3D-printing of ceramic aerogels by spatial photopolymerization

Recent progress in the development of highly active dyeing photoinitiators based on 1,3-bis(p-substituted phenylamino)squaraines for radical polymerization of acrylates

“…1 There are many benefits of this technique, called briefly the "5E" principles and including the features: economy, efficiency, enabling, energy saving and being environmentally friendly. 2,3 The light-mediated polymerization reactions are commonly used in the production of protective and decorative coatings, such as lacquers and paints, 4,5 inks, 6 adhesives, [7][8][9] hydrogels, [10][11][12] and dental composites, 13,14 as well as in 3D printing, [15][16][17][18][19] and many others. However, it should be mentioned that the scope of application of photopolymerization is constantly expanding and continues to surprise.…”

Digital Light Processing 3D‐Printed Silica Aerogel and as a Versatile Host Framework for High‐Performance Functional Nanocomposites

“…As a revolutionary manufacturing technique, 3D printing including stereolithography/digital light processing (SLA/DLP, vat‐photopolymerization‐based), powder bed fusion, inkjet, and fused deposition modeling/direct ink writing (FDM/DIW, extrusion‐based) and so on, has facilitated innovations in materials science due to its features of high accuracy, low material cost, multi‐material compatibility, and ability to rapid build digitally designed complex objects on demand. [ 1 , 2 , 3 , 4 ] Combinations of sol‐gel methods and suitable drying processes (e.g., freeze‐drying and supercritical drying) with 3D printing protocols have been developed to engineer desirable carbon, [ 5 , 6 ] biomass, [ 7 ] metal, [ 8 ] and silica‐based aerogels [ 9 , 10 , 11 ] for emerging applications in lightweight support materials, energy storage, catalysis, sensors, and medicine. Silica aerogel is by far the most widely used type of aerogel because its density can be tuned over a wide range and its characteristics include high porosity, large specific surface area, superior thermal insulation, acoustic impedance, fire resistance, adjustable transparency and high intrinsic modulus suitable for use as a reinforcement for composites.…”

“…[ 18 , 19 , 20 ] Moreover, the removal of the organic components from DLP‐printed silica‐based aerogels inevitably damages the aerogel structure. [ 11 ]…”

“…[18][19][20] Moreover, the removal of the organic components from DLP-printed silica-based aerogels inevitably damages the aerogel structure. [11] In this study, we developed a two-step acid-base catalytic procedure for the fabrication of acrylate-modified silica sols and reveal the temporal evolution of their photorheological behavior for the first time. When this modified silica sol with a very low acrylate content was close to its gelation point, maintaining a low viscosity enabled a fast and stable photo-controllable sol-gel transition that can be used for 3D printing of silica wet gels by a commercial DLP printer.…”

Versatile Thermal‐Solidifying Direct‐Write Assembly towards Heat‐Resistant 3D‐Printed Ceramic Aerogels for Thermal Insulation

“…[15][16][17] Stereolithography presents a significant advantage in obtaining submicron structures, but the shape maintenance of 3D-printed parts still depends on the photochemical reaction of specific resin. [18] Comparatively, the DIW technique is easily implemented by depositing viscoelastic ink through a nozzle, the superiority of which lies in the fine compatibility of inks. [13,14] Various materials including nanoparticles, nanowires or nanofibers, and nanosheets can be integrated into ink formulation to obtain tunable printing rheology and endow 3D-printed aerogels with designed functions.…”