Hair gel

Introduction:

A gel (from the lat gelu—freezing, cold, ice or gelatus—frozen, immobile) is an apparently solid, jelly-like material formed from a colloidal solution. By weight, gels are mostly liquid, yet they behave like solids due to the addition of a gelling agent. Recent experimental studies^[1] indicate colloidal gel formation can be described as a Spinodal decomposition, analogous to a gas-liquid phase separation.

Hair styled with hair gel

Hair gel is a hairstyling product that is used to stiffen hair into a particular hairstyle The results it produces are usually similar to but stronger than those of hair spray and weaker than those of hair glue or hair wax. A version of gel, known as “Mousse”, was patented in the mid-1980s by Michael J. Hoover.

Types

Many brands of hair gel in North America and the United Kingdom come in numbered variants. Higher numbered gels maintain a greater “hold” on hair, while lower numbers do not make the hair as stiff and in some products give the hair a wet look. A category typically referred to as “ethnic” gels are designed and manufactured specifically for sculpting the hair texture common to African Americans Ampro Industries is a common example of this category.

Some forms of hair gel include temporary Hair coloring for the hair, including variants in unnatural colors associated with various subcultures, and is popular within the goth and raver subcultures.

Cationic polymers

Cationic polymers are one of the main functional component of hair gel. The positive charges in polymer cause it to stretch, making the gel more viscous. Hair gel withholds procedures that allow men and women to make their hair styled and textured in ways they desire.This is because the stretched-out polymer takes up more space than a coiled polymer and thus resists the flow of solvent molecules around it. The positive charges also bind the gel to the negatively charged amino acids on the surface of the keratin molecules in the hair. More complicated polymer formulas exist, e.g. a copolymer of vinylpyrrolidone, methacrylamide, and N-vinylimidazole

Composition

A solid network spans the volume of a liquid medium. Both by weight and volume, gels are mostly liquid in composition and thus exhibit densities similar to liquids. However, they have the structural coherence of a solid. The network can be composed of a wide variety of materials, including particles, polymers and proteins.

Cationic polymers

Cationic polymers are positively charged polymers. Their positive charges prevent the formation of coiled polymers. This allows them to contribute more to viscosity in their stretched state, because the stretched-out polymer takes up more space than a coiled polymer and this resists the flow of solvent molecules around it. Cationic polymers are a main functional component of hair gel, because the positive charged polymers also bind the negatively charged amino acids on the surface of the keratin molecules in the hair. More complicated polymer formulas exist, e.g., a copolymer of vinylpyrrolidone, methacrylamide, and hydrogel N-vinylimidazole.^[2]

Types of gels

Hydrogels

Hydrogel is a network of polymer chains that are water-insoluble, sometimes found as a colloidal gel in which water is the dispersion medium. Hydrogels are superabsorbent (they can contain over 99% water) natural or synthetic polymers. Hydrogels also possess a degree of flexibility very similar to natural tissue, due to their significant water content.

Common uses for hydrogels include

• currently used as scaffolds in tissue engineering. When used as scaffolds, hydrogels may contain human cells in order to repair tissue.
• environmentally sensitive hydrogels. These hydrogels have the ability to sense changes of pH, temperature, or the concentration of metabolite and release their load as result of such a change.
• as sustained-release delivery systems
• provide absorption, desloughing and debriding capacities of necrotics and fibrotic tissue.
• hydrogels that are responsive to specific molecules, such as glucose or antigens can be used as biosensors as well as in DDS.
• used in disposable diapers where they “capture” urine, or in sanitary napkins
• contact lenses (silicone hydrogels, polyacrylamides)
• medical electrodes using hydrogels composed of cross linked polymers (polyethylene oxide,polyAMPS and polyvinylpyrrolidone)
• Water gel explosives

Other, less common uses include

• breast implants
• granules for holding soil moisture in arid areas
• dressings for healing of burn or other hard-to-heal wounds. Wound gels are excellent for helping to create or maintain a moist environment.
• reservoirs in topical drug delivery; particularly ionic drugs, delivered by iontophoresis (see ion exchange resin)

Common ingredients are e.g. polyvinyl alcohol, sodium polyacrylate, acrylate polymers and copolymers with an abundance of hydrophilic groups.

Natural hydrogel materials are being investigated for tissue engineering, these materials include agarose, methylcellulose, hylaronan, and other naturally derived polymers.

Organogels

An organogel is a non-crystalline, non-glassy thermoreversible solid material composed of a liquid organic phase entrapped in a structuring network. The liquid can be e.g. an organic solvent, a mineral oil or a vegetable oil. The solubility and particle dimensions of the structurant are important characteristics for the elastic properties and firmness of the organogel. Often, these systems are based on self-assembly of the structurant molecules^[3][4].

Organogels have potential for use in a number of applications, such as in pharmaceuticals ^[5], cosmetics, art conservation^[6], and food^[7]. An example of formation of an undesired thermoreversible network is the occurrence of wax crystallization in crude oil ^[8].

Xerogels

A xerogel is a solid formed from a gel by drying with unhindered shrinkage. Xerogels usually retain high porosity (25%) and enormous surface area (150-900 m²/g), along with very small pore size (1-10 nm). When solvent removal occurs under hypercritical (supercritical) conditions, the network does not shrink and a highly porous, low-density material known as an aerogel is produced. Heat treatment of a xerogel at elevated temperature produces viscous sintering (shrinkage of the xerogel due to a small amount of viscous flow) and effectively transforms the porous gel into a dense glass.

Properties

Many gels display thixotropy – they become fluid when agitated, but resolidify when resting. In general, gels are apparently solid, jelly-like materials. By replacing the liquid with gas it is possible to prepare aerogels, materials with exceptional properties including very low density, high specific surface areas, and excellent thermal insulation properties.

Sound-induced gelation

The palladium complex is synthesised from palladium acetate and N,N’-Bis(salicylidene)pentamethylenediamine in boiling benzene and forms the anti conformer (left) and the syn conformer (right)

Sound induced gelation is described in 2005 ^[9] in an organopalladium compound that in solution transforms from a transparent liquid to an opaque gel upon application of a short burst (seconds) of ultrasound. Heating to above the so-called gelation temperature T_gel takes the gel back to the solution. The compound is a dinuclear palladium complex made from palladium acetate and a N,N’-Bis-salicylidene diamine. Both compounds react to form an anti conformer (gelling) and a syn conformer (non-gelling) which are separated by column chromatography. In the solution phase the dimer molecules are bent and self-locked by aromatic stacking interactions whereas in the gel phase the conformation is planar with interlocked aggregates. The anti conformer has planar chirality and both enantiomers were separated by chiral column chromatography. The (-) anti conformer has a specific rotation of -375° but is unable to gelate by itself. In the gel phase the dimer molecules form stacks of alternating (+) and (-) components. This process starts at the onset of the sonication and proceeds even without further sonication.

Applications

Many substances can form gels when a suitable thickener or gelling agent is added to their formula. This approach is common in manufacture of wide range of products, from foods to paints, adhesives.

In fiber optics communications, a soft gel resembling “hair gel” in viscosity is used to fill the plastic tubes containing the fibers. The main purpose of the gel is to prevent water intrusion if the buffer tube is breached, but the gel also buffers the fibers against mechanical damage when the tube is bent around corners during installation, or flexed. Additionally, the gel acts as a processing aid when the cable is being constructed, keeping the fibers central whilst the tube material is extruded around it.

How to Gel Your Hair

Gel can be especially useful for wavy and curly hair, to hold those waves and curls throughout the day. Here’s the quick and easy way to apply gel to your hair.

Steps

1. Wash hair thoroughly.
2. Rinse hair, just as thoroughly.
3. Towel dry hair with paper towels or soft cotton. If you have hair that frizzes easily you may want to dry your hair after applying gel.
4. Dispense a small dab of hair gel onto your palm.
5. Rub hands together, spreading the gel evenly.
6. Consider some of the several ways for applying gel:

• Starting at the front of the head, quickly, and evenly apply the gel to your hair, working it in deeply using your fingers. Make sure you apply the gel through to the root.
• Flip your head over and scrunch in the gel evenly. This is good to obtain volume for curly or wavy hair, especially at the roots.

1. Brush or shape hair to desired style. You can also scrunch or twist your hair with your fingers to encourage curls.

Tips

• After you put the gel on your fingers wave them in the air for a few seconds, then apply. This helps to get the right consistency before application.
• Use only the needed gel strength for your hair. Too much hold gives you “helmet head,” and that just doesn’t look good on anyone but DEVO. Same thing goes for amount of hair gel. Just a small amount is usually sufficient. Try using a leave in conditioner under gel to soften its effects.
• Remember that certain styles, if kept for a long time, will use a large amount of gel. Opt for high-maintenance hairstyles only for special occasions. If you can, try using stronger gel around the tips rather than normal strength throughout your head.
• Gel takes time to freeze over. Be patient, and do not use more just because it hasn’t frozen.
• Your hair may have a crunchy texture if you use a lot of gel. Flip your hair forward and use your fingers to gently scrunch your hair. This should leave you with soft, yet defined hair.

Warnings

• Wash your hair out ASAP if your gel causes discoloration or itchiness of the scalp- you could be allergic to an ingredient.
• Do not go overboard on gel. Do not spend a huge amount of money if you have short hair, but do spend a fair amount if you have a demanding style. Other than that, you can purchase $3-$6 gel at your local supermarket and it will do the exact same thing the $20 brand-name gel will do.
• Your gel may leave a white residue behind and flake off. This is not an inherent problem with gel; it is caused by several factors. You could be using too much gel- so use less gel or upgrade to a higher strength for the same amount of hold. You could be using too high a strength of gel- so use a lower strength. You also could be using cheap gel of low quality.
• Avoid using gel near or on the roots if you have oily hair or if you wear your hair for more than one day without washing.

Things You’ll Need

• Gel
• Comb/Brush