scholarly journals Aerogel, a high performance material for thermal insulation - A brief overview of the building applications

2019 ◽  
Vol 111 ◽  
pp. 06069 ◽  
Author(s):  
Larisa Meliță ◽  
Cristiana Croitoru
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
High Performance ◽  
Sol Gel ◽  
Research Work ◽  
Solid Material ◽  
Good Choice ◽  
High Price ◽  
Material Structure ◽  
Liquid Component

In this paper data regarding the utilization of aerogel as a promising material for thermal insulation of the residential and commercial buildings are presented. Also, research work and developments in synthesis, properties and characterization of silica aerogels will be addressed. Aerogel is a synthetic porous ultralight material derived from a gel in which the liquid component of the gel has been replaced with a gas. The result is a solid with extremely low density and low thermal conductivity. Sol-gel is the most used method of preparation. Aerogel melts at 1200ºC and the thermal conductivity is almost 0. Is a solid material with the smallest density because contains about 99.8% air. This material has almost unlimited potential, believing that they might find application in most human activities and areas. Aerogel insulation is a good choice because nearly neutralizes all three methods of heat transfer: convection, conduction and radiation. The resistance to convective transfer is given by the fact that air does not circulate in the material structure. The resistance to thermal transfer by conduction is given by the majority of gaseous components. If using a carbon based gel, a high resistance to radiation transfer is obtained. Therefore, the most used aerogel for thermal insulation is the silica aerogel with carbon as nanostructured material. The high price makes it currently inaccessible and less used material. But, inevitably, the aerogel will quickly become one of the most attractive materials in the future.

scholarly journals Properties and Microstructure Distribution of High-Performance Thermal Insulation Concrete

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2091 ◽  
Author(s):  
Malek Mohammad ◽  
Eyad Masad ◽  
Thomas Seers ◽  
Sami G. Al-Ghamdi
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Insulation ◽  
High Performance ◽  
Lightweight Concrete ◽  
Concrete Mixture ◽  
Unit Weight ◽  
Expanded Perlite ◽  
Micro Computed Tomography ◽  
Structural Applications

The aim of this experimental study is to develop high strength and lightweight concrete mixture suitable for structural applications. This work investigates the effect of replacing normal aggregate either partially or totally with expanded perlite aggregate. This material allows for better thermal insulation properties, thus decreasing the energy usage within the life cycle of the concrete structure. Expanded perlite aggregate was used in concrete by 20%, 40%, 60%, 80%, and 100% in replacement of the natural aggregate. Material characterization tests of compressive strength, flexural strength, and thermal conductivity were carried out for six concrete mixtures. In addition, microstructure analysis was performed with the aid of a micro-computed tomography system to investigate the effects and relation of microstructure quantities on material properties. The proposed concrete mixture, which has 100% of expanded perlite aggregate, has a unit weight of 1703 kg/m3 and achieved reduction percentage of thermal conductivity around 62% (1.81 to 0.69 W·m−1·K−1) and a compressive strength of 42 MPa at 28 days; and thus is ideal for structural applications with enhanced properties.

scholarly journals Ag-NPs/MWCNT composite-modified silver-epoxy paste with improved thermal conductivity

RSC Advances ◽  
2019 ◽  
Vol 9 (36) ◽  
pp. 20663-20669 ◽  
Author(s):  
Yanchao Li ◽  
Guoyou Gan ◽  
Yukuan Huang ◽  
Xianglei Yu ◽  
Junhua Cheng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Performance ◽  
Heat Dissipation ◽  
Critical Issue ◽  
Good Choice ◽  
Ag Nps ◽  
Silver Epoxy ◽  
Electronic Paste

Heat dissipation is a critical issue in high-performance electronics, which needs to be solved, and an electronic paste is a good choice to solve this issue.

Orthogonal Experimental Study on Thermal Insulation Mortar Containing Mixed Ceramic Sand and Vitrified Micro Bead Aggregates

2012 ◽  
Vol 450-451 ◽  
pp. 659-662
Author(s):  
Zhi Lling Xie ◽  
Lin Zhu Sun ◽  
Fang Yang
Keyword(s):  
Thermal Conductivity ◽  
Experimental Study ◽  
Compressive Strength ◽  
Thermal Insulation ◽  
High Performance ◽  
Orthogonal Experiments ◽  
Coefficient Of Thermal Conductivity ◽  
Mixed Ceramic ◽  
Relevant Factors ◽  
Density Coefficient

Mixed light aggregates can effectively reduce the coefficient of thermal conductivity of composite materials. Through orthogonal experiments of thermal insulation mortar containing mixed ceramic sand and vitrified micro bead aggregates, we analyzed the law of influence of relevant factors on the dry bulk density, coefficient of thermal conductivity and compressive strength of mortar containing mixed ceramic sand and vitrified micro bead aggregates and provided basic data for further improvement of such thermal insulation mortar so as to promote the development and application of high performance thermal insulation materials.

Possibilities of Using Natural Fibres for Production of Particular Insulation for Use in Civil Engineering

2015 ◽  
Vol 1124 ◽  
pp. 111-116
Author(s):  
Martina Reif ◽  
Jitka Peterková ◽  
Jiri Zach
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Civil Engineering ◽  
Research Work ◽  
Natural Fibers ◽  
Cellulose Fibers ◽  
Natural Fibres ◽  
Insulation Materials ◽  
Bast Fibers

The paper deals with the development options of particular insulation based on a blend of recycled cellulose fibers and natural (mainly) bast fibers. The paper presents the results of research work in the field of addiction thermal insulation, acoustic and mechanical properties of experimentally produced insulators on density..Keywords: Natural fibers, thermal conductivity, insulation materials, straw, fibreboard, cellulose fibers

scholarly journals Development of lightweight structural concrete with the use of aggregates based on foam glass

2021 ◽  
Vol 1205 (1) ◽  
pp. 012014
Author(s):  
J Zach ◽  
J Bubeník ◽  
M Sedlmajer
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Lightweight Concrete ◽  
Foam Glass ◽  
Research Work ◽  
Acoustic Properties ◽  
Added Value ◽  
Glass Waste ◽  
Recycled Glass ◽  
Foamed Glass

Abstract Lightweight concretes are increasingly being used in the construction industry, either for the overall lightweighting of the structure itself, reducing material consumption for construction and thus CO2 emissions, or for specific reasons such as improving the thermal insulation properties of the structure or acoustic properties. Today, lightweight concretes with lightweight expanded aggregates (expanded clay, agloporite) are most commonly used. This paper deals with the production of lightweight concretes lightweighted with foamed glass-based aggregates. Foamed glass is a lightweight material characterised by a very good ratio of thermal insulation and mechanical properties. Foamed glass is made of approximately 90% recycled glass waste (mostly mixed), which cannot be used in any other way, as well as water glass and glycerine. When concrete is lightened with foamed glass, these concretes achieve unique properties while conserving primary aggregate resources, avoiding landfilling of glass waste and efficiently using the waste material to produce lightweight concrete with higher added value. The paper discusses the possibilities of developing lightweight structural concretes using glass foam-based aggregates to achieve higher strength classes while reducing the weight and thermal conductivity of the concrete. As part of the research work, new types of lightweight concrete with a bulk density in the range of 1750–1930 kg/m3 and a thermal conductivity from 0.699 to 0.950 W/(m·K) were developed.

Robust and superhydrophobic thiourethane bridged polysilsesquioxane aerogels as potential thermal insulation materials

2016 ◽  
Vol 4 (28) ◽  
pp. 10801-10805 ◽  
Author(s):  
Fangxin Zou ◽  
Peng Yue ◽  
Xinghua Zheng ◽  
Dawei Tang ◽  
Wenxin Fu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Sol Gel ◽  
Vacuum Drying ◽  
Drying Method ◽  
Low Thermal Conductivity ◽  
Insulation Materials ◽  
Sol Gel Process ◽  
Bridged Polysilsesquioxane

Novel thiourethane bridged polysilsesquioxane aerogels prepared by a sol–gel process and vacuum drying method exhibit extraordinary mechanical properties and low thermal conductivity.

Fabrication of Infrared Opacifiers Loaded Al2O3 Aerogel-SiO2 Fiber Mat Composites with High Thermal Resistance

2020 ◽  
Vol 19 (03) ◽  
pp. 1950021
Author(s):  
Shangyan Wen ◽  
Jiayi Zhu ◽  
Qiang Yin ◽  
Yutie Bi ◽  
Hongbo Ren ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Thermal Insulation ◽  
Sol Gel ◽  
Doping Content ◽  
Low Thermal Conductivity ◽  
Sic Particles ◽  
Sol Gel Process ◽  
High Thermal Resistance ◽  
Insulation Performance

The infrared opacifiers loaded Al2O3 aerogel-SiO2 fiber mat composites were fabricated by the sol–gel process. The effects of the content of the TiO2 and SiC particles on thermal insulation performance of the Al2O3 aerogel-SiO2 fiber mat composites were studied. The results showed that the optimum doping content of TiO2 and SiC for Al2O3 aerogel-SiO2 fiber mat composites were 10[Formula: see text]mol.% and 0.5[Formula: see text]mol.%, respectively. The optimum TiO2-Al2O3 aerogel-SiO2 fiber mat composite had the low thermal conductivity of 0.021[Formula: see text]W/(m[Formula: see text][Formula: see text][Formula: see text]K) at 35∘C and 0.031[Formula: see text]W/(m[Formula: see text][Formula: see text][Formula: see text]K) at 600∘C. Meanwhile, the SiC-Al2O3 aerogel-SiO2 fiber mat composite also had the low thermal conductivity of 0.022[Formula: see text]W/(m[Formula: see text][Formula: see text][Formula: see text]K) at 35∘C and 0.025[Formula: see text]W/(m[Formula: see text][Formula: see text][Formula: see text]K) at 600∘C.

Chemical Synthesis of Fine Powders

MRS Bulletin ◽  
1990 ◽  
Vol 15 (1) ◽  
pp. 18-25 ◽  
Author(s):  
J. Livage ◽  
M. Henry ◽  
J.P. Jolivet ◽  
C. Sanchez
Keyword(s):  
High Performance ◽  
Colloidal Particles ◽  
Sol Gel ◽  
Solid Material ◽  
Narrow Particle Size Distribution ◽  
Molecular Precursors ◽  
Inorganic Oxides ◽  
Fine Powders ◽  
Sol Gel Process ◽  
Gel Processing

Interest in the synthesis of submicron monodispersed powders is increasing. Such powders find applications in the ceramic industry when high performance materials are required. Sintering time and temperature can be significantly reduced with powders of narrow particle-size distribution. Fine colloidal particles can be made by a variety of methods, from the vapor phase or the liquid phase.The sol gel process offers new approaches to the synthesis of fine powders. Starting from molecular precursors, such as metal alkoxides or aqueous solutions, an oxide network is obtained via inorganic polymerization reactions. These reactions occur in solution, and the term “sol-gel processing” is often used to describe the synthesis of inorganic oxides by wet chemical methods. It offers many advantages compared to the conventional powder route. One unique advantage is the ability to go all the way from the molecular precursor to the solid material, permitting better control of the entire process and allowing synthesis of “tailor-made” powders.

scholarly journals Effects of the Heat Treatment in the Properties of Fibrous Aerogel Thermal Insulation

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 2001 ◽  
Author(s):  
Ákos Lakatos ◽  
Attila Csík ◽  
Anton Trník ◽  
István Budai
Keyword(s):  
Thermal Conductivity ◽  
Heat Treatment ◽  
Thermal Annealing ◽  
Thermal Insulation ◽  
Structural Changes ◽  
Glass Fibers ◽  
Material Structure ◽  
Scanning Calorimetry ◽  
Plastic Foams ◽  
Isothermal Heat Treatments

Nowadays, besides the use of conventional insulations (plastic foams and wool materials), aerogels are one of the most promising thermal insulation materials. As one of the lightest solid materials available today, aerogels are manufactured through the combination of a polymer with a solvent, forming a gel. For buildings, the fiber-reinforced types are mainly used. In this paper, the changes both in the thermal performance and the material structure of the aerogel blanket are followed after thermal annealing. The samples are put under isothermal heat treatments at 70 °C for weeks, as well as at higher temperatures (up to 210 °C) for one day. The changes in the sorption properties that result from the annealing are presented. Furthermore, the changes in the thermal conductivity are followed by a Holometrix Lambda heat flow meter. The changes in the structure and surface of the material due to the heat treatment are investigated by X-ray diffraction and with scanning electron microscopy. Besides, the above-mentioned measurement results of differential scanning calorimetry experiments are also presented. As a result of using equipment from different laboratories that support each other, we found that the samples go through structural changes after undergoing thermal annealing. We manifested that the aerogel granules separate down from the glass fibers and grow up. This phenomenon might be responsible for the change in the thermal conductivity of the samples.

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