Development of two-dimensional nano Mts/SA phase change materials for self-adjusting temperature of pavement

• The 2DMts were designed as a novel card house structure and coated SA. • The formed 2DMt/SA nanocomposite has a good heat storage performance (221.6 J/g) and thermal stability. • The phase transition temperature range of the composite material expanded to 40–80 °C. • A new type of self-adjusting temperature pavement coating was designed and investigated. In order to solve the problem of high temperature of pavement and alleviate the heat island effect, a new type of self-adjusting temperature pavement coating was designed and investigated. The designed coating well reduced the pavement temperature. Montmorillonite (Mt) was exfoliated to less than 19.78 nm on a large scale by the freezing/thawing method to form two-dimensional Mt nanosheets (2DMts). The 2DMts were designed as a novel card house structure and then encapsulated with stearic acid (SA). The formed 2DMt/SA nanocomposite has a good heat storage performance (221.6 J/g) and thermal stability. In addition, the phase transition temperature range of the composite material expanded to 40–80 °C, and this temperature range can adapt to a variety of climatic conditions. In addition, the actual cooling effect of the self-adjusting temperature pavement coating was tested. When the composite material volume fraction is 12 %, the temperature will be reduced by approximately 5 °C in 1 h compared to the uncoated asphalt block. This study provides new ideas and possibilities for reducing the pavement temperature and alleviating the heat island effect.