ANDRADE NETO, Davino Machado. Magnetic ressonance imaging contrast agents obtained by fast sonochemistry approach. 2016. 84 f. Dissertação (Mestrado em Química)-Universidade Federal do Ceará, Fortaleza, 2016. / Submitted by Aline Mendes (alinemendes.ufc@gmail.com) on 2017-01-25T19:35:32Z No. of bitstreams: 1 2016_dis_dmandradeneto.pdf: 4658452 bytes, checksum: 4d05fbe6bccc67518a89306c468793a6 (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2017-01-26T20:28:31Z (GMT) No. of bitstreams: 1 2016_dis_dmandradeneto.pdf: 4658452 bytes, checksum: 4d05fbe6bccc67518a89306c468793a6 (MD5) / Made available in DSpace on 2017-01-26T20:28:31Z (GMT). No. of bitstreams: 1 2016_dis_dmandradeneto.pdf: 4658452 bytes, checksum: 4d05fbe6bccc67518a89306c468793a6 (MD5) Previous issue date: 2016 / Functionalized Fe3O4 nanoparticles (NPs) have emerged as a promising contrast agent for magnetic resonance imaging (MRI). Their synthesis and functionalization methodology strongly affects their performance in vivo. Although thermal decomposition is the most commonly used growth methodology reported in the literature, it has proven to be time-consuming, expensive, and laborious. Therefore, this work describes a rapid and facile sonochemical methodology to synthesize and functionalize Fe3O4 NPs with excellent physico-chemical properties for MRI. In this work, a sonochemistry approach was used to produce, in 12 min, Fe3O4 NPs functionalized with polysodium acrylate (PAANa), trisodium citrate (CIT), branched polyethylenimine (BPEI), and sodium oleate. X-ray diffraction and transmission electron microscopy demonstrated that the NPs were composed of a single inverse spinel phase with an average diameter of 9–11 nm and a narrow size distribution. It was confirmed by Mössbauer spectroscopy and magnetic measurements that the obtained NPs were transitioning to the superparamagnetic regime and possessed excellent magnetization saturation values (59–77 emu/g). Fourier transform infrared spectroscopy proved that the sonochemistry approach provided conditions that induced a strong interaction between Fe3O4 and the capping agents. Furthermore, dynamic light scattering experiments evidenced that samples coated with PAANa, CIT, and BPEI possess colloidal stability in aqueous solvents. Emphasis must be placed on PAANa-coated NPs, which also presented remarkable colloidal stability under simulated physiological conditions. Finally, the obtained NPs exhibited great potential to be applied as an MRI contrast agent. The transverse relaxativity values of the NPs synthesized in this work (277–439 mM-1s-1) were greater than those of commercial NPs and those prepared using other methodologies. Therefore, this work represents significant progress in the preparation of Fe3O4 NPs, providing a method to prepare high-quality materials in a rapid, cost-effective, and facile manner. / Nanopartículas (NPs) funcionalizadas emergiram como promissores candidatos para serem aplicadas como agente de contraste para imagem por ressonância magnética nuclear e sua metodologia de síntese e funcionalização afetam fortemente sua performance in vivo. A metodologia mais utilizada para a produção dessas NPs funcionalizadas é a decomposição térmica, a qual tem provado ser financeiramente desfavorável, laboriosa além de requisitar longos tempos de execução. Portanto, este trabalho tem como objetivo descrever uma metodologia fácil e rápida, através do método sonoquímico, para a síntese e funcionalização de NPs de Fe3O4 com excelentes propriedades físico-químicas com objetivo de serem aplicadas como agente de contraste para imagem por ressonância magnética nuclear. Neste trabalho, o método sonoquímico foi usado para produzir, em 12 min, NPs de Fe3O4 funcionalizadas com policrilato de sódio, citrato de sódio, polietilenamina ramificada e oleato de sódio. Difração de raios-X e microscopia eletrônica de transmissão demonstraram que as NPs produzidas são compostas de uma única fase de espinélio inverso de 9-11 nm de diâmetro e uma distribuição de tamanho estreita. Foi confirmado por meio da espectroscopia Mössbauer e medidas magnéticas que as NPs sintetizadas estão em transição para o regime superparamagnético e que possuem excelente valor de magnetização de saturação (59-77 emu/g) para aplicações biomédicas. Espectroscopia de infravermelho por transformada de Fourier provou que a radiação sonoquímica forneceu condições adequadas para que acontecesse uma interação forte entre o núcleo magnéticos e os agentes fucionalizantes. Além disso, experimentos de espalhamento dinâmico de luz confirmaras que as amostras recobertas com moléculas orgânicas hidrofílicas possuem estabilidade coloidal em solventes aquosos. Destaque deve ser dado a nanopartícula magnética recoberta com poliacrilato de sódio, que demonstrou excelente estabilidade coloidal em condições fisiológicas simuladas. Finalmente, as NPs obtidas se mostraram serem promissores candidatos a agentes de contraste. Uma vez que seus valores de relaxatividade transversal foram maiores que os agentes de contraste comerciais e daqueles preparados por outras metodologias sintéticas. Portanto, este trabalho trás um grande avanço no que se refere a preparação de NPs de Fe3O4 funcionalizadas para aplicações biológicas, uma vez que materiais de alta qualidade foram preparados de forma rápida e fácil.

abstract: Titanium oxide (TiO2), an abundant material with high photocatalytic activity and chemical stability is an important candidate for photocatalytic applications. The photocatalytic activity of the TiO2 varies with its phase. In the current project, phase and morphology changes in TiO2 nanotubes were studied using ex-situ and in-situ transmission electron microscopy (TEM). X-ray diffraction and scanning electron microscopy studies were also performed to understand the phase and morphology of the nanotubes. As prepared TiO2 nanotubes supported on Ti metal substrate were amorphous, during the heat treatment in the ex-situ furnace nanotubes transform to anatase at 450 oC and transformed to rutile when heated to 800 oC. TiO2 nanotubes that were heat treated in an in-situ environmental TEM, transformed to anatase at 400 oC and remain anatase even up to 800 oC. In both ex-situ an in-situ case, the morphology of the nanotubes drastically changed from a continuous tubular structure to aggregates of individual nanoparticles. The difference between the ex-situ an in-situ treatments and their effect on the phase transformation is discussed. Metal doping is one of the effective ways to improve the photocatalytic performance. Several approaches were performed to get metal loading on to the TiO2 nanotubes. Mono-dispersed platinum nanoparticles were deposited on the TiO2 nanopowder and nanotubes using photoreduction method. Photo reduction for Ag and Pt bimetallic nanoparticles were also performed on the TiO2 powders. / Dissertation/Thesis / M.S. Materials Science and Engineering 2014

O presente trabalho é parte de um projeto maior que abrange pesquisadores de áreas complementares em química que visam a elaboração de estratégias sintéticas voltadas para a síntese de monômeros fenilacetilênicos derivados de aminoácidos ou calcogenetos onde, a partir desses, deverão ser construídos polímeros helicoidais de estruturas planejadas passíveis de funcionalização em nanopartículas de ouro e/ ou prata (NPsAu e NPsAg, respectivamente), que sejam capazes de modificar suas conformações frente a estímulos externos, formando assim, sensores poliméricos suportados em superfície de nanopartículas metálicas. A dissertação de mestrado que apresentaremos se dedica a um fragmento desse todo que trata especificadamente de estudos envolvendo a organofuncionalização de NPsAu e NPsAg com compostos orgânicos de selênio, bem como o desenvolvimento de metodologias na preparação de entidades monoméricas fenilacetilênicas derivadas de aminoácidos e organoselenetos. Por fim, alguns dos monômeros preparados serão polimerizados e devidamente caracterizados. Sendo assim, o trabalho foi dividido em duas partes, onde a primeira trata da preparação e funcionalização de organoselenetos em NPs e a segunda discorre sobre a síntese e polimerização dos monômeros. No que diz respeito à funcionalização de NPs com organoselenetos, foi preparada uma série de disselenetos derivados de aminoálcoois e aminoácidos. A proposta síntética na preparação desses compostos foi baseada na reação de substituição nucleofílica de segunda ordem de mesilatos ou haletos orgânicos por disselenolato de dilítio, o qual é gerado pela redução de selênio elementar por trietilboroidreto de lítio. Os organoselenetos foram funcionalizados em NPsAu e NPsAg pela simples mistura em etanol, cujos materiais híbridos resultantes dessa reação foram caracterizados por espetroscopia Raman. No capítulo que trata da síntese de monômeros, procedeu-se primeiramente a preparação de blocos construtores fundamentais contendo a porção fenilacetilênica e na sequência a homologação com aminoácidos protegidos ou selenetos orgânicos munidos de grupos alquílicos. Alguns dos monômeros preparados foram submetidos a reações de polimerização e co-polimerização gerando polímeros helicoidais com sentido helicoidal predominante, o que pôde ser confirmado por dicroísmo circular. Os objetivos do projeto foram alcançados com êxito e a maioria dos problemas em potencial puderam ser solucionados. O presente trabalho foi a primeira empreitada do projeto maior ao qual este está vinculado e proporcionará subsídios para os demais estudantes envolvidos alcançarem resultados em termos de aplicação. / The present work is part of a bigger project involving researchers of complementary areas in chemistry concerned on development of new synthetic strategies towards phenylacetylenic monomers bearing amino acid and/or organoselenide derivatives, that will be used to prepare helical polymers with planned structure capable to functionalize gold and silver nanoparticles (AuNPs and AgNPs, respectively) which could modify their conformations when submitted to external stimuli, acting as a polymeric sensor supported in the surface of the metal nanoparticles. This master\'s dissertation is devoted to a fragment of the whole work which involves studies regarding the AuNPs and AgNPs organofunctionalization with selenium organic compounds, as well as the development of new methodologies for the preparation of phenylacetylenic monomers synthesis bearing amino acid and selenide derivatives. Some of the prepared compounds have been polymerized and characterized. In this way, the work was divided in two chapters, whereas the first deals with organoselenium compound preparation and NP functionalization, and the synthesis and polymerization of the monomers. Regarding the NPs functionalization with organoselenides, a series of amino alcohol and amino acid diselenide derivatives was prepared. The synthetic approach was based upon the second order nucleofilic substitution of organic mesylates and halides by dilithium disselenolate, wich way was generated reducing elemental selenium with lithium tryethylborohydride. The NPs were functionalized with the diselenides after the mixture of both in ethanol, and the resulting hybrid materials were characterized by Raman spectroscopy. In the second chapter, we report on the fundamental building blocks preparation containing the phenylacetylenic group and its homologation with amino acids or organic selenides. Some of the final monomers were submitted to polymerization reactions, generating one hand preferred helical polymers, which was confirmed by circular dichroism. The main goal of the project were successfully reached and the potential problems could be solved. The present work was the first step of the major project in which it is tied and will give subsidy to other students involved to reach some results application.

O estudo de nanopartículas plasmônicas de ouro sob o ponto de vista conceitual foi o foco desta tese, explorando principalmente os efeitos do envoltório molecular e a intensificação dos espectros SERS tendo em vista aplicações em sensoriamento químico. Como moléculas sonda, foram selecionadas espécies multifuncionais, como a 2,4,6-trimercapto-1,3,5-triazina (TMT), 4,5-diamino-2,6- dimercaptopirimidina (DadMcP ou Dad) e a mercaptoetilpirazina (PZT), que apresentam grupos tióis capazes de ancorar nas nanopartículas de ouro, deixando outros sítios livres para interagir com substratos e complexos metálicos. Observou-se que o envoltório molecular formado no método de Turkevich, é bastante dependente das condições de síntese, tendo sido possível detectar a presença do intermediário da reação de oxidação do citrato na superfície das nanopartículas, sob condições controladas, influenciando drasticamente o comportamento SERS. Foi feito um estudo sistemático da molécula sonda 2,4,6-trimercapto-1,3,5-triazina ancorada nas nanopartículas de ouro, tanto por troca da camada passivante (citrato), como por síntese in situ com e sem agente redutor. Esses sistemas foram investigados, sob diferentes condições, como sensores SERS para metais. Esse estudo foi ampliado para a molécula sonda 4,5-diamino-2,6-dimercaptopirimidina (DadMcP), explorando a influência do tempo na coordenação dessa espécie na superfície e o efeito de diferentes eletrólitos nos processos de agregação. Finalmente, foram apresentadas fortes evidências da ocorrência de processos fotoinduzidos envolvendo as nanopartículas funcionalizadas, com destaque para a mercaptoetilpirazina (PZT), cujo comportamento mostrou-se bastante inusitado, gerando filmes fotoagregados sob influência da luz UV com possível aplicação em fotolitografia. / The study of plasmonic gold nanoparticles under the conceptual point of view was the focus of this thesis, exploring mainly, the effects of molecular shell and the intensification of SERS spectra aiming at applications in chemical sensing. For the probe molecules, multifunctional species were selected, such as a 2,4,6-trimercapto- 1,3,5-triazine (TMT), 4,5-diamine-2,6-dimercaptopyrimidine (DadMcP or Dad) and mercaptoethylpyrazine (PZT) which present thiol groups able to anchor onto gold nanoparticles, leaving available sites for further interaction with substrates and metal complexes. It was observed that the molecular shell in Turkevich\'s method is very dependent on the synthesis condition, being possible to detect the intermediate product of citrate oxidation reaction in the nanoparticle surface, under controlled conditions, dramatically influencing the SERS behavior. A systematic study was conduct with the probe molecule 2,4,6-trimercapto-1,3,5-triazine anchored to gold nanoparticles either by changing the passivating layer (citrate), or for in situ synthesis with and without a reducing agent. These systems were investigated under different conditions as SERS sensors for metals. This study was extended to the probe molecule 4,5-diamine-2,6-dimercaptopyrimidine, exploiting the influence of time in the coordination of such species and also the effect of different kinds of eletrolytes in the aggregation process. Finally, it has been presented strong evidences for the occurence of photoinduced processes involving functionalized nanoparticles with emphasis on mercaptoethylpyrazine, whose bahavior has proved to be very unusual, generating photoaggregated films under UV light influence, with possible applications in photolithography.

Orientador: Heloise de Oliveira Pastore / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-24T05:33:50Z (GMT). No. of bitstreams: 1 Vieira_RomuloBatista_M.pdf: 2977230 bytes, checksum: 57a4048c4901f10fbcf41751f5c96040 (MD5) Previous issue date: 2013 / Resumo: A síntese dos silicatos lamelares bem como as modificações com polietilenimina (PEI) foram confirmadas através de difração de raios-X (DRX), espectroscopia no infravermelho (FT-IR), ressonância magnética nuclear (RMN) de C e Si. Modificações do tipo não covalentes (intercalação) e covalentes (reação de sililação) nos silicatos lamelares foram realizadas com PEI de forma sintetizar um novo tipo de adsorvente que tenha boas propriedades para a adsorção de CO2. Diversas metodologias para a modificação de PEI foram propostas e todas conseguiram ligar covalente ou não-covalentemente a PEI nas lamelas da magadiita. Verificou-se uma relação entre a concentração de íons hexadeciltrimetilamônio (CTA) presentes e a eficiência no grau de funcionalização de grupos cloropropil na magadiita. Quando realizou-se troca iônica com a PEI protonada, os melhores de resultados foram obtidos em pH 9, sugerindo que as aminas terciárias presentes na PEI foram protonada primeiramente. Através da dessorção à temperatura programada de CO2 (TPD-CO2) para os materiais estudados: magadiita impregnada com PEI (MAG-PEIx) e magadiita trocada com CTA na razão molar de 25 % (25CTA-MAG-PEIx); foi possível identificar a presença de dos sítios de adsorção presentes na PEI: camada exposta de PEI e PEI bulk, além de mostrar que o modelo de adsorção segue o modelo de subsuperfície. Os resultados de TPD-CO2 tiveram suas curvas de dessorção ajustadas ao modelo cinético de Avrami, apresentando uma boa correlação e mostrando que há interações diferentes entre o adsorvente (aminas primárias, secundárias e grupos Si-OH) e o CO2. Os melhores resultados de adsorção mostraram uma capacidade de 6,11 mmol g, na temperatura de adsorção de 75 °C, durante 3 h. / Abstract: The syntheses of layered silicates as well as changes in PEI were confirmed by X-ray diffraction (XRD), infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) C and Si. Non-covalent modifications of the type (intercalation) and covalent (silylation reaction) in the layer silicates were performed with polyethylenimine (PEI) in order to synthesize a new type of adsorbent that has good properties for the adsorption of CO2. Several methodologies for modification of PEI have been proposed and succeeded to bind covalent or non-covalent into the interlayer space of magadiite. There was a relationship between the concentration of hexadecyltrimethylammonium ions (CTA) present and the efficiency in the degree of functionalization of the magadiite chloropropyl groups. When the ion exchange was carried out with the protonated PEI, the best results were obtained at pH 9, suggesting that the tertiary amines are protonated first. CO2-TPD for the materials studied: magadiite impregnated with PEI (MAG-PEIx) and magadiite exchanged with CTA at molar ratio 25% (25CTA-MAG-PEIx) was possible to identify the presence of different adsorption sites present in PEI: exposed layer of PEI and PEI bulk, and show that the adsorption model follows the subsurface model. The results of the desorption curves was fitted by Avrami kinetic model, showing a good correlation and revealing different interactions between the adsorbent (primary, secondary and Si-OH groups) and CO2. The best results showed adsorption capacity of 6.11 mmol g, at 75 ° C for 3h. / Mestrado / Quimica Inorganica / Mestre em Química

The work described in this thesis concerns development, synthesis and characterisation of new molecular compounds and materials based on the carbon allotropes fullerene (C60) and graphene. A stepwise strategy to a symmetric ferrocene-linked dumbbell of fulleropyrrolidines was developed. The versatility of this approach was demonstrated in the synthesis of a non-symmetric fulleropyrrolidine-ferrocene-tryptophan triad. A new tethered bis-aldehyde, capable of regiospecific bis-pyrrolidination of a C60-fullerene in predominantly trans fashion, was designed, synthesised and reacted with glycine and C60 to yield the desired N-unfunctionalised bis(pyrrolidine)fullerene. A catenane dimer composed of two bis(pyrrolidine)fullerenes was obtained as a minor co-product. From the synthesis of the N-methyl analogue, the catenane dimer could be separated from the monomeric main product and fully characterised by NMR spectroscopy. Working towards organometallic fullerene-based molecular wires, the N-unfunctionalised bis(pyrrolidine)fullerene was coupled to an activated carboxyferrocene-fullerene fragment by amide links to yield a ferrocene-linked fullerene trimer, as indicated by mass spectrometry from reactions carried out at small scale A small library of conjugated diarylacetylene linkers, to be coupled to C60 via metal-mediated hydroarylation, was developed. Selected linker precursors were prepared and characterised, and the hydroarylation has been adapted using simple arylboronic acids. Few-layer graphene was prepared and dip-deposited from suspension onto a piezoelectric polymer substrate. Spontaneous side-selective deposition was observed and, from the perspective of non-covalent interaction, rationalised as being driven by the inbuilt polarization of the polymer. Aiming for selectively edge-oxidized graphene, a number of graphitic materials were treated with a combination of ozone and hydrogen peroxide under sonication. This mild, metal-free procedure led to edge-oxidation and exfoliation with very simple isolation of clean materials indicated by microscopy, spectroscopy, and thermogravimetric analysis.

The field of metal-catalyzed C–H bond functionalizations is an incredibly vibrant and spans beyond the formations of biaryl motifs. The introduction chapter will cover the mechanistic aspects of the C–H bond functionalization with metal-carboxylate complexes. The mechanistic facets of this reaction will be the main conducting line between the different sections and chapters of the first part of this thesis. In the second chapter, will be described additives that can readily promoted C–H bond arylation of poorly reactive substrates. More specifically, we will revisit the intramolecular direct arylation reaction we will demonstrate the effect of pivalic acid as a co-catalyst by developing milder reaction conditions. In the third chapter we be described experimental and computational studies which suggested that the a single pathway might be involved in the palladium-catalyzed C–H bond functionalization of a wide range of (hetero)arene. Following this we will describe a general set of conditions for the direct arylation of wide range of heteroarenes. Also, we will present two different strategies to selectively and predictably arylate substrates containing multiple functionalizable C–H bonds. In the fourth chapter will be presented our efforts toward the development of new C–H bond functionalization methods in which we could apply our knowledge on the C–H bond cleavage and apply it to the formation of new scaffolds. The development of two new palladium-catalyzed methods were also described. In the fifth chapter, our effort toward the development of ligands to specifically promoted C–H bond cleavage will be presented. In the sixth chapter will be presented the latest results on the study of the mechanism of the C–H bond cleavage combining experimental and computational studies. In part B of this thesis will be presented our strategy toward the total synthesis of ginkgolide C that included two gold(I)-catalyzed reactions as key steps in the preparation of the spiro[4.4]nonane core of this natural product. The first studies on the feasibility of the key steps of the synthesis will be described.

Dicyclopentadiene (DCPD), a tricyclic olefin, is available from the C5 fraction of petroleum feedstocks. Owing to its high reactivity (due to the presence of a strained alkene), low cost, and lack of other commercial uses, DCPD has been extensively pursued as a monomer for use in ring-opening metathesis polymerization processes. The olefin metathesis reaction, for which Yves Chauvin, Robert H. Grubbs, and Richard R. Schrock received the 2005 Nobel prize, is among the most attractive approaches to polymerize olefins, allowing production of high-molecular weight polymers including linear macromolecules, block copolymers, and crosslinked materials. Polydicyclopentadiene (PDCPD), which can be produced using a variety of early- and late-transition metal catalysts, is a thermoset polymer with a highly crosslinked structure. PDCPD has excellent impact strength, high storage modulus, good chemical resistance, wide service temperature range, and low density. As a result, it has found broad commercial utility in industrial manufacturing. Additionally, the reaction injecting molding (RIM) process used for DCPD polymerization makes it possible to precisely control the shape and dimensions of PDCPD products. Owing to its lack of chemical functionality, however, polydicyclopentadiene has many limitations. Previously, our research group developed a modified dicyclopentadiene monomer by adding an electron withdrawing group – a methyl ester functional group – on the pendent cyclopentene ring of the monomer. Polymerization of this functionalized monomer led to a novel thermoset material – methyl ester functionalized polydicyclopentadiene (fPDCPD) – that exhibits tunable surface hydrophobicity. In experiments described in this dissertation, my collaborators and I confirmed the thermal crosslinking mechanism of fPDCPD using a combination of solution-state and solid-state NMR, FTIR, and Raman spectroscopy. We also explored the surface chemistry of our novel material, by harnessing the embedded functional group in order to exert finer control over hydrophobicity, and to control interactions with biological organisms through the conjugation of biologically relevant functional groups. To further extend the utility of our functionalized dicyclopentadiene monomer, we synthesized a series of statistical polymers: fPDCPD-stat-PDCPD. Once again, we used a wide range of characterization methods, and showed that we can both tune the surface hydrophobicity of the copolymers and manipulate the mechanical properties by adjusting the molar fractions of functionalized and non-functionalized monomers. Chemical structures of these copolymers were interrogated by NMR, FTIR, and Raman spectroscopy. Frontal ring-opening metathesis polymerization was applied in an effort to study the kinetics of (co)polymerization. Finally, to lay the groundwork for future fPDCPD manufacturing, we successfully optimized the production of fDCPD monomers to half-kilo scale and fPDCPD polymers at 20-gram scale, while developing a reaction-injection molding process that permitted the production of dimensionally controlled fPDCPD objects. This in turn allowed us to conduct a rigorous assessment of the mechanical properties of our fDCPD through dynamic mechanical analysis (DMA), which established for the first time that our functionalized material has a comparable storage modulus to that of the parent (unmodified) PDCPD. The development of fPDCPD is approaching a new stage where it is ready to be commercialized and mass produced. We hope that our novel fPDCPD material will soon play a crucial role in replacing traditional metallic components in vehicle design and engineering material manufacturing. / Graduate / 2021-12-14

In this dissertation, three aspects about surface and interface engineering of conjugated polymers and nanomaterials will be discussed. (i) There is a significant promise for electroactive conjugated polymers (ECPs) in applications of electrochemical devices including energy harvesting, electrochromic displays, etc. Among these, ECPs has also been developed as electroactive materials in electrochemical supercapacitors (ESCs). Compared with metal oxides, ECPs are attractive because they have good intrinsic conductivity, low band-gaps, relatively fast doping-and-undoping process, the ease of synthesis, and tunable electronic and structural properties through structural modifications. Here, Multiple-branch-chain 3,4-ethylenedioxythiophene (EDOT) derivatives was designed as crosslinkers in the co-electropolymerization of EDOT to optimize its morphology and improve the cycling stability of PEDOT in the supercapacitor applications. High-surface-area π-conjugated polymeric networks can be synthesized via the electrochemical copolymerization of the 2D (trivalent) motifs benzo[1,2-b:3,4-b’:5,6-b’’]trithiophene (BTT) and tris-EDOT-benzo[1,2-b:3,4-b’:5,6-b’’]trithiophene (TEBTT) with EDOT. Of all the material systems studied, P(TEBTT/EDOT)-based frameworks achieved the highest areal capacitance with values as high as 443.8 mF cm-2 (at 1 mA cm-2), higher than those achieved by the respective homopolymers (PTEBTT and PEDOT) in the same experimental conditions of electrodeposition (PTEBTT: 271.1 mF cm-2 (at 1 mA cm-2); PEDOT: 12.1 mF cm-2 (at 1 mA cm-2). (ii) In electrochemical process, the suitable choice of appropriate electrolytes to enlarge the safe working potential window with electrolyte stability is well known to improve ECPs’ performance in ESCs applications. Ionic liquids (ILs) are ion-composed salts and usually fluid within a wide temperature range with low melting points. There are many unique characteristics for these intrinsic ion conductors, including high ionic conductivity, wide electrochemical voltage windows in neutral conditions, fast ion mobility in redox reaction process (>10-14 m2 V-1 s-1), low vapor pressure, and environmental stability. These properties qualified ambient-temperature ILs to be applied as supporting medium for various devices and materials processing applications in both industry and academia, overcoming the limitation of volatile organic compounds (VOCs). Especially, ILs have been utilized as superior medium to electrodeposit metals, alloys, semiconductors and ECPs in the application of supercapacitors. Electropolymerization of EDOT and its derivative 4,4'-dimethoxy-3,3'-bithiophene (BEDOT) have been studied in three kinds of imidazolium-based ionic liquids and conducting salt in VOCs with different anions both as the growth medium and the supporting electrolyte, to assess the influence of these anions on their morphology and electrochemical activity. It is found these thiophene polymers grown in ILs with higher viscosity and lower diffusion shows much slower growth rate and orderly morphologies than in Tetrabutylammonium hexafluorophosphate (TBAPF6) dissolved in acetonitrile (ACN), and gives better electrochemical performance via cyclic voltammetry (CV) and galvanostatic charge-and-discharge (CD) studies. Polymers displayed multiple redox peaks in several cases, the possible reasons and origins are discussed. The synthesized polymer can be affected greatly by both the ILs with different anion/cation, and its mutal interation with targeted monomer.. As far as known, there is no systematic study on how the anions of ILs and common organic solution could play a role as a medium both for polymerization and post-polymerization electrolyte for PEDOT and its derivatives. This study can be used as an easy reference and provide experimental diagnositc data when selecting ionic liquids to investigate and optimize thiophene-based electrochemical systems, such as batteries and supercapactiors. (iii) Another aspect about interface chemistry of direct functionalization of nanodiamond with maleimide has also been addressed. Functional nanodiamonds are promising candidates for extensive practical applications in surface science, photonics and nanomedicine. Here, a protocol of direct functionalization is described by which maleimide-derivatized substituents can be appended to the outer shell of thermally annealed nanodiamonds through Diels-Alder reaction. This protocol can be carried out in room temperature, ambient atmosphere, without catalyst, and provide functionalized nanodiamonds with good solubility in organic solution. Also, this method can be applied for other maleimide derivatives,e.g.m aleimide-fluorescene, which can be applied in fluorescence labeling, sensing, and drug delivery. A series of techniques, especially Fourier transform infrared spectroscopy (FTIR), and Solid State Nuclear Magnetic Resonance (SS-NMR) was conducted for the analysis of surface chemistry and the investigation of the two-point binding strategy in details.

Reduced graphene oxide as outstanding candidate electrode material for supercapacitor has been investigated. This thesis includes two topics. One is that three kinds of reduced graphene oxides were prepared by hydrothermal reduction under different pH conditions. The pH values were found to have great influence on the reduction of graphene oxides. Acidic and neutral media yielded reduced graphene oxides with more oxygen-functional groups, lower specific surface areas but broader pore size distributions than those in basic medium. Variations induced by the pH changes resulted in great differences in the supercapacitor performance. The graphene produced in the basic solution presented mainly electric double layer behavior with specific capacitance of 185 F/g, while the other two showed additional pseudocapacitance behavior with specific capacitance of 225 F/g (acidic) and 230 F/g (neutral), all at a constant current density of 1A/g. The other one is that different reduced graphene oxides were prepared via solution based hydrazine reduction, low temperature thermal reduction, and hydrothermal reduction. The as- prepared samples were then investigated by UV-vis spectroscopy, X-ray diffraction, Raman spectroscopy, and Scanning electron microscope. The supercapacitor performances were also studied and the hydrothermally reduced graphene oxide exhibited the highest specific capacitance.