We obsess over food labels, wanting to know whether or not our next snack is gluten free, high in fiber, low in sugar, or non-fat. But have you taken the same time to consider what is in the products you’re putting on nails and skin – and how those make your favorite products work? We’ll take you through a little Chemistry 101 – click on one of the product names below (gel, acrylic, and moisturizer) to find out what ingredients make it work the way it does.
Instead of combining an acrylic monomer with a polymer powder, gels come premixed in the form of acrylic oligomers. As opposed to the thousands or millions of monomer links in polymer, oligomer has a limited number of monomer links—between 5 and 500. Urethane acrylate oligomers are the most commonly used in gels, as diacrylates or dimethacrylates, and the size of these molecules is much larger than acrylic monomers, making for no evaporation or odor. Products with different purposes contain different additives in addition to the oligomers—base gels or gel primers will have priming molecules, building or sculpting gels will have silica or polymers to thicken the formula and color gels will have pigments.
“NSI gels are specifically formulated with a unique combination of several types of oligomers. Some of these include urethane acrylate, bis-GMA and urethane dimethacrylate, which create the structure and backbone of the gel system,” explains Risé Carter, national director of sales and education for Philadelphia-based NSI. “It is the quantities of each of these ingredients and the addition of other substances that make NSI gels unique and proprietary. NSI has created a special ‘recipe’ after experimenting with numerous formulas. Think about how different a recipe would be if you altered the number of eggs or cups of flour.”
The other big difference between acrylics and gels is the initiator. Instead of simply air-drying, gels require exposure to light, most often a UV light, to cure. The element that starts the curing process is called the photo initiator (PI). Gels with different PIs from various manufacturers will cure at different speeds, especially if the gels contain color pigments, which block some of the light.
“Let’s take one ingredient that changes how a gel cures in the light, the amount of heat that is created and felt on the natural nail, and the amount of UV light energy needed for the gel to cure properly,” Carter says. “That’s the PI. There are numerous PIs available, and the type and quantity of this substance will vary greatly from one company to another.” PIs are light-sensitive and decompose into free radicals to start the polymerization process. They also absorb UV light and convert it into energy needed to drive the process.
“The specific combinations and types of PIs used in a system greatly dictate the properties of the gel. In general, the more PIs there are in a formula, the faster it cures,” continues Carter. “This can have a downside. High amounts of PIs can cause excessive exotherms and heat up on the clients’ nails. This is especially uncomfortable for clients whose nails have been damaged by filing or drilling, or by the use of harsh abrasives.”
properties of the gel. In general, the more PIs there are in a formula, the faster it cures,” continues Carter. “This can have a downside. High amounts of PIs can cause excessive exotherms and heat up on the clients’ nails. This is especially uncomfortable for clients whose nails have been damaged by filing or drilling, or by the use of harsh abrasives.”
The more thickly a gel is applied, the more PIs are present, resulting in an exothermic reaction with a higher temperature. Thick layers allow less light to reach the bottom layers because the energy has already been used to excite the PIs in the top layers. This is why thinner layers of UV gel cure more thoroughly and create less heat. Too high a concentration of PIs can mean brittleness, service breakdown, discoloration and over-cured product. Too low a concentration equals weakness, loss of adhesion, a higher risk of allergic reaction and under-cured product.
“Using the proper photoinitiators—and in the correct amounts—in a UV gel are two of the most difficult tasks facing scientists who formulate these types of products,” Carter says. Three of the most important factors in UV curing are: A proper balance between the PI and UV lamp, the intensity of available UV light and the duration of the UV exposure.
The concept behind the acrylic enhancements we see today came from the dental industry; legend has it that a dentist put acrylic dental product on his wife’s nails because she bit them. But that same product caused problems when nail techs got ahold of it because it included methyl methacrylate (MMA), which damaged nails and fingers. After the use of MMA was prohibited by the Food and Drug Administration, Dr. Stuart Nordstrom found a better formulation for acrylic enhancements and founded Creative Nail Design, paving the way for current chemistries.
All enhancement systems include monomers and polymers. A monomer is a single molecule that can chemically bond with other monomer molecules with the help of an initiator, a compound that induces a chemical reaction. This reaction, known as polymerization, results in many monomers bonding together to form polymers. Acrylic systems typically have monomers in liquid form and polymers in powder form, which combine together to create enhancement material. Of course, those aren’t the only ingredients in the product.
Liquid monomer is comprised of acrylic monomers, typically ethyl methacrylate; cross-linking monomers, which are chemicals such as dimethacrylate or trimethacrylate added to strengthen the formula; catalysts to speed up the chemical reaction; and inhibitors, which are preservatives that prevent the monomer from curing on its own. In odorless acrylics, ethyl methacrylate is replaced by methoxyethoxy ethyl methacrylate, which consists of larger molecules and evaporates more slowly.
The composition of powder polymer changes quite a bit from company to company. It can contain polymers and initiators as well as pigments to give the acrylic color and silica to keep the formula flowing. Whatever the recipe, polymerization begins when the powder polymer comes into contact with the acrylic monomer and begins to cure, or dry.
The right acrylic powder formula will help a tech create high-quality, durable enhancements. The advanced polypure polymer technology in Tarzana, California-based Charisma Nail Innovations’ Acrylic Powders, for example, allows for the following characteristics: product that better fuses onto nails, virtually eliminating air bubbles; no crystallization; softer product that reduces filing time, has more flexibility and prevents breakage; drier application, resulting in maximum control, workability and minimal use of monomer; and a powder that can be used with any liquid.
Testing is just as important for acrylics as for any other nail product, and doing this in a global marketplace offers many benefits. To test acrylic powders, Lysa Comfort, owner of Charisma and head of the research and development department, consults with the chemist at her powder supply company in order to fully understand the features and benefits. To see how the product wears in a practical application, Comfort uses the product for two to five months on about 15 to 20 clients. Additionally, she consults the Korean Nail Expert Association, which tests the product overseas and provides feedback. Then she sends samples to her major distributors in places such as Southeast Asia and Europe so they can test the product in different climates.
According to Comfort, the texture of powders makes a big difference. Charisma’s powder is a soft polymer that is easily filed, which reduces technician labor. The soft polymer also soaks off easily.
Other chemical agents also come into play with enhancement services. Priming agents help enhancement product of any type adhere better to the nail plate and are typically comprised of a corrosive called methacrylic acid, which removes oil from the nail plate. Some priming agents are “acid-free,” which involves a milder acid primer with much larger methacrylic molecules.
Women have been rubbing natural remedies of all sorts into their skin for millennia. But products available on the modern market are formulated with key ingredients that serve different purposes. Some of our favorite creams and lotions not only smell good, but they’re also deep-penetrating moisturizers that help heal and repair dry, cracked skin. Let’s take a look at how they work.
Humectants, such as glycerin, hylauronic acid and propylene glycerol, attract water from the surface of the skin down into its lower layers, which helps shed the outer layer of skin to reveal smoother cells underneath. Occlusives like mineral oil and paraffin are often greasy and increase the water content of the skin by slowing evaporation of water from the epidermis. These ingredients are most effective when applied to damp skin. The emollients in moisturizers, such as lanolin, remain in the outermost layer of the epidermis of the skin and keep the skin lubricated, which maintains the skin’s smooth feeling after the moisturizer is applied and absorbed. There are also many different types of additives, such as aloe, citric acid and mineral salts, that can work to produce certain results.
Key ingredients in Burmax Co.’s FantaSea Hundred Dollar Crème, for example, are champagne grape seed oil, aloe vera, liposomes and caviar extract. “Grape seed oil extracted from grapes grown in the Loire Valley in France is highly potent in antioxidants and humectants. These draw moisture to the skin,” says Deborah Goldschmid, vice president of the Holtsville, New York-based company. “Aloe vera soothes and smooths, and also helps to protect skin by penetrating the layers of skin. Liposomes hold moisture to skin like small magnets and give it a silky texture. Caviar extract contains omega-3 and vitamins and gives nourishment to the skin to create a luxurious feel. This creates the cream’s rich, thick texture.”
CND Cucumber Heel Therapy is a powerful moisturizing complex that helps to heal and repair dry, cracked skin on feet. “One of the key ingredients that makes it such an intense moisturizer is the seven-percent concentration of urea, which is derived from corn,” says Doug Schoon, president of Schoon Scientific and chief scientific advisor for Vista, California-based CND. Urea is a humectant available for retail sale that’s also an effective callus softener.
CND AHA Sea Serum is a powerful callus treatment only available to the salon professional, with a marine alpha hydroxy acid complex to soften calluses and smooth skin. “One of the key ingredients in this product is lactic acid, which is gentler than glycolic acid,” Schoon says. “The lactic acid absorbs into the callus, softening it for removal and making it easier for the nail professional to smooth the feet. Another benefit of lactic acid is that once it’s absorbed, it converts into a skin moisturizer, which helps to keep the callus soft and smooth.”
When it comes to creating a product, CND begins the process by talking to nail professionals to determine their needs. The company then takes that information and figures out what cutting-edge technologies are available to develop the product. Research and testing can take six months to one year, and adjustments are made based on feedback received from testers. Once the product is determined to be “effective,” developers play with color and aroma. “Before any product can be sold, it must be reviewed by toxicologists for safety testing and then tested for stability to make sure that it will stay the same color and texture during its shelf life,” Schoon adds. “And we always follow a product into the field to measure how well it is doing.”
Image (UV lamp): iStockphoto/Thinkstock