Four organic aerogels were prepared by the sol-gel method from polymerization of resorcinol with formaldehyde catalyzed by Na CO . These aerogels were further pyrolyzed in N in order to obtain their corresponding carbon aerogels, 2 3 2 and after that activated with either steam or CO to obtain activated carbon aerogels. Another series of organic aerogels and 2 their pyrolyzed and activated deri...

Monolithic aerogels of high molecular weight polyethylene (Mw= 3x106- 6x106 g/mol) have been prepared by solvent extraction with supercritical carbon dioxide from thermoreversible gels prepared in decalin. These low density and highly porous aerogels present an apparent porosity up to 90%. The aerogel morphology observed by scanning electron microscopy (SEM) is characterized by spherulitic stru...

Water extractable arabinoxylan (WEAX) aerogels were prepared by extracting the solvent from the alcogels (WEAX hydrogels with an alcohol as the solvent) with carbon dioxide under supercritical conditions. WEAX aerogels were characterized using scanning electron microscopy and adsorption and desorption nitrogen isotherms. The micrographs indicate a heterogeneous porous network structure in WEAX ...

Silica monolith aerogels with different degrees of hydrophobicity by incorporating methyltrimethoxysilane (MTMS) or trimethylethoxysilane (TMES) in standard sol-gel synthesis were prepared. Excellent properties of the aerogels, obtained with the sol-gel synthesis, were preserved with supercritical drying with CO2. The degree of the hydrophobicity of the aerogels was tested by measuring the cont...

HCl-Catalyzed Polymerization of Benzoxazine and Chemical Transformations along Pyrolysis to Microporous Carbons in Advanced and Emerging Polybenzoxazine Science and Technology Report Title This chapter describes a room-temperature HCl-catalyzed synthesis of polybenzoxazine aerogels from bisphenol A, formaldehyde and aniline that cuts the typical multi-day high-temperature (?130 oC) route to a f...

A brief overview of siloxane-based low-density aerogels and aerogels-like xerogels is presented. Aerogels are highly porous solids composed of inorganic oxides, metals, cross-linked polymers and carbons, and are known to possess a number of excellent physical properties such as high visible-light transparency with low refractive index, low dielectric properties, and extremely-low thermal conduc...

In this paper an overview about the applications of Aerogels in the fields of pharmacy, cosmetics, medicine, agriculture and biotechnology is given. The in situ encapsulation of proteins and enzymes into aerogels was shown to be a very promising technique leading to the increase of biocatalytical activity. Furthermore aerogels are used as host matrix for bio-active compounds, which improve or e...

Aerogels refer to a new class of materials holding air in their structure. They are highly porous solids having a large inner surface area. They are extremely light, low heat conductive, and high sound absorbent materials. Therefore, aerogels have excellent performance in applications such as heat insulators, particle filters, particle trappers, and catalyst carriers 1 . Aerogels are prepared s...

To aid the development of IGCC technologies, the unique properties of aerogels were exploited to research purifying systems for H2S, NO, and Hg that are durable and efficient. Aerogels can be used to capture hot gases based on their high surface areas and great tendency to form composites with various other sorbents or structural supports. Silica aerogels are at the heart of the study. Sol-gel ...

Silica aerogels prepared by the sol-gel process are often used as solid desiccants in enthalpy wheels for dehumidifying ventilation air in air-conditioning systems. These hygroscopic materials have good moisture adsorption and desorption characteristics due to their porous structure. The current study is focused on the evaluation of the mass diffusivity of solid silica aerogels and silica aerog...