An All-Ceramic, Anisotropic, and Flexible Aerogel Insulation Material

Abstract

To exploit the high-temperature superinsulation potential of anisotropic thermal management materials, the incorporation of ceramic aerogel into the aligned structural networks is indispensable. However, the long-standing obstacle to exploring ultralight superinsulation ceramic aerogels is the inaccessibility of its mechanical elasticity, stability, and anisotropic thermal insulation. In this study, we report a recoverable, flexible ceramic fiber-aerogel composite with anisotropic lamellar structure, where the interfacial cross-linking between ceramic fiber and aerogel is important in its superinsulation performance. The resulting ultralight aerogel composite exhibits a density of 0.05 g/cm3, large strain recovery (over 50%), and low thermal conductivity (0.0224 W m–1 K–1), while its hydrophobicity is achieved by in situ trichlorosilane coating with the water contact angle of 135°. The hygroscopic tests of such aerogel composites demonstrate a reversible thermal insulation. The mechanical elasticity and stability of the anisotropic composites, with its soundproof performance, shed light on the low-cost superelastic aerogel manufacturing with scalability for energy saving building applications.

Wearable Aramid–Ceramic Aerogel Composite for Harsh Environment

“…The in situ gas bubble through foaming agent urea could support the pore formation in aerogel under the ambient pressure drying. [16,24] The aramid fibers construct the percolation networks while silica aerogel would crosslink and deposit onto the fiber networks. The interfacial bonding between aramid fiber and aerogel after gelation could further prevent the fibrous networks from collapsing.…”

“…In the past decades, significant efforts have been dedicated to the development of aerogel fibers. [20][21][22][23][24] For example, cellulose aerogel fibers show a low thermal conductivity at room temperature, [20,25] whereas graphene aerogel fibers demonstrate tunable thermal conversion and storage, providing broad applications in the next-generation wearable systems. [26,27] On the other hand, to provide the fundamental understanding about the design of a high-temperature protection system, a recent research work studied the ablation and thermal behavior of silica-reinforced polymer composite, revealing the heat transfer, decomposition gases generation, and the subsequent diffusion process in composite.…”

Cost-Effective Additive Manufacturing of Ambient Pressure-Dried Silica Aerogel

“…The first batch was added and followed by blending for 3 h, then the second batch was added and also blended for 3 h. Sequentially adding the HPMC will help it to be thoroughly dissolved into the suspension, whereas directly adding the entire batch will cause HPMC to tangle together and makes the ink difficult to blend. Finally, CTAB (VWR, Radnor, PA) was added as the surfactant to form uniformly distributed gaseous bubbles, which will be developed into the porous structure after printing [25][26][27]. Unlike the conventional way to make printable ink, where a defoamer-like chemical such as 1-Octanol is added to make smooth and continuous paste (slurry) [28,29], the proposed approach in this work took the opposite route by adding a foaming agent to generate the pore-supporting porous structure.…”

Scalable and robust silica aerogel materials from ambient pressure drying

“…Improvement of mechanical properties of aerogels range from the development of aerogel-like monoliths by different methods such as (i) cross-linking the aerogel particle with polymer cross-linkers of the triacrylate family 27 , (ii) the use of a co-precursor approach 28,29 as a way to control the cross-linking density --and hence flexibility of the resulting aerogel, and (iii) the use of silica aerogel as unique nanostructured filler for epoxy nanocomposites 30 . Another commonly applied technique incorporates a fiber matrix in the preparation of fiber/aerogel composite products [31][32][33][34][35] . Cellulose-based fibers, which can also be referred to as "green" fibers, have become a rather popular alternative over the past couple of years, not only because of its relative low-cost and environmental-friendly nature, but also due to its ease of production --typically obtained from 85% recycled paper --and versatility that has made them into a viable alternative for the production of sound absorbers 36 , fireresistant boards 37 , as well as other eco-friendly building materials.…”