Self-assembly and aggregation of melamine and melamine-uric/cyanuric acid investigated by STM and AFM on solid surfaces.
The self-assembly and aggregation of melamine (M), and a mixture of melamine with uric/cyanuric acid (UA/CA) are investigated by performing scanning tunneling microscopy (STM) and atomic force microscopy (AFM) on graphite and mica surfaces at room temperature. Two-dimensional (2D) porous molecular networks and disordered adlayers are found, respectively, in the M and UA-M assembly on graphite. Uniformly dispersed nanoparticles of M and UA-M are found at various concentrations by AFM. Owing to complementary NH...O and NH...N hydrogen bonds, the CA-M mixture forms 2D densely packed adlayers and nanoscale crystals on graphite and aggregates into three-dimensional (3D) clusters on the surfaces. The size of the cluster is dependent on the molecular concentration. The results provide important information for the self-assembly of triazine compounds and are significant in the study of kidney disease related to melamine.
Zhang
Xu
X
Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China.
Chen
Ting
T
Chen
Qing
Q
Wang
Ling
L
Wan
Li-Jun
LJ
D018625:Microscopy, Atomic Force; D016252:Microscopy, Scanning Tunneling; D008958:Models, Molecular; D015394:Molecular Structure; D013499:Surface Properties; D014227:Triazines / Q000737:chemistry*; D014527:Uric Acid / Q000737:chemistry*
D014227:Triazines; D014527:Uric Acid; C004632:cyanuric acid; C011907:melamine