A Co-Precursor Approach Coupled with a Supercritical Modification Method for Constructing Highly Transparent and Superhydrophobic Polymethylsilsesquioxane Aerogels

Abstract

Polymethylsilsesquioxane (PMSQ) aerogels obtained from methyltrimethoxysilane (MTMS) are well-known high-performance porous materials. Highly transparent and hydrophobic PMSQ aerogel would play an important role in transparent vacuum insulation panels. Herein, the co-precursor approach and supercritical modification method were developed to prepare the PMSQ aerogels with high transparency and superhydrophobicity. Firstly, benefiting from the introduction of tetramethoxysilane (TMOS) in the precursor, the pore structure became more uniform and the particle size was decreased. As the TMOS content increased, the light transmittance increased gradually from 54.0% to 81.2%, whereas the contact angle of water droplet decreased from 141° to 99.9°, ascribed to the increase of hydroxyl groups on the skeleton surface. Hence, the supercritical modification method utilizing hexamethyldisilazane was also introduced to enhance the hydrophobic methyl groups on the aerogel’s surface. As a result, the obtained aerogels revealed superhydrophobicity with a contact angle of 155°. Meanwhile, the developed surface modification method did not lead to any significant changes in the pore structure resulting in the superhydrophobic aerogel with a high transparency of 77.2%. The proposed co-precursor approach and supercritical modification method provide a new horizon in the fabrication of highly transparent and superhydrophobic PMSQ aerogels.

Novel, flexible, and transparent thin film polyimide aerogels with enhanced thermal insulation and high service temperature

“…[76][77][78] Though some previously reported inorganic silica aerogels showed higher optical transparency compared to the fabricated PI aerogels, in this work, the fabricated PI aerogels presented significantly higher mechanical flexibility and thermal stability. [79][80][81][82]…”

Experimental Characterization of the Thermal Conductivity and Microstructure of Opacifier-Fiber-Aerogel Composite

“…Thus, aerogels have wide application prospects in the fields of adsorbtion, catalysts, thermal insulation, sensors, integrated circuits, etc. [ 2 , 3 , 4 ]. Aerogels are usually known as superinsulation materials because of their thermal conductivity, and can be much less than the thermal conductivity of still air [ 5 ].…”

Influence of Polymethylsilsesquioxane Content to the Thermal Stability of Meta-Aramid Fiber Insulation Paper

“…The modified material has the dual advantages of inorganic nanomaterials and organic polymer materials. POSS can improve the thermal stability [4,6,9,10,11,12], mechanical properties [4,6,12,13,14], hydrophobicity [15,16,17], flame retardancy [18,19,20], and dielectric properties [21,22,23] of the polymer at the molecular level; this modification method has been widely studied by researchers.…”