Synthesis and Luminescence of POSS-Containing Perylene Bisimide-Bridged Amphiphilic Polymers

A novel well-defined amphiphilic fluorescent polymer containing asymmetric perylene bisimide was designed and synthesized by combining reaction of perylene anhydride with amino functional polyhedral oligomeric silsesquioxane (POSS) and atom transfer radical polymerization (ATRP) of <i>N</i>-isopropylacrylamide (NIPAM). All the intermediate and final products were characterized by NMR, Fourier transform infrared spectroscopy (FT-IR), elemental analyses, and gel permeation chromatograph (GPC). Self-assembly of the amphiphilic polymers was investigated in aqueous solution and POSS-containing hybrid nanoparticles were obtained and characterized by dynamic laser light scattering (DLS) and transmission electron microscopy (TEM). The novel hybrid nanoparticles exhibit attractive high red fluorescence at 645 nm due to the significant effect of the bulky POSS moieties. Moreover, based on the thermoresponsive PNIPAM coronas, the fluorescence intensity of the self-assembled hybrid nanoparticles can be further enhanced and tuned by changing temperature

2,2′-Biimidazole-Based Conjugated Polymers as a Novel Fluorescent Sensing Platform for Pyrophosphate Anion

Three novel conjugated polymers based on 2,2′-biimidazole have been successfully designed and synthesized through the Suzuki coupling reactions, and their fluorescence sensing ability to metal ions and anions was investigated. The emission of the two polymers with hydrophilic side chains can be efficiently quenched by Cu²⁺ through a photoinduced electron transfer process. Moreover, the polymer–Cu²⁺ complexes exhibit excellent “turn on” sensing properties for detection of pyrophosphate (PPi) anion. These complex sensors possess high selectivity avoiding the interference from other anions, very fast response (less than 3 min) to PPi, and the detection limit of about 0.17 ppm. In addition, the linear detection range of PPi can be tuned conveniently by changing the amount of Cu²⁺ ions. Thus, the conjugated polymers can be used as a novel fluorescent sensing platform, and this work provides a new strategy for the development of PPi sensors

From 1D Polymers to 2D Polymers: Preparation of Free-Standing Single-Monomer-Thick Two-Dimensional Conjugated Polymers in Water

Recently, investigation on two-dimensional (2D) organic polymers has made great progress, and conjugated 2D polymers already play a dynamic role in both academic and practical applications. However, a convenient, noninterfacial approach to obtain single-layer 2D polymers in solution, especially in aqueous media, remains challenging. Herein, we present a facile, highly efficient, and versatile “1D to 2D” strategy for preparation of free-standing single-monomer-thick conjugated 2D polymers in water without any aid. The 2D structure was achieved by taking advantage of the side-by-side self-assembly of a rigid amphiphilic 1D polymer and following topochemical photopolymerization in water. The spontaneous formation of single-layer polymer sheets was driven by synergetic association of the hydrophobic interactions, π–π stacking interactions, and electrostatic repulsion. Both the supramolecular sheets and the covalent sheets were confirmed by spectroscopic analyses and electron microscope techniques. Moreover, in comparison of the supramolecular 2D polymer, the covalent 2D polymer sheets exhibited not only higher mechanical strength but also higher conductivity, which can be ascribed to the conjugated network within the covalent 2D polymer sheets