Despite the availability of numerous two-dimensional (2D) materials with structural ordering at the atomic or molecular level, direct construction of mesoscale-ordered superstructures within a 2D monolayer remains an enormous challenge. Here, we report the synergic manipulation of two types of assemblies in different dimensions to achieve 2D conducting polymer nanosheets with structural ordering at the mesoscale. The supramolecular assemblies of amphipathic perfluorinated carboxylic acids and block co-polymers serve as 2D interfaces and meso-inducing moieties, respectively, which guide the polymerization of aniline into 2D, freestanding mesoporous conducting polymer nanosheets. Grazingincidence small-angle X-ray scattering combined with various microscopy demonstrates that the resulting mesoscale-ordered nanosheets have hexagonal lattice with d-spacing of about 30 nm, customizable pore sizes of 7–18 nm and thicknesses of 13–45 nm, and high surface area. Such template-directed assembly produces polyaniline nanosheets with enhanced π–π stacking interactions, thereby resulting in anisotropic and record-high electrical conductivity of approximately 41 S cm–1 for the pristine polyaniline nanosheet based film and approximately 188 S cm–1 for the hydrochloric acid-doped counterpart. Our moldable approach creates a new family of mesoscale-ordered structures as well as opens avenues to the programmed assembly of multifunctional materials.

Philosophiae Doctor - PhD / The overall aim of this thesis was to prepare nanostructured more processable heteronuclear sulphonated polyanyline nanocomposites with electroconductive properties suitable for applications in biosensors. The sulphonated self-assembled polyaniline and derivatised polyaniline nanocomposites (SPAHs) were prepared by chemical oxidative polymerisation or electrical decomposition. The SPAHs prepared include those of polyaniline (PANi), poly-o-methoxyaniline (POMA) and poly-2.5 dimethoxyaniline (PDMA). Two types of sulphonic acids of heteronuclear aromatic hydrocarbons were used in the production of sulphonated SPAH composites. These were anthracene sulphonic acid (ASA) and naphthalene sulphonic acids (NSA) wich played both doping and surfactant roles. / South Africa

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The polyaniline (PAni) is a conjugated polymer that had attracted attention in the last years, due to its easy to prepare, good environmental stability and high conductivity. Their applications include the use in recharged batteries, sensors, semipermeable membranes, anticorrosive coatings and electronic devices. Besides these characteristics, PAni cannot be easily obtained as a thickness fi lms and also with good mechanical properties, because this, its practical use is limited. Then the modification on its structure with the aim of to optimize the processability and the thermal properties, maintaining the conductivity inherent of the polymer, is of fundamental importance. This work has the objective of improve the electrical properties and the thermal resistance of hybrid materials based on a conjugated polymer (PAni), a biopolymer with filmogenic property (chitosan) and a clay (Nanomer I-24). The preparation of these hybrid materials was performed by in situ chemical polymerization in presence of p-toluene sulphonic acid as dopant. The samples obtained were characterizaed by Thermogravimetric Analysis (TGA) and Differential Scanning Calorimeter (DSC), to evaluate the thermal properties of the samples, confirming that this way of preparation permits that the temperature of processing be optimized to these hybrid materials. The Infrared (FTIR - Fourier transform infrared) and Raman spectroscopy were used to assign t he kind of interaction between the polymers, suggesting that a copolymerization between PAni and chitosan occurred. Conductivity and spectroelectrochemical measurements of the samples showed that the hybrid materials maintained their electrical and electrochromic properties. / Conselho Nacional de Desenvolvimento Científico e Tecnológico / A Polianilina (PAni) é um polímero conjugado que tem atraído bastante atenção nos últimos anos devido à sua facilidade de preparação, boa estabilidade ambiental e alta condutividade. Suas aplicações incluem o uso em baterias recarregáveis, sensores, membranas semipermeáveis, revestimentos anticorrosivos, e dispositivos eletrônicos. Apesar destas características, a PAni não pode ser obtida facilmente na forma de fi lmes finos com boas propriedades mecânicas e, por isso, seu uso prático é limitado. Sendo assim, é de fundamental importância a busca por modificações na sua estrutura que venham a otimizar a processabilidade e as suas propriedades térmicas, mas que retenham a condutividade inerente do polímero conjugado. Este trabalho tem como objetivo aperfeiçoar as propriedades elétricas e a resistência térmica de materiais híbridos a base de polímero condutor (PAni - Polianilina), biopolímero com propriedade filmogênica (Quitosana) e nanocargas minerais (argila Nanomer-I 24). A preparação dos materiais híbridos foi realizada através da polimerização química in situ na presença do ácido dopante p-tolueno sulfônico (p-TSA). As amostras obtidas foram caracterizadas por análise termogravimétrica (TGA) e calorimetria diferencial de varredura (DSC) para avaliar suas propriedades térmicas, confirmando que esta forma de preparação possibilita temperaturas de processamento otimizadas para os materiais híbridos e a Difração de Raio – X (DRX) mostrou uma possível esfoliação da argila na matriz polimérica, caracterizando um nanocompósito. Os espectro de Infravermelho (FTIR) e Raman foi utilizada para atribuir o tipo de interação entre os polímeros, sugerindo que houve um processo de copolimerização entre a PAni e a Quitosana. As medidas de condutividade e a caracterização espectroeletroquimica das amostras obtidas mostraram que os materiais híbridos mantiveram as propriedades elétricas e eletrocrômicas inerentes a PAni.

Pokrok ve vývoji nanotechnologií nám poskytuje dobrou příležitost k vývoji nových špičkových zařízení. Tato práce si klade za cíl vyrobit, popsat a změřit grafenové pH senzory na dvou různých substrátech - polymeru parylenu C a SiO2. Tento pH senzor je prvním krokem ve vývoji nositelné náplasti monitorující stav kůže a možné infekce. Grafen je 2D materiál na bázi uhlíku se zajímavými vlastnosti a nadějnými aplikacemi. Úspěšně jsme provedli dva různé experimenty sloužící k charakterizaci grafenových senzorů a jejich odezvu na různé hodnoty pH. V prvním experimentu jsme použili horní elektrolytické hradlo k určení bodu neutrality (Diracův bod). Druhý experiment popsal změnu rezistence grafenu jako funkce pH. Dále jsme také funkcionalizovali grafen polyanilinem, abychom zlepšili jeho vlastnosti. Prokázali jsme citlivost grafenových senzorů na pH pro oba substráty a objevili jsme několik výzev jako potřebu kontroly iontové síly, experimentů samotných a destrukce grafenu.

Tato diplomová práce je zaměřená na výrobu Au-PANI-Au nanodrátů. Prezentovaná výroba nanodrátů je založená na elektrochemické depozici různých kovů a polymerizaci polyanilínu do porézních šablon z porézní anodické aluminy připravených anodizací hliníku. Teoretická část pojednává o základech elektrochémie a porézní anodické aluminy.

The implementation of polymer membranes in gas separation applications has been investigated to a great extent. Nevertheless, only a few types of polymers are used in commercial applications, disclosing the need for new materials with superior membrane performance to make membrane processes a more competitive technology over the conventional ones. Based on this context, this work focuses on the development of new polymeric membranes. Polyaniline (PANI), a multifaceted polymer that can change its structural properties upon various modification procedures, was chosen as membrane material. PANI membranes possess attractive O2/N2 selectivities, wherefore it is an interesting candidate for the use in gas separation applications, such as generation of oxygen-enriched air or inert gas generation. However, membranes made from neat PANI are suffering from brittleness and thus create leak paths through the membrane. Therefore PANI was blended with polybenzimidazole (PBI), a temperature stable polymer with good film-forming properties facilitating the preparation of thin, stable polymer films. Furthermore, several techniques were investigated including acid-doping, thermal treatment, and addition of titanate nanotubes (TiNTs) to enhance the separation properties. The materials that have been prepared are: 1)...

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