The growing global energy demand requires solutions that improve energy efficiency in all sectors. The civil construction sector is responsible for a large part of global energy consumption. In this context, phase change materials (PCMs) can be incorporated into construction materials to improve the energy efficiency of buildings. The purpose of this study was to incorporate a PCM to jute fabric, applying it in civil construction as a reinforcement for cement matrices. In order to do that, a method of immersing jute fabric in liquid phase change material, and then coating it with a polymer, was proposed. Treated jute fabric was then used to produce a laminated composite with a cementitious matrix. Morphological, mechanical and chemical characterization of jute textiles was performed, as well as an analysis of the composites’ mechanical and thermal behavior. The results verified that jute textiles absorbed 102% PCM in weight, which was successfully contained in the capillary porosity of jute. The PCM was able to delay the composite’s temperature increase by up to 24 °C. It was concluded that this method can be used to incorporate PCM to natural textiles, producing composites with thermal energy storage properties.
The inherent polarity and hydrophilic nature of lignocellulosic fibers and the nonpolar characteristics of polyolefins create challenges in achieving good adhesion between the two materials. This study aimed to evaluate the effect of surface activation of jute fibers on the fiber-matrix interface of a jute fiber-polyester composite. The fibers were pretreated with hot water and exposed to corona discharge for 5 or 10 min. The fibers were evaluated by thermogravimetric analysis, infrared spectroscopy, and scanning electron microscopy. Pullout tests were conducted to evaluate the behavior of jute fibers in the polyester matrix when embedded at 5, 10, 20, and 30 mm depths. The pretreatments did not affect the thermal properties of the fibers; however, they promoted oxidation and increased surface roughness. Hot water pretreatment resulted in partial removal of surface waxes and enhanced bonding. Pullout tests revealed that fibers subjected to hot water immersion, followed by 10 min of corona discharge, exhibited approximately a 34% increase in adhesion strength compared to untreated fibers. It was concluded that corona pretreatment improves fiber-matrix adhesion by activating the surface and increasing the roughness of the fibers.
Two bio-oleogels were investigated. These materials were produced with a combination of canola and soybean oil with 4, 6, 8, and 10% of beeswax (by weight). Sensible heat storage capacity, melting parameters, and enthalpies were investigated by the differential scanning calorimetry (DSC) test. An ordinary DSC dynamic test was performed. Cycles of heating and cooling were performed, as well as tests with different heating rates. According to the results, the materials present a melting temperature between −16 to −12 °C and a total latent heat between 22.9 and 367.6 J/g. BC10 (canola oil with 10% beeswax) was the sample with the best performance, with a latent heat of 367.6 J/g and a melting temperature of −13.6 °C, demonstrating its possible use as a phase change material for cold storage.
28 October 2024 in Construction and Building Materials
The construction industry’s pursuit of eco-friendly materials has sparked interest in bamboo, a renewable resource with exceptional physical and mechanical properties. This study analyzed the integration of Dendrocalamus giganteus bamboo with phase change materials (PCMs) to enhance thermal energy storage in building applications, aiming to improve temperature regulation and reduce energy consumption for climate control. The study compared the performance of bamboo impregnated with an industrial PCM or coconut oil, used in conjunction with a polyurethane resin (PU) coating treatment, assessing their thermal regulation performance against traditional building materials such as ceramic tiles, fiber cement, and metal sheets. From an anatomical perspective, the pores within bamboo culms offered ample space for PCM storage, resulting in a substantial heat storage capacity. Thermal behavior tests conducted in a wind tunnel revealed that the impregnated bamboo samples effectively mitigate temperature fluctuations by aligning them with the PCM’s phase change temperature. Additionally, it was observed that air flow velocity had an impact on this phenomenon. The study concluded that bamboo culms impregnated with PCM hold promise for temperature regulation in construction applications, with variations in airflow exerting an impact on the outcomes obtained.