Microencapsulation for hydrophobic enhancement in soils

Functionalizing soils to render them hydrophobic allows their use in infrastructure to restrict water infiltration and thus prevent infrastructure failure and long-term degradation. The use of hydrophobized soils offers the following benefits over existing techniques such as geosynthetics and clays: (1) organic coatings can be used to induce hydrophobicity, and (2) the level of hydrophobicity can be tailored to suit various applications (from impermeable to semi-permeable).

There is a need is to prepare infrastructure for a changing climate by devising systems of an adaptable nature, which reduce wetting as required. Microencapsulation approaches, initially developed for self-healing applications emerge as a potential solution to enhance or switch from hydrophilic. These approaches have been successfully implemented with cementitious construction materials. The healing principle is based on the rupture of microcapsules by fissures which releases healants, leading to precipitation and proliferation of crystalline products filling the fissures and improving significant properties such as permeability and strength.

This collaborative effort will investigate the effectiveness of microencapsulation for hydrophobic enhancement in soils. The research plan will draw from the experience of the PI Kanellopoulos and Co-I Lourenço in self-healing concrete and hydrophobicity, respectively, to test physicochemical methods to encapsulate and release hydrophobic substances in soils. As one of the first studies on microencapsulation in soils, the outcomes of this project will also lay the foundations for future research aimed at encapsulating other cargoes to manipulate and enhance other soil properties.