title: Ferromagnetic behaviour of anthropogenic multi-walled carbon nanotubes trapped in spider web indoor.
abstract: Black carbon (BC) (as partly burnt black particulate matter) present indoor are deposited on interior surfaces of the indoors (easily visualize over the blades of electric fan/exhausts and over domestic spider webs) are known to be a potential indoor pollution problem. We detect with the help of indoor spider webs the floating BC contains a significant amount of defective multiwalled carbon nanotubes (MWCNTs) possessing room temperature ferromagnetism. Microscopic studies shows a lot of internal and surfacial defects in these indoor-MWCNTs. Electron paramagnetic resonance (EPR) showed the presence of very stable carbon centred radicals in these indoor-MWCNTs. Room temperature ferromagnetism most importantly originated by the presence of a large amount of unpaired spin frustrated carbon centred radicals (trapped in defects, junctions and fractures) which are inadvertently formed during the pyrolysis of carbonaceous materials through routine domestic activities.
authors.forename: Sumit Kumar
authors.initials: SK
authors.lastname: Sonkar
authors.forename: Kumud Malika
authors.initials: KM
authors.lastname: Tripathi
authors.forename: Sabyasachi
authors.initials: S
authors.lastname: Sarkar
mesh_terms: D016902:Air Pollution, Indoor; D000818:Animals; D002244:Carbon / Q000737:chemistry; D006798:Housing; D006859:Hydrogen / Q000737:chemistry; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon / Q000737:chemistry*; D013053:Spectrophotometry; D013112:Spiders; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D037742:Nanotubes, Carbon; D002244:Carbon; D006859:Hydrogen