Student Seminar
Name: Ms. Shreya Sasmal
Title- NIR Reflective “Cool” Inorganic Pigments: An Overview
Date & Time: Thursday, 29th February at 4.00 p.m.
Venue: Rajarshi Bhattacharya Memorial Lecture Hall, Chemical Sciences Building
Abstract:
Urban Heat Island (UHI) has become a significant issue in the modern world. UHI is basically the relative warmth of a city compared to the surrounding rural areas. The solar spectrum consists of 5% ultraviolet (UV) radiation, 43% visible radiation and 52% near-infrared (NIR) radiation. Almost half of the Sun’s energy is from NIR radiations. Materials used in urban areas for the pavement of roads and roofs such as asphalt, concrete, lime and plasters absorb significantly more solar radiation. With such increase in heat, there is a need for variable energy in the form of air conditioning to keep the interiors of the buildings cool to maintain a comfortable lifestyle. Thus, UHI effect has both environmental and economic hazards.
The use of roof coatings with high near-infrared reflectance (NIR) has been proved to be an effective alternative to alleviate the UHI effect. Cool roofs will reflect the Sun’s radiation, especially near-infrared (NIR) radiation, minimizing the amount of energy absorbed by the building, resulting in a cooler surface. Due to reduction in roof temperature, there is a decrease in the energy required to keep homes and buildings maintained at a comfortable temperature.
Design and development of cool pigments for surface coating applications, coloration of plastics and ceramics have gained wide popularity in recent years. Research efforts are also directed towards the development of environmentally acceptable pigments which do not release any toxic materials into the environment during their production, use and disposal. In this seminar, I will discuss about the synthesis of some of the colored cool pigments and their comparison with standard pigments.
References:
1) S. Jose, D. Joshy, S.B. Narendranath and P. Periyat, Recent advances in infrared reflective inorganic pigments, Sol. Energy Mater. Sol. Cells; 2019, 194, 7-27.
2) A. Rosati, M. Fedel and S. Rossi, NIR reflective pigments for cool roof applications: A comprehensive review, J. Clean. Prod; 2021, 313, 127826