Silica Aerogel

In this work, a new approach to apply silica aerogel into textiles by laser treatment and laminating technique was used to fabricate aerogel-encapsulated textiles. Thermal insulation performance of the prepared multilayer aerogel-encapsulated laminated fabrics was characterized in terms of thermal conductivity, thermal resistance and thermal diffusivity by Alambeta instrument. Infrared thermography data were collected by FLIR ThermaCAM TVS300 thermal camera. The ORIENTEC STA-1225 Universal Testing Machine was employed for testing the compression properties like compression resistance, compression resilience and thickness loss. Results showed that the aerogel-encapsulated structure has significant effect on thermal insulation enhancement. A temperature gap of 1℃ to 1.5℃ was observed between aerogel-filled samples and regular ones. It is also found that nonwoven fabrics with aerogel-filled voids generally have lower compression resistance than regular nonwovens, samples with air-fille...

This work aimed to develop vinyl/methyl-decorated silica-based aerogel-like hybrids and evaluate their performance as novel oil/organic solvent adsorbents. Silica hybrids were prepared in two series by co-condensation of vinyltrimethoxysilane (VTMS) either with methyltrimethoxysilane (MTMS) (VM-series) or tetraethylorthosilicate (TEOS) (VT-series) followed by surface methylation with TMCS at ambient pressure. By gradual vinyl substitution, the changes in the physicochemical and morphological properties of the hybrids were monitored using complementary characterization techniques, such as FTIR, 29Si-NMR, SEM, N2 porosimetry, small angle neutron/X-ray scattering and contact angle measurements. The results confirmed the significant structural changes in VT-series with increasing VTMS content, whereas it had only a limited effect on the network formation in VM-series. In VT-series, the samples were predominantly mesoporous in nature, even up to a high VTMS content (75 mol%), resulting i...

The paper analyses questions concerning the integration of architecture and art. The objective of this publication is to examine visual interferences that occur in architecture and to determine their effects on how the building is seen and on the architectural space. This phenomenon is an important artistic issue that opens the way for new compositional values in architecture. Visual interferences can occur when there are at least two layers of an image composed of repetitive elements, put in a certain order. Overlapping of graphical layers results in image concentration, and in this way compositions such as lines, circles and polygons are created, which are known as interference patterns. In art glass, it is possible to remove image layers from each other, thus obtaining an additional effect. This creates visually mobile surfaces, which react to movement of the observer. The present paper will analyse this phenomenon with the aim to determine what principles govern the occurrence o...

Aerogels, the lowest-density solids in the world, have very effective thermal insulation properties with their extremely high surface area and porous structure. Recently, there has been an increasing interest in using aerogels in the textile industry, especially to obtain functional and technical textiles. In this study, thermal and solar properties of polyester fabrics coated at different concentrations (1 %, 2 %, and 4 %) of aerogels with different particle sizes (~ 8 µm, 0 – 80 µm, 0 – 0.5 mm) were investigated. It was observed that the aerogel particle size and concentration had a significant effect on the thermal and solar properties, and the lowest thermal conductivity coefficient and thermal resistance values (0.036 W/mK and 14.33 m2 K/W, respectively) appeared at the largest particle size and maximum concentration. In contrast, the solar reflectance values of the coated samples decrease up to 62 % with increasing aerogel particle size. In a conclusion, the coating method wit...

Since we increasingly spend time indoors, natural light inside of interiors becomes more and more important for visual comfort and overall human health through setting of circadian rhythm, and can additionally help with energy savings. Aerogel glass bricks are a new building component for perimeter walls, combining structural properties of glass and the thermal insulation capabilities of aerogel with the aesthetic and daylight-transmitting qualities of both. This paper describes the development and thermal and structural characterization and simulation of a highly thermally insulating aerogel glass brick. The aim was to create an aesthetically pleasing building component with excellent thermal insulation properties that is capable of transmitting daylight.

This paper explores the design, development, and thermal simulations of an aerogel glass brick, as well as guarded hot-plate measurements and a compression experiment. Measurements of thermal insulating properties and simulations revealed that the aerogel glass brick could reduce energy consumption significantly compared to other conventional building materials for perimeter walls, while also transmitting daylight. Additionally, its aesthetic qualities can make it suitable not only for use in modern construction projects, but also in refurbishment of older objects.

The measured thermal conductivity is 53 mW/(m·K), in agreement with thermal simulation results of 51 mW/(m·K), and the measured compressive strength of the brick is 45 MPa. These data suggest that the aerogel glass brick is a viable option for architects and engineers looking for a sustainable and efficient construction component for perimeter walls. Structurally, the brick should allow building large and high spans and its thermal insulation properties can significantly reduce energy consumption, while its aesthetic and daylight-transmitting qualities make it visually appealing.

For thermal insulation of buildings it is used in building countless insulating materials. Nowadays, heat insulation material based on oil products. The selection and use of insulation materials have to pay attention to their fire-technical characteristics. If a fire combustion products of synthetic insulating materials and their harmful effects or endanger human encroachment firefighter in the building. The article describes several types of insulation material in terms of chemical composition, the toxicity and effect of the fire. We describe the combustion products and their toxic properties to humans. Finally, it summarized some points for the right organizations to intervene in harmful environment with toxic gases.

A molecular dynamics (MD) simulation study has been performed to investigate the structural transition of nickel metal using Pak-Doyama potential. The local atomic structure was analyzed through the radial distribution function (RDF), coordination number distribution and 3D visualization. It was shown that the splitting of RDF second peak appears when the liquid transforms to amorphous solid. We found that the liquid state contains a significant amount of nano-crystalline nucleations, which strongly depends on the temperature and MD time steps. Accordingly, the simulation shows that the crystallization is originated from expanding of nano-crystalline nucleations.

The oil industry is plagued with regular incidences of spills into the environment, causing environmental damage to flora and fauna, especially in marine environments where spills easily travel long distances from their sources. This study was carried out to investigate a simple two-step process for the conversion of waste cigarette filters into a superhydrophobic and oleophilic sorbent for application in oil/water separation and spill clean-up. Ultrasonically cleaned filters were surface modified by chemical vapour deposition using methyltrichlorosilane. The results show that the functionalised waste filters achieved superhydrophobic properties with a water contact angle of 154 ± 3.5°, adsorbing 16 to 26 times their weights in various oils, which is a better oil sorption performance than those of commercially available non-woven polypropylene adsorbents. Also, the sorption capacity did not significantly deteriorate after 20 cycles of reuse, with up to 75% sorption capacity retained...

Novel hybrid core-shell structures, in which up-converting (UC) NaYF4:Yb,Tm core converts near-infrared (NIR) to visible (Vis) light via multiphoton up-conversion processes, while anatase TiO2-acetylacetonate (TiO2-Acac) shell ensures absorption of the Vis light through direct injection of excited electrons from the highest-occupied-molecular-orbital (HOMO) of Acac into the TiO2 conduction band (CB), were successfully synthesized by a two-step wet chemical route. Synthesized NaYF4:Yb,Tm@TiO2-Acac powders were characterized by X-ray powder diffraction, thermogravimetric analysis, scanning and transmission electron microscopy, diffuse-reflectance spectroscopy, Fourier transform infrared spectroscopy, and photoluminescence emission measurement. Tetracycline, as a model drug, was used to investigate the photocatalytic efficiencies of the core-shell structures under irradiation of reduced power Vis and NIR spectra. It was shown that the removal of tetracycline is accompanied by the forma...

Poly-ε-caprolactone (PCL) is a biodegradable aliphatic polyester that can be used in the field of biomaterials. Electrospinning is the name given to the process of producing micro and nanoscale fibers using electrostatically charged polymeric solutions under certain conditions. Almost all synthetic and naturally occurring polymers can undergo electrospinning using suitable solvents or mixtures prepared in certain proportions. In this study, silica aerogels were obtained by the sol-gel method. PCL-silica aerogel fibers were synthesized by adding 0.5, 1, 2, and 4% ratios in the PCL solution. Blood contact analysis was performed on the produced fibers with UV-VIS. According to the results obtained, 0.5, 1, 2, and 4% nano-silver were added to the fiber-containing 4% aerogel. Then, SEM-EDS and FTIR analyses were performed on all fibers produced. Antimicrobial tests were performed on fibers containing nano-silver. As a result, high-performance blood coagulation fibers were developed using...

In recent years, research on bio-based materials, such as rice husk is steadily gaining momentum. Despite their huge developmental potential, rice husks are often left unutilised following the harvesting season, wasting a natural wealth that could be explored. Their high silica content makes them potential fillers to replace commercial precipitated silica in the polymer industry, composites and building materials for construction. In this study, highly pure silica with small particle size and high surface area was extracted from rice husks via solvent-thermal treatment, followed by leaching with different concentrations of hydrochloric acid (HCl). This treatment method was modified from TAPPI T204 (2007) and TAPPI T264 (1997) standards, which are used for wood extraction in the pulp and papermaking industry. By using this method, rice husk silica (RHS) that was leached with 1.0 M HCl recorded the highest particle purity with 99.99% of SiO2 content and the highest BET surface area of...

Poly-ε-caprolactone (PCL) is a biodegradable aliphatic polyester that can be used in the f ield of biomaterials. Electrospinning is the name given to the process of producing micro and nanoscale fibers using electrostatically charged polymeric solutions under certain conditions. Almost all synthetic and naturally occurring polymers can undergo electrospinning using suitable solvents or mixtures prepared in certain proportions. In this study, silica aerogels were obtained by the sol-gel method. PCL-silica aerogel fibers were synthesized by adding 0.5, 1, 2, and 4% ratios in the PCL solution. Blood contact analysis was performed on the produced fibers with UV-VIS. According to the results obtained, 0.5, 1, 2, and 4% nano-silver were added to the fiber-containing 4% aerogel. Then, SEM-EDS and FTIR analyses were performed on all fibers produced. Antimicrobial tests were performed on fibers containing nano-silver. As a result, high-performance blood coagulation fibers were developed using PCL with aerogel, and an antimicrobial effect was achieved with nano-silver particles. It is thought that the designed surface will be preferred in wound dressing and biomaterial in tissue engineering, as it provides a high amount of cell adhesion with a small amount of blood and contains antimicrobial properties.

A molecular dynamics (MD) simulation study has been performed to investigate the structural transition of nickel metal using Pak-Doyama potential. The local atomic structure was analyzed through the radial distribution function (RDF), coordination number distribution and 3D visualization. It was shown that the splitting of RDF second peak appears when the liquid transforms to amorphous solid. We found that the liquid state contains a significant amount of nano-crystalline nucleations, which strongly depends on the temperature and MD time steps. Accordingly, the simulation shows that the crystallization is originated from expanding of nano-crystalline nucleations.

Recycling plastic waste has been one of the most significant challenges in the recent decade. The reuse of one of the most produced cellular plastics (i.e. EPS) within a conventional construction binder can contribute, simultaneously, to waste elimination and improving energy performances of the building envelopes. This work investigates the recycling of expanded polystyrene (EPS) waste within a cement-based matrix. The aim is to develop a lightweight, energy-efficient composite for eco-construction. Portland cement was mixed with a small amount of gypsum (4 wt%) before adding EPS aggregates ranging from 0–0.6 wt%. The thermal properties were determined using two different non-destructive methods, the transient plane source technique (Hot Disk Method) and the Flash method. The experimental results showed a remarkable decrease of 54, 12, and 36% in thermal conductivity, thermal diffusivity, and density, respectively. These results indicate the improvement of thermal resistance of EPS...

This work is the first attempt to prepare microporous polytetrafluoroethylene (PTFE) fibrous layers embedded with aerogels/phase change materials. For preparation of this layer, the needle-less electrospray technology of water dispersion of individual components is used. Microstructure characteristics, including surface morphology and particle size distribution, and various properties of the prepared materials were investigated and explained. Transport performance of the fibrous layers embedded with aerogels/phase change materials, such as the transmission of heat, air, and water vapor was evaluated and discussed in details. It was found that the electro-sprayed materials composed by spherical particles with rough surface had compact disordered stacking structure. Aerogels and phase change materials (PCMs) play different roles in determining structural parameters and transport properties of the materials. Those parameters and properties could be flexibly adjusted by optimizing the s...

Linear focal Cherenkov ring camera (LFC-Camera) has been developed for single shot measurement of longitudinal phase space distribution of quasi-relativistic electron beam, where the electron’s velocity still depends on its energy. The LFC-camera employs velocity dependence of opening angle of Cherenkov light produced by electron beam to observe its energy (momentum) distribution. Since the Cherenkov light contains the time information if the radiator medium is thin enough, we can get the longitudinal phase space distribution measuring both time and energy spectra simultaneously using a streak camera. We employ a thin silica aerogel with water-free hydrophobic treatment as Cherenkov radiator. We have evaluated characteristics of the silica aerogel radiator, and demonstration of the LFC-camera at a beam diagnosis section of t-ATCS is being proceeded. LINEAR FOCAL CHERENKOV-RING CAMERA Concept and Principle A test accelerator for an intense coherent THz light source project (test Acce...

Rice husk is widely recognized as significant biomass containing cellulose, lignin and silica. Usually, rice husk is combusted for energy purposes but it contributes to severe environmental pollution. Therefore, the integrated components of rice husk (i.e. silica) can be extracted and converted into value-added products. However, the metallic impurities must be removed before further extraction. Generally, rice husk is leached with conventional acids such as HCl and nitric acid, however, the present study has used aqua regia and compared the results with conventional acids. The leached rice husk samples were characterized using TGA, SEM and EDX. The results of the present work indicate that the aqua regia carries a significant leaching potential to remove metallic impurities from rice husk with 1 M and 2 M solutions removing more than 98% and 99% of impurities respectively. However, its brief chemical stability compels it to be prepared and used immediately.

Brick is an essential material in the field of architecture and it has been the most widespread construction material for architectural constructions from past to present. This has led to continuous improvement in brick production. In this study, the aim is to inspect the effects of silica aerogel produced from boron waster to compressive strength and thermal performance of bricks. Firstly, silica aerogel was produced by using boron waste obtained from Turkey/Eskişehir/Kırka region. After, silica aerogel produced was mixed into the brick in different proportions, and was baked in 900 °C and 1000 °C to create mixed brick samples. Finally, samples produced was experimented with compressive strength and thermal conductivity coefficient and SEM images were taken. As a result, the increase of aerogel amount caused decrease in compressive strength and thermal conductivity coefficient values in both temperatures. It was observed that amorphous structure increased with the increase of silica aerogel and partial holes and cracks emerged in SEM images. Additionally, when compressive strength was used as basis, it was determined that AB1 sample could be used as holder, while AB2, AB3 and AB4 samples could be used as coating or back filling material in traditional structures. Use of wastes which contain silica such as boron waste in aerogel production is thought to be an appropriate solution for waste disposal.

Cenozoic tectonic-magmatic-metallogenic events in East Iran, Middle East and also in Lesser Caucasus (data by N.A. Imamverdiyev et al.) have some common similarities. Important geological -metallogenic +-OIL / HC correlation for the Alpine time exists (metallogeny of East Iran led by outstanding regional trio: E. Romanko, A. Houshmandzadeh, and M.A.A. Nogole-Sadat). Geological northeastern (NE) zoning and "hot" tectonics due to the African superplume activity including, probably, known delamination of lithosphere during collision of mantle lithosphere ca. 13 Ma is principal here. Intraplate alkaline-subalkaline rocks of the region studied including Quaternary real carbonatites of Hanneshin, Afghanistan were derived from enriched African superplume-related mantle sources being enriched in HFSE-Nb, Ta, Zr, Y, P, Ti. Late Cenozoic High-K calc-alkaline rocks in the Lesser Caucasus could be deal with African superplume activity too despite their subduction-related rock geochem-...

Following the trend of energy-efficient construction, renders with thermal insulation properties have been studied for replacing conventional renders. However, there are still few studies on the durability of these renders that may become a barrier for their implementation. In this study, the performance of lightweight renders for thermal insulation to accelerated aging cycles and freeze/thaw cycles is discussed. For this purpose, renders with regranulated expanded cork (GEC), silica aerogel (SA), and expanded polystyrene (EPS) were produced and tested for compressive strength, ultra-sound velocity, Young’s modulus, and thermal conductivity before and after accelerated aging cycles (hygrothermal, IR and freeze/thaw cycles). With this study, a comparison between the influence of different aggregates on renders is carried out in order to understand their effect on different properties of renders.