The ever-growing interest in 2D materials across scientific fields has led to the discovery of compounds with unique electrical, optical, chemical, and thermal properties. These characteristics are influenced by their all-surface nature and nanoscale confinement, which can be altered by extrinsic factors like defects, dopants, strain, adsorbed molecules, and contaminants. In this talk, Prof. Duesberg presented the evidence of polymeric adlayers on top of layered transition metal dichalcogenides (TMDs), a finding not easily detected by conventional methods like Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), or scanning electron microscopy (SEM). Highly resolved time-of-flight secondary ion mass spectrometry (TOF-SIMS) was employed to analyze the atomically thin layers, which consist of hydrocarbons and preferentially adsorb to the hydrophobic van der Waals surfaces of TMDs. This discovery holds significant implications for the investigation, processing, and applications of 2D materials specially for the ones sensitive to surface properties such as electronics and tribology.