Rapid synthesis of water-glass based aerogels by in situ surface modification of the hydrogels

Bhagat, Sharad D.; Kim, Yong-Ha; Ahn, Young-Soo; Yeo, Jeong-Gu

doi:10.1016/j.apsusc.2006.07.016

Cited by 77 publications

(32 citation statements)

References 21 publications

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“…The aerogel skeleton of Aerogel B became thinner as the methyl groups on the pore surface were oxidized during calcination. After the serious volume shrinkage during the APD, the unmodified Xerogel C did not show any porous microstructure under SEM observation, which reflects the importance of surface modification and elimination of capillary stress to obtain the porous aerogel structure [11,13]. Fig.…”

Section: Mechanism Of Solvent Exchange/surface Modificationmentioning

confidence: 99%

“…Recently, a new ambient pressure drying (APD) technique has been developed to overcome the disadvantages of conventional supercritical aerogel process, and made the manufacture and application of silica aerogel in large scale possible [12][13][14][15]. The key steps of this novel preparation method were solvent exchange and surface modification before the APD treatment.…”

Section: Introductionmentioning

confidence: 99%

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Preparation and characterization of a novel silica aerogel as adsorbent for toxic organic compounds

Liu

Sha

Cooper

et al. 2009

Colloids and Surfaces A: Physicochemical and Engineering Aspect

108

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a b s t r a c tHydrophobic and hydrophilic silica aerogels were prepared from cheap waterglass precursors via surface modification of wet gels, ambient pressure drying (APD) route and calcination treatment. Xerogel was also synthesized as a comparison to test the influence of microstructure on the adsorption behaviours. Ethanol (EtOH)/chlorotrimethylsilane (TMCS)/hexane solution was employed to replace the surface silanol groups (Si OH) with alkyl, and to prevent the condensation and shrinkage of the gel structure during the APD process. The synthesized silica aerogels, characterized by using Fourier transform infrared spectra (FTIR), nitrogen adsorption/desorption measurement, element analyses and differential scanning calorimeter (DSC), etc., are porous and translucent solids with surface area of 546-907 m 2 /g. The transition temperature from hydrophobic to hydrophilic was tested around 395 • C, which corresponds to the disappearance temperature of the CH 3 peaks in FTIR. The materials were tested for adsorption capacities on rhodamine B (RhB) and dieldrin, which represented soluble and slightly soluble organic compounds, respectively. Results showed that the hydrophobic silica aerogel exhibited strong adsorption capacity on slightly soluble organic compounds while hydrophilic silica aerogel was much more effective on adsorbing soluble compounds from aqueous solution. Adsorption properties of the silica aerogel remain stable after 5 adsorption/desorption cycles.

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Section: Mechanism Of Solvent Exchange/surface Modificationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Preparation and characterization of a novel silica aerogel as adsorbent for toxic organic compounds

Liu

Sha

Cooper

et al. 2009

Colloids and Surfaces A: Physicochemical and Engineering Aspect

108

View full text Add to dashboard Cite

show abstract

“…The water glass being the cheapest source of silica it has widely been used for the preparation of silica aerogels via ambient pressure drying [11]. However, the huge consumption of expensive silylating agent for the surface modification of the hydrogels and solvent used for the water replacement makes this route quite expensive [12,13].…”

Section: Introductionmentioning

confidence: 99%

High specific surface area TEOS-based aerogels with large pore volume prepared at an ambient pressure

Sarawade

Kim

et al. 2007

Applied Surface Science

148

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“…Ambient drying of the formed gel instead of supercritical drying is gaining momentum as it is a safer and less costly procedure. Its synthesis constitutes the mixing of a silica source (TMOS, TEOS, PEDS) with ethanol or acetone in acid or base environment, the formation of gel, its polymerization and, finally, its drying [4][5][6]. While the received products exhibit excellent properties, the materials that are used as silica source are both expensive and hazardous.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of innovative insulation materials

et al. 2018

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Abstract. Insulation elements are distinguished in inorganic fibrous and organic foamed materials. Foamed insulation materials are of great acceptance and use, but their major disadvantage is their flammability. In case of fire, they tend to transmit the flame producing toxic gases. In this paper, the synthesis and characterization of innovative inorganic insulation materials with properties competitive to commercial is presented. Their synthesis involves the mixing of inorganic raw material and water with reinforcing agent or/and foaming agent leading to the formation of a gel. Depending on raw materials nature, the insulation material is produced by freeze drying or ambient drying techniques of the gel. The raw material used are chemically benign and abundantly available materials, or industrial by-products and the final products are non-toxic and, in some cases, non-flammable. Their density and thermal conductivity was measured and found 0.02-0.06 g/cm 3 and 0.03-0.04 W/mK, respectively.

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Rapid synthesis of water-glass based aerogels by in situ surface modification of the hydrogels

Cited by 77 publications

References 21 publications

Preparation and characterization of a novel silica aerogel as adsorbent for toxic organic compounds

Preparation and characterization of a novel silica aerogel as adsorbent for toxic organic compounds

High specific surface area TEOS-based aerogels with large pore volume prepared at an ambient pressure

Synthesis and characterization of innovative insulation materials

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