**3. Experimental Section**

Commercially manufactured inorganic fullerene-type tungsten disulfide (IF-WS2) was obtained in the form of a commercial lubricant Nanolub (NanoMaterials Ltd., Ness Ziona, Israel). The sample was washed with ethanol to remove additives; the solvent was separated using an Eppendorf (New York, NY, USA) Model 5418 centrifuge and the IF-WS2 particles dried at room temperature in a desiccator. The sample was studied by XRD and SEM before being subject to treatments and as postmortem.
