Thermal resistance and compressive strain of underwater aerogel–syntactic foam hybrid insulation at atmospheric and elevated hydrostatic pressure

Abstract

The purpose of this study was to present a new underwater thermal insulation designed for flexibility and high thermal resistance. The insulation was a hybrid composite of two constituents: syntactic foam and an insulating aerogel blanket. Methods for treating and combining the constituents into a hybrid insulation of several designs are presented. A final configuration was selected based on high thermal resistance and was tested for thermal resistance and compressive strain to a pressure of 1.2 MPa (107 msw, meters of sea water) for five continuous pressure cycles. The thermal resistance and compressive strain results were compared to foam neoprene and underwater pipeline insulation. It was found that the hybrid insulation has a thermal resistance significantly higher than both foam neoprene and underwater pipeline insulation at atmospheric and elevated hydrostatic pressures (1.2 MPa). The total thermal resistance of the hybrid insulation decreased 32% at 1.2 MPa and returned to its initial value upon decompression. It was concluded that the hybrid insulation, with modifications, could be used for wetsuit construction, shallow underwater pipeline insulation, or any underwater application where high thermal resistance, flexibility, and resistance to compression are desired.

Preparation and Surface Characterization of Polymer Nanoparticles Designed for Incorporation into Hybrid Materials

“…They are extremely light and have very high internal surface areas. These materials consist of three-dimensional silica networks with pores of nanometer dimensions, and are expected to show a huge increase in their applications due to their excellent thermal and acoustic insulation properties. , However, the structure of aerogels has very low compressive strength and high susceptibility toward fracture. In order to overcome this problem while maintaining the isolation properties of the materials, we developed polymer nanoparticles with a core of low glass transition temperature ( T g ) and a shell containing groups that can be covalently attached to the porous silica structure during the synthesis.…”

Hybrid Silica/Polymer Aerogels Dried at Ambient Pressure

“…4,5 These include catalysis, optics, electronics, sensors, coatings, biochemistry, medicine, and others. [6][7][8][9][10][11][12][13] A promising field to sol-gel hybrid inorganic-organic materials, namely, the silica-based ones, is thermal-acoustic insulation. Indeed, silica aerogels are known for their unique properties in this field: they are nonflammable, extremely light (densities in the range 3-500 kg‚m -3 ), and excellent thermal and acoustic insulators (thermal conductivity in the range 0.01-0.02 W m -1 K -1 and acoustic impedance between 103 and 106 kg‚m -2 ‚s -1 ).…”

“…The sol−gel process has emerged as the most successful method to synthesize hybrid organic−inorganic composites since the mild conditions involved in this soft chemistry process are ideal for avoiding damage to the organic components. The variety of inorganic and organic precursors available, as well as the multiplicity of strategies to the synthesis of hybrid sol−gel materials, broaden the range of structures and properties achievable and allow an impressive number of possible applications. , These include catalysis, optics, electronics, sensors, coatings, biochemistry, medicine, and others. − …”

Performance of immersion suits: A literature review

“…New materials were developed to construct the immersion suit as well. Bardy et al [40] compared the thermal resistance of a suit fabricated from aerogel-syntactic foam hybrid insulation with that of a foam neoprene suit [40]. It was concluded that unless the surface depressions were eliminated, foam neoprene provided more thermal protection.…”