Coatings and especially organic ones application is the commonest and in many cases, cheapest and easiest method to protect the structures and equipment from corrosion and sometimes provide decorative appearance. There are many aggressive agents which can make disorder in coating performance. In the today's generation of protective coatings, it is important to provide several functionalities with the essential possibility to react on external impact, such as distortion of the coating integrity, surface pollution and bacterial attack, intelligently. Providing smartness for coating is a young novel to mitigate/solve many of these problems, thus the coating shows an adequate response against mechanical/chemical damages or even environmental changes to neutralize the negative results. Self-healing, self-cleaning, pH sensitive, temperature sensitive, selective absorption of gaseous pollutants and corrosion sensing coatings are a small group of large family of smart ones. These properties have been achieved through organic or inorganic additives in micro or nano size. Creation and manipulating these additives in order to achieve smart coatings with new functionality has been extensively described in literature and patents over the last 10 years.
This extensive study describes the principles of this novel multifunctional/smart coating background, concept and advantages and discusses the smartness and performance on the basis of laboratory results which have been presented by different authors up to now (self-healing, anti-bacterial, high temperature resistance and self-cleaning coatings). Also various approaches for achieving smart and multi-functionality are mentioned. The effects of different parameters on their performance and serviceability are also explained.