Characterization of natural clay from Meknes for a future valorization in the preparation of sustainable ecosystems intended essentially for the thermal insulation of buildings

Abstract

The sustainable development of thermal insulation requires the search for innovative, durable, and eco-friendly materials and composites able to satisfy all requirements of the construction industry. In this context, the purpose of this research is to investigate a natural clay from the Meknes region located in north-central of Morocco, to assess its potentiality in developing high-quality hybrids, It's mainly intended to be used in construction industry, through the insertion of polymers within the interfoliar space of the clay minerals. We concentrated on the investigation of the various physicochemical, mineralogical and thermal characteristics to have a clear identification of the minerals existing in the natural clay as well as its adsorption ability. The standard techniques and procedures, intended to estimate the physico-chemical parameters, were combined with the other usual methods like X-ray diffraction and Thermo-gravimetric analysis to have the maximum information on the structure, the chemical and mineralogical composition, and the thermal behavior of the clay from Meknes. Consequently, the results showed that the clay was dominated by quartz and calcite with the coexistence of an important quantity of illite, smectite, and kaolinite. After purifying, the clay minerals smectite, illite, and kaolinite are concentrated as shown in X-ray diffraction patterns. Thus, the confirmation of the phases present was done by treatment with ethylene glycol and heating of the clay fraction to 490°C. As for the physico-chemical properties, the purified clay revealed an average value of cationic exchange capacity of about 29 meq/100g and a specific surface of about 204 m2/g. The porosity was p=0.75 and the moisture measurement gave the value H=4.21%. In addition, a percentage of 55.69% was assigned to the swelling index and the loss on ignition was 11.42%. Finally, the presence of swelling clay mineral (smectite) and the relatively high values of physico-chemical properties, encourage the valorization of this material in the production of high-performance clay-polymer hybrids in the construction field.