Cellulosic and Polyurethane Aerogels

Rigacci, Arnaud; Achard, Patrick

doi:10.1007/978-1-4419-7589-8_10

Cited by 12 publications

(4 citation statements)

References 64 publications

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“…We initially investigated the effect of solvent composition on aerogel properties for different DMSO–acetone mixtures where X DMSO is the volume fraction of DMSO in the solvent mixture, both common solvents for isocyanate based aerogel synthesis . The samples prepared in solvents with X DMSO < 7.5% displayed precipitation rather than gelation, and no aerogels could be prepared.…”

Section: Resultsmentioning

confidence: 99%

“…Most industrial aprotic solvents have lower δ H-bonding parameters (Table 1) and the requirement for a high δ H-bonding parameter imposes the use of DMSO or THF (Table 1), or an alternative solvent with high δ H-bonding , as part of the solvent blend. The observation that other studies on polyurethane aerogels also use solvent blends containing either DMSO or THF 17 may indicate that our optimum solvent systems may also be useful for related PUR or PUR−PIR formulations. However, a Hansen solubility parameter study for polyurea aerogels identified solvent systems with δ H-bonding between 3 and 5 MPa 1/2 as optimal, 22 in stark contrast to our data on the PUR−PIR system.…”

Section: Acs Applied Materials and Interfacesmentioning

confidence: 96%

“…Aerogels are low-density, open-porous, predominantly mesoporous solids with a wide range of application in thermal insulation, , catalysis, − oil-spill cleanup, CO 2 capture, − etc. Aerogels can be prepared from a wide variety of materials such as silica, , polyurethane, − polyurea, − polyimide, biopolymers, ,, graphene, carbon nanotubes, various metals, , and hybrids thereof. − Many aerogels are thermal superinsulators with a thermal conductivity (λ) lower than that of standing air (26 mW·m –1 ·K –1 ) because the pore sizes are small compared to the mean free path length of air (70 nm at ambient temperature), limiting heat conduction through the gas phase. In addition, the low solid fraction and the nanostructure and tortuosity of the skeleton limit the solid-state conduction.…”

Section: Introductionmentioning

confidence: 99%

“…On the order of 10 5 m 3 of silica aerogel are produced annually by a range of producers in the form of powders, granulate, and blankets, mostly for thermal insulation applications. Silica aerogels are also by far the most studied system academically, and the gelation, aging, hydrophobization, and drying steps are well understood. , Polyisocyanate based aerogels are arguably the second most investigated system − and a recent target for commercialization (e.g., Slentite by BASF and Airloy by Aerogel Technologies). Compared to silica, polyisocyanate based aerogels offer improved mechanical properties and a subsequently lower dust release but typically have a somewhat higher thermal conductivity.…”

Section: Introductionmentioning

confidence: 99%

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Superinsulating Polyisocyanate Based Aerogels: A Targeted Search for the Optimum Solvent System

Zhu

Snellings²,

Koebel

et al. 2017

ACS Appl. Mater. Interfaces

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Polyisocyanate based aerogels combine ultralow thermal conductivities with better mechanical properties than silica aerogel, but these properties critically depend on the nature of the gelation solvent, perhaps more so than on any other parameter. Here, we present a systematic study of the relationship between the polyurethane-polyisocyanurate (PUR-PIR) aerogel microstructure, surface area, thermal conductivity, and density and the gelation solvent's Hansen solubility parameters for an industrially relevant PUR-PIR rigid foam formulation. We first investigated aerogels prepared in acetone-dimethyl sulfoxide (DMSO) blends and observed a minimum in thermal conductivity (λ) and maximum in specific surface area for an acetone:DMSO ratio of 85:15 v/v. We then prepared PUR-PIR aerogels in 32 different solvent blends, divided into three series with δ, δ, and δ fixed at 15.94, 11.30, and 7.48 MPa, respectively, corresponding to the optimum parameters for the acetone:DMSO series. The aerogel properties display distinct dependencies on the various solubility parameters: aerogels with low thermal conductivity can be synthesized in solvents with a high δ parameter (above 7.2) and δ around 16.3 MPa. In contrast, the δ parameter is of lesser importance. Our study highlights the importance of the gelation solvent, clarifies the influence of the different solvent properties, and provides a methodology for a targeted search across the solvent chemical space based on the Hansen solubility parameters.

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Section: Resultsmentioning

confidence: 99%

Section: Acs Applied Materials and Interfacesmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Superinsulating Polyisocyanate Based Aerogels: A Targeted Search for the Optimum Solvent System

Zhu

Snellings²,

Koebel

et al. 2017

ACS Appl. Mater. Interfaces

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Silica Aerogels

Malfait¹,

Wernery²,

Zhao³

et al. 2021

Encyclopedia of Glass Science, Technology, History, and Culture

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Hierarchical Assembly of Surface Modified Silk Fibroin Biomass into Micro‐, and Milli‐Metric Hybrid Aerogels with Core‐Shell, Janus, and Composite Configurations for Rapid Removal of Water Pollutants

Bruder

Ludwig

Opitz

et al. 2021

Adv Materials Inter

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Multifunctional aerogels, with intriguing micro‐morphologies and macroscopic sizes, are fabricated for the first time from silk fibroin (SF) biopolymer extracted from Bombyx mori silkworm cocoon to optimize the adsorption performances of heavy metal ions and soluble organic pollutants. By a synergistic combination of approaches such as surface‐modification of SF with polyethyleneimine (PEI) and its hierarchical cryo‐assembly with graphene oxide into various macrostructures, namely core‐shell, composite, and Janus, series of millimetric aerogels (2–3 mm) with interesting center divergent honeycomb micro‐morphologies are prepared. In addition, cryo‐assembly assisted electro‐spraying of SF‐PEI led to obtaining micro‐aerogels (74 µm), possessing a wrinkled surface morphology with a high surface area. The aerogel beads exhibit superior adsorption capacities for Cu2+ (186.7 mg g−1, in 240 min) with a regeneration potential, but also for anionic dyes, for example, methylene orange (811.3 mg g−1) and organic solvents (1138 g g−1% for chloroform). The large adsorption capacities and fast adsorption kinetics of cations obtained by these aerogels are attributed to their impressive micro‐morphologies and small geometries, enabling rapid diffusion and cations uptake. Therefore, the sustainability, biodegradability, ease of fabrications, rapid, and reusable adsorption performance make aerogel beads of this study highly potent for multipollutant adsorption.

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Cellulosic and Polyurethane Aerogels

Cited by 12 publications

References 64 publications

Superinsulating Polyisocyanate Based Aerogels: A Targeted Search for the Optimum Solvent System

Superinsulating Polyisocyanate Based Aerogels: A Targeted Search for the Optimum Solvent System

Silica Aerogels

Hierarchical Assembly of Surface Modified Silk Fibroin Biomass into Micro‐, and Milli‐Metric Hybrid Aerogels with Core‐Shell, Janus, and Composite Configurations for Rapid Removal of Water Pollutants

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