Abstract: 

The use of darker colours for aesthetic purposes has been steadily growing in the construction field. This application has led buildings to have non-efficient thermal characteristics, due to the colour’s high absorption of solar radiation. Consequently, this increases the energy demand for cooling. To overcome the rise in energetic costs and ecologic footprint, these nanocomposites, which may be incorporated in conventional black colourants, ally the aesthetic side and the functional one by absorbing solar radiation in the visible spectrum, and at the same time increasing reflectance in the infrared spectrum in 40% when compared to conventional coatings.

 

Background: 

The use of darker colours for aesthetic purposes has been steadily growing in the construction field. This application has led buildings to have non-efficient thermal characteristics, due to the colour’s high absorption of solar radiation. Consequently, this increases the energy demand for cooling. To overcome the rise in energetic costs and ecologic footprint, these nanocomposites, which may be incorporated in conventional black colourants, ally the aesthetic side and the functional one by absorbing solar radiation in the visible spectrum, and at the same time increasing reflectance in the infrared spectrum in 40% when compared to conventional coatings. 

Benefits: 

This invention provides an improvement over traditionally used dark colourants, without compromising colour at the human eye level, bringing a large increase in the overall reflectivity. Incorporating these nanomaterials in coatings allows an effective control of the radiative properties through the tunning of their optical properties. Improvements in the durability of construction materials are also provided by this invention, due to the reduction of thermal stresses.

 

Potential comercial use/applications: 

The invention relates to the technical field of coatings, specifically in the context of exterior-finish black colourants. This technology has clear commercial advantages over traditional dark coatings, since it attains a substantial increase in reflectiveness without compromising the colour’s original characteristics. In general, any coated dark-coated surface that’s under the effect of solar radiation can benefit from this invention, as it greatly reduces the absorption of radiation, decreasing thermal damage and increasing the structure’s life cycle. 

 

Co-owners: 
University of Porto