Frontier 100 mir ftir

The density ρ of the sintered glass parts was measured by the Archimedes principle using a lab scale Quintix 124‐1S and a density kit analytical balance YDK03 (Sartorius AG, Germany). The sintered fused silica parts were weighed in the dry state (m). Afterward, they were immersed in DI water (T = 20.5 °C) with a small amount of surfactant and the buoyancy mass m_b was determined. The density was calculated using following equation, with ρ_H2O being the density of water
$$\rho =\frac{m{\rho }_{{\mathrm{H}}_2\mathrm{O}}}{-m_{\mathrm{b}}}$$
The shrinkage was determined by measuring three different FDM‐printed parts in the green part stage and after sintering with a caliper. The theoretical linear shrinkage Y_s can be calculated in dependence of the solid loading Φ, theoretical density ρ_t, and final density ρ_f of the manufactured object using following equation
$$Y_{\mathrm{s}}=1-{\left(\frac{\mathrm{\Phi }}{{\rho }_{\mathrm{t}}/{\rho }_{\mathrm{f}}}\right)}^{\frac{1}{3}}$$
Optical inline transmission was determined by using a UV–vis spectrometer of type Evolution 201 (Thermo Scientific, Germany) and an FTIR spectrometer of type Frontier 100 MIR‐FTIR (Perkin Elmer, Germany). Total UV–vis transmission and reflectance were measured using a UV–vis–NIR spectrophotometer of type UV‐3600i Plus (Shimadzu, Japan) equipped with an integrating sphere attachment of type ISR‐1503 (Shimadzu, Japan). Fused silica glass slides (2 mm thickness, Toppan Photomasks, Inc., USA) were used as a reference sample for all measurements.

Unmodified PEG (Mn~10,000), methacrylic anhydride, and 4-dimethylaminopyridine (DMAP) were utilized to synthesize the linear crosslinker PEGDMA. The chemical synthesis of PEGDMA was performed as follows: In a 1000 mL round bottom flask, 100 g of PEG (10 mmol, 1 eq) and 300 mL of anhydrous tetrahydrofuran were stirred, and the flask was heated with an oil bath with a temperature of 50 °C. After the PEG was dissolved, 3.08 g of methacrylic anhydride (20 mmol, 2 eq.) and 61 mg DMAP (0.5 mmol, 0.05 eq.) were added, and the mixture was heated to reflux for 16 h. After the reaction, the solvent was removed under vacuum, and the rest of the mixture was precipitated in 1.5 L cold diethyl ether three times to remove all residual methacrylic acid and DMAP. The white solid was collected and dried in a vacuum oven at 30 °C and 0.1 mbar for 20 h; 96.3 g PEGDMA was thus received (yield: 94.8%). The synthesized PEGDMA was characterized using a Fourier transform infrared (FTIR) spectrometer (Frontier 100 MIR-FTIR, Perkin Elmer, Germany). The peak at 1670–1700 cm⁻¹ indicated the expected carbon–carbon double bonds in the PEGDMA (see Figure S1).

The transmission of the nanocomposite as well as the fully densified MAS ceramics were measured using a UV–vis spectrometer type Evolution 201 (Thermo Scientific, Germany). Additionally, the transmission measurement in IR‐range was performed using a Fourier transform infrared (FTIR) spectrometer of type Frontier 100 MIR‐FTIR (Perkin Elmer, Germany). The samples were prepared by UV‐casting between two glass slides using a UV light source of type Superlite 400 (Lumatec, Germany) operating at a wavelength of 300–400 nm.