World's famous hotels,
water fountains, and other buildings adopt to change the color of their
lightening to create a stunning environment. Green... red... yellow... and blue!
Garden chameleons change their body color amazingly fast. How would it feel, to
wear clothes that changes color by itself every now and then?
Clothes normally change their
color once it fades. New type of dyes are discovered which will change the
color of the clothes once they are exposed to sunlight. Photochromic dyes
create a dramatic effect on the clothes and make them to change their color,
when the clothes are exposed under sunlight and absorb the ultra violet
radiation. Once the radiation is removed, the dyes resume their original color.
Depending upon the environment, day or night, sunlight or shadow, the clothes
can change their colors.
Photochromic means the ability to
change color when exposed to sunlight. These dyes generate a dynamic reversible
color change under the sunlight or ultra violet (UV) light. When under sunlight,
or UV radiation, the molecular structure changes allowing the photochromic
compound to turn into a dark color, and the effect can be reversed when the
light is faded. An optical medium contains one or more dyes and polymer which
forms liquid crystalline phases. Information is written in the liquid
crystalline polymer layer through a laser. The polymer gets heated up above a
phase transition temperature. When it is cooled, the change is frozen in a
glass state. The material posses high contrast storage, high sensitivity, good
stability and resolution. These dyes are off-white when they are not exposed to
sunlight or UV radiation. It gains color when exposed to sunlight or UV light.
These dyes can be applied to
fabrics through conventional printing, dyeing, extrusion and spraying methods.
It can be used in a variety of other applications:
- It can be used on garments to
print brand name or logo to prevent its duplication.
- Can be used for security devices
that can be observed spectroscopically or by specialized instruments.
- Can be used in packaging industries.
- Can be used in making
fashionable materials like footwear, furnishings etc.
- Used to make ophthalmic lens
that changes its clear color to dark while at outdoors.
Constraints to its Commercial
Despite of the amazing effects,
these dyes create on the garments; it is still not commercially successful. The
nature of photochromic dyes not being water soluble makes it impossible to
apply on wool or cotton. These dyes only dissolve in solvents which are
compatible with synthetic textiles. Apart from this, these dyes do not have the
capacity to withstand heat. Therefore it gets damaged and loses its properties
when the process of dyeing fabrics is to be carried out at high temperatures.
Photochromic dyes can create a
new trend in the fashion industry. It will be of great aid to apparel
manufacturers by providing novel marketing opportunities. Outfits with changing
motifs, letters, and patterns that are visible in the sunlight and fades in the
shadow will clearly make a fashion statement, and a revolution in the apparel