title: Effective dipole-dipole interactions in critical nanofluids.
abstract: It is long known that the effective dipole-dipole coupling is averaged to zero when the spin carrying atoms are involved in a fast random movement in an unconfined fluid. The presented theory shows that if (i) the fluid is confined in long closed nanotubes, (ii) the fluid is in the vicinity of the second order phase transition, and (iii) the mobility of the spin carrying atoms of the fluid is high then the effective dipole-dipole coupling of the fluid is characterized by a finite global value that is independent of the spacing between all the atoms and independent of the length of the nanotubes. We report how the two regimes of the strong and weak effective dipole-dipole couplings in the vicinity and far from the critical point (CP), respectively, can be discriminated in the NMR experiments. Strong enhancements of the signals in the free induction decay, the line shape and the superradiation that result from the abnormally large effective dipole-dipole coupling in the vicinity of the CP are predicted.
authors: Institute of Problems of Chemical Physics, RAS, Chernogolovka, Moscow Region 142432, Russia. rudavets@gmail.com
authors: M G
authors: MG
authors: Rudavets
mesh_terms: D003198:Computer Simulation; D060526:Magnetic Fields; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D012996:Solutions / Q000737:chemistry*; D055672:Static Electricity
chemical_list: D012996:Solutions