title: Melamine as an effective supramolecular modifier and stabilizer in a nanotube-constituted supergel.
abstract: Self-assembly of N-fluorenyl-9-methoxycarbonyl glutamic acid (Fmoc-Glu) in water generates metastable single-wall nanotubes. These nanotubes entangle and bundle together to form unstable gels that shrink with time and finally result in lamellar crystalline precipitates. Melamine (Mm) was employed as a supramolecular modifier and stabilizer to improve the stability of the nanotubes. Mm interacts with the carboxyl-rich surfaces of the nanotubes via H-bonds and static electronic forces to diminish the high affinity of individual nanotubes and facilitate Fmoc-Glu supergelation (critical gelation concentration <0.1 wt %). Although the basic process of nanotube formation is not disturbed, Mm inverts the supramolecular helicity of nanotubes from P to M.
authors.affiliation: School of Chemistry and Chemical Engineering and Key Laboratory of Colloid and Interface Chemistry of Ministry of Education, Shandong University, Jinan 250100 (PR China), Fax: (+86) 531-88564464.
authors.forename: Pengyao
authors.initials: P
authors.lastname: Xing
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Chu
authors.forename: Mingfang
authors.initials: M
authors.lastname: Ma
authors.forename: Shangyang
authors.initials: S
authors.lastname: Li
authors.forename: Aiyou
authors.initials: A
authors.lastname: Hao
keywords: amino acids; gels; nanotubes; self-assembly; supramolecular chemistry