Although there have been many attempts to fabricate aerogels in combination with other materials, research in the field of aerogel/fibrous assemblies is scares and therefore, studies in this field are needed. In this research, a sodium silicate based aerogel was synthesized through an ambient pressure drying method. The resultant material was powdered by a mild ball-milling process. The physical and chemical properties of the synthesized aerogel were studied by analytical methods such as FTIR, BET, BJH, TGA, and SEM, together with determination of the density, porosity and hydrophobicity. Excessive dusting of the aerogel/fibrous assemblies is of major concern. The main purpose of this research is to contemplate the feasibility of fabrication of two purposely designed aerogel/fibrous assemblies and their physical characteristics such as sound and thermal insulation capabilities, hydrophobic and structural properties. In all previous researches, the textiles used in conjunction with the aerogels were initially impregnated in the primary sol, prior to formation of aerogels on their surface. In this work contrary to the previous researches, in order to protect weak structure of the aerogel and to reduce dust releasing phenomenon, nano-structured aerogel filled electro-spun PET superfine fibers were fabricated. Thus, the micro-size nano-structured aerogel powder was used instead of small precursor molecules as filler and coated with a layer of PET polymer in form of superfine fibers. Modification in the insulation properties, air/water vapor permeability, hydrophobicity and dyeability of the fabricated materials in terms of aerogel particle content were investigated. Aerogel content of the fibers was proved by FTIR and EDX analysis methods. SEM and AFM micrographs indicated the successful fabrication of the bead-on-string structured superfine fibers with diameters of 176.2-400.0 nm. It was observed that the heat transfer percentage was decreased proportionally with increase in the aerogel content. The sample containing 4% aerogel exhibited the lowest heat transfer, which approximately corresponds to one third of the sample with no aerogel. It was found that addition of the aerogel to the electro-spinning solution enhanced the sound absorption coefficient (NAC) of the superfine fibers within a frequency range of 250 to 4000 Hz. The measured NACs for the superfine fibers containing high aerogel content were found to be more than those of other samples for the given frequencies. On the other hand, the superfine fibers with low aerogel contents exhibited high NACs at frequencies less than 1000 Hz. In general, it was found that addition of aerogels to the fibers not only leads to higher hydrophobicity (higher water contact angles) but also higher dyeability. Despite of the slight increase in the air permeability of the fibrous webs composed of the superfine fibers containing 2 and 4% aerogel, no significant differences in water vapor permeability was observed by addition of the aerogel to the fibers. In the next phase of the project, commercially available spun-bonded fabrics were coated with pigment printing and also, polyurethane foam printing pastes containing aerogel. Therefore, easily dispersion of aerogel powder in the pastes and limited penetration of the pastes in the aerogel pores were achieved. The effects of these two printing pastes were compared by SEM and digital microscope analysis. Thermal resistance, sound absorption coefficient, hydrophobicity, abrasion fastness and flexural modulus of the coated fibrous webs were also determined. Results showed that the sample coated with foam printing paste containing 6 and 10 pph aerogel exhibited higher thermal resistance in comparison with the other foam and pigment printing paste coated samples. It was found that addition of the aerogel to the printing pastes enhances the NAC of the coated samples within frequency range of 250 to 4000 Hz. In addition, samples coated with the printing pastes containing aerogel showed better hydrophobic properties. The results indicated better flexural properties for the samples coated with the pigment printing pastes in comparison with those coated with the foam printing pastes. Additionally, samples coated with the printing pastes containing aerogel powder showed less than 2-3% weight loss after abrasion. This was attributed to the presence of the polyurethane binder in the coatings.