Photoinduced motions in azo-containing polymers.

Progress in preparation, processing and applications of polyaniline

Laboratoire de Génie Enzymatique et Biomoléculaire, Institut de Chimie et Biochimie Moléculaires et Supramoléculaires, 43 Boulevard du 11 Novembre 1918, Villeurbanne F-69622, France, UMR5246, Centre National de La Recherche Scientifque, Villeurbanne F-69622, France, Université de Lyon, Lyon F-69622, France, Université Lyon 1, Lyon F-69622, France, Institut National des Sciences Appliquées de Lyon, EÄ cole d’Ingénieurs, Villeurbanne F-69621, France, and EÄ cole Supérieure Chimie Physique EÄ lectronique de Lyon, Villeurbanne F-69616, France

DNA biosensors and microarrays.

Processible conjugated polymers: from organic semiconductors to organic metals and superconductors

In nature, living organisms are constantly producing different macromolecules for their metabolic needs. These macromolecules, such as polysaccharides, polynucleotides, proteins, or polyesters, are essential to organism survival. Their synthesis generally involves in vivo enzyme-catalyzed chaingrowth polymerization reactions of activated monomers, which are generally formed within the cells by complex metabolic processes. Because of their diversity and renewability, microbial polymers such as polysaccharides, bacterial polyhydroxyalkanoates (1) and polyanions such as poly(γ-glutamic acid) (2) have received increasing attention as candidates for industrial applications. In many cases, microorganisms carry out polymer syntheses that are impractical or impossible to accomplish with conventional chemistry. Thus, microbial catalysts enable the production of materials that might otherwise be unavailable. Microbial polymers are synthesized from renewable low-cost feedstocks, and the polymerizations operate under mild process conditions with minimal environmental impact. In addition, microbial polymers provide products that, when disposed, can degrade to nontoxic products.

https://homepages.rpi.edu/~grossr/_doc/publication/Chem.%20Rev.%202001,%20101,%202097-2124.pdf

Polymer Synthesis by In Vitro Enzyme Catalysis

A novel strategy for the enzymatic synthesis of a water-soluble, conducting polyaniline (PANI)/sulfonated polystyrene (SPS) complex is presented. The enzyme horseradish peroxidase (HRP) is used to polymerize aniline in the presence of a polyanionic template, sulfonated polystyrene. The synthesis is simple, and the conditions are mild in that the polymerization may be carried out in a 4.3 pH buffered aqueous solution, with a stoichiometric amount of hydrogen peroxide and a catalytic amount of enzyme. UV−visible absorption, FTIR, GPC, elemental analysis, and conductivity measurements all confirm that the electroactive form of PANI, similar to that which is traditionally chemically synthesized, is formed and complexed to the SPS. The reversible redox activity of the polyaniline displays a unique hysteresis loop with pH change. Cyclic voltammetry studies show only one set of redox peaks over the potential range of −0.2 to 1.2V, which suggests that the PANI/SPS complex is oxidatively more stable. The conductiv...

Enzymatically Synthesized Conducting Polyaniline

It was recently reported that water soluble conducting polyaniline may be prepared using a new template-guided enzymatic approach. To address the mechanistic role of the template in this reaction, various macromolecular and surfactant templates were investigated. It was found that the template provides a necessary type of “local” environment where the pH and charge density near the template molecule is different from that of the bulk solution. 13C and 1H NMR studies showed that this “local” environment serves as a type of nano-reactor that is critical in anchoring, aligning, and reacting the aniline monomers and ultimately controls what form of polyaniline (conducting or insulating) is obtained during reaction. Strong acid polyelectrolytes, such as sulfonated polystyrene (SPS), are the most favorable because they provide a lower, local pH environment that serves to both charge and preferentially align the aniline monomers through electrostatic and hydrophobic interactions to promote the desired head-to-ta...

The Role of Template in the Enzymatic Synthesis of Conducting Polyaniline

Peroxidase-catalyzed template-guided polymerization of aniline has been carried out in aqueous micellar solutions of surfactants, such as sodium dodecylbenzenesulfonate, (SDBS), hexadecyltrimethylammonium bromide (CTAB), and polyoxyethylene(10) isooctylphenyl ether (Triton X-100). The properties of these enzymatically synthesized polyanilines strongly depend on the structure of the surfactants used in the formation of micelles as shown by the UV−vis−near-IR absorption spectroscopy. The micelles formed by strong acid surfactants such as SDBS are suitable templates for the enzymatic synthesis of conducting polyaniline. In solution, the micelles may serve as nanoreactors for the aniline monomer prior to the reaction and provide the necessary low-pH local environment for the growth of conducting polyaniline. The formation of low-pH local environment is further confirmed by the pH change of the bulk solution after the loading of aniline onto the micelles. FTIR, NMR, and UV−vis−near-IR absorption spectroscopy a...

Enzymatic Synthesis of Conducting Polyaniline in Micelle Solutions

Large-amplitude surface relief gratings on enzymatically synthesized poly(4-phenylazophenol) dye films were holographically induced without postprocessing steps. Recording of the gratings is strongly dependent on the polarization of the writing beams. The phase shift of the topographic grating with respect to the interference pattern was inferred by analyzing a Gaussian laser beam induced surface deformation on the dye film. The mechanism for the surface deformation and grating formation are explained in the framework of the optical field gradient force model.

Photoinduced Surface Relief Grating on Amorphous Poly(4-phenylazophenol) Films

Enzymatic synthesis, employing horseradish peroxidase (HRP), has been used to prepare a novel photoactive azopolymer, poly(4-phenylazophenol), from 4-phenylazophenol. FTIR, FT-Raman, and NMR (1H, 13C) spectroscopy show that the coupling reaction occurs primarily at the ortho positions with some coupling at the meta positions of the phenol ring of the monomer as well. This results in the formation of a branched polyphenylene backbone with pendant azo functionalities on every repeat unit of the macromolecules. This enzymatically synthesized azophenol polymer has an extremely high dye content (nearly 100%) and is soluble in most polar organic solvents, and good optical quality thin films are easily formed. Polymer solutions show reversible trans to cis photoisomerization of the azobenzene groups with long relaxation time. The poly(azophenol) film exhibits photoinduced absorption dichroism and large photoinduced birefringence with unusual relaxation behavior. The resulting azobenzene loaded polymer behaves as...

Wei Liu

Papers

Enzymatically Synthesized Conducting Polyaniline

The Role of Template in the Enzymatic Synthesis of Conducting Polyaniline

Enzymatic Synthesis of Conducting Polyaniline in Micelle Solutions

Photoinduced Surface Relief Grating on Amorphous Poly(4-phenylazophenol) Films

Enzymatic Synthesis of Photoactive Poly(4-phenylazophenol)