Chemical Ingredients
Ethanol
Ethanol is a polar organic compound, classified as a primary alcohol meaning that the hydroxyl group is bonded to the primary carbon in the chain and the only hydroxyl group present. It’s chemical formula is C2H5OH, and it is because of the short carbon chain and presence of a hydroxyl group that it’s physical properties arise. Ethanol is volatile, flammable, colourless and hygroscopic, which means that it is a substance that readily attracts water from its surroundings through absorption or adsorption. Furthermore, ethanol is able to form hydrogen bonds, a relatively strong type of intermolecular attraction, this can arise when a molecule has hydrogen directly bonded to a highly electronegative atom such as nitrogen, fluorine or oxygen. Ethanol not only fulfills that requirement, but also has an oxygen molecule with the same two lone pairs of electrons as in water. Hydrogen bonding therefore can occur, which is the strongest type of intermolecular attraction and even as strong as a weak covalent bond. Ethanol also has additional solvent properties which means it can dissolve many compounds allowing it to be a highly useful component of hand sanitizer.
​Aloe Vera Gel
Aloe vera acts as our organic gelling agent to bind together the ingredients and give it a more solid structure. It also acts as an emollient, counteracting the harsh alcohol and preventing it from drying out the skin. Due to its monosaccharide polymers, aloe vera gel is highly stable, non-toxic and completely biodegradable. The β 1-4 glycosidic bond configuration of acemannan, a D-isomer mucopolysaccharide (a long polysaccharide with repeating disaccharide units), is important to understanding the therapeutic effects of aloe vera gel, as humans lack the enzymes to be able to break these bonds down. The structurally unique acemannan in aloe vera makes it a characteristic compound of the aloe species amongst other well known plant mannans (which have distinct side-chains or are unacetylated and insoluble).
Hydrogen Peroxide
Hydrogen peroxide has the chemical formula H2O2 and is a pale blue liquid at room temperature but appears colourless in solution, however at low temperatures it appears as a crystalline solid. It is a weak acid, meaning that it only partially dissociates in solution; but it has strong oxidising effects making it a powerful bleaching agent, topical anti-infective and good disinfectant within hand sanitizer. It is known to be unstable, decomposing into hydrogen and oxygen with the release of heat. Ethanol can undergo reaction with and be oxidised by hydrogen peroxide, forming acetic acid which is the second simplest form of carboxylic acid with a 2 carbon chain with a methyl group attached to the carboxyl group. Dilute forms of acetic acid are present in common house cleaning products and in hand sanitizer.
Essential Oils
Essential oils are a concentrated hydrophobic liquid containing volatile chemical compounds, meaning that they evaporate easily at normal temperatures. They are made of the essence of a plant, containing the characteristic fragrances of the plants. Essential oils are generally extracted using steam distillation, as the steam from the water carries the vapor of the volatile compounds to a condenser where it is returned to the liquid state while the non-volatile compounds (such as water) remain in the boiling container. Essential oils are used most notably in aromatherapy, a style of alternative medicine seeking to induce relaxation, provide respiratory disinfection and psychological stimulation.