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 ◽  
...  

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

2020 ◽  
Vol 19 (03) ◽  
pp. 1950021
Author(s):  
Shangyan Wen ◽  
Jiayi Zhu ◽  
Qiang Yin ◽  
Yutie Bi ◽  
Hongbo Ren ◽  
...  

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.


Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3287
Author(s):  
Indra Mawardi ◽  
Sri Aprilia ◽  
Muhammad Faisal ◽  
Samsul Rizal

Oil palm wood is the primary biomass waste produced from plantations, comprising up to 70% of the volume of trunks. It has been used in non-structural materials, such as plywood, lumber, and particleboard. However, one aspect has not been disclosed, namely, its use in thermal insulation materials. In this study, we investigated the thermal conductivity and the mechanical and physical properties of bio-insulation materials based on oil palm wood. The effects of hybridization and particle size on the properties of the panels were also evaluated. Oil palm wood and ramie were applied as reinforcements, and tapioca starch was applied as a bio-binder. Panels were prepared using a hot press at a temperature of 150 °C and constant pressure of 9.8 MPa. Thermal conductivity, bending strength, water absorption, dimensional stability, and thermogravimetric tests were performed to evaluate the properties of the panels. The results show that hybridization and particle size significantly affected the properties of the panels. The density and thermal conductivity of the panels were in the ranges of 0.66–0.79 g/cm3 and 0.067–0.154 W/mK, respectively. The least thermal conductivity, i.e., 0.067 W/mK, was obtained for the hybrid panels with coarse particles at density 0.66 g/cm3. The lowest water absorption (54.75%) and thickness swelling (18.18%) were found in the hybrid panels with fine particles. The observed mechanical properties were a bending strength of 11.49–18.15 MPa and a modulus of elasticity of 1864–3093 MPa. Thermogravimetric analysis showed that hybrid panels had better thermal stability than pure panels. Overall, the hybrid panels manufactured with a coarse particle size exhibited better thermal resistance and mechanical properties than did other panels. Our results show that oil palm wood wastes are a promising candidate for thermal insulation materials.


2015 ◽  
Vol 1124 ◽  
pp. 111-116
Author(s):  
Martina Reif ◽  
Jitka Peterková ◽  
Jiri Zach

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


Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 823 ◽  
Author(s):  
Ákos Lakatos ◽  
Anton Trník

Nowadays, the usage of thermal insulation materials is widespread not only in the building sector but also in the vehicle industry. The application of fibrous or loose-fill insulation materials like glass wool or mineral wool as well as aerogel is well known. Aerogel-based materials are among the best solid materials for thermal insulation available today; they are prepared through a sol–gel process. For building walls, the glass-fiber-enhanced types are the frequently used ones. They are prepared by adding the liquid–solid solution to the fibrous batting, which is called a sol–gel process. In the present paper, the changes in the most important building physical properties of aerogel blankets after thermal annealing are presented. The samples were subjected to isochronal heat treatments from 70 to 210 °C for 24 h. The changes in the thermal conductivity were followed by Holometrix Lambda heat flow meter, and differential scanning calorimetry results were also recorded. From the measured values, together with the densities, the most important thermal properties were calculated, such as thermal resistance, diffusivity, effusivity (heat absorption), and thermal inertia. In this paper, we attempt to clarify the role played by thermal annealing in the transient thermal properties of aerogel materials. Besides presenting the measurement results, a theoretical background is given. The investigations of not only the steady-state but also the transient thermal parameters of the materials are momentous at the design stage.


2014 ◽  
Vol 541-542 ◽  
pp. 141-145
Author(s):  
Bo Liu ◽  
Shou De Wang ◽  
Shuai Yang ◽  
Chen Chen Gong ◽  
Ling Chao Lu

Cement-based foam insulation board is a lightweight thermal insulation and have a characteristic of energy saving. The effects of material constitution on the properties of mechanical properties, dry densityand thermal conductivity for thermal insulation materials. The subject of fast hardening sulphoaluminate cement as cementitious materials, polystyrene particles as a lightweight thermal insulation material, adding a certain amount of water reducer, cellulose ethers, air entraining agent to make thermal insulation materials. The experimental results shows that the appropriate material constitution is following: the cement-bead ratio is 12, the ratio is 0.65, the water-cement ratio is 0.4, the content of water reducer is 0.5%, the content of cellulose ether is 0.4%, the content of the air entraining agent is 0.4% .This mix ratio test of mechanical properties are: flexural strength is 0.72MPa, compressive strength is 1.24MPa, dry density is 375kg/m3, water content is 2.3%, water absorption is 10.8%, softening coefficient is 0.95 and coefficient of thermal conductivity is 0.053 W/ (m K).


2017 ◽  
Vol 873 ◽  
pp. 153-157 ◽  
Author(s):  
Jia Jiu Diao ◽  
Xin Qin Liao ◽  
Can Fa Diao

The use of performance, application status and existing problems of organic and inorganic thermal insulation materials, which are commonly used in the external walls of the building, are described in detail in this paper. Organic thermal insulation materials with low thermal conductivity, good thermal insulation performance, but with the flammable, low fire rating, poor safety, then it needing for flame retardant treatment. However, Inorganic thermal insulation materials with flame retardant, high fire rating, good safety performance, but poor thermal insulation properties than the organic insulation materials, so it needs to develop a low thermal conductivity of inorganic insulation materials.In the end, we pointed out that the inorganic insulation materials with low thermal conductivity and excellent comprehensive properties are expected to be the first choice for building thermal insulation materials.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3310
Author(s):  
Santu Golder ◽  
Ramadas Narayanan ◽  
Md. Rashed Hossain ◽  
Mohammad Rofiqul Islam

Reducing building energy consumption is a significant challenge and is one of the most important research areas worldwide. Insulation will help to keep the building’s desired temperature by reducing the heat flow. Additionally, proper insulation can provide an extended period of comfort, leading to reduced building energy requirements. Encapsulated air is the major aspect of most thermal insulation materials. Low thermal conductivity is a good characteristic of thermal insulation materials. Aerogel has low thermal conductivity, so it is suitable for glazing and insulation purposes. This research paper investigates the effectiveness of aerogel as an insulation material in buildings by incorporating a translucent aerogel-glazing system in the window and aerogel insulation in the wall of a building. Experimental investigation of a 10 mm thick aerogel blanket surrounded box was conducted to assess its performance. Additionally, a CFD simulation was conducted, and the results of temperature degradation for the wall showed good agreement with experimental results. Additionally, the CFD simulation of temperature decay was compared between the aerogel-glazed window and argon-glazed window. It was found that the aerogel-glazed window has slower temperature decay compared to the argon-glazed window. The results showed that integrating aerogel in the glazing system and wall insulation in a building has the potential to reduce the building’s energy consumption. Moreover, a numeric simulation was conducted, and showed that the building’s annual energy consumption is reduced by 6% with the use of aerogel insulation compared to fiberglass.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Huijun Wu ◽  
Yantao Chen ◽  
Qiliang Chen ◽  
Yunfei Ding ◽  
Xiaoqing Zhou ◽  
...  

Flexible silica aerogel composites in intact monolith of 12 cm were successfully fabricated by reinforcing SiO2aerogel with electrospun polyvinylidene fluoride (PVDF) webs via electrospinning and sol-gel processing. Three electrospun PVDF webs with different microstructures (e.g., nanofibers, microparticles, and combined nanofibers and microparticles) were fabricated by regulating electrospinning parameters. The as-electrospun PVDF webs with various microstructures were impregnated into the silica sol to synthesize the PVDF/SiO2composites followed by solvent exchange, surface modification, and drying at ambient atmosphere. The morphologies of the PVDF/SiO2aerogel composites were characterized and the thermal and mechanical properties were measured. The effects of electrospun PVDF on the thermal and mechanical properties of the aerogel composites were evaluated. The aerogel composites reinforced with electrospun PVDF nanofibers showed intact monolith, improved strength, and perfect flexibility and hydrophobicity. Moreover, the aerogel composites reinforced with the electrospun PVDF nanofibers had the lowest thermal conductivity (0.028 W·m−1·K−1). It indicates that the electrospun PVDF nanofibers could greatly improve the mechanical strength and flexibility of the SiO2aerogels while maintaining a lower thermal conductivity, which provides increasing potential for thermal insulation applications.


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