Hydrophobic Silica Aerogels

Anderson, Ann M.; Carroll, Mary K.

doi:10.1007/978-3-030-27322-4_14

Cited by 3 publications

(1 citation statement)

References 179 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The intrinsic microstructure of aerogels is similar to a three‐dimensional, open network of nanoparticles, and is often described as a “pearl necklace” configuration [2]. This unique microstructure gives aerogels exceptional properties such as a large specific surface area (

&gt;

1000 m

^2

/ g), low thermal conductivity(

&lt;

0.02 W/mk), and remarkably low density (

&lt;

0.05 g/cm

^3

) [3, 4]. However, this porous nature also leads to brittleness and limits their wider use beyond pure insulation applications.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the microstructural connectivity and compressive behavior of particle aggregated silica aerogels

Xiong,

Abdusalamov,

Itskov

et al. 2024

Proc Appl Math and Mech

View full text Add to dashboard Cite

Porous media such as aerogels can exhibit unique properties including low thermal conductivity, low bulk density, and low sound velocity. However, the limited mechanical properties of aerogels restrict their widespread application. This study focuses on understanding the mechanical behavior of aggregated silica aerogels by investigating their microstructural connectivity and densification mechanisms under uniaxial compression. The interparticle connectivity is generated using the diffusion‐limited cluster–cluster aggregation (DLCA) algorithm, and the particle connections are modeled by beam elements that account for contact interaction. The mechanical response of representative volume elements (RVEs) is analyzed in both linear and nonlinear regimes while applying periodic boundary conditions. The model is correlated with experimental compression test data to validate the simulation results. With increasing compressive strain, load transitions between multiple backbone paths appear in the network structure. Thus, the simulation model provides insight into the compression process. Moreover, the simulation model enables the examination of the influence of various model parameters and facilitates the evaluation of the power–law relationship between the elasticity modulus and porosity of aerogels.

show abstract

&gt;

1000 m

^2

/ g), low thermal conductivity(

&lt;

0.02 W/mk), and remarkably low density (

&lt;

0.05 g/cm

^3

) [3, 4]. However, this porous nature also leads to brittleness and limits their wider use beyond pure insulation applications.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the microstructural connectivity and compressive behavior of particle aggregated silica aerogels

Xiong,

Abdusalamov,

Itskov

et al. 2024

Proc Appl Math and Mech

View full text Add to dashboard Cite

show abstract

Mesoscopic structure modeling of silica aerogels using cluster‐cluster aggregation

Xiong,

Abdusalamov,

Itskov

2024

Proc Appl Math and Mech

View full text Add to dashboard Cite

Silica aerogels are nanostructured materials known for their low density, high porosity, and excellent thermal insulation properties. Among silica aerogels, organosilane‐derived aerogels have received considerable interest for their additional chemical functionalities such as hydrophobicity and flexibility. This work investigates the mesoscopic modeling of such aerogels, extending an aggregation based model developed for conventional silica aerogels. The pH of sol–gel polymerizations is one of the most critical reaction and processing parameters in determining the porosity, density, strength, and transparency of the resulting gels. Achieving optical transparency in aerogels depends on the presence of homogeneous mesoporous network structures. To account for the effect of pH, a relationship between pH and adhesion probability was incorporated into a three‐dimensional cluster‐cluster aggregation (CCA) model, providing insight into the gelation process. In addition, size‐dependent diffusivities are considered in this study. By incorporating different factors into the CCA model, the gelation kinetics are evaluated. The obtained mesoscopic structure is compared with experimental characterizations, together with preliminary mechanical simulations.

show abstract

Rapid Aerogel Fabrication Facilitates a Range of Applications

Anderson,

Carroll

2024

Preprint

View full text Add to dashboard Cite

Rapid supercritical extraction (RSCE) methods for the preparation of aerogel materials have advantages over other methods of aerogel fabrication, including significantly shorter timescales from mixing chemicals to obtaining aerogels and lower chemical waste; however, they are not employed widely. In this retrospective article, three RSCE methods that have been used for preparation of monolithic silica aerogel are described. Each involves placing a gel precursor mixture into a contained mold and bringing the temperature and pressure inside the mold above the critical point of the solvent in the pores of the wet gel. The RSCE method that uses a contained mold and a hydraulic hot press has also been employed for preparation of a variety of types of aerogel. Its use in development of aerogel-based windows, in applications in which dopants are readily incorporated into aerogels, and in preparation of aerogels with curvilinear shapes are emphasized. Advantages as well as limitations of RSCE methods are discussed.

show abstract

Hydrophobic Silica Aerogels

Cited by 3 publications

References 179 publications

Analysis of the microstructural connectivity and compressive behavior of particle aggregated silica aerogels

Analysis of the microstructural connectivity and compressive behavior of particle aggregated silica aerogels

Mesoscopic structure modeling of silica aerogels using cluster‐cluster aggregation

Rapid Aerogel Fabrication Facilitates a Range of Applications

Contact Info

Product

Resources

About