Search Results (4)

This study examines the influence of nanofillers on the ultraviolet (UV) penetration depth of photopolymer resins used in stereolithography (SLA) 3D printing, and their impact on printability. Three nanofillers, multiwalled carbon nanotubes (MWCNT), graphene nanoplatelets (xGNP), and boron nitride nanoparticles (BNNP), were incorporated into a commercially available photopolymer resin to prepare nanocomposite formulations. The UV penetration depth (Dp) was assessed using the Windowpane method, revealing a significant reduction with the addition of nanofillers. At a concentration of 0.25 wt.%, MWCNT showed the highest reduction in Dp (90%), followed by xGNP (65%) and BNNP (33%). SLA 3D printing was performed at varying nanofiller concentrations to evaluate printability. The findings highlight a strong correlation between Dp and the maximum printable nanofiller concentration, with MWCNT limiting printability to 0.05 wt.% due to its low Dp, while BNNP allowed printing up to 1.5 wt.%. Mechanical testing showed substantial improvements in hardness and elastic modulus, even at low nanofiller concentrations, with BNNP outperforming other fillers. Compared to a clear photopolymer, the elastic modulus for 3D printed nanocomposite samples with 0.05 wt.% nanofiller compositions showed an improvement of 43% for MWCNT, 63% for xGNP, and 104% for BNNP. The hardness results showed an improvement of 86% for MWCNT, 103% for xGNP, and 179% for BNNP. These results underscore the importance of Dp in determining the layer thickness and print success in SLA 3D printing. Practical applications include the design of advanced photopolymer nanocomposites for biomedical devices, electronics, and lightweight structural components. This research provides valuable insights for tailoring material properties to meet the demands of high-performance additive manufacturing. Full article

This study presents an innovative approach to improving the mechanical and viscoelastic properties of 3D-printed stereolithography (SLA) nanocomposites by incorporating graphene nanoplatelets (xGNP) into photopolymer matrices. Utilizing an SLA 3D printer, photopolymer formulations with xGNP concentrations of up to 0.25 wt% were successfully produced. Post-print curing was carried out using two different methods: ultraviolet (UV) curing and high-temperature curing at 160 °C. Mechanical characterization using nanoindentation showed a significant increase in elastic modulus by 104% and an increase in hardness by 85% for nanocomposites containing 0.25 wt% xGNP. Furthermore, dynamic mechanical analysis (DMA) revealed a 39% improvement in storage modulus for samples without post-curing and an improvement of approximately 30% for samples subjected to high-temperature curing. These significant improvements highlight xGNP’s potential to not only increase the performance of SLA 3D-printed components but also streamline the manufacturing process by reducing or eliminating energy-intensive post-curing steps. This innovative integration of graphene nanoplatelets paves the way for the production of high-performance, functional 3D-printed products and offers significant advances for various industries with a high impact. The results highlight the transformative role of nanomaterials in additive manufacturing and position this work at the forefront of materials science and 3D printing technology. Full article

Dispersing nanoparticles and increasing the photosensitizer concentration have been regarded as effective approaches for improving the performance of a holographic storage material. In this paper, SiO₂ nanoparticle (NP)-dispersed PQ/PMMA nanocomposite material (SiO₂ NP-PQ/PMMA) with a high PQ doping concentration was prepared. By introducing the co-monomer methyl isobutyl ketone (MIBK) that comes from an SiO₂ NP colloidal solution, the concentration of PQ in the system increased to 1.2 wt %. We investigated the performance of polarization holographic recordings in both traditional PQ/PMMA and nanocomposite material SiO₂ NP-PQ/PMMA with the orthogonally polarized signal and reference waves. With the dispersion of the SiO₂ NPs colloidal solution and the increase in the PQ concentration, diffraction efficiency and photoinduced birefringence were multiplied. In addition, high-quality holographic image reconstruction was achieved by our homemade material. Full article

Nanocomposites based on transparent polymer matrices containing nanoparticles (NPs) of noble metals are modern-day materials that can be specially designed for photonics, linear and nonlinear optics, laser physics and sensing applications. We present the improved photosensitive nanocomposites doped with Au and Ag NPs allowing fabrication of high effective submicrometer dimensional diffraction structures using holographic method. A general approach for the fabrication of holographic structures using a two-component mixture of the monomers of different reactivity was developed. Two different methods, ex situ and in situ, were studied to introduce Au and Ag NPs in the polymer matrix. The diffusion model of the grating formation upon holographic exposure as well as the process of Ag NP synthesis in a polymer matrix is considered. The influence of the NP size on the polymerization process, material dynamic range and nonlinear properties were investigated. The mechanisms and characteristics of the nanocomposite nonlinear optical response are discussed. Full article