 |
 |
|
|
|
|
What are the uses of Zinc Oxide ?
Zinc Oxide or ZnO, a chemical
compound is a fine white powder that is almost insoluble in
water but soluble in acids and alkalis. It exists in nature in
form of the mineral zincite. Due to its white powder like
appearance, zinc oxide is also known as zinc white. When
crystalline zinc oxide is heated, it becomes yellow and when
cooled again changes back to its usual white. This is termed as
the piezoelectric effect. At a temperature of about 1975 degree
centigrade it breaks into zinc vapor and oxygen. It has a
variety of uses. It was first used industrially for the
production of white paint. Today apart from paints it is also
used in rubber, ceramics and optical glass. It is one of the
main ingredients in animal foods and fertilizers.
Uses
• It is used in gas sensors.
• ZnO is a very strong whitening pigment. When added to the
various cosmetic products like the creams, sunscreens and
lotions, it gives a very bright white color. However, too much
of zinc usage is not good for the skin. Cosmetics containing too
much of this leaves white patches on the skin.
• Minor skin irritations like small cuts, burns, nappy rash,
poison ivy etc can be treated by using Zinc Oxide. But it is
only meant for external use. A small portion can be applied
evenly on the affected area for recovery.
• Zinc oxide is used for coatings on paper.
• It is used in fertilizers to compensate the zinc deficiency in
plants due to poor soil quality.
|
|
|
|
|
|
|
|
|
|
• Zinc oxide is used for separating
hydrogen sulphide from gases and liquids.
• Two key ingredients in the manufacture of any rubber products
are zinc oxide and stearic acid. In many rubber mixtures zinc
oxide is used as filler.
• Very pure forms of ZnO are used for the manufacture of baby
cream, toothpaste and deodorants.
• It is used for the manufacture of other zinc compounds like
zinc sulphate, zinc phosphate, zinc chloride, zinc nitrate.
Apart from the regular commercial
uses as mentioned above, zinc oxide also has many high tech
uses.
Few of them are listed below
• It is used for enhancing fire resistance qualities in
plastics.
• Zinc oxide is also used for battery applications. |
|
• It is also used for the production
of magnetic ferrites and varistors.
• It is used in the manufacture of lubricants.
• Zinc oxide is also used for galvanizing steel.
• It is used as an anti-fouling agent in marine paints.
• It is used as an additive in latex paint formulations to
protect from mildew.
Zinc Oxide is produced in three
different methods
one wet chemical method and two thermal methods. In the wet
method, zinc is first accumulated from all the components
containing the same and then precipitated as Zinc Carbonate.
This precipitate of zinc carbonate is then calcinated to form
zinc oxide. In both the thermal processes (one from metal and
the other from ores), zinc vapor is produced which is then
burned to form the zinc oxide.
Zinc and all is its compounds are very important for human
health. Its deficit can give rise to a number of problems which
include stagnating growth, reducing the efficiency of the
immunity system, skin disorders, malfunctioning of the gastro
intestine and other problems related to blood. Unfortunately,
zinc deficiency is a major problem in the developing countries.
Studies have shown that approximately 200 enzymes in our body
need zinc. The use of zinc oxide started almost 300 years ago
for dermatological purposes - initially as a constituent of
calamine and later for its own preparations. Calamine is a
natural product which consists of various zinc containing
compounds. Earlier this was made into powder and then applied on
the skin. This is somewhat different from the present day
calamine which comprises of zinc oxide and iron oxide-the
formula that was standardized in the year 1947 by the National
Formulary in the United States.
|
|
The ultraviolet rays released by the
sun attribute the development of skin cancer. Research has shown
that in the United States of America there were almost 1,000,000
skin cancer cases this year.
Skin
cancer can be divided into two kinds: Melanoma and Non Melanoma
Melanoma This cancer is
formed from melanocytes. Melanocytes can be defined as the cells
that are responsible for the production of melanin in our
bodies. Though melanoma usually occurs on the skin, it can also
occur on the central nervous system, eyes and nails. This form
is the most fatal of the two and is responsible for the maximum
number of deaths related to skin cancer.
Non-Melanoma This form is
comparatively less dangerous and is actually a combination of
two skin cancers- Basal Cell Carcinoma and Squamous Cell
Carcinoma. Though this type of cancer is pretty recurrent, being
much less fatal does not cause a huge number of deaths. |
|
|
|
Apart from skin cancer, the ultraviolet
rays are also responsible for wrinkling, discoloring and reducing
elasticity of the skin. In fact almost 90% of the skin changes that
are usually attributed to ageing are actually due to overexposure in
the sun. If we can protect ourselves from these harmful rays, there
would have been no need for any anti wrinkle or anti ageing creams -
our skin would remain as youthful as it was at the age of twenty!
Thus to protect the skin the skin from all these, the sunscreen
lotions were invented. Way back in the 1920s, when it first came
into the market, these lotions contained organic molecules which
were responsible for the absorption of these harmful radiations. One
of the best known organic sunscreens was Para-Amino-Benzoic-Acid
which got patented in 1943. However, these organic sunscreens had
one problem. In the process of absorbing the radiations, they were
also absorbed into the skin and giving rise to allergies or other
skin irritations. With the course of time, sunscreens comprising of
inorganic substances started coming to the market. The common ones
included zinc oxide, titanium dioxide and iron oxide. These
sunscreens became more popular than their organic counterparts as
they absorbed the radiations without being absorbed themselves in
the skin.
Among the modern day inorganic sunscreen lotions, the zinc oxide is
considered to be the safest. It had been used as a skin healer in
the past centuries and is known to be the most effective sunblock!
This chemical compound has the capacity to block all the damaging
radiations. It is because of this that we see our cricket players
rubbing zinc oxide paste on their noses and lips. During the World
Wars, pilots were provided with zinc oxide paste to protect them
from the various elements.
|
|
Article Contributed By: Sukanya
Banerjee
|
|
|
|
|
