title: Modulating self-assembly behavior of a salt-free peptide amphiphile (PA) and zwitterionic surfactant mixed system.
abstract: A salt-free surfactant system formed by a peptide amphiphile with short headgroup (PA,C16-GK-3) and a zwitterionic surfactant (dodecyldimethylamine oxide, C12DMAO) in water has been systematically investigated. The microstructures and properties of C16-GK-3/C12DMAO mixed system were characterized using a combination of microscopic, scattering and spectroscopic techniques, including transmission electron microscopy (TEM), field emission-scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR), circular dichroism (CD) and rheological measurements. Rich phase transitions have been observed by adjusting the concentration of C16-GK-3. Investigation of the hydrogels of C16-GK-3/C12DMAO with TEM, SEM and AFM showed that all of these hydrogels form nanobelts. The nanobelt formation is performed in a hierarchical manner: β-sheet peptides and C12DMAO first interact each other to form small aggregates, which then arrange themselves to form one dimensional (1D) left-handed ribbons. The ribbons further aggregated into flat and rigid nanobelts. We proposed a mechanism to interpret the self-assembly process according to the specific peptide structure as well as multiple equilibria between the hydrogen bonding interactions between the headgroups of C16-GK-3, between C12DMAO molecules and the headgroups of C16-GK-3, chirality of the amino acid residues and hydrophobic interactions of the alkyl chains.
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, Shanda nanlu No. 27, Jinan 250100, PR China.
authors.forename: Han
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, Shanda nanlu No. 27, Jinan 250100, PR China.
authors.forename: Jichao
authors.initials: J
authors.lastname: Sun
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, Shanda nanlu No. 27, Jinan 250100, PR China; National Engineering Technology Research Center for Colloidal Materials, Shandong University, Shanda nanlu No. 27, Jinan 250100, PR China. Electronic address: xinx@sdu.edu.cn.
authors.forename: Xia
authors.initials: X
authors.lastname: Xin
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, Shanda nanlu No. 27, Jinan 250100, PR China.
authors.forename: Wenlong
authors.initials: W
authors.lastname: Xu
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, Shanda nanlu No. 27, Jinan 250100, PR China.
authors.forename: Jinglin
authors.initials: J
authors.lastname: Shen
authors.affiliation: National Engineering Technology Research Center for Colloidal Materials, Shandong University, Shanda nanlu No. 27, Jinan 250100, PR China.
authors.forename: Zhaohua
authors.initials: Z
authors.lastname: Song
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, Shanda nanlu No. 27, Jinan 250100, PR China. Electronic address: shilingyuan@sdu.edu.cn.
authors.forename: Shiling
authors.initials: S
authors.lastname: Yuan
mesh_terms: D015394:Molecular Structure; D010316:Particle Size; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D013499:Surface Properties; D013501:Surface-Active Agents / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D010455:Peptides; D013501:Surface-Active Agents
keywords: Hydrogels; Nanobelts; Peptide amphiphiles; Self-assembly; β-sheet