A research team at HZDR and the University of Rostock has recovered intact nanodiamonds formed when high-energy laser pulses compressed PET, the plastic used in bottles. The peer-reviewed, open-access study appears in Diamond and Related Materials and reports particles averaging about 3 nanometers, with a detailed measurement of 3.23 ± 0.79 nm. No explosives were used. Yet the result is not plastic recycling, and the quantity produced demands scrutiny.
- First intact recovery: Laser-shocked PET produced nanodiamonds that survived capture.
- Planetary purpose: The experiment simulates Uranus and Neptune, not plastic waste processing.
- Scale gap: Each shot yields roughly 0.6 micrograms; one gram would need about 1.5 million shots.
A planetary-physics experiment, not a recycling route
PET was chosen because its carbon-hydrogen-oxygen composition mimics the interiors of Uranus and Neptune, where pressures exceed a megabar and temperatures reach thousands of kelvin—conditions called warm dense matter. The project follows a 2022 Science Advances paper with 44 authors from the same group, which observed diamond formation between 72 and 125 GPa and suggested oxygen helps diamond precipitate in ice giants. It also hinted at making nanodiamonds by laser-compressing PET. The input is commercial PET tape, 75 microns thick in the successful campaign, though the press release cites a 100-micron film. The plastic is a Neptune simulant that happens to leave diamonds behind.
How the diamonds survived the shock
The central achievement is recovering intact nanodiamonds after laser-driven shock compression. When the compression wave reaches the sample’s rear and exits into vacuum, ejecta travel faster than 10 km/s. Molecular-dynamics simulations show nanodiamonds survive impact only below about 11 km/s, so they needed a very soft catcher. Aluminum and copper collectors failed: foils exposed to 51 and 54 shots produced none. The solution was a vacuum-compatible, water-soluble ionic gel made from an ionic liquid and polyvinyl alcohol, developed as an undergraduate project by one co-author. The sample providing clear evidence accumulated ejecta from 133 shots. The laser used a 5-nanosecond square pulse at 3 TW/cm² on the L4n-P3 station at ELI Beamlines, south of Prague. The abstract cites about 100 GPa and 4,000 K; the sample that yielded nanodiamonds experienced about 80 GPa and 3,800 K.
Ten trillion particles, but only micrograms
The release says each shot sends ‘approximately ten trillion’ nanodiamonds into the catcher—10^13 particles of nearly identical size. With about 3,000 carbon atoms each, that implies roughly 0.6 micrograms of diamond per shot, consistent with the thesis’s statement that the amount per shot is on the order of micrograms. But the release also says about 100 shots produced ‘a few hundred micrograms,’ implying 2–3 micrograms per shot—four to five times the particle-based estimate. One figure does not fit. Using the conservative estimate, one gram would require about 1.5 million shots. The release says the laser fires three times per minute; the first author’s thesis says one shot every three minutes, and the facility-design paper sets a maximum target of one per minute. At the thesis rate, 1.5 million shots mean more than nine years of continuous operation; even the optimistic rate implies more than a year. The paper publishes neither the mass fraction converted nor an energy cost.
What the method can and cannot promise
HZDR’s release argues scalability is likely because fusion research is advancing efficient, high-repetition high-energy lasers. That is the release’s argument, not an author quote. Dominik Kraus, a professor at Rostock and director of HZDR’s Institute of High Energy Density Physics, is quoted in the release, but on another point. The target is to move from hundreds of micrograms to the milligram range. The abstract calls the work a ‘potential path’ to a relatively clean, scalable and sustainable approach—conditional, not achieved. Detonation synthesis supplies about 65% of the nanodiamond market, yields roughly 5-nanometer particles and reaches about 90% yield relative to soot. The entire market is estimated at $464 million in 2026, about €413 million, with health and pharmaceuticals as the main destination. The laser method’s advantage is not volume: it is the ultra-small size with a narrow distribution, the absence of explosives and the ability to dope the precursor for custom nanodiamonds. Those traits matter for quantum sensors, medical contrast agents and catalysts—applications the authors cite against today’s polishing and abrasive uses. The thesis adds a caveat: recovered nanodiamonds resemble commercial detonation grades but show an increased graphitic pre-peak, suggesting more graphitization; ‘high purity’ is stronger than the data. The group’s next step is an attempt to produce BC8, a predicted carbon phase denser than diamond and less brittle, at higher pressures. The first experiment is planned for November.
If successful, BC8 would be a materials-science milestone. For now, the nanodiamond result is a lab first with a narrow, valuable output—not a solution to plastic waste. Its importance will depend on whether the team can widen the yield, quantify conversion efficiency and turn precursor doping into useful, specialized particles.