Manufacturing Process
From graphite to pristine C60 crystals: our 10-step precision pipeline
Raw Material Preparation
High-purity synthetic graphite rods (99.99% carbon, 6-12mm diameter) are precision-machined and baked at 1000°C under vacuum for 2-4 hours to remove moisture.
Vacuum Chamber Setup
304 stainless steel vacuum chamber evacuated to <10&supmin;³ Torr, then backfilled with 99.999% pure helium to optimal 150 Torr operating pressure.
Arc Discharge (Krätschmer-Huffman)
DC arc at 150A / 20-25V creates 3000-4000°C plasma. Carbon sublimes, clusters form in helium, and C60 cages self-assemble through thermodynamic stability. The iconic truncated icosahedron closes in 10-100ms.
Soot Collection
Ultra-fine fullerene-containing soot (10-15% C60) scraped from cooled chamber walls. The carbon-black powder has near-zero bulk density at ~0.05 g/cm³.
Soxhlet Extraction
24-48 hours of Soxhlet extraction with HPLC-grade toluene. Clear solvent transforms to stunning magenta-purple as C60 dissolves at 2.8 mg/mL. The signature purple is unmistakable.
Chromatographic Purification
Column chromatography on activated alumina separates fullerenes by polarity. The vivid purple C60 band races ahead, cleanly separated from reddish-orange C70. Like a chemical rainbow.
HPLC Final Purification
Preparative HPLC on Cosmosil Buckyprep column at 50-200 bar achieves 99.5-99.9% purity. UV detection at 330nm guides precision fraction collection.
Vacuum Sublimation
Triple-pass vacuum sublimation at 600°C / 10&supmin;&sup6; Torr. Molecules travel from hot to cold zone, depositing as pristine metallic-bronze crystals. Each pass removes residual solvents and C70 traces, achieving 99.95-99.99% purity.
Quality Control
Rigorous QC: MALDI-TOF confirms m/z 720.00 (C60 molecular ion). UV-Vis fingerprint at 404-408nm. HPLC area purity ≥99.95%. TGA, FTIR, XRD, and ICP-MS complete the certificate of analysis.
Argon Packaging
Sealed under 99.999% argon in amber glass vials within a controlled glove box (<1 ppm O&sub2;). Light-protected, moisture-free packaging ensures 2-5 year shelf stability.
