Following Polymer Degradation with Nanodiamond Magnetometry

Area of Science:

• Materials Science
• Biomedical Engineering
• Nanotechnology

Background:

• Degradable polymers are essential in biomedical applications, necessitating accurate monitoring of their degradation processes.
• Current methods for tracking polymer degradation may lack the real-time precision required for complex biological environments.
• Understanding polymer degradation is crucial for predicting device lifetime and ensuring patient safety.

Purpose of the Study:

• To introduce and validate diamond magnetometry as a novel technique for real-time, nanoscale tracking of polymer degradation.
• To demonstrate the sensitivity and applicability of diamond magnetometry in monitoring the degradation of polylactic acid (PLA) films and nanoparticles.
• To correlate changes in nanodiamond properties with polymer erosion and viscosity.

Main Methods:

• Incorporation of nanodiamonds, possessing a fluorescent defect sensitive to magnetic fields, into polylactic acid (PLA) matrices (films and nanoparticles).
• Utilizing diamond magnetometry, specifically relaxometry (T1 measurements), to detect paramagnetic species and monitor changes in nanodiamonds.
• Exposure of nanodiamond-polymer composites to alkaline conditions to induce degradation and measurement of T1 constants and nanodiamond mobility.

Main Results:

• A gradual decrease in T1 constants was observed as PLA films eroded under alkaline conditions, indicating sensitivity to polymer degradation.
• Increased mobility of nanodiamonds within the polymer matrix was detected, allowing for estimation of changes in polymer viscosity.
• Degradation rates determined by diamond magnetometry showed strong agreement with established techniques like quartz crystal microbalance, FTIR, and AFM.

Conclusions:

• Diamond magnetometry provides an unprecedentedly sensitive and precise method for real-time monitoring of polymer degradation at the nanoscale.
• The technique is versatile and can be applied to various polymers beyond PLA, offering insights into degradation kinetics and material property changes.
• This approach opens new avenues for evaluating the long-term performance and safety of degradable biomedical polymers.