Dependence of the elastic moduli of porous silica gel prepared by the sol-gel method on heat-treatment

Adachi, Taiki; Sakka, Sumio

doi:10.1007/bf01129933

Cited by 78 publications

(57 citation statements)

References 16 publications

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“…However, they are typical for such SFB-type silica particles, as reported for sol-gel-derived hollow silica spheres and silica microcapsules by Zhang et al (2009Zhang et al ( , 2010 and submicron-sized silica spheres by Romeis et al (2012Romeis et al ( , 2014 and Paul et al (2015), respectively. In difference to this, Romeis et al (2014) and Paul et al (2015) reported E values of 71 ± 1.4 GPa for heat-treated SFB-type silica spheres approaching the values known for bulk fused silica (72-76 GPa) (Adachi and Sakka, 1990). Similar values of the E are observed by Paul et al (2015) from in situ compression experiments for 200 nm-sized vitreous silica spheres in the SEM and TEM with the e-beam blanked.…”

Section: Membranes In the Temsupporting

confidence: 49%

“…The σf of 5.4 GPa is slightly below values reported for silica glass fibers with comparable dimensions (Brambilla and Payne, 2009), but clearly exceeds tensile strength values reported for microscale silica fibers with E-glass (ranging from ~2.1 to 3.4 GPa) and basaltic glass compositions (ranging from ~1 to 4 GPa) (Lund and Yue, 2010). The E of 76 GPa is in the range of values known for bulk fused silica (Adachi and Sakka, 1990). Silva et al (2006) performed bending experiments on silica nanowires with diameters ranging from 280 to 1950 nm and observed values of E similar to ours (measured at beam-off conditions).…”

Section: Membranes In the Temmentioning

confidence: 52%

“…An E value of ~21 GPa is observed in case of low dose e-beam irradiation (beam current density of ~10 −4 A cm −2 ), while at e-beam irradiation with higher dose (beam current density of ~10 −2 A cm −2 ) an E of ~ 45 GPa is observed (Mačković et al, 2014). Also in this case, the E values of 21 and 45 GPa are significantly lower than the value known for bulk fused silica (72-76 GPa) (Adachi and Sakka, 1990). However, they are typical for such SFB-type silica particles, as reported for sol-gel-derived hollow silica spheres and silica microcapsules by Zhang et al (2009Zhang et al ( , 2010 and submicron-sized silica spheres by Romeis et al (2012Romeis et al ( , 2014 and Paul et al (2015), respectively.…”

Section: Membranes In the Temmentioning

confidence: 55%

“…After the first pulling cycle (at a strain of 25%), a tensile stress of 6.8 GPa is observed. The Young's modulus (E) of 49 GPa, which is evaluated from the linear fit in the low deformation regime of the engineering stress-strain curve, is clearly below values known for bulk fused silica (72-76 GPa) (Adachi and Sakka, 1990), most probably caused by the e-beam. Moreover, this E value of 49 GPa has to be interpreted with care, since e-beam irradiation in principle could induce plastic flow of silica glass already in the early stages of deformation.…”

Section: Membranes In the Temmentioning

confidence: 85%

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A Novel Approach for Preparation and In Situ Tensile Testing of Silica Glass Membranes in the Transmission Electron Microscope

et al. 2017

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The mechanical behavior of glasses in the micro-and nanometer regime increasingly gains importance in nowadays modern technology. However, suitable small-scale preparation and mechanical testing approaches for a reliable assessment of the mechanical properties of glasses still remain a big challenge. In the present work, a novel approach for site-specific preparation and quantitative in situ tensile testing of thin silica glass membranes in the transmission electron microscope (TEM) is presented. Thereby, advanced focused ion beam techniques are used for the preparation of nanoscale dog bone-shaped silica glass specimens suitable for in situ tensile testing. Small amounts of gallium are detected on the surface of the membranes resulting from redeposition effects during the focused ion beam preparation procedure. Possible structural changes of silica glass upon irradiation with electrons and gallium ions are investigated by controlled irradiation experiments, followed by a structural analysis using Raman spectroscopy. While moderate electron beam irradiation does not alter the structure of silica glass, ion beam irradiation results in minor densification of the silica glass membranes. In situ tensile testing of membranes under electron beam irradiation results in distinctive elongations without fracture confirming the phenomenon of superplasticity. In contrast, in situ tensile testing in the absence of the electron beam reveals an elastic/plastic deformation behavior and finally leads to fracture of the membranes. The Young's moduli of the glass membranes pulled at beam-off conditions in the TEM are comparable with values known for bulk fused silica, while the tensile strength is in the range of values reported for silica glass fibers with comparable dimensions. The impact of electron beam irradiation on the mechanical properties of silica glass membranes is further discussed. The results of the present work open new avenues for dedicated preparation and nanomechanical characterization of silica glass and further contribute to a fundamental understanding of the mechanical behavior of such glasses when being scaled down to the nanometer regime.

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Section: Membranes In the Temsupporting

confidence: 49%

Section: Membranes In the Temmentioning

confidence: 52%

Section: Membranes In the Temmentioning

confidence: 55%

Section: Membranes In the Temmentioning

confidence: 85%

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A Novel Approach for Preparation and In Situ Tensile Testing of Silica Glass Membranes in the Transmission Electron Microscope

et al. 2017

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“…71 Similar values have been reported for silica microcapsules. 72,73 The difference was attributed to production process of the silica particles.…”

Section: Deformation Behavior Of Silica Particlessupporting

confidence: 75%

A novel apparatus for in situ compression of submicron structures and particles in a high resolution SEM

Romeis

Paul

Ziener

et al. 2012

Review of Scientific Instruments

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We report on the development and characterization of a novel in situ manipulation device to perform stressing experiments on the submicron scale inside a high resolution field emission scanning electron microscope. The instrument comprises two main assembly groups: an upper part for positioning and moving a mounted probe and a force sensor as well as a specimen support as lower part. The upper part consists of a closed loop tripod piezoelectric scanner mounted on a self-locking coarse positioning stage. Two interlocked steel springs and a linear variable differential transformer measuring the springs’ deflections compose the lower part of the instrument. This arrangement acts as force-sensor and sample support. In comparison to already well-established concepts a wide measuring range is covered by adjusting the spring constant between 30 N/m and 50000 N/m. Moreover, the new device offers striking advantages with respect to force calibration and sample deformation measurements. Force calibration is performed using the eigenfrequency of the force detection system directly inside the SEM. Deformation data are obtained with high accuracy by simultaneously recording displacements above and below the specimen. The detrimental apparatus compliance is determined, and the influence on measured data subsequently minimized: an easy to validate two-springs-in-series model is used for data correction. A force resolution in normal direction of 100 nN accompanied by a sample deformation resolution of 5 nm can be achieved with the instrument using an appropriate load cell stiffness. The capabilities and versatility of this instrument are exemplified by compression experiments performed on submicron amorphous silica particles.

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Monodisperse Polymer Particles

Konno

Nagao

2014

Encyclopedia of Polymer Science and Technology

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This review summarizes recent advances in the synthesis of monodisperse polymer particles with polymerization in solutions. After introducing the monodisperse polymer particles and their potential applications, we first focused on common polymerization techniques for monodisperse polymer particles ranging from sub‐micrometers to micrometers. Among the techniques, soap‐free emulsion polymerization, which is a surfactant‐free heterogeneous polymerization in water without any organic solvents, was reviewed in detail from an environmentally friendly viewpoint. Then, soap‐free emulsion polymerizations for obtaining monodisperse polymer particles with hybrids or composite structures were discussed. Synthetic methods for functional, highly monodisperse composite particles such as fluorescent polymer particles and magnetic polymer particles are presented. It also includes preparations of anisotropic polymer particles such as dumbbell‐, snowman‐, rod‐, and raspberry‐shaped particles and particles having a depression. Finally, template applications of the composite particles with polymer‐removable methods for the creation of hollow or movable part in different shell shapes are discussed.

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Dependence of the elastic moduli of porous silica gel prepared by the sol-gel method on heat-treatment

Cited by 78 publications

References 16 publications

A Novel Approach for Preparation and In Situ Tensile Testing of Silica Glass Membranes in the Transmission Electron Microscope

A Novel Approach for Preparation and In Situ Tensile Testing of Silica Glass Membranes in the Transmission Electron Microscope

A novel apparatus for in situ compression of submicron structures and particles in a high resolution SEM

Monodisperse Polymer Particles

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