Halloysite clay nanotube composites as coating materials with enhanced properties

Abstract

Energy efficiency and thermal control are of critical importance as the world moves from traditional fossil fuel energy sources and looks to limit resource and environmental impacts. This paper describes the development of a novel thermal insulative coating material prepared by blending natural clay nanotubes (halloysite nanotubes - HNT) with latex primers. This represents a “green” approach to an insulative paint, focused on naturally occurring HNTs as the primary additive and useful in multiple applications, including new or existing construction. The HNTs were mixed with 0.5–4% weight ratios using several blending approaches. Investigation of the study included changes in viscosity, adhesion, and thermal properties of the primers resulting from the addition of the HNTs. Results indicated that viscosity and shear stress increased gradually. Impact on the adhesion properties was also found depending on the host surface material. The addition of the HNTs altered the thermal conductivity properties of the primer materials. SEM images showed good dispersion of HNTs in the primer irrespective of mixing technique. A comparison was made between the properties of the latex primers after the HNTs were mixed. The outcome of the study has the potential to modify the thermal conductivity properties of commonly used coating materials and, thus, limit energy loss through walls and ceilings.