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

Abstract

The conventional manufacturing processes of aerogel insulation material is largely relying on the supercritical drying, which suffers from issues of massive energy consumption, high-cost equipment, and prolonged processing time. With the consideration of large market demand of the aerogel insulation material in the next decade, a low-cost and scalable fabrication technique is highly desired. In this paper, a direct ink writing (DIW) method is used to three-dimensionally fabricate the silica aerogel insulation material, followed by room-temperature and ambient pressure drying. Compared to the supercritical drying and freeze-drying, the reported method significantly reduces the fabrication time and costs. The cost-effective DIW technique offers the capability to print complex hollow internal structures, coupled with the porous structure, is found to be beneficial to the thermal insulation property. The addition of fiber to the ink assures the durability of the fabricated product, without sacrificing the thermal insulation performance. The foam ink preparation methods and the printability are demonstrated in this paper, along with the printing of complex three-dimensional geometries. The thermal insulation performance of the printed objects is characterized, and the mechanical properties are also examined. The proposed approach is found to have 56% reduction in the processing time. The printed silica aerogels exhibit a low thermal conductivity of 0.053 W m−1 K−1.

Nanoengineering Porous Silica for Thermal Management

“…A previous study showed that the flexible composite has a compressive strength of 2.19 MPa, while the additive manufactured composite with 20 wt % fiber has a tensile strength of 15.84 MPa. 15,32 When the aerogel concentration is below 30 wt %, the slip between fibers would cause the bun seal curves, and for the sample with an aerogel concentration bigger than 30 wt %, the porous silica aggregates and fiber framework becomes a integrate porous solid with a higher density, so the maximum strength increases significantly.…”

A Review of Post-Processing Technologies in Additive Manufacturing

“…The surface roughness was decreased from 7 µm to 0.155 µm with the MAF method. Guo et al [137] presented an experimental and analytical study on the internal surface quality improvement of Inconel 718 by abrasive flow machining (AFM). The results showed that good surface quality can be achieved with low extrusion pressure, high viscosity, low temperature, and large particle size.…”

Comparison of the properties of silica aerogel doped with two different laser dyes: Crystal violet and Rhodamine B

“…at a low cost, using an ambient pressure drying approach. Currently, the most commonly used methods for measuring ambient pressure are: Network reinforcement and solvent exchange are two aspects of drying (Guo et al, 2021). Wet gels have a surface modified by (Chandradass, Kang, & Bae, 2008;Rao, Nilsen, & Einarsrud, 2001;Shi, Wang, & Liu, 2006).…”