Light-driven 3D printing is gaining significant attention for its unparalleled build speed and high-resolution in additive manufacturing. However, extending vat photopolymerization to multifunctional, photoresponsive materials poses challenges, such as light attenuation and interference between the photocatalysts (PCs) and photoactive moieties. This study introduces novel visible-light-driven acrylic resins that enable rapid, high-resolution photoactive 3D printing. The synergistic combination of a cyanine-based PC, borate, and iodonium coinitiators (HNu 254) achieves an excellent printing rate and feature resolution under low-intensity, red light exposure. The incorporation of novel hexaarylbiimidazole (HABI) crosslinkers allows for spatially-resolved photoactivation upon exposure to violet/blue light. Furthermore, a photobleaching mechanism inhibited by HNu 254 during the photopolymerization process results in the production of optically-clear 3D printed objects. Real-time Fourier transform infrared spectroscopy validates the rapid photopolymerization of the HABI-containing acrylic resin, whereas mechanistic evaluations reveal the underlying dynamics that are responsible for the rapid photopolymerization rate, wavelength-orthogonal photoactivation, and observed photobleaching phenomenon. Ultimately, this visible-light-based printing method demonstrates: (i) rapid printing rate of 22.5 mm h^-1, (ii) excellent feature resolution (≈20 µm), and (iii) production of optically clear object with self-healing capability and spatially controlled cleavage. This study serves as a roadmap for developing next-generation "smart" 3D printing technologies.

Light-driven 3D printing is gaining significant attention for its unparalleled build speed and high-resolution in additive manufacturing. However, extending vat photopolymerization to multifunctional, photoresponsive materials poses challenges, such as light attenuation and interference between the photocatalysts (PCs) and photoactive moieties. This study introduces novel visible-light-driven acrylic resins that enable rapid, high-resolution photoactive 3D printing. The synergistic combination of a cyanine-based PC, borate, and iodonium coinitiators (HNu 254) achieves an excellent printing rate and feature resolution under low-intensity, red light exposure. The incorporation of novel hexaarylbiimidazole (HABI) crosslinkers allows for spatially-resolved photoactivation upon exposure to violet/blue light. Furthermore, a photobleaching mechanism inhibited by HNu 254 during the photopolymerization process results in the production of optically-clear 3D printed objects. Real-time Fourier transform infrared spectroscopy validates the rapid photopolymerization of the HABI-containing acrylic resin, whereas mechanistic evaluations reveal the underlying dynamics that are responsible for the rapid photopolymerization rate, wavelength-orthogonal photoactivation, and observed photobleaching phenomenon. Ultimately, this visible-light-based printing method demonstrates: (i) rapid printing rate of 22.5 mm h^-1, (ii) excellent feature resolution (≈20 µm), and (iii) production of optically clear object with self-healing capability and spatially controlled cleavage. This study serves as a roadmap for developing next-generation "smart" 3D printing technologies.

In this study, single-chain atomic crystals (SCACs), Mo₃Se₃^-, which can be uniformly dispersed, with an atomically thin diameter of ∼0.6 nm were modified to disperse in an organic solvent. Various surfactants were chosen to provide steric hindrance to aqueous-dispersed Mo₃Se₃^- by modifying the surface of Mo₃Se₃^-. The organic dispersions of surface-modified Mo₃Se₃^- SCACs in nonpolar solvent (toluene, benzene, and chloroform) were stable with a uniform diameter of 2 nm, and they have enhanced stability from oxidation (>10 days). With the surfactants that have a polystyrene tail group (PS-NH₂), the surface-modified Mo₃Se₃^- SCAC showed high compatibility with a polystyrene polymer matrix. Using the surface-modified Mo₃Se₃^- SCAC, a homogeneous Mo₃Se₃^-/polystyrene/toluene organogel was prepared. More importantly, the Mo₃Se₃^-/polystyrene organogel exhibits significantly enhanced mechanical properties, with the improvement of 202.27% and 279.52% for tensile strength and elongation, respectively, compared with that of the pure organogel. The surface-modified Mo₃Se₃^- had a similar structure with a polymer matrix, and the properties of the polymer can be improved even with a small addition of Mo₃Se₃^-.

The pressing need to reduce volatile organic compounds (VOCs) emissions has driven advancements in sustainable waterborne coating technologies. However, achieving high mechanical performances and aesthetic qualities, particularly high gloss and transparency, remains challenging for waterborne clearcoats. In this study, a novel acrylic polyol resin tailored for high-performance waterborne two-component (2 K) polyurethane clearcoat systems was developed. Using a reactive surfactant and internally crosslinked particles synthesized via a pre-emulsion process, we significantly enhanced particle stability, film uniformity, and surface smoothness. By systematically optimizing the crosslinker structure and concentration, superior gloss (improved from 76.8 to 89.3 at 20°) and enhanced mechanical properties (higher indentation hardness and modulus values compared to commercial clearcoat) were achieved. A hydrophilically modified isocyanate crosslinker was incorporated to form a waterborne polyurethane clearcoat through analysis of the blending and film formation processes. Incorporating a hydrophobically modified alkali-swellable emulsion (HASE) thickener improved rheological control, resulting in superior leveling and reduced surface roughness ( R a reduced from 0.05 μm to 0.03 μm). Moreover, the scalability of the developed system was demonstrated successfully through the synthesis of a 20 kg batch, retaining excellent gloss and uniform particle distribution comparable to laboratory-scale results. Overall, this study offers an innovative, scalable, and eco-friendly solution for high-performance waterborne clearcoats suitable for sustainable industrial applications. • A novel acrylic polyol resin for waterborne clearcoats was developed using a reactive surfactant and internal crosslinking. • The HASE thickener improved leveling and reduced roughness through enhanced rheological control. • Compared to commercial waterborne polyol resin, the SR-EG0.5 resin showed higher gloss (89.3° at 20°) and a smoother surface.