Influence of the secondary structure on the AIE-related emission behavior of an amphiphilic polypeptide containing a hydrophobic fluorescent terminal and hydrophilic pendant groups

AIE-related emission of polypeptide containing an AIE-active terminal is correlated with secondary structures (α-helix, β-sheet and random coil) of the peptide chains.

Fabrication of conductive polymer nanofibers through SWNT supramolecular functionalization and aqueous solution processing

Polymeric thin films and nanostructured composites with excellent electrical properties are required for the development of advanced optoelectronic devices, flexible electronics, wearable sensors, and tissue engineering scaffolds. Because most polymers available for fabrication are insulating, one of the biggest challenges remains the preparation of inexpensive polymer composites with good electrical conductivity. Among the nanomaterials used to enhance composite performance, single walled carbon nanotubes (SWNTs) are ideal due to their unique physical and electrical properties. Yet, a barrier to their widespread application is that they do not readily disperse in solvents traditionally used for polymer processing. In this study, we employed supramolecular functionalization of SWNTs with a conjugated polyelectrolyte as a simple approach to produce stable aqueous nanotube suspensions, that could be effortlessly blended with the polymer poly(ethyleneoxide) (PEO). The homogeneous SWNT:PEO mixtures were used to fabricate conductive thin films and nanofibers with improved conductivities through drop casting and electrospinning. The physical characterization of electrospun nanofibers through Raman spectroscopy and SEM revealed that the SWNTs were uniformly incorporated throughout the composites. The electrical characterization of SWNT:PEO thin films allowed us to assess their conductivity and establish a percolation threshold of 0.1 wt% SWNT. Similarly, measurement of the nanofiber conductivity showed that the electrospinning process improved the contact between nanotube complexes, resulting in conductivities in the S m(-1) range with much lower weight loading of SWNTs than their thin film counterparts. The methods reported for the fabrication of conductive nanofibers are simple, inexpensive, and enable SWNT processing in aqueous solutions, and offer great potential for nanofiber use in applications involving flexible electronics, sensing devices, and tissue engineering scaffolds.

Amorphous and crystalline blends from polytyrosine and pyridine-functionalized anthracene: hydrogen-bond interactions, conformations, intramolecular charge transfer and aggregation-induced emission

A new pyridine-terminated fluorophore of (E)-4-(2-(anthracen-9-yl)vinyl)pyridine (AnPy) with intramolecular charge transfer and aggregation-induced emission properties was synthesized and was blended with polytyrosine (PTyr) through hydrogen-bond interactions.

Surface-initiated polymerization from carbon nanotubes: strategies and perspectives

Carbon nanotubes (CNTs) represent one of the most promising materials in nanoscience today, with their unique electronic, chemical and mechanical properties. Strong van der Waals interactions and poor solubility greatly affect their potential for applications in various fields. In the past decade, great efforts have been undertaken to modify CNTs into organophilic material via covalent and non-covalent grafting strategies. This review focuses on advances in various strategies used for the surface initiated polymerization and provides perspectives on grafting polymers covalently from CNTs.