Chemistry

Center for Macromolecular Science and Engineering University of Florida, Gainesville, FL 32611 (USA)["* I Financial support from the Air Force Office of Scientific Research (F49620-96-1-0067), and the National Science Foundation REU program is gratefully acknowledged. Special thanks to Gentex Corporition for the donation of conductive oxide coated glass and to 3M for the donation of Li [N (S02CF,) 2].

We describe the template polymerization of EDOT with sulfonated poly (amic acid)(SPAA), resulting in a stable conducting polymer aqueous dispersion, PEDOT-SPAA, with particle size ca. 63 nm. In films of PEDOT-SPAA, the sulfonated poly (amic acid) template undergoes imidization within 10 min at temperatures greater than 150° C, resulting in PEDOT-sulfonated poly (imide)(PEDOT-SPI) with 10-fold conductivity enhancement. This material is highly thermally stable as compared to PEDOT-PSS.

Abstract. Electrochromic nanofibers of conducting polymer (terthiophene) have been deposited over a conventional paper sheet by means of the electrospinning technique, and subsequently photopatterned by means of UV radiation. The synthesis of a processable precursor copolymer with a norbornylene matrix and pendant units of terthiophene makes the electrospinning process available, and allows for chemical or electrochemical crosslinking of the precursor copolymer to obtain a conducting polymer.

Solid-state electrochromic windows from 3, 4-propylenedioxythiophene (ProDOT) derivatives using dual polymer electrochromic architecture were fabricated and their electro-optical characteristics were recorded. DibenzylProDOT (DiBz-ProDOT) and biphenylmethyloxymethyl ProDOT (BPMOM-ProDOT) were used as cathodically coloring polymers, whereas bis (2-(3, 4-ethylenedioxy) thienyl)-N-methyl carbazole (BEDOT-NMCz) was used as their complementary anodically coloring polymer.

A general procedure to calculate the maximum contrast from an electrochromic material is presented. The obtained results were tested by spectroelectrochemical studies of two different conducting polymer films: poly-3, 4-ethylenedioxy-thiophene (PEDOT) and poly-3, 6-bis (2-(3, 4-ethylenedioxy) thienyl)-N-methylcarbazole (PBEDOT-NMCz). The presented methodology constitutes a useful tool for the optimization of electrochromic devices.

Herein we report the photolithography of electrochromic conjugated polymer (CP) films on the micron scale without exposing the CP to high energy UV radiation. The synthesis of polynorbornene-based precursor copolymers having units with pendant terthiophenes and photocrosslinkable units allows for photopatterning at an earlier stage with respect to the polymerization (chemically or electrochemically) that yields the conducting polymer.

DNA–magnetite hybrid nanofibers were fabricated by electrospinning a spin dope consisting of oleic acid coated magnetite nanoparticles and DNA–CTMA in ethanol/chloroform mixed solvent. The fabricated nanofibers exhibit superparamagnetic behaviour owing to embedded magnetite nanoparticles.

A series of derivatized bis (pyrrol-2-yl) arylenes, specifically 1, 4-bis (pyrrol-2-yl) benzene (1e, BPB), 1, 4-bis (pyrrol-2-yl)-2, 5-dimethoxybenzene (2e, BPB (OCH3) 2), 1, 4-bis (pyrrol-2-yl)-2, 5-diethoxybenzene (3e, BPB (OC2H5) 2), 1, 4-bis (pyrrol-2-yl)-2, 5-didodecyloxybenzene (4e, BPB (OC12H25) 2), 2, 6-bis (pyrrol-2-yl) naphthalene (5e, BPN), and 4, 4'-bis (pyrrol-2-yl) biphenyl (6e, BPBP) have been synthesized. Cyclic voltammetry shows these monomers to oxidize at relatively low potentials to form cation radicals.

Abstract The photostability of the nonlinear optical dye, Hemi-22, improves upon encapsulation in DNA thin films. The interactions of Hemi-22 with DNA, along with the intrinsic properties of DNA are responsible for these remarkable improvements in the photostability of the dye in comparison to the dye in a poly (methyl methacrylate) as a control.

With the availability of electrochromic conjugated polymers [1] exhibiting transitions of the three primary colors, fullcolor electrochromic displays could be realized in the near future.[2] Although many, but not all, of the color transitions have been addressed, there is a need for rapid and wide-area processing methods as well as materials with response times within the millisecond regime in order to obtain an active display.

Poly (3, 4-ethylenedioxy) thiophene-poly (styrene sulfonate)(PEDOT-PSS) was used as the conductive component in a matrix of chemically different insulating polymers to form an array of vapor detectors. Such composites produced larger relative differential resistance responses when exposed to polar analytes than did the corresponding carbon black filled polymer composite detectors. However, the PEDOT-PSS composites produced smaller responses than carbon black composites when exposed to nonpolar analytes.

A new methodology for the electrochemical characterization of any device constituted by two electroactive films of conducting polymers, such as electrochromic windows, artificial muscles, polymeric batteries or supercapacitors, is proposed. During electrochemical characterization of dual polymer devices, the charge consumed by the device and the independent potential evolution vs. a reference electrode (oxidation states) of the two constituent materials are followed.

Abstract. The dual polymer configuration is commonly used when constructing electrochromic devices (ECDs) due to the expected electrochemical stability and enhanced optical properties. In this configuration, two different polymers are used which are optically complementary.

Conventional approaches to chemical sensors have traditionally made use of a “lock-and-key” design, wherein a specific receptor is synthesized in order to strongly and highly selectively bind the analyte of interest. 1-6 A related approach involves exploiting a general physicochemical effect selectively toward a single analyte, such as the use of the ionic effect in the construction of a pH electrode.

Detection of multiple cancer biomarker proteins in human serum and tissue at point-of-care is a viable approach for early cancer detection, but presents a major challenge to bioanalytical device development. This article reviews recent approaches developed in our laboratories combining nanoparticle decorated electrodes and multilabeled secondary antibody labeled particles to achieve high sensitivity for the detection of cancer biomarker proteins.

We report the synthesis and electrochemical polymerization of a series of bisheterocycle-N-substituted carbazoles. These monomers exhibit low peak oxidation potentials (E p, m) which range from 0.15 to 0.46 V vs Ag/Ag+, indicating facile polymerization. Repeated scan electrochemical polymerization for these monomers proceeds rapidly, relative to carbazole, to form stable electroactive films.