb UV light and prevent it from bleaching the coloured pigments in the polish.
This article was originally published on the Compound Interest website under a Creative Commons Attribution 4. Read the original article here. Visit elsevier. A field as broad as chemistry is cross-disciplinary by nature. This conventional nail polish is not the only option, however. Gel nail polish is an alternative formulation which consists of methacrylate compounds and photoinitiating compounds such as benzoyl peroxide.
Instead they are applied in layers which are exposed to ultraviolet light; this kicks off a polymerisation process which solidifies the polish. In both conventional and gel nail polishes, plasticisers are also used. These are compounds added to stop the polish from easily cracking or chipping. They remain behind when the solvents evaporate or when the polish is cured with UV light; in fact they are used in a wide range of plastics, not just polishes, and help to add flexibility.
The plasticisers used in nail polishes are not without a degree of controversy. Dibutyl phthalate DBP was a widely used plasticiser but its use has been banned in the EU since due to concerns over the possibility of of it interfering with the human hormone system.
It has also been phased out in the US, and other plasticisers have taken its place, including camphor, glyceryl tribenzoate, and triphenylphosphate TPPP. The latter, increasingly used as a replacement for DBP, has also been linked to concerns regarding hormone disruption, showing that finding safe replacements for banned ingredients in cosmetics is not always easy.
The key ingredients in nail polishes are the compounds that give them their colours. Look for : Benzophenone, often followed by a dash and the number one. Look for : Trimethyl pentanyl diisobutyrate, triphenyl phosphate, camphor, and ethyl tosylamide.
Dyes and pigments : Often the main reason a polish is chosen is the color. Multiple ingredients make up that particular shade. Dyes, for one, are soluble, while pigments are not soluble in the solvents used. Dyes are often organic materials while pigments are not. Essie's two-step Gel Couture line stays put, no UV light needed. Add on the Gel Couture Top Coat as the final step.
Context's line of minimalist colors is vegan, cruelty-free, and nontoxic. This celadon shade will be our go-to this summer. Oribe's gorgeous line of polish offers highly-pigmented color in a single coat.
Butter London's high-shine polish contains bamboo extract and diamond powder to strengthen and brighten nails. Sally Hansen's polish is a classic for a reason. Marc Jacobs's Hi-Shine Polish is designed to give a bright, freshly lacquered finish. Now that you know what nail polish is made of, here are 18 of the all-time best drugstore nail polishes , according to Byrdie editors.
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