𝐍𝐓𝐔 𝐬𝐜𝐢𝐞𝐧𝐭𝐢𝐬𝐭𝐬 𝐝𝐞𝐯𝐞𝐥𝐨𝐩 𝐧𝐨𝐧-𝐭𝐨𝐱𝐢𝐜 ‘𝐥𝐢𝐠𝐡𝐭-𝐚𝐜𝐭𝐢𝐯𝐚𝐭𝐞𝐝’ 𝐜𝐨𝐦𝐩𝐨𝐮𝐧𝐝 𝐟𝐨𝐫 𝐬𝐚𝐟𝐞𝐫 𝟑𝐃 𝐩𝐫𝐢𝐧𝐭𝐢𝐧𝐠 𝐚𝐧𝐝 𝐚𝐝𝐯𝐚𝐧𝐜𝐞𝐝 𝐛𝐢𝐨𝐦𝐚𝐭𝐞𝐫𝐢𝐚𝐥𝐬

Scientists from Nanyang Technological University, Singapore (NTU Singapore) have developed a new class of light-activated compounds that could lead to safer and more versatile applications in 3D printing, cosmetics, and medicine.

These compounds, known as aryl diazirine photoinitiators, are used to solidify liquid resins into hard plastics with speed and precision using light. The current industry-standard photoinitiators often face issues of toxicity and poor solubility in water.

The NTU study, published in NPG Asia Materials this month, demonstrates that the new aryl diazirine photoinitiators are not only non-toxic to human cells but also offer superior performance, including reduced material shrinkage and compatibility with water-based sustainable resins.

𝐀 𝐬𝐚𝐟𝐞𝐫, 𝐠𝐫𝐞𝐞𝐧𝐞𝐫 𝐚𝐥𝐭𝐞𝐫𝐧𝐚𝐭𝐢𝐯𝐞

#Photoinitiators are a key ingredient in everything from the adhesives that seal electronics to the biocompatible hydrogels used in tissue engineering. When exposed to light, they kickstart a chemical reaction called polymerisation, which turns liquid materials solid in seconds.

However, the most common photoinitiators, such as diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (#TPO) and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (#BAPO), have been identified as reproductive toxins, creating an urgent need for safer alternatives. In fact, both TPO and BAPO are being #banned in some regions, such as European Union (#EU), due to health concerns. The ban has disrupted the gel-nail sector, which relied on TPO for fast and reliable curing.

The NTU team, led by Assoc Prof Terry W. J. Steele from the School of Materials Science and Engineering, found that #aryldiazirines are a highly effective and biocompatible replacement.

Assoc Prof Steele said: “The industry is facing a major challenge as the most effective and widely used photoinitiators are being regulated out of existence due to toxicity. Our goal was to develop a new 'activator' that is not only safe and biocompatible but also improves on the performance of existing materials. We have created a solution that addresses the toxicity problem head-on while opening new possibilities for innovation.”

𝐎𝐯𝐞𝐫𝐜𝐨𝐦𝐢𝐧𝐠 𝐤𝐞𝐲 𝐭𝐞𝐜𝐡𝐧𝐢𝐜𝐚𝐥 𝐡𝐮𝐫𝐝𝐥𝐞𝐬

One of the significant findings of the study is the new photoinitiators’ ability to reduce the shrinkage that typically occurs when a liquid resin hardens. The aryl diazirines release nitrogen gas during the curing process, a feature that can be tuned to counteract this contraction, leading to more stable and reliable finished products.

source : #NanyangTechnologicalUniversity