Energy-saving Materials Research Articles

Preparation and performance study of modified diatomite based PCM for construction

Phase change energy storage technology provides a good solution to the spatial and temporal mismatch of energy use in buildings, but organic solid–liquid phase change materials suitable for the building sector limit their application due to leakage problems. To mitigate the effects of the above problems, diatomite (DME) is designed as the carrier for encapsulation in this experiment. Adsorption performance of DME is improved through double effects of 600°C high-temperature calcination and hydrochloric acid modification. The binary low eutectic mixture was prepared by co-melting of lauric acid (LA) and octadecyl alcohol (OD) with mass ratio of 70:30. Shape-stabilized composite phase change material (SSCPCM) was prepared by vacuum adsorption method with LA-OD and DME with a mass ratio of 35:65 and the melting temperature and latent heat of SSCPCM are 39.10°C and 54.02 J/g. It was experimentally evaluated that the surface impurities of modified DME under microscopic conditions were removed and LA-OD was uniformly embedded in the micropores of DME, and the prepared SSCPCM was able to maintain a thermal inertia of 39°C with good thermal properties and thermal stability, thus SSCPCM could be used as a building energy-saving material to reduce building energy consumption, in addition to expanding the utilization of inorganic mineral materials.

Cork Façades as an Innovative and Sustainable Approach in Architecture: A Review of Cork Materials, Properties and Case Studies.

Façades give the first impression of a structure, reflecting the overall aesthetic appeal, architectural styles, cultural influences, and technological advancements. Emphasis on sustainability is increasing, with a shift towards eco-friendly and energy-saving materials, triggered by decreasing the environmental impact of construction. Cork is a green competitive material for various engineering and design applications due to its biological formation, sustainable production and a portfolio of properties including low density, impermeability, viscoelastic behaviour and high thermal insulation that derive from its cellular and chemical features. This work presents cork materials used in building façades and their properties, also giving information on cork production and processing into cork-based products as a review of the existing published research, while also identifying knowledge gaps and further research needed. Historical examples of cladding of constructions with raw cork are given, while the contemporary innovative use of cork façades was triggered by some designs of well-known architects with outdoor application of expanded cork agglomerates. Examples of different historical and contemporary constructions were assembled and critically assessed by the authors. The aim is to give integrated information of cork as a natural, renewable and sustainable material to raise the interest of designers, architects and engineers to explore cork, blending aesthetics with environmental responsibility, targeting a more sustainable and resilient built environment.

Thermochromic Vanadium Dioxide Nanostructures for Smart Windows and Radiative Cooling.

The pursuit of energy-saving materials and technologies has garnered significant attention for their pivotal role in mitigating both energy consumption and carbon emissions. In particular, thermochromic windows in buildings offer energy-saving potential by adjusting the transmittance of solar irradiation in response to temperature changes. Radiative cooling (RC), radiating thermal heat from an object surface to the cold outer space, also offers a potential way for cooling without energy consumption. Accordingly, smart window and RC technologies based on thermochromic materials can play a crucial role in improving energy efficiency and reducing energy consumption in buildings in response to the surrounding temperature. Vanadium dioxide (VO2) is a promising thermochromic material for energy-saving smart windows and RC due to its reversible metal-to-insulator transition, accompanying large changes in its optical properties. This review provides a brief summary of synthesis methods of VO2 nanostructures based on nanoparticles and thin films. Moreover, this review emphasizes and summarizes modulation strategies focusing on doping, thermal processing, and structure manipulation to improve and regulate the thermochromic and emissivity performance of VO2 for smart window and RC applications. In last, the challenges and recent advances of VO2-based smart window and RC applications are briefly presented.

Application of Energy-Saving Materials in Architectural Design

The conventional process of building construction is associated with issues such as the waste of construction materials and environmental pollution. Sustainable development highlights the importance of energy conservation and eco-friendly practices. It is essential to use energy-efficient and green materials in building designs to ensure the healthy growth of construction companies. This article discusses the advantages and principles of incorporating energy-saving materials in architectural design. It examines the strategies and critical control points for using energy-saving materials in architectural design, offering guidance for the sustainable development of the construction industry.

Synergistic Effect of B4C and Multi-Walled CNT on Enhancing the Tribological Performance of Aluminum A383 Hybrid Composites

The requirement for high-performance and energy-saving materials motivated the researchers to develop novel composite materials. This investigation focuses on utilizing aluminum alloy (A383) as the matrix material to produce hybrid metal matrix composites (HMMCs) incorporating boron carbide (B4C) and multi-walled carbon nanotube (MWCNT) through a cost-effective stir casting technique. The synthesis of HMMCs involved varying the weight fractions of B4C (2%, 4%, and 6%) and MWCNT (0.5%, 1%, and 1.5%). The metallographic study was carried out by field emission scanning electron microscopy (FESEM) mapped with EDS analysis. The results indicated a uniform dispersion and robust interfacial interaction between aluminum and the reinforced particles, significantly enhancing the mechanical properties. Micro-hardness and wear characteristics of the fabricated HMMCs were investigated using Vickers microhardness testing and the pin-on-disc tribometer setup. The disc is made of hardened chromium alloy EN 31 steel of hardness 62 HRC. The applied load was varied as 10N, 20N, 30N with a constant sliding speed of 1.5 m/s for different sliding distances. The micro-hardness value of composites reinforced with 1.5 wt% MWCNT and 6 wt% B4C improved by 61% compared to the base alloy. Additionally, the wear resistance of the composite material improved with increasing reinforcement content. Incorporating 1.5% CNT and 6% B4C as reinforcements results in the composite experiencing about a 40% reduction in wear loss compared to the unreinforced aluminum alloy matrix. Furthermore, the volumetric wear loss of the HMMCs was critically analyzed with respect to different applied loads and sliding distances. This research underscores the positive impact of varying the reinforcement content on the mechanical and wear properties of aluminum alloy-based hybrid metal matrix composites.

A recyclable and durable magnetic cobalt nanoparticle-embedded mesoporous graphene nanohybrid for removal of pollutants from aqueous media

Cobalt nanoparticles (Co NPs) embedded in mesoporous graphene (MG) were prepared via a hydrothermal reaction followed by carbothermal reduction in an argon atmosphere. This cobalt nanoparticle-embedded mesoporous graphene (CoMG) was systematically investigated for structural, morphological, and magnetic properties before and after 10 successive cycles of adsorption and regeneration, using methylene blue (MB) dye as a model pollutant. The CoMG nanohybrid has a superior specific surface area of 807 m2 g−1, with a significant mesopore volume of 1.63 cm3 g−1 that allows fast and high pollutant removal efficiency of ∼84 % within 30 min as well as the maximum adsorption capacity of 178.6 mg g−1 with MB solution of 100 mg L−1, which is well described with pseudo-second-order adsorption kinetics. The consecutive adsorption−regeneration experiments revealed that the CoMG nanohybrid retained more than half of the initial dye removal efficiency even after being reused 10 times. After the tenth cycle, the regenerated CoMG maintained a high specific area of 688 m2 g−1 and a large mesopore volume of 1.51 cm3 g−1, indicating the long-lasting porous structure of the CoMG nanohybrid. The metallic cobalt phase and ferromagnetic nature of the Co NPs in the nanohybrid are retained because of the host MG, which prevents nanoparticle aggregation and serves as a protective environment for the embedded Co NPs in aqueous media during the adsorption−regeneration cycle tests of the adsorbent. The experimental results demonstrate that the CoMG nanohybrid has superior pollutant removal capacity and maintains more than half of the initial efficiency even after 10 cycles of use, making it a cost-efficient and energy-saving material for the removal of organic pollutants from aqueous media and in other environmental applications.

Evaluation of LEED-certified office buildings in Turkey in terms of sustainable material use

Environmental issues such as ozone depletion, global warming, water pollution, and melting glaciers in the polar regions have been exacerbated by industrial and chemical activities, as the Industrial Revolution led to unlimited use of our limited natural resources. Approaches have been developed to solve human and environmental health problems. Efforts are underway to minimize the adverse effects of buildings on the environment. This process helps reduce materials' environmental damage and select environmentally friendly materials. For these reasons, producing recyclable, ecologically friendly, and energy-saving materials has gained importance. This article used a case study method to analyze sustainable material usage using twenty LEED-certified office projects in Turkey. Twenty new buildings, including Certificate One, Silver Three, Gold Eight, and Platinum Eight, have been evaluated regarding sustainable materials according to LEED criteria. Tables containing material and resource application principles have been created to assess the selected buildings in terms of sustainable material principles, and these prepared tables provide information about sustainable material use. The evaluation is based on eight criteria and sources of LEED material, including recyclable materials, renewable materials, rapidly renewable, certified wood, regional materials, construction waste management, and re-use of materials. As a result of the study, it was determined that 95% to 75% of the five categories with the weakest application among the eight basic materials and resource principles failed to be below the desired level and should be improved.

REASONABLE USE OF HEAT AND HEAT CONDUCTIVITY PROPERTIES OF HEAT PRESERVING COATINGS

In addition to discussing the current techniques for figuring out the thermal conductivity of these heat-insulating coatings, the piece also details the outcomes of experimental research on the analysis and advancement of energy-saving materials and their application to recently built modern buildings and structures.

ELECTROLYSIS CONDITIONS EFFECT ON THE VANADIUM-CONTAINING COATINGS COMPOSITION

The development of functional materials with predictable properties is one of the priority directions in modern research. Obtaining new energy-saving materials for reducing the cost of hydrogen production in an electrochemical way is relevant for the hydrogen energy industry. Such electrode materials should have catalytic activity for the hydrogen evolution reaction. Catalytic properties can be predicted for coating alloys of the iron subgroup metals with vanadium, molybdenum, and tungsten. The aforementioned metals can be co-deposited from aqueous solutions with iron subgroup metal catalysts through the formation of cluster intermetallic compounds with Me-V, Mo, W bond adsorbed on the cathode surface. The induced co-deposition of cobalt with vanadium from the complex citrate electrolyte via stationary and pulse electrolysis modes was investigated in the current work. As a result of the research, it was found that the uniform microcrystalline light-gray high-quality cobalt-vanadium alloy coating is possible to be deposed from a citrate electrolyte with content of 0,1 mol/dm3 vanadium (in terms of metal) as a citrate complex The process was carried out at a current density of 1–15 A/dm2 by stationary electrolysis mode and 2–10 A/dm2 by pulse electrolysis mode, with a different ratio of pulse time to pause time, at a temperature range of 35–40°С and pH = 3,0–3,5. According to the results of the X-ray fluorescence (XRF) spectrometry, the maximum content of vanadium in the coating obtained via the programmable electrolysis mode is 1.20–1.45%, which is tens of times more than in the coating deposited by the stationary electrolysis mode (vanadium content 0.007-0.017%) under similar conditions. The obtained result may be a confirmation of the hypothesis of vanadium additional reduction from oxo-anions by adsorbed hydrogen atoms that formed on the cathode surface during the pause period. According to the results of the analysis of 2D graphs, the optimal parameters of the process for obtaining a cobalt-vanadium coating with the vanadium maximum content in the alloy and the coating current yield of 80% have been established.

Simulation of Carbon Emission Reduction in Power Construction Projects Using System Dynamics: A Chinese Empirical Study

Power construction projects (PCPs) consume a large amount of energy and contribute significantly to carbon emissions. There is relatively little research on carbon emission reduction in PCPs, especially in predicting carbon emission reduction from a dynamic perspective. After identifying the influencing factors that promote the carbon emission reduction effect of PCPs, this study adopted a dynamic analysis method to elucidate the relationship between the variables. A quantitative carbon emission reduction system for PCPs with 51 variables was established using the system dynamics model, and the system simulation was performed using Vensim PLE software. Finally, a sensitivity analysis was conducted on four key factors: R&D investment, the prefabricated construction level, the scale of using energy-saving material, and the energy efficiency of transmission equipment. The results show that: (1) The reduction in carbon emissions from PCPs continues to increase. (2) R&D investment is the most significant factor for improving the carbon emission reduction in PCPs. (3) The value of the above four influencing factors should be increased within a reasonable range so that the four factors can work better to promote the carbon emission reduction effect of PCPs. This paper creatively proposes a dynamic prediction model for carbon emission reduction in the PCP, and the research results provide the scientific basis for government supervision and enterprise decision-making.

Expanded titanium-bearing blast furnace slag phase change aggregate: Preparation, performance and phase change energy storage mortar application

Expanded titanium-bearing blast furnace slag (ETS), containing rich connected pores, largely accumulated, due to low hydration activity and particle strength. In this study, the pore system of ETS was fully utilized to load paraffin for fabrication of phase change aggregate (PCA), and then the PCA was used to prepare phase change energy storage mortar (PCEM) and mechanical properties, thermal performances and energy-saving efficiency were subsequently evaluated. The results indicated that the 28-day and 56-day compressive strength of mortar containing 100 % PCA reached to 7.8 MPa and 8.6 MPa. The energy saving efficiency of building reached to 8.1 %, the peak indoor temperature of building decreased by 1.2 °C and 2.3 °C in spring and summer, respectively. These facts give confidence of ETS consumption in building energy-saving materials.

Application of Green Energy-Saving Technologies in Green Buildings in Real Estate Construction

Energy saving and low-carbon environmental protection are not only simple policy requirements but also bring impetus to the development of green buildings. The real estate construction business has become concerned. The construction process not only consumes huge capabilities and resources, but also causes varying degrees of damage to environmental products. Therefore, the comprehensive application of green building energy-saving technology in real estate development does not cater to the needs and preferences of current consumers, but is based on major challenges in the construction of national ecological civilization and future industry trends. This article mainly starts with the basic form and function of energy-saving technology in green buildings and discusses the effective application of building ground construction. This text analyzes the green building energy-saving technology and its current application status. Some problems exist: the building materials are not up to standard, and the process is not kept in mind. Some green energy-saving technologies have been applied in real estate construction: increasing the green energy-saving material markets and the supervision of material procurement, improving workers' ability to apply green and energy-saving technologies, correcting the attitude towards green building energy-saving technology, coordinating design and planning in real estate construction, determining the application criteria of green technology, and adhering to the principle of on-site and improve the energy-saving effect.

Transparent thermochromic VO2/PAN nanocomposite films prepared by electrospinning-hot pressing technique

The global energy consumption in the building sector is enormous annually, and the energy consumed in the building part is mainly used for heating, ventilation, and air conditioning. Smart windows can effectively reduce the energy consumed for heating, ventilation, and air conditioning. Vanadium dioxide (VO2) has been widely used in the preparation of thermochromic smart window films due to its excellent properties, but the low luminous transmittance of VO2-based smart films has been one of the main issues limiting their application. In this paper, we utilized the electrospinning technology to prepare VO2/PAN nanocomposite films with polyacrylonitrile (PAN) as the matrix and VO2 as the filler. Then, the VO2/PAN nanocomposite films were heat-treated by the hot pressing technique. The VO2/PAN nanocomposite films with excellent performance were finally obtained. VO2/PAN nanocomposite films had stable morphology, uniform VO2 distribution, and high thermal stability. Besides, the hot-pressing process could significantly improve the mechanical properties of the films, and the maximum tensile strength of VO2/PAN nanocomposite film was 24.15 MPa. Moreover, according to UV–vis spectra, when the loading of VO2 was 20 %, the luminous transmittance (Tlum) of VO2/PAN nanocomposite film was 68.66 % and the solar modulating ability (ΔTsol) was 0.28 %. Hence, this research offered a new option for the preparation of energy-saving materials that could replace smart glass.

VAK-Based E-Module for Grade IV Elementary School Students

Lack of teacher ability to develop teaching materials causes boredom. The aim of this research is to develop a Visual Auditory Kinesthetic (VAK) based learning e-module aimed at students in the fourth grade of elementary school, a solution that researchers can offer. This research is a mixed method-based development research using the 4 D (Four-D) research model. Data collection methods use observation, interviews and questionnaires. The research subjects were 4 experts and 1 teacher. The test subjects were shown to fourth grade elementary school students. The data analysis technique uses qualitative and quantitative descriptive analysis. The research results show that material experts and media experts carry out product testing, while teachers and students carry out assessments. The results show overall results for material experts are 91 percent in the very good category, overall media experts are 89 percent in the very good category, practitioners overall are 95 percent in the very good category, and students overall are 93 percent in the very good category. Therefore, it can be concluded that learning e-modules that focus on energy-saving materials for fourth grade elementary school students are suitable for use. The implication of this research is that this learning e-module can help teachers and students as a learning tool to support learning, especially in energy saving material.

Strength and Chemical Characterization of Ultra High-Performance Geopolymer Concrete: A Coherent Evaluation

The objective of this review article is to analyze published data encompassing compressive strength, tensile strength, elastic modulus, and flexural strength, as well as the utilization of scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), and x-ray diffraction (XRD) for Ultra High-Performance Geopolymer Concrete (UHP-GC), with the focus of establishing the current research trends regarding its mechanical, microstructural, and chemical characteristics. After a critical evaluation of the published data from the literature findings, it became evident that UHP-GC can attain a remarkably high level of engineering performance. In UHP-GC, the optimum percentage of silica fume as a slag partial replacement to achieve high compression, tensile, and elastic modulus were traced to be 25, 30, and 35%, respectively. The optimum ratio of sodium silicate to sodium hydroxide and sodium hydroxide molarity for UHP-GC were identified to be 3.5 and 16, respectively. All in all, the review provides a thorough understanding of the review gap and distinct functions of different raw materials in decreasing porosity and enhancing the formation of geopolymeric gels that not only bond but also strengthen UHP-GC. UHP-GC stands as an energy-saving material in concrete technology, poised to forge a path towards a sustainable future for the building sector. Doi: 10.28991/CEJ-2023-09-12-020 Full Text: PDF

Feasibility & analysis of translucent concrete

In this research, we have demonstrated how concrete is a necessary substance that is used widely in the current world, nearly everywhere infrastructure and development based on cutting-edge materials and processes are needed by humanity. Translucent concrete is a material made of concrete with light-transmitting qualities that enable light to flow through it by the use of embedded material, most commonly optical fibres. It is a green energy-saving material that uses sunlight as a light source to lower the amount of power used for lighting. Many academic fields now share an interest in the idea of “green architecture,” and new materials are constantly being produced to meet the needs of this design. Translucent concrete, also known as light-transmitting concrete, is one of those cutting-edge materials that, when combined with other light components like optical fibres, allows outside light to enter interior areas. This study compiles and summarises earlier research on the uses of translucent concrete, the ideal ratio and configuration of optical fibres, and the material's mechanical, thermal, energy-saving, and light-transmitting qualities. We went over the outstanding research that has been done, particularly in the last ten years, on transparent concrete approaches. Despite the benefits, research confirms that translucent concrete studies have a number of shortcomings.

Challenges and Optimization of Building-Integrated Photovoltaics (BIPV) Windows: A Review

PV windows are seen as potential candidates for conventional windows. Improving the comprehensive performance of PV windows in terms of electrical, optical, and heat transfer has received increasing attention. This paper reviews the development of BIPV façade technologies and summarizes the related experimental and simulation studies. Based on the results of the literature research, the average comprehensive energy-saving rate of BIPV façades can reach 37.18%. Furthermore, limitations and optimization directions of photovoltaic integrated shading devices (PVSDs), photovoltaic double-skin façades, and photovoltaic windows are presented. To improve the energy-saving potential of windows as non-energy efficiency elements of buildings, smart PV windows are proposed to be the key to breakthrough comprehensive performance. However, not all switchable windows concepts can be applied to PV windows. Typical studies on smart windows and PV windows are sorted out to summarize the challenges and optimization of smart PV window technical solutions. Considering the technological innovations in smart PV windows, two requirements of energy-saving materials and building envelopes are put forward. The advances in materials and the building envelope are complementary, which will promote the sophistication and promotion of solar building technology.

Discussion on the Effectiveness of JGJ 26-2018 "Energy Efficiency Design Standard for Residential Buildings in Severe Cold and Cold Areas"

Building energy consumption is a substantial part of total energy consumption and is rising in the context of energy crises and environmental issues. To maximize energy savings and limit carbon emissions, the government recommends updating construction requirements. The Ministry of Housing and Urban-Rural Development of China proposed JGJ 26-2018 "Energy Saving Design Standard for Residential Structures in Extreme Cold and Cold Regions" in accordance to national policy. Several reports noted that some Chinese design requirements just stack energy-saving materials and technology without actually reducing energy consumption. This study proves the JGJ 26-2018's legitimacy. This essay first selects three major variables that have the largest impact on the energy consumption of buildings in extreme cold and cold areasexterior walls, roofs, doors, and windowsand then gathers four cases of housing restoration of these three essential components according to JGJ 26-2018. The partial success of the strategy is proven by comparing energy consumption before and after building renovations, which provides a reference for energy-saving residential building design in severe cold and cold regions.

Regulating Electrostatic Interactions toward Thermoresponsive Hydrogels with Low Critical Solution Temperature.

Low critical solution temperature (LCST) of commonly used thermoresponsive polymers in water is basically dominated by hydrophobic interactions. Herein, a novel thermoresponsive system based on electrostatic interactions is reported. By simply loading aluminum chloride (AlCl3 ) into non-responsive poly(2-hydroxyethyl acrylate) (PHEA) hydrogels, PHEA-Al gels turn to have reversible thermoresponsive behavior between transparent and opaque without any volume change. Further investigations by changing metal ion-polymer compositions unravel the necessity of specific electrostatic interactions, namely, cation-dipole bonding interactions between hydroxy groups and trivalent metal ions. The thermoresponsive hydrogel demonstrates high transparency (≈95%), excellent luminous modulation capability (>98%), and cyclic reliability, suggesting great potential as an energy-saving material. Although LCST control by salt addition is widely known, salt-induced expression of thermoresponsiveness has barely been discussed before. This design provides a new approach of easy fabrication, low cost, and scalability to develop stimuli-responsive materials.

Enhanced infrared radiation of LaAlO3 ceramics via Co2+ doping

Infrared radiation (IR) ceramics are generally recognized as energy-saving materials for thermal equipment. In this work, as novel infrared radiation ceramics, Co2+-doped LaAlO3 ceramics were synthesized via a solid-phase reaction method, and the influence of the Co2+ doping concentration on the infrared emissivity of ceramics was systematically investigated. The original Al element position was replaced by Co in Co2+-doped LaAlO3, leading to lattice distortion, oxygen vacancy generation and the "Co2+→Co3+" transformation. The increase in doped Co content leads to enhanced impurity absorption, free carrier absorption and lattice vibration absorption, which significantly improve infrared emissivity. The average emissivity values in the 0.76–2.5 μm and 2.5–14 μm bands of the LaAl0.6Co0.4O3-δ specimen (40 mol% Co) are 0.89 and 0.86 respectively, which are 324% and 28% higher than those of pure LaAlO3. This novel Co2+-doped LaAlO3 ceramic with high infrared emissivity has significant application prospects for energy-saving applications of thermal equipment.