title: Tunable helical assemblies of L-alanine methyl ester-containing polyphenylacetylene.
abstract: The self-assemblying behaviors of L-alanine methyl ester-containing polyphenylacetylene (PPA-Ala, in Chart 1 ) were investigated upon the evaporation of its solvent on mica and on air/water interfaces. The introduction of chiral amino acid attachments to the polyphenylacetylene backbone induced a helical conformation of the backbone, which was stabilized by various noncovalent interactions, especially hydrophobic effect and hydrogen bonds. The helicity of the polymer was further amplified in its higher-order self-assemblies as the formation of helical fibers on the surface of mica upon natural evaporation of its THF solution. By LB technique, the polymer chains were guided to form ordered parallel ridges and highly aligned, with their helical conformation still remaining. The reorganization of the chiral polymer chains on air/water interface was associated with the additional hydrophobic effect of PPA-Ala on an air/water interface. The polymer backbones had to adopt different arrangements to minimize their contact with water, and this adjustment led to the formation of aligned polymer ridges under proper surface pressure.
authors.affiliation: School of Chemistry, Shenzhen University, Shenzhen, China. phbingsl@gmail.com
authors.forename: Bing Shi
authors.initials: BS
authors.lastname: Li
authors.forename: Jacky W Y
authors.initials: JW
authors.lastname: Lam
authors.forename: Zhen-Qiang
authors.initials: ZQ
authors.lastname: Yu
authors.forename: Ben Zhong
authors.initials: BZ
authors.lastname: Tang
mesh_terms: D000114:Acetylene / Q000031:analogs & derivatives* / Q000737:chemistry; D000388:Air; D000409:Alanine / Q000031:analogs & derivatives* / Q000737:chemistry; D000538:Aluminum Silicates / Q000737:chemistry; D013237:Stereoisomerism; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D000538:Aluminum Silicates; D014867:Water; C068145:alanine methyl ester; C044736:phenylacetylene; D000114:Acetylene; D000409:Alanine; C011934:mica