Synthesis of encapsulation of binary mixture by silica and its performance in pure cementitious system

Abstract

Microencapsulation of binary mixture of 75% stearic acid (SA) + 25% capric acid (CA) (as core) has been amalgamated by silica (as shell) through sol-gel method. The obtained silica binary mixture (Si-BM) microcapsules was characterized in detail by sophisticated instruments such as field emission scanning electron microscope (FESEM), Fourier transformation infrared spectroscopy (FTIR), X-ray diffractometer (XRD), differential scanning calorimeter (DSC), and thermogravimetric (TG/DTA) were exploited to identify shape and mean size, functional groups, nature of crystallinity, and weight loss of Si-BM. The obtained microcapsules were regular in shape, crystalline state, mean size about 6.03 μm and the encapsulation efficiency of Si-BM found to be 71%. The dissimilar microcapsules such as Si-BM and melamine formaldehyde phase change material (MF-PCM) were assimilated (1, 3, and 5 wt%) into cement paste to elucidate thermal-mechanical properties. As the amount of Si-BM increases, the compressive strength increased by 10% and thermal conductivity of cement paste is increased by 9% as compared to MF-PCM. Novelty StatementEncapsulation of binary mixture is synthesized with silica through chemical method. The nonidentical different dosage of microcapsules such as MF-PCM and Si-BM were incorporated into pure cement system to determine its effect on mechanical and thermal properties of cementitious system. These data will be useful to further incorporation in mortar and concrete for energy storage as well as thermal load reduction on buildings.

Encapsulation methods for phase change materials – A critical review

“…Srinivasaraonaik et al [209] combined the stearic acid (SA) and capric acid (CA) (75:25) as core materials wrapped by the silica shell by using the sol-gel method. They compared the thermal conductivity, specific heat, and mechanical properties between microcapsules with MF and silica as shells, then incorporated to cement paste.…”

Thermo-physical and mechanical investigation of cementitious composites enhanced with microencapsulated phase change materials for thermal energy storage

“…PCM can be employed to store/release large amounts of thermal energy, predominantly via the latent branch, during melting or solidification at a nearly constant temperature. Ordinary construction materials, like concrete or mortar, only have an intrinsic sensible heat storage capacity, which varies between approximately 0.75 and 1.00 J/g×K [12] [13]. In contrast with this, organic PCM can provide excellent latent heat storage capacity of approximately 180-230 J/g [14].…”