(Please note this particular zinc oxide is non-nano which is what most people are looking for when it comes to skincare applications among other things.)
“Philosopher’s Wool”, “Chinese White”, and “Flowers of Zinc,” – these are some of the names given to a compound that’s uses range from rubber to ceramics; concrete to medicine; cigarettes to food; paints to electronics and everything in between. Its official name is Zinc Oxide, and its uses are expanding as fast as technology is advancing. Many of its uses take advantage of its ability to conduct heat, antibacterial and UV-protection properties as well as its ability to act as a binding agent when mixed with other substances.
Zinc Oxide can occur naturally as the mineral zincite. This rare crystal has been found the Franklin and Sterling Hill Mines in New Jersey. These crystals can also be formed artificially and are a natural by-product of smelting zinc. Both natural and synthetic crystals can be colored dark red, orange, yellow and green. However to keep up with a nearly one million tons per year industrial demand for zinc oxide, most is created artificially by several different processes:
The American process involves heating zinc composites (such as the above mentioned by-products of zinc smelting) with carbon in order to create zinc vapor. This vapor then reacts with the oxygen in the air to produce zinc oxide that, as it cools, can be collected. The more common method is the French process. This similar process utilizes metallic zinc heated inside a graphite container that can withstand extreme temperatures.
Specialized laboratory processes can synthesis zinc oxide for various niche applications (such as creating nanowire, thin film, or mass production). The white powdered form can be created by running an electric current through a solution of sodium bicarbonate with a zinc anode inside. The resulting zinc hydroxide gas produced is heated and decomposes into zinc oxide. Extremely pure forms of zinc oxide have exciting applications in nanotechnology. Compatible with well-developed silicon technologies zinc oxide nanowires have potential use in computing, solar energy and beyond.
A long but vague history
Thought to be used to treat skin conditions for thousands of years, without modern classifications and terminology it is impossible to know for certain what our ancestors were using. Our first known use of the product was in paints and pigments in 1834. Because zinc oxide doesn’t turn black in air contaminated with sulfur, it makes an excellent bright white permanent paint. It is also non-toxic and more economical than other available technologies at the time. One drawback was that zinc oxide itself becomes brittle as it dries. Art work from the late 1890’s and early 1900’s developed cracks over time.
Uses of Zinc Oxide
Zinc Oxide can be added to creams and lotions to add sun protection. This makes it perfect for the “do-it-yourselfer” who is concerned about the harmful effects of ultraviolet radiation on the skin. It is the best broad spectrum UVA and UVB reflector approved for use as a sunscreen by the Food and Drug Administration. This is because zinc oxide does not absorb into the skin when applied with a lotion. Instead it sits on top of the skin and reflects both UVA and UVB light. Because it isn’t absorbed into the skin, it doesn’t irritate or cause allergic reactions.
Roughly half of the world’s use of Zinc Oxide is done in the rubber industry. It is an important ingredient in turning sticky rubber into more durable and form with an ability to resist the growth of mold and fungi as well as impart a resistance to ultra violet light. It is also used in the ceramic industry to create various finishes. Small amounts added to a finish creates a glossy shiny surface. While larger amounts create a matte and crystalline finish. Its high heat capacity and temperature stability combined with its low expansion make it perfectly suited for ceramics.
One of the most significant advances in concrete has found zinc oxide quite beneficial. Self-compacting concrete is a relatively new form of concrete that is able to be poured inside formwork, around reinforcements and through narrow passageways. Self-compacting concrete is then able to consolidate by itself without vibration, simply by its own weight. A study, “Sythesis of Zinc Oxide Nanoparticles and Their Effect on the Compressive Strength and Setting Time of Self-Compacted Concrete Paste as Cementitious Composites,” by Mohammad Reza Arefi and Saeed Rezaei-Zarchi found that the addition of zinc oxide nanoparticles at different concentrations improved “the flexural strength of self-compacting concrete.” This addition also reduced the number of harmful pores inside the concrete thus increasing the mechanical strength.
Found in calamine lotion, baby powder, anti-dandruff shampoos and diaper rash ointment, zinc oxide has many medical uses. The basic antibacterial and deodorizing properties also result in it being used as an additive in cotton fabrics, rubber and food packaging. These characteristic isn’t exclusive to zinc oxide, but can also be found in silver. Both have fine particles with a relatively large surface area, but silver’s use is uneconomical.
Added to charcoal, it used in cigarette filters to reduce the amount of harmful chemicals from tobacco smoke. As a pigment in paints it has resulted in a color called Chinese white. It also is a primary ingredient in many mineral makeup products.
It is also long been used to add a corrosive resistant finish on metals, especially useful on iron which reacts with organic coatings resulting in a loss of adhesion. Zinc Oxide coatings are used on energy-saving and heat-protecting windows. The coating lets visible light through while reflecting infrared radiation. Applied on the inside of a window helps keep heat inside a room, while on the outside help keeps the heat out.
Many have expressed concern that zinc oxide may be absorbed into the skin, however scientific studies have found no evidence that any ill-effects of direct contact with skin. Try adding zinc oxide into your repertoire of homemade ingredients. From adding SPF to your lotions and lip balms, to helping preventing dandruff in your shampoos, zinc oxide might become your best friend.
The above information is for general research purposes only and is not a representation or warranty of any kind. This material is not intended to diagnose, treat, cure or prevent any disease. The user of this material is solely responsible for determining fitness for any particular use; requesting and reviewing the applicable Material Safety Data Sheet; and compliance with all applicable laws and regulations. Terms and conditions apply.