Building Energy Materials  
Superinsulating materials
Advanced sol-gel materials

RT1-Superinsulating Materials and Systems
  • Scale-up of Aerogel Production
  • Superinsulating Aerogel Materials Research
  • Vacuum Insulation Glazing
  • Scale-up of Aerogel Production

    Silica aerogels possess the lowest ambient pressure thermal conductivity known to man and the growth potential of aerogels insulation products is in excess of 50 % by volume per annum. However, the widespread application of silica aerogels in the building environment is hindered by the high production costs of these materials. In 2013, a one-pot production process was patented by Empa. This process allows to produce silica aerogel granulate by ambient pressure drying within only 5 hours from start to finish. The production process was recently scaled up in a pilot reactor which allows producing 70 liters at a time. The aerogel granulate produced by this method has a thermal conductivity of 17.9 mW/m*K, as low as that of commercially available granulate.

    Nano-interpenetrating Biodegradable Polymer-silica Hybrid Aerogels
    Silica aerogels are receiving ever growing attention because of their exceptional physical properties such as low density, low thermal conductivity, high porosity and high specific surface area. However, their brittle/fragile character has often restricts the field of applications. Recent improvements in the re-inforcement of silica aerogels have been achieved typically through synthetic polymers, such as fiber-glass, polyester, non-woven polyprolylene, polyimide, electrospun polyurethane etc., but the reinforce-ment typically comes at the cost of an increase in thermal conductivity. We used biodegradable materials, such as pectin, cellulose (Zhao et al. 2015), chitosan etc., to produce reinforced hybrid aero-gels with improved mechanical properties (yield strength ranges from 1.9 to 27.5 MPa at 80 % strain), without a degradation of superinsulating performances (ë = 0.014 to 0.017 W/m·K). In addition, the dust release is minimal compared to reference SiO2 aerogels and commercial SiO2 composites reinforced by fibrous polymer blankets. Their unique combination of mechanical and thermal properties makes these biopolymer-silica aerogel hybrids candidates to revolutionize superinsulation.
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