25th Anniversary Article: Chemically Modified/Doped Carbon Nanotubes &amp; Graphene for Optimized Nanostructures &amp; Nanodevices

Maiti, Uday Narayan; Lee, Wonjun; Lee, Jun Young; Oh, Youngtak; Kim, Ju Young; Kim, Ji Eun; Shim, Jongwon; Han, Tae Hee; Kim, Sang Ouk

doi:10.1002/adma.201303265

Cited by 504 publications

(367 citation statements)

References 472 publications

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“…For this gel a uniform network of partially overlapping graphene sheets without any apparent preferential orientation is observed, similar to GO-based gels. [ 47,59,60 ] Raman spectra of printed and dried layers (data not shown) indicate that the material consists mainly of few layer graphene.…”

Section: Resultsmentioning

confidence: 99%

Conductive Screen Printing Inks by Gelation of Graphene Dispersions

Arapov

Rubingh

Abbel

et al. 2015

Adv Funct Materials

149

119

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vital [ 25 ] as it facilitates thick layers (of up to 100 µm) in a single pass, however, at the expense of a lower printing defi nition.Following screen printing typically posttreatments such as drying, annealing, or top-coating are employed to maximize conductivities. The conditions of post-treatment defi ne the substrate that can be used for printing. For example, ink annealing at 250 °C and higher for 30 min [ 18,24,25 ] signifi cantly limits the range of suitable substrates and fundamentally limits high speed R2R industrial realization. Thus, the design of graphene inks that meet the requirements of current R2R applications is still to be accomplished.There are several reports on the preparation of graphene-based inks comprising either graphene oxide (GO), [ 17,19,23,[27][28][29][30] or graphite exfoliated with [ 13,16,18,22,24,25 ] and without [ 20 ] surface active agents. The preparation of inks based on GO is relatively simple. However, due to the low conductivity of GO these inks require harsh post-treatments that make them less relevant to industrial applications. Liquid-phase exfoliation of graphite with or without surfactant by ultrasonication, [ 20,[31][32][33][34] or high-shear mixing [ 22,35 ] is a fl exible, and in the latter case a scalable manufacturing approach. [ 35 ] Nevertheless prolonged high shearing still requires separation of nonexfoliated graphite while the resulting dispersions consist mainly of small (<500 nm) graphene sheets. [ 33,34,36 ] Hence the quality [ 20 ] is far from the one obtained by micromechanical cleavage. [ 37 ] In contrast, expanded graphite (EG) demonstrates much better dispersibility than graphite due to signifi cantly weakened van der Waals interactions on account of an increased distance between the layers. [ 13,[38][39][40] This results in much shorter times and smaller energy input to obtain well-exfoliated concentrated dispersions of typically large (>1 µm) fl ake graphene. [ 39,41 ] Colloidal stability, however, as for the exfoliation of graphite, requires the presence of surface active agents and can be adjusted accordingly. The quality of graphene in EG depends on the precursor used for expansion. For instance, EG obtained from GO exhibits a highly defective structure, [ 41,42 ] whereas EG obtained from either donor-or acceptor-type intercalation compounds (IC) exhibits a much smaller amount of defects and, thus, is more suitable for highly conductive inks. [39][40][41] One of the approaches for ink preparation comprises stabilization of graphene dispersions by surfactants or surface active polymers on account of charge or van der Waals repulsion. This stabilization has been studied and reported by many research

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Section: Resultsmentioning

confidence: 99%

Conductive Screen Printing Inks by Gelation of Graphene Dispersions

Arapov

Rubingh

Abbel

et al. 2015

Adv Funct Materials

149

119

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“…By exploiting organic synthetic tools,21, 22 one can tune the molecular HOMO–LUMO gap8 by 1) changing the size and edge of the carbon‐based aromatic framework; 2) varying the molecular planarity upon insertion of bulky substituents or bridging chains; 3) changing the aromatic properties of the constituent monomeric units; 4) varying the peripheral functionalization through the insertion of electron‐donating or electron‐ withdrawing substituents; 5) enclosing structural defects; 6) promoting supramolecular interactions between individual molecules governing their organization into a condensed phase, and 7) replacing selected carbon atoms by isostructural and isoelectronic analogues (i.e., doping). In particular, the heteroatom‐doping approach23, 24 is increasingly becoming important, as significant perturbation of the optoelectronic properties can be obtained without a substantial structural modification 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36…”

Section: Introductionmentioning

confidence: 99%

Tailoring Colors by O Annulation of Polycyclic Aromatic Hydrocarbons

Miletić

Fermi

Orfanos

et al. 2017

Chemistry A European J

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The synthesis of O‐doped polyaromatic hydro‐ carbons in which two polycyclic aromatic hydrocarbon sub units are bridged through one or two O atoms has been achieved. This includes high‐yield ring‐closure key steps that, depending on the reaction conditions, result in the formation of furanyl or pyranopyranyl linkages through intramolecular C−O bond formation. Comprehensive photophysical measurements in solution showed that these compounds have exceptionally high emission yields and tunable absorption properties throughout the UV/Vis spectral region. Electrochemical investigations showed that in all cases O annulation increases the electron‐donor capabilities by raising the HOMO energy level, whereas the LUMO energy level is less affected. Moreover, third‐order nonlinear optical (NLO) measurements on solutions or thin films containing the dyes showed very good values of the second hyperpolarizability. Importantly, poly(methyl methacrylate) films containing the pyranopyranyl derivatives exhibited weak linear absorption and NLO absorption compared to the nonlinearity and NLO refraction, respectively, and thus revealed them to be exceptional organic materials for photonic devices.

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“…Tuning of the dimensions and assembled structures of graphene oxide is a key route to enhance its performance, and among them, three-dimensional (3D) structures have been widely explored (Chen et al, 2011;Choi et al, 2012;Liu et al, 2012;Xu et al, 2013b). Recently, amphiphilic liquid crystalline graphene oxide (LC GO) has been widely reported to introduce a new perspective into self-assembly of graphene materials (Aboutalebi et al, 2011b(Aboutalebi et al, , 2014bKim et al, 2011;Chidembo et al, 2013;Jalili et al, 2013;Maiti et al, 2014;Shen et al, 2014). The amphiphilicity and self-assembly properties are more pronounced in the case where ultra-large GO sheets have been utilized to prepare LC GO dispersions in both water and organic solvents (Aboutalebi et al, 2011b;Jalili et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Liquid Crystalline Graphene Oxide/PEDOT:PSS Self-Assembled 3D Architecture for Binder-Free Supercapacitor Electrodes

et al. 2014

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Binder-free self-assembled 3D architecture electrodes have been fabricated by a novel convenient method. Liquid crystalline graphene oxide was used as precursor to interact with poly(3,4-ethylene-dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) in dispersion in order to form a conductive polymer entrapped, self-assembled layer-by-layer structure. This advanced network containing PEDOT:PSS enabled us to ascribe the superior electrochemical properties of particular graphene sheets. This layer-by-layer self-assembled 3D architecture of best performing composite (reduced graphene oxide-PEDOT:PSS 25) showed excellent electrochemical performance of 434 F g −1 through chemical treatment.To highlight these advances, we further explored the practicality of the as-prepared electrode by varying the composite material content. An asymmetric supercapacitor device using aqueous electrolyte was also studied of this same composite. The resulting performance from this set up included a specific capacitance of 132 F g −1 . Above all, we observed an increase in specific capacitance (19%) with increase in cycle life emphasizing the excellent stability of this device.

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25th Anniversary Article: Chemically Modified/Doped Carbon Nanotubes & Graphene for Optimized Nanostructures & Nanodevices

Cited by 504 publications

References 472 publications

Conductive Screen Printing Inks by Gelation of Graphene Dispersions

Conductive Screen Printing Inks by Gelation of Graphene Dispersions

Tailoring Colors by O Annulation of Polycyclic Aromatic Hydrocarbons

Liquid Crystalline Graphene Oxide/PEDOT:PSS Self-Assembled 3D Architecture for Binder-Free Supercapacitor Electrodes

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