scholarly journals Instrumented Indentation of Super-Insulating Silica Compacts

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 830 ◽  
Author(s):  
Belynda Benane ◽  
Sylvain Meille ◽  
Geneviève Foray ◽  
Bernard Yrieix ◽  
Christian Olagnon
Keyword(s):  
Mechanical Properties ◽  
Porous Silica ◽  
Silica Aerogels ◽  
Spherical Indentation ◽  
Porous Structures ◽  
Instrumented Indentation ◽  
Multi Scale ◽  
Precipitated Silica ◽  
Highly Porous ◽  
Porosity Fraction

Highly porous silica compacts for superinsulation were characterized by instrumented indentation. Samples showed a multi-scale stacking of silica particles with a total porous fraction of 90 vol %. The two main sources of silica available for the superinsulation market were considered: fumed silica and precipitated silica. The compacts processed with these two silica displayed different mechanical properties at a similar porosity fraction, thus leading to different usage properties, as the superinsulation market requires sufficient mechanical properties at the lowest density. The measurement of Young’s modulus and hardness was possible with spherical indentation, which is an efficient method for characterizing highly porous structures. Comparison of the mechanical parameters measured on silica compacts and silica aerogels available from the literature was made. Differences in mechanical properties between fumed and precipitated compacts were explained by structural organization.

scholarly journals Enhancing Density-Based Mining Waste Alkali-Activated Foamed Materials Incorporating Expanded Cork

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 523-540
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Pore Size ◽  
Physical And Mechanical Properties ◽  
Critical Parameters ◽  
Porous Structures ◽  
Foaming Agent ◽  
Al Powder ◽  
Highly Porous ◽  
Alkali Activated

This study focuses on the development of an alkali-activated lightweight foamed material (AA-LFM) with enhanced density. Several mixes of tungsten waste mud (TWM), grounded waste glass (WG), and metakaolin (MK) were produced. Al powder as a foaming agent was added, varying from 0.009 w.% to 0.05 w.% of precursor weight. Expanded granulated cork (EGC) particles were incorporated (10% to 40% of the total volume of precursors). The physical and mechanical properties of the foamed materials obtained, the effects of the amount of the foaming agent and the percentage of cork particles added varying from 10 vol.% to 40% are presented and discussed. Highly porous structures were obtained, Pore size and cork particles distribution are critical parameters in determining the density and strength of the foams. The compressive strength results with different densities of AA-LFM obtained by modifying the foaming agent and cork particles are also presented and discussed. Mechanical properties of the cured structure are adequate for lightweight prefabricated building elements and components.

scholarly journals Expansion volume of alkali activated foamed cork composites from tungsten mining mud waste with aluminium

2019 ◽  
Vol 274 ◽  
pp. 03002
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes ◽  
Haroon Ihsan ◽  
John Pickstone ◽  
Nuno Estrada
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical And Mechanical Properties ◽  
Mechanical And Thermal Properties ◽  
Porous Structures ◽  
Expansion Process ◽  
Foaming Agent ◽  
Al Powder ◽  
Highly Porous ◽  
Alkali Activated

Several mixes of alkali activated foams from tungsten mud waste (MW), grounded glass (GG) and metakaolin (MK) were developed incorporating expanded granulated cork (EGC). This study presents preliminary results of the expansion process obtained with the addition of aluminium (AL) powder as a foaming agent. 0.3 wt.%, 0.4 wt.% to 0.5wt.% of AL powder were added to the alkali activated matrix. The physical and mechanical properties of the obtained foams, the effects of the type and amount of the foaming agent added are presented and discussed. Highly porous structures were obtained, with overall expansion up to 68.2% when the AL powder was added. The size and distribution of pores are shown. The compressive strength of foams in the case of highly porous structures achieved of 1.2 MPa for the samples containing 0.5 wt.% of AL powder. Mechanical and thermal properties of the cured structure are good and can therefore be used for applications in acoustic panels and lightweight prefabricated components for thermal insulation purposes.

Bimetallic FeCo Nanocrystals Supported on Highly Porous Silica Aerogels as Fischer–Tropsch Catalysts

2012 ◽  
Vol 142 (9) ◽  
pp. 1061-1066 ◽  
Author(s):  
Danilo Loche ◽  
Maria F. Casula ◽  
Anna Corrias ◽  
Sergio Marras ◽  
Pietro Moggi
Keyword(s):  
Porous Silica ◽  
Silica Aerogels ◽  
Fischer Tropsch ◽  
Highly Porous

Structural modifications of highly porous silica aerogels upon densification

1991 ◽  
Vol 24 (5) ◽  
pp. 781-787 ◽  
Author(s):  
A. Emmerling ◽  
R. Gerlach ◽  
R. Goswin ◽  
J. Gross ◽  
G. Reichenauer ◽  
...  
Keyword(s):  
Porous Silica ◽  
Silica Aerogels ◽  
Structural Modifications ◽  
Highly Porous

scholarly journals Hybrid Silica-Based Fillers in Nanocomposites: Influence of Isotropic/Isotropic and Isotropic/Anisotropic Fillers on Mechanical Properties of Styrene-Butadiene (SBR)-Based Rubber

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2413
Author(s):  
Mariapaola Staropoli ◽  
Vincent Rogé ◽  
Enzo Moretto ◽  
Joffrey Didierjean ◽  
Marc Michel ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Silica Nanoparticles ◽  
Synergetic Effect ◽  
Mechanical Analysis ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Precipitated Silica ◽  
Scanning Transmission ◽  
Styrene Butadiene

The improvement of mechanical properties of polymer-based nanocomposites is usually obtained through a strong polymer–silica interaction. Most often, precipitated silica nanoparticles are used as filler. In this work, we study the synergetic effect occurring between dual silica-based fillers in a styrene-butadiene rubber (SBR)/polybutadiene (PBD) rubber matrix. Precipitated Highly Dispersed Silica (HDS) nanoparticles (10 nm) have been associated with spherical Stöber silica nanoparticles (250 nm) and anisotropic nano-Sepiolite. By imaging filler at nano scale through Scanning Transmission Electron Microscopy, we have shown that anisotropic fillers align only in presence of a critical amount of HDS. The dynamic mechanical analysis of rubber compounds confirms that this alignment leads to a stiffer nanocomposite when compared to Sepiolite alone. On the contrary, spherical 250 nm nanoparticles inhibit percolation network and reduce the nanocomposite stiffness.

A facile method to fabricate monolithic alumina–silica aerogels with high surface areas and good mechanical properties

2020 ◽  
Vol 40 (6) ◽  
pp. 2480-2488 ◽  
Author(s):  
Fei Peng ◽  
Yonggang Jiang ◽  
Junzong Feng ◽  
Liangjun Li ◽  
Huafei Cai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Surface ◽  
Silica Aerogels ◽  
Surface Areas ◽  
Monolithic Alumina
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