Аннотация:A method for preparing a supramolecular hydrogel composed of a mixture of L-cysteine, and silver nitrate is reported. The main features of the hydrogel are gelation at low content of the dispersed phase (~ 0.01%) induced by addition of various salts (sulfates, sulfites, chlorides, bromides, and others) and thixotropic behavior. On the basis of experimental data, the mechanism of gelation is suggested. It is assumed that filament-like aggregates in the system are formed from silver mercaptide zwitterions due to noncovalent bonding as a result of self-assembly processes, addition of a salt leads to physical cross-linking, and gel network formation. An atomistic computer model is developed to confirm the supposed mechanism of gelation. It is established that resulting molecular configurations are stabilized by the interactions of –NH3+ and –C(O)O– groups of silver mercaptide zwitterions comprising neighboring clusters. These assumptions are taken as a basis of a mesoscopic model to study the processes of nucleation and growth of filament-like aggregates on a large spatial scale.
http://www.hrpub.org/journals/article_info.php?aid=160