Photophysical Properties Of Polymers Research Articles

Synthesis and fluorescent properties of diblock terpolymer micelles modified with an aromatic thioether-based AIE fluorophore

Aggregation-induced emission (AIE) is a rapidly evolving field particularly suited for bioapplications including imaging and sensing. We introduce a water-soluble block copolymer/AIE micelle system, in which we incorporate an aromatic thioether-based fluorophore with AIE properties into an amphiphilic diblock terpolymer via covalent post-modification. For that, we synthesized a series of poly(ethylene oxide)-block-poly(styrene-co-hydroxyethyl methacrylate) (PEO-b-P(S-co-HEMA)) diblock terpolymers by atom transfer radical polymerization featuring a hydrophilic PEO block, and a hydrophobic block of PS statistically segmented with HEMA for covalent fluorophore attachment. Synthetic steps were monitored with NMR and IR spectroscopy, mass spectrometry, and gel permeation chromatography (GPC). Self-assembly of the fluorophore-modified block copolymers in water resulted in micelles with fluorescent properties attributed to the immobilized AIEgen within the micelle core. The micelle morphology was analyzed with transmission electron microscopy (TEM) and dynamic light scattering (DLS), while photophysical properties of polymers and micelles were comprehensively investigated with fluorescence spectroscopy. In perspective, the presented diblock terpolymer can be modified with a range of compatible fluorophores, which allows the direct comparison of fluorophore performance in identical assemblies.

Creation of Carbazole-Based Fluorescent Porous Polymers for Recognition and Detection of Various Pesticides in Water.

The development of sensitive, fast, and portable methods for detecting the residual toxic pesticides is essentially important because of the increasing concerns for public health and safety. For this purpose, three fluorescent porous organic polymers containing pendant N-benzyl carbazole, N-benzyl dibromo-carbazole, and N-benzyl dimethoxy-carbazole groups were synthesized via a one-step polymerization reaction. The resultant polymers emit bright cyan, blue, and green light under the ultraviolet lamp, respectively, with the Brunauer-Emmett-Teller area up to 858 m2 g-1 and tunable pore sizes in the range of 0.5-36 nm. Six pesticides including trifluralin, isopropalin, glyphosate, fenitrothion, imidacloprid, and cyfluothrin are selected as the analytes to investigate the recognition and detection ability of polymers in terms of the different photo-physical properties of polymers, chemical structure of organic pesticides as well as the pore sizes of polymers, and molecular sizes of pesticides. It is interesting to find that, even though in water medium, the measured fluorescent quenching Stern-Volmer coefficient for trifluralin still reaches 26,040 L mol-1 and is nearly unchanged under both acidic or basic service conditions. Moreover, the test paper prepared from the polymer exhibits a rapid fluorescent response when contacting the aqueous trifluralin dispersion liquid, and the sensitivity remains stable after recycling use for twelve times.

Synthesis and Characterization of Indolo[3,2-b]indole Based Copolymers for Bulk Heterojunction Polymer Solar Cell

A series of donor-acceptor low band gap polymers (DINIBT-C8, DINIBT-C10 and DINIBT-EH) containing 5,10-dihydroindolo[3,2-b]indole (DINI) as an electron donating unit and benzothiadiazole (BT) as an electron accepting unit with various kinds of alkyl chains (octyl; C8, decyl; C10 and ethyl hexyl; EH) on the donor unit have been designed, synthesized, and characterized for bulk heterojunction polymer solar cell applications. Due to the presence of long alkyl chains on the donor unit, all the polymers showing good solubility in common organic solvents. The frontier orbital energy levels of polymers were calculated using cyclic voltametry analysis. The influence of alkyl chains on the photo-physical properties of polymers were carried out. Among the three polymers, the DINIBT-C8 shows higher absorption coverage and good energy level matching with acceptor PC71BM than that of the other two polymers. Thus, the bulk-heterojunction polymer solar cells (BHJ PSCs) were fabricated using DINIBT-C8:PC71BM as an active layer with the configuration of ITO/PEDOT/ DINIBT-C8:PC71BM/LiF/Al. The DINIBT-C8 shows the maximum PCE of 0.16%.

Construction of diads and triads copolymer systems containing perylene, porphyrin, and/or fullerene blocks

AbstractA series of conjugated copolymers containing perylene, porphyrin, and/or fullerene units on the main chain have been synthesized. The structures and photophysical properties of polymers were characterized by FTIR, NMR, UV–vis, and fluorescence spectroscopy, gel permeation chromatography, and cyclic voltammetry. The photoinduced charge transfer properties of the films were also measured by a three‐electrode cell technique. A rapid, steady, and reproducible cathodic photocurrent response for each polymer was produced when the film was irradiated by a white light. The SEM and TEM images displayed the aggregation superstructures of the polymers. In chloroform, polySPeZnP2F could form a large quantity of spherical nanoparticles. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5863–5874, 2006

Synthesis and Photophysical Properties of Polymers Containing a Novel Class of Light Emitters

Synthesis and Photophysical Properties of Polymers Containing a Novel Class of Light Emitters