Enhancing the hydrophobicity of the mineral wool through surface modification with organo-silane

Mineral wool materials are consistently preferred material to be used for building thermal insulation because of their low heat conductivity, making energy-efficient structures impossible to construct without highly insulating thermal envelopes. A mineral wool with a hydrophobic external surface could be used for several applications where hydrophobicity would be helpful. Organo-silanes are one of the most promising materials to impart hydrophobic character to varied surfaces to achieve performance properties such as dust-resistant coatings on building glass, solar panels with self-cleaning surfaces, biofouling resistant paints, self-cleaning car windshields etc. In this study, mineral wool was treated with methyltrimethoxysilane (MTMS) to achieve hydrophobic surfaces.A Fourier Transform Infrared Spectrometer is used to confirm the successful deposition of organosilane/siloxane networks on glass wool fibre surfaces. The hydrophobicity of treated wool was assessed and quantified using a contact angle measurement. Contact angle measurement was used to quantify the hydrophobicity of treated wool. The thermal conductivity of treated mineral wool fiber was calculated using the portable Lee's disc method. To determine the thermal stability and crystallinity of the treated wool, X-ray diffraction spectroscopy and thermogravimetric analysis were used, respectively. The treated mineral wool exhibited excellent thermal stability up to 800 °C, and wettability tests proved the treated surface highly hydrophobic, allowing water droplets to roll off with contact angles up to 134.9°. Surface modification reduced thermal conductivity by 20%, showing good thermal resistance. Here, we show easy and sustainable methods of treating mineral wool surfaces, which can serve as a thermal insulation option under humid conditions.