Compression induced helical nanotubes in a spreading film of a bolaamphiphile at the air/water interface.
Inspired by the elegant helical structures endowed by mother nature, we designed an L-glutamic acid terminated bolaamphiphile and obtained helical nanotubes through the manipulation on the two-dimensional Langmuir films at the air/water interface. It has been found that on the subphase with a pH value lower than 3, stable monolayers with plateau regions were obtained for the bolaamphiphile. Although a flat and uniform morphology was observed for the film deposited at a surface pressure below the plateau region, helical nanotube structures were obtained when the film was compressed over the plateau region. It was suggested that the compression of the monolayer at the air/water interface caused the one end of the bolaamphiphile to leave from the water surface and form an intermediate monolayer in which one end group attached on the water surface and the other extruded in the air. Such an intermediate monolayer subsequently rolled into a helical structure due to the chiral nature of the L-glutamic acid headgroup.
Gao
Peng
P
Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, P. R. China.
Liu
Minghua
M
D019245:Compressive Strength; D018698:Glutamic Acid / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D044367:Phase Transition
D018698:Glutamic Acid