A brand new 3D printing technique 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 strong buildings. The work, revealed in Nature Communications, has the potential to make supplies manufacturing extra sustainable and environmentally pleasant.
The method makes use of a liquid polymer resolution often known as poly(N-isopropylacrylamide), or PNIPAM for brief. When this PNIPAM ink is extruded by 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 strong 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 resulting from their sturdy attraction to water. This removing of water causes the hydrophobic polymer chains within the PNIPAM ink to densely mixture, making a strong type.
“That is all executed beneath ambient circumstances, without having for extra steps, specialised gear, poisonous chemical compounds, warmth or stress,” stated research senior writer 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 sometimes require energy-intensive steps and harsh substances. In distinction, this new course of harnesses the easy interplay between PNIPAM and salt water at room temperature to attain the identical end result, however with out the environmental value.
Plus, this course of is reversible. The strong buildings produced might be simply dissolved in contemporary water, reverting to their liquid type. This permits the PNIPAM ink to be reused for additional printing. “This provides a easy and environmentally pleasant strategy to recycle polymer supplies,” stated Bae.
To show the flexibility of their technique, the researchers printed buildings out of PNIPAM inks containing different supplies. For instance, they printed {an electrical} circuit utilizing an ink manufactured from PNIPAM blended with carbon nanotubes, which efficiently powered a lightweight bulb. This printed circuit may be dissolved in contemporary water, showcasing the potential for creating water-soluble and recyclable digital parts.
Bae and her group envision that this straightforward and reversible 3D printing method may 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 embody 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 by the UC San Diego Supplies Analysis Science and Engineering Middle (MRSEC, grant DMR-2011924) and the Primary Science Analysis Program by the Nationwide Analysis Basis of Korea funded by the Ministry of Schooling (grant RS-2023-00241263).
Disclosures: Jinhye Bae, Joseph Liu and Donghwan Ji filed a patent for this work by the UC San Diego Workplace of Innovation and Commercialization. The authors declare no competing pursuits.