Molecular Rebar Design, a nanomaterials firm primarily based in Austin, Texas, has patented a brand new additive manufacturing (AM) composition that makes use of oxidized discrete carbon nanotubes (CNTs) with bonded dispersing brokers to boost 3D printing resins. The patent, printed below US20210237509A1, outlines strategies to enhance resin properties for functions equivalent to vat photopolymerization, sintering, and thermoplastic fusion.
The inventors, Clive P. Bosnyak, Kurt W. Swogger, Steven Lowder, and Olga Ivanova, suggest formulations that enhance electrical conductivity, thermal stability, and mechanical energy, whereas overcoming dispersion challenges widespread with CNTs in composite supplies.
Functionalized CNTs for additive manufacturing
On the core of the invention is the chemical functionalization of CNTs with dispersing brokers bonded to their sidewalls, enabling larger facet ratios and extra homogeneous dispersions. These dispersions combine into UV-curable acrylates, thermoplastics, and elastomers, yielding improved inexperienced energy, sinterability, and quicker treatment charges.
The patent emphasizes the good thing about utilizing bimodal or trimodal distributions of CNT diameters (single-, double-, or multi-wall) to tune materials efficiency. Extra fillers equivalent to carbon black, silica, and metallic powders will also be included for functions starting from digital encapsulation to impact-resistant elements.
Experimental validation
To validate the invention, the candidates oxidized carbon nanotubes utilizing nitric acid and covalently bonded them with polyether dispersing brokers equivalent to Jeffamine M2005. These modified CNTs had been included into photopolymer resin formulations. In tensile testing, specimens produced with the dispersions demonstrated enhanced mechanical efficiency, with yield strengths exceeding 50 MPa and Younger’s modulus values above 2.8 GPa.
Impression energy improved by as much as 90% in sure formulations in comparison with management samples with out CNTs. These efficiency positive factors counsel suitability for functions demanding excessive strength-to-weight ratios, equivalent to aerospace, electronics, and structural parts.
Nanotube improvements in AM
Carbon nanotubes (CNTs) have lengthy been explored for additive manufacturing (AM) as a result of their distinctive mechanical and electrical properties. Nonetheless, challenges equivalent to poor dispersion and inconsistent facet ratios have hindered their widespread adoption in AM processes. Current developments purpose to beat these limitations by integrating oxidation and dispersion strategies into scalable manufacturing strategies.
For example, researchers at Rice College have developed a novel acid-based solvent that forestalls the widespread “spaghetti impact” of CNTs tangling collectively. This innovation simplifies the processing of CNTs, probably enabling their scale-up for industrial 3D printing functions.
Equally, a analysis workforce led by the College of Glasgow has created a 3D printable CNT-based plastic materials able to sensing its personal structural well being. This materials, impressed by pure porous constructions, affords enhanced toughness and energy, with potential functions in medication, prosthetics, automotive, and aerospace design.
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Characteristic picture exhibits schematic diagram of functionalized carbon nanotubes. Picture by way of Molecular Rebar Design.
