Recyclable thermo-insulating panels made by reversible gelling of dispersed silica aerogel microparticles

Hydrophobic silica aerogel composite materials are considered as one of the most promising thermal insulation materials in energy-saving buildings. With the increasing negative effect on the environment of construction waste, it is necessary to develop an effectively recyclable thermal aerogel material for the building industry. In this work, we firstly employed a reversible gelling of hydrophobic silica aerogel microparticles dispersed with methyl cellulose surfactant (MCS) to prepare recyclable thermo-insulating panels (RTIP). The RTIP, with low bulk density (<0.05 g/m(3)) and thermal conductivity (0.027 W/(mK) at 20 degrees C), has a splintering mass loss of the composite material as low as 1% after 2 h continuous high-frequency oscillation, which was attributed to the rigid support of gelatinized MCS layers. Through mechanical mixing to re-dissolving in water, the reproducible RTIP can be obtained by the same gelling and drying process, with fairly stable hydrophobicity and thermal conductivity after 10 cycles. The strategy demonstrated here provides a new paradigm for developing environmentally-friendly materials for thermal-insulating buildings. [GRAPHICS]

Automated summary

This study developed a reversible gelling method to prepare a recyclable thermal insulation material for buildings called RTIP. The RTIP showed low bulk density, low thermal conductivity, and achieved fairly stable hydrophobicity and thermal conductivity after multiple cycles of re-dissolving and drying. This work provides a new paradigm for developing environmentally-friendly thermal insulation materials for buildings.