Photocurable Sol-Gel Formulations for the Fabrication of Titanium Carbide/Carbon Nanocomposites via Digital Light Processing.

Additive manufacturing of carbide materials has received significant attention in the past years due to the ability to fabricate complex structures over different length scales. However, the typical limitations for powder-laden inks, such as nozzle clogging, rheological and geometric constraints, particle sedimentation, light-scattering and absorbing phenomena, narrow the range of available processes to manufacture carbide materials via conventional particle-based systems. To address these shortcomings, we have developed a one-pot synthetic route for the preparation of sol-gel-based UV-photocurable formulations, aiming at the fabrication of titanium carbide/carbon nanocomposites using digital light processing printing, pointing to potential applications in the field of nuclear physics.

Volumetric Additive Manufacturing of SiOC by Xolography.

Additive manufacturing (AM) of ceramics has significantly contributed to advancements in ceramic fabrication, solving some of the difficulties of conventional ceramic processing and providing additional possibilities for the structure and function of components. However, defects induced by the layer-by-layer approach on which traditional AM techniques are based still constitute a challenge to address. This study presents the volumetric AM of a SiOC ceramic from a preceramic polymer using xolography, a linear volumetric AM process that allows to avoid the staircase effect typical of other vat photopolymerization techniques.

3D-printed zeolite 13X-Strontium chloride units as ammonia carriers.

The selective catalytic reduction (SCR) system in automobiles using urea solution as a source of NH suffers from solid deposit problems in pipelines and poor efficiency during engine startup. Although direct use of high pressure NH is restricted due to safety concerns, which can be overcome by using solid sorbents as NH carrier. Strontium chloride (SrCl) is considered the best sorbent due to its high sorption capacity; however, challenges are associated with the processing of stable engineering structures due to extraordinary volume expansion during the NH sorption.

Improving glass nanostructure fabrication.

A new method offers high-resolution three-dimensional printing and low-temperature firing.

Biodiesel Processing Using Sodium and Potassium Geopolymer Powders as Heterogeneous Catalysts.

This work investigates the catalytic activity of geopolymers produced using two different alkali components (sodium or potassium) and four treatment temperatures (110 to 700 °C) for the methyl transesterification of soybean oil. The geopolymers were prepared with metakaolin as an aluminosilicate source and alkaline activating solutions containing either sodium or potassium in the same molar oxide proportions. The potassium-based formulation displayed a higher specific surface area and lower average pore size (28.

Ag- or Cu-modified geopolymer filters for water treatment manufactured by 3D printing, direct foaming, or granulation.

In this work, we compared the main characteristics of highly porous geopolymer components for water treatment applications manufactured by 3D printing, direct foaming, or granulation. Furthermore, different approaches to impregnate the materials with Ag or Cu were evaluated to obtain filters with disinfecting or catalytic properties. The results revealed that all of the investigated manufacturing methods enabled the fabrication of components that possessed mesoporosity, suitable mechanical strength, and water permeability, even though their morphologies were completely different.

Optimization and Characterization of Preceramic Inks for Direct Ink Writing of Ceramic Matrix Composite Structures.

In a previous work, an ink based on a preceramic polymer, SiC fillers, and chopped carbon fibers was proposed for the production of Ceramic Matrix Composite (CMC) structures by Direct Ink Writing (DIW) and subsequent pyrolysis. Thanks to the shear stresses generated at the nozzle tip during extrusion, carbon fibers can be aligned along the printing direction. Fumed silica was added to the ink in order to enhance its rheological properties; however, the printed structures still showed some deformation in the Z direction.

The molten glass sewing machine.

We present a fluid-instability-based approach for digitally fabricating geometrically complex uniformly sized structures in molten glass. Formed by mathematically defined and physically characterized instability patterns, such structures are produced via the additive manufacturing of optically transparent glass, and result from the coiling of an extruded glass thread. We propose a minimal geometrical model-and a methodology-to reliably control the morphology of patterns, so that these building blocks can be assembled into larger structures with tailored functionally and optically tunable properties.

Stereolithography of SiOC Ceramic Microcomponents.

The first example of the fabrication of complex 3D polymer-derived-ceramic structures is presented with micrometer-scale features by a 3D additive manufacturing (AM) technology, starting with a photosensitive preceramic precursor. Dense and crack-free silicon-oxycarbide-based microparts with features down to 200 μm are obtained after pyrolysis at 1000 °C in a nitrogen atmosphere.