The objective of this study is to analyze the effects of using surfactant (CTAB) and cellulose nanofibers (NFC) as an admixture in cement mortars. We examined composite properties as porosity, compression energy, thermal conductivity and hydration. The results showed that with the addition of 0.7% by weight of NFC per emulsion in the presence of a cationic surfactant (CTAB). The new material produced presented a dry porosity between 4.7% and 4.4%, compressive strength between 9.8 and 22.9 MPa, and thermal conductivity between 0.95 and 2.25 W•m −1 •K −1 . Thus we show better mechanical and thermal performance than that traditional Portland cement mortar with a density similar. In addition, the mortar made by emulsion of ordinary portland cement, cellulose nanofiber and organophilic clay (OC) treated with cetyltrimethylammonium bromide (CTAB) obtained has good resistance under high temperature and water, as well as excellent thermal insulation performance under high temperature and humidity conditions. This study verified that the presence of NFC promotes hydration, leading to the production of more calcium silicate and portlandite gel.

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In this research, Cellulose Nanofibers (NFC) modified with a eutectic of lauric acid (LA) was prepared as a new form-stable phase change material (NFC-LA). Thermal properties of this composite were investigated by Differential Scanning Calorimetry (DSC). The results revealed that the melting temperature and latent heat of NFC/LA were 21.56 °C and 88.5 J/g, respectively; and the super cooling degree for the NFC-LA composite decreased to 13.99 °C when compared to 20.28 °C of the pure lauric acid. Natural clay was purified and modified with Cetyltrimethyl ammonium bromide (CTAB) to prepare organoclay. Through FTIR spectra, we have confirmed that the clay was successfully modified. The PCM-composite was then added to the organoclay to obtain a new composite denoted NFC-LA-OC. this latter was added to cement and was investigated as a reinforcement material in cement mortars for thermal energy storage application. The prepared material can both solve the leakage problem associated to the phase change material, and reduce or even avoid the use of heating and air conditioning systems, which are energy-intensive systems, and therefore reduce energy consumption.