Titanium dioxide is one of the widely used colorants which is used to give color to several products we use in our day-to-day chores. The chemical formula for Titanium Dioxide is TiO2. Although it is very commonly used in several products in our daily life, there are many unknown facts or lesser-known sides of its use and properties. We must acquaint ourselves with these properties and uses as it may help us to bring more human-friendly products for the service of mankind. One such fact is the use of titanium dioxide in fighting the deadly surging skin cancer and environmental changes taking place around us.
Titanium dioxide has a brilliant and sharp white color which along with properties like resistance to Ultraviolet radiation and its ability to scatter light makes it a wonderful candidate for giving these properties to the products it is being used in.
Titanium Dioxide (TiO2) is used in the production of paints, drugs, paper for writing, floor tiles, and even food items. It is also known as photocatalyst and its addition to paints, cement, and floor tiles can cause the breakdown of pollution-causing agents. The dashing white-colored appearance of titanium dioxide makes it one of the most coined raw materials for the paints industry.
It has been over one century since the use of titanium dioxide was established in a wide range of industries. Chemically it is classified as an inorganic compound and other useful properties include non-toxicity, non-reactivity, and high luminance. These are the reasons why they give a bright aspect to the products to which they are added.
It is known to be one of the brightest substances because it scatters Ultraviolet rays on one hand and absorbs them on the other hand.
As discussed above, the sharp white color and ultraviolet absorbing and scattering properties add to the favor of Titanium Dioxide usage in different sectors.
Enlisting all of the uses of titanium dioxide might be a daunting task but we’ll try to do so here briefly.
Whether it is the paints manufacturers or coating manufacturers, TiO2 is a go-to chemical for white color. It is also being used in inks for printing presses, packaging, cosmetics, and toothpaste. It is also being used as a food colorant. Some other commonly known uses are in the industries such as pharmaceutical and sunscreen manufacturers. That’s a mesmerizing range of uses from the non-edible spectrum to the edible spectrum of usage.
Let’s discuss all of them in a quick but detailed overview here:
Paints, coatings, and plastics
Usage in Paints and Coatings industry:
Titanium white is the alternative name for Titanium dioxide TiO2 when it is used as a pigment. Numerically it is known as Pigment White 6 and CI77891. It gives the brightest white color.
In the early 20th century, lead was used as a whitening agent and as we all know, lead is a pretty toxic substance to be used in multiple products. But it was not that easy to use titanium dioxide as a replacement for the lead as a whitening agent mainly because of higher costs.
Pigment White 6 or titanium dioxide is now considered the primary component for white paint and almost half of the usage of titanium dioxide is in the paints industry.
The ability of titanium dioxide to scatter visible light is primarily due to its high refractive index and owing to this property it adds bright white color to any product to it is added. The quality of reflection produced by it is unmatched.
The white color on the wings of wind turbines is also owed to titanium dioxide’s ability as a whitening agent. Besides its color, it also protects against ultraviolet radiation. You also might have noticed that windows are often painted white, primarily for the same reason as wind turbines.
Titanium Dioxide for Masterbatch:
Most have heard the word masterbatch, but we are not very familiar with the actual meaning of it. Masterbatch is a form of pigments in which different pigments are mixed and then cooled down and turned into a granular form which is then used to give color to different materials when they are being developed.
Titanium dioxide masterbatch often called white masterbatch gives bright white color to different forms of plastics. The intensity of the white color depends upon the amount of Titanium Dioxide used in combination with other pigments or fillers. Different types of plastic carriers such as PE, PS, and PP use titanium dioxide masterbatch as their whitening agent to produce plastic formations such as lamination, films, etc.
Some advantages of using a titanium dioxide masterbatch are bright white color and opacity, high-temperature resistance, non-toxic, and UV radiation resistance.
Some applications of these masterbatches:
In agricultural settings, a white masterbatch is used to create white plastic sheets often used in vegetable-growing farms for covering purposes.
Packaging industries are hugely dependent on titanium dioxide masterbatch granules as they give white color to all the white label boxes and product boxes.
There are many applications where it can be used but we’ll limit the discussion here.
Titanium Dioxide for Inks:
Printing inks are widely used in printing books, titanium dioxide gives white printing ink opacity and brightness. The more opacity it has, the better it covers the page. Sometimes it is also used in combination with colored inks to give those colors brightness and crispiness which makes them appealing to the reader. Titanium dioxide inks have low abrasion levels, which provides an essential advantage of high-quality printing and smooth texture which is often disturbed by printers using another kind of inks due to friction in the printing process.
The other properties imparted by titanium dioxide inks are:
Brightness and Opacity
Chemical and heat stability
Now that we have discussed the uses of titanium dioxide, we’ll now have a look at the properties of TiO2.
The wide range of applications of titanium dioxide is dependent upon its physical properties of it.
High Melting Point:
Its melting point is quite high i.e., 1843°C which makes it stable under sunlight.
High Boiling Point:
As we know, the boiling point is always higher than the melting point. The melting point for Titanium dioxide is 2972°C. For this reason, it is always found in solid form, and it is insoluble in water.
You might be thinking that titanium dioxide should be of pure white color but that isn’t the case. It appears yellowish white to the naked eye, but it does give a bright white color to any product it is added to. The yellowish appearance is mainly because of the absorption of ultraviolet light.
High Refractive Index:
This property makes it a very good substance to be used in white paints as it scatters light more than other white pigments and results in a more whitening appearance.
This property has been discussed in detail. UV light highlights this property of titanium Dioxide. As a photocatalytic agent, it degrades a lot of environmental pollutants.
The discussion on different aspects of titanium dioxide can go on for hours but we’ll keep it short and crisp and leave the rest for the next articles.
Titanium Dioxide has been known to have high resistance to heat (stable over a wide range of temperatures). Resistance to degradation by climate and weather changes is also a desirable property.
How many Grades of Titanium Dioxide are there?
Like many other chemicals, titanium dioxide can exist in many forms which makes it applicable to several industries. Titanium Dioxide is generally produced in two different grades which are Rutile Titanium Dioxide and Anatase Titanium Dioxide. For use in the paint, plastic, and ink industry, rutile titanium dioxide is applied. And in industries like paper or ceramics, anatase grade is commonly used. Besides other chemical properties, both of these grades have no smell or taste and it is insoluble.
pigment-grade TiO2 particles are approximately 200-350 nm in dimension and this form accounts for 98 percent of total production. It is used mainly for light scattering and surface opacity applications, such as paint – this includes its use as a base for various color paints or as a standalone ‘brilliant’ white.
You might have noticed that packaged foods are somewhat more colorful than their fresh counterparts. This is mainly due to the use of food color pigments. Being used in food items, these pigments must not be harmful to the body. Titanium dioxide is one of the best for this use and it is known as E171. It gives white color to the food and even enhances the texture of food. Besides whitening and texture, it is also used as a softener and abrasive in some sweet products.
Again, like other uses of titanium dioxide, here it is also used for its white color and consistency-producing properties. Many cosmetics products such as creams must be white to give a transparent but glowing look when applied on the surface of the skin, and this is what titanium dioxide is responsible for.
Sunlight contains ultraviolet radiation, and they are quite harmful to bare skin. This is where titanium dioxide is helpful, as it is a primary ingredient in sunscreen products. The risk associated with nano-sized titanium dioxide used in sunscreens is not the same as micro forms of it. The rutile form is one of the most common forms being used in cosmetics and there has been no observed skin damage associated with this form. The same goes for sunscreens being used for kids and people with sensitive skin particularly because they don’t absorb UV radiation and other types of sunscreens absorb UV radiation.
Talking of the environmental facts of titanium dioxide, many sunscreens which have titanium dioxide are proven to be less harmful to coral reefs than those having other agents in their composition.
Special attention must be paid to all the chemicals being used in cosmetics as the rate of skin cancer and cosmetic-associated cases continue to rise all over the world. UV radiation-absorbing components in cosmetics are the main culprits behind these problems.
Titanium dioxide is one of the miraculous chemicals which is quite useful in many environmentally friendly uses.
Buildings are often coated in white paint to keep them cool as the white color reflects lighter and results in lower absorption of heat. Titanium dioxide is the main component of these paints. Cool buildings mean there are low requirements for heating which in turn leads to lesser environmental pollution caused due to the production of energy. Only a single coat of paint is required to cover the surface which makes it an efficient component decreasing the amount of paint used to cover a single surface.
Another environmentally friendly aspect of titanium dioxide is that it is used as a photocatalytic agent (which means that it can downgrade multiple environmental pollutants in various products and thus decrease pollution). These products include cement, paints, windows, and tiles. Car exhausts and some gas exhausts of power plants also use titanium dioxide as a photocatalytic agent.
As a photocatalyst, titanium dioxide might be used as a source of clean energy production. Hydrogen fuels are becoming a trend lately and one way to produce them can be through hydrolysis which is mediated by Titanium Dioxide. Hydrolysis of water by titanium dioxide will yield oxygen and hydrogen, oxygen can be emitted into the environment without any hazard and hydrogen can be used in hydrogen-powered engines. Similarly, titanium oxide is used in some solar cells where they replicate the process similar to photosynthesis to produce an electric current.
What is the composition of titanium dioxide?
Titanium dioxide is formed when titanium, which is found in large amounts in the earth’s crust reacts with the oxygen present in the atmosphere. Titanium coexists with iron and calcium in the earth’s core.
Titanium dioxide consists of two oxygen atoms and one titanium atom. Chemically it is a stable compound with almost no reactivity with other compounds under normal circumstances. This is the reason why it has found many uses in multiple fields.
What is the source of Titanium Dioxide?
Titanium Dioxide is found mostly alongside iron as a mineral ilmenite and sometimes it is present in the rutile form which is simply TiO2. Both of these mineral forms are found around the world in different rocks and sands. The mineral is mainly supplied from Australia, Vietnam, China, India, and South Africa.
How Is Titanium Dioxide extracted from nature?
The process of extracting titanium dioxide is dependent upon where and in which form titanium oxide is found in minerals and depending upon these differences, titanium dioxide can be extracted by two main methods.
- Sulphate Process of Extraction
- Chloride Process of Extraction
Out of ilmenite and rutile mineral forms of titanium dioxide, the former is the main source of Titanium dioxide yielding more than half of its ilmenite form.
Ilmenite can be converted into pure titanium dioxide using the above two mentioned procedures.
Let’s discuss both of these extraction processes briefly.
The Sulphate method of extraction is currently the most popular one and yields around two-thirds of the total titanium dioxide produced in the EU. While the chloride process is used less than the sulfate method, it only yields a little over one-third of total titanium dioxide in the EU.
Will Titanium Dioxide survive the Evolution of Technology?
As we mentioned earlier in our discussion, titanium dioxide is much more commonly used in our daily life than most of the public knows. It is believed that it will certainly sustain the gusts of time and stand firm for a long time coming ahead although work is underway to improve its usage and decrease the number of resources used to manufacture it. We hope that things will turn out great owing to the effort being put in.