A brand new 3D printing methodology developed by engineers on the College of California San Diego is so easy that it makes use of a polymer ink and salt water resolution to create stable buildings. The work, printed in Nature Communications, has the potential to make supplies manufacturing extra sustainable and environmentally pleasant.
The method makes use of a liquid polymer resolution generally known as poly(N-isopropylacrylamide), or PNIPAM for brief. When this PNIPAM ink is extruded via a needle right into a calcium chloride salt resolution, it immediately solidifies because it makes contact with the salt water. Researchers used this course of to print stable buildings with ease.
This fast solidification is pushed by a phenomenon known as the salting-out impact, the place the salt ions draw water molecules out of the polymer resolution on account of their sturdy attraction to water. This elimination of water causes the hydrophobic polymer chains within the PNIPAM ink to densely mixture, making a stable kind.
“That is all achieved underneath ambient circumstances, without having for extra steps, specialised gear, poisonous chemical substances, warmth or strain,” mentioned research senior creator Jinhye Bae, a professor within the Aiiso Yufeng Li Household Division of Chemical and Nano Engineering on the UC San Diego Jacobs Faculty of Engineering.
Conventional strategies for solidifying polymers usually require energy-intensive steps and harsh substances. In distinction, this new course of harnesses the straightforward interplay between PNIPAM and salt water at room temperature to attain the identical consequence, however with out the environmental value.
Plus, this course of is reversible. The stable buildings produced could be simply dissolved in recent water, reverting to their liquid kind. This enables the PNIPAM ink to be reused for additional printing. “This presents a easy and environmentally pleasant strategy to recycle polymer supplies,” mentioned Bae.
To show the flexibility of their methodology, the researchers printed buildings out of PNIPAM inks containing different supplies. For instance, they printed {an electrical} circuit utilizing an ink fabricated from PNIPAM combined with carbon nanotubes, which efficiently powered a lightweight bulb. This printed circuit may be dissolved in recent water, showcasing the potential for creating water-soluble and recyclable digital parts.
Bae and her group envision that this easy and reversible 3D printing method might contribute to the event of environmentally pleasant polymer manufacturing applied sciences.
Paper: “Sustainable 3D printing by reversible salting-out results with aqueous salt options.” Co-authors embrace Donghwan Ji, Joseph Liu, Jiayu Zhao, Minghao Li and Yumi Rho, UC San Diego; and Hwanshoo Shing and Tae Hee Han, Hanyang College, Korea.
This work was supported by the Nationwide Science Basis via the UC San Diego Supplies Analysis Science and Engineering Heart (MRSEC, grant DMR-2011924) and the Primary Science Analysis Program via the Nationwide Analysis Basis of Korea funded by the Ministry of Training (grant RS-2023-00241263).
Disclosures: Jinhye Bae, Joseph Liu and Donghwan Ji filed a patent for this work via the UC San Diego Workplace of Innovation and Commercialization. The authors declare no competing pursuits.
