Structural determination of a semiconductive tetramer of aniline by IR, UV-visible, ESR, XPS and mass spectroscopy techniques

Nalwa, Hari Singh

doi:10.1007/bf00544683

Cited by 14 publications

(15 citation statements)

References 38 publications

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“…In UV–Vis spectra (Figure 3a), the solution of MASA in distilled water did not have any adsorption above 300 nm. Similar to TA in N , N ‐dimethyl formamide, all solutions of MASA‐TA in double distilled water had two absorptions around 301 nm (π–π * transition in benzene ring) and 562 nm (π B‐ ‐π Q exciton transition from benzenoid ring to quinoid ring) 11, 20, 23. Altogether, the above characterization of MASA‐TA confirmed the successful introduction of TA to MASA.…”

Section: Resultssupporting

confidence: 59%

Synthesis of Water Soluble, Biodegradable, and Electroactive Polysaccharide Crosslinker with Aldehyde and Carboxylic Groups for Biomedical Applications

Wang

Huang

et al. 2010

Macromolecular Bioscience

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We report the synthesis and characterization of a polysaccharide crosslinker of tetraaniline grafting oxidized sodium alginate with large aldehyde and carboxylic groups. We demonstrate that this copolymer has the following properties: it is water soluble under any pH, biodegradable, electroactive, and noncytotoxic; it can self-assemble into nanoparticles with large active functional groups on the outer surface; it can crosslink materials with amino and aminoderivative groups like gelatin to form hydrogels, and thus the electroactivity is readily introduced to the materials. This copolymer has potential applications in biomedical fields such as tissue engineering, drug delivery, and nerve probes where electroactivity is required.

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Section: Resultssupporting

confidence: 59%

Synthesis of Water Soluble, Biodegradable, and Electroactive Polysaccharide Crosslinker with Aldehyde and Carboxylic Groups for Biomedical Applications

Wang

Huang

et al. 2010

Macromolecular Bioscience

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“…Due to the transient nature of the intermediates, it is also possible that different pathways are involved at high vs. low proton concentrations. Many different reaction pathways and possible oligoaniline structures have been proposed in literature for aniline polymerization, ranging from N-phenylquinonediimine, [55,57,64] to linear tetramer, [65,66] to azane, [44] to phenazine constitutional units, [43] to a series of macromolecules based on 1,4-Michael-type addition on benzoquinoimine. [67] The work of Stejskal and Sapurina [43] suggests that aniline polymerization under any conditions goes through the same initial reaction sequences involving the same N-phenylphenazine-type trimer or tetramer formation.…”

Section: Resultsmentioning

confidence: 99%

Polyaniline Morphology and Detectable Intermediate Aggregates

Ding

Yang

Currier

et al. 2010

Macro Chemistry & Physics

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Formation of detectable intermediate aggregates is found to affect the morphologies of PANI nanomaterials, leading to either tubular or rod structures with striated growth and rough surfaces. By simply varying the ratio of initial proton and aniline concentration, a wide range of product morphologies can be synthesized. The intermediates form visible aggregates that can be separated by centrifugation or filtration. In addition to UV‐Vis monitoring of the intermediate aggregates, OCP and pH measurements are used to monitor the reaction process. GPC measurements show that the corresponding final products formed typically are not homogeneous. The correlation of intermediates formation and aggregation with product morphology suggests a route to controlled synthesis of PANI nanomaterials.magnified image

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“…[29][30][31] Alternative reaction pathways and Self-Assembled Polyaniline Nanotubes with Rectangular Cross-Sections many possible chemical structures of the oligoanilines formed at high pH have also been proposed in recent years. [3,[32][33][34] These vary from linear tetramer, [32] to phenazine constitutional units, [3] to azane, [33] to a series of macromolecules from 1,4-Michael type reaction. [34] The work of Stejskal and coworkers [3,12] suggest that different nanostructures (NFs, granulars, microspheres, and NTs etc.)…”

Section: Resultsmentioning

confidence: 99%

Self‐Assembled Polyaniline Nanotubes with Rectangular Cross‐Sections

Ding

Currier

Zhao

et al. 2009

Macro Chemistry & Physics

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Nanomaterials made from the conducting polymer polyaniline (PANI) have very unique applications due to their high surface area and ease of processing. The link between synthesis conditions and morphology of PANI nanomaterials has been the subject of numerous investigations in recent years. Formation mechanisms for different morphologies have also been proposed. In this work, we report a self‐assembly method to make high yield PANI nanotubes with rectangular holes and outer contours by qualitatively and purposely controlling reaction rate. We find that aggregation of detectable and separable reaction intermediates is directly correlated with PANI nanotubes formation, consistent with the observation of oligoaniline precipitates reported in the literature. Control over intermediate aggregates morphology is studied systematically. By controlling the reaction rate through adjusting acid and oxidant concentrations, we can slow down the aggregation rate of the intermediates to largely enhance the yield of nanotubes with rectangular cross‐sections. To understand the correlation between the intermediates aggregation and the morphology of the resulting PANI tubes, the morphologies of intermediate aggregates and final nanotubes were characterized using SEM, STEM, and TEM. Open circuit potential (OCP) was used to monitor the polymerization process. Molecular weight distribution results were also obtained for the intermediate aggregates and the final products. Based on our study, we propose a simple PANI nanotube formation mechanism.

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Structural determination of a semiconductive tetramer of aniline by IR, UV-visible, ESR, XPS and mass spectroscopy techniques

Cited by 14 publications

References 38 publications

Synthesis of Water Soluble, Biodegradable, and Electroactive Polysaccharide Crosslinker with Aldehyde and Carboxylic Groups for Biomedical Applications

Synthesis of Water Soluble, Biodegradable, and Electroactive Polysaccharide Crosslinker with Aldehyde and Carboxylic Groups for Biomedical Applications

Polyaniline Morphology and Detectable Intermediate Aggregates

Self‐Assembled Polyaniline Nanotubes with Rectangular Cross‐Sections

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