A powerful tool for graphene functionalization: Benzophenone mediated UV-grafting

Roppolo, Ignazio; Chiappone, Annalisa; Bejtka, Katarzyna; Celasco, Edvige; Chiodoni, Angelica; Giorgis, Fabrizio; Sangermano, Marco; Porro, Samuele

doi:10.1016/j.carbon.2014.05.025

Cited by 46 publications

(48 citation statements)

References 70 publications

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“…It is well known in the literature that BP, when UV irradiated, is able to abstract an extractable hydrogen atom from the environment creating semipinacol radicals. Even if the whole mechanism was confirmed by conventional structural, morphological, and electrical characterization, 26 a deep investigation of the interaction between semipinacol groups and RGO surfaces by specific spectroscopic techniques remained a challenge in order to give an insight of the GO surface chemistry and its functionalization. Moreover, we proposed that during this step some semipinacol radicals could recombine with latent radicals on the RGO surface, inducing the grafting of these molecules.…”

Section: Resultssupporting

confidence: 70%

“…14 Moreover, due to the presence of intrinsically labile oxygen groups on the surface and at the edges of GO sheets, it is relatively easy to attach and chemically bond polymer chains, or to recover graphene-like properties through reduction processes with the aim of obtaining reduced graphene oxide (RGO). 26 This process demonstrated to be fast, easy to implement and adaptable to a great variety of monomer functionalities. In a previous work, we have recently proposed a UV-mediated functionalization mechanism, with the purpose of synthesizing a polymer-grafted RGO, using benzophenone as a radical intermediate for GO reduction and to achieve further functionalization of RGO sheets.…”

Section: Introductionmentioning

confidence: 99%

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Study of benzophenone grafting on reduced graphene oxide by unconventional techniques

et al. 2015

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ARTICLE This journal isUnderstanding the mechanisms acting behind the functionalization of graphene is of paramount importance for the application of functionalized graphene in polymeric nano -composite materials. This work reports the study of the influence of benzophenone in a UV-mediated grafting process on graphene oxide, carried out by unconventional spectroscopic techniques, such as electron spin resonance and thermogravimetric analysis coupled with in -situ infra-red spectroscopy. Using these techniques, a direct investigation of the grafting was achieved for the first time, while up to now only indirect evidences were provided, opening new perspectives for the study of small molecules grafting on graphene sheets. The presence of benzophenone grafted on reduced graphene oxide surface was demonstrated, and in particular an unstable radical species attributable to the semipinacol radical of benzophenone was revealed, which is a key step of the functionalization process. Moreover, X -ray photoelectron spectroscopy demonstrated that the grafting process effectively reduced graphene oxide recovering the properties of graphene, contemporarily leaving active sites for a further polymer functionalization.

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Section: Resultssupporting

confidence: 70%

Section: Introductionmentioning

confidence: 99%

Study of benzophenone grafting on reduced graphene oxide by unconventional techniques

et al. 2015

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“…The extract was deposited on a silicon wafer to perform FT-IR analyses ( Figure S1d, Supporting Information). The main FT-IR peaks correspond to those expected from partially reduced GO, [ 22 ] however PANI and PSS peaks are still visible, confi rming their strict bond to RGO. Their surfactant effect is the most probable cause of RGO solubility in DMSO.…”

Section: Resultsmentioning

confidence: 77%

“…In this work, the synthesis of a PANI doped with polystyrene sulfonate (PSS) printable ink containing RGO (reduced graphene oxide) (here named PANI-PSS-RGO, in contracted form for the fi gures: PPG) starting from dianiline (DANI) is presented. In graphene oxide (GO), the oxidized form of graphene, oxygen functional groups are present on the basal planes and edges [ 22 ] of graphene sheets. GO can be reduced to RGO, partially restoring the structure of graphene and its improved electrical performances.…”

Section: Introductionmentioning

confidence: 99%

Impedance Hyperbolicity in Inkjet‐Printed Graphene Nanocomposites: Tunable Capacitors for Advanced Devices

Chiolerio

Porro

Bocchini

2016

Adv Elect Materials

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constant and any other evolution is based on device architecture alone. [ 2 ] Based on these considerations, how can the computational power of today's electronic environment be further increased and the power consumption concurrently reduced? The sources of power consumption in a microprocessor are three: dynamic power consumption (charging and discharging of parasitic capacitances during commutation), dynamic shortcircuit power consumption (due to accidental simultaneous conduction between some transistors in the closed state during operation), and leakage power consumption (due to leakage currents fl owing even when the system is in idle mode, which accounts for a total of 40%). [ 3 ] Thus, the major heat source is due to dynamic operation and could be mitigated by reducing parasitic capacitances. Scaling lateral cell size requires enormous efforts from the technological point of view. Better, compensating parasitic capacitances by means of negative capacitors, is a route never attempted due to the lack of simple solutions providing a single material featuring such property: frequently negative capacitance is emulated by a network of standard components and is pretty a complex tool, requiring more than ten transistors. [ 4 ] Placing discrete/integrated components and boosting commercial products by either extending their working frequency range or reducing their power consumption would require a simplification for electronic engineers.Impedance properties of multicomponent organic materials based on polyaniline (PANI) showed revolutionary phenomena such as negative permittivity, giant magnetoresistance, and negative supercapacitance [ 5,6 ] and exciting corresponding applications, in particular electrochemical supercapacitors. [7][8][9] These effects are thought to be due to short range exchange energy transfer (EET) between the two components [ 10 ] and quantum relativistic effects. [ 11 ] PANI has become one of the most important intrinsically conducting polymers (ICPs) and has been intensively studied in the last two decades. [12][13][14] Recent works [ 6,15 ] have demonstrated that PANI can be used for the synthesis of functional inks that can be processed by digital printing, showing unusual electronic properties such as negative supercapacitance in the low-frequency range. A peculiar charge versus DC voltage behavior, shaped as the typical "butterfl y" diagram, is a clear evidence for underlying An easy method for the fabrication of a completely tunable capacitor based on inkjet-printed hybrid organic systems is here reported. The quantum relativistic properties of graphene-induce electronic resonances between the polyaniline polymeric matrix and the graphene fi ller, with extremely long transfer rates. These events induce peculiar physical phenomena due to impedance hyperbolicity, such as voltage-controlled phase shifting. The apparent capacitance is shown to diverge to infi nity having a sign dependent on the frequency sweep direction. Hence devices may be geometrically tuned to operate with desired ca...

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“…Chemical and electrochemical reductions have been explored widely as the most effective routes of reduction [19][20][21][22][23]. By the way, photo-irradiation which involves UV irradiation of GO has also been demonstrated that can reduce GO [24] which is assisted in the presence of a photoinitiator and other catalysts [25][26][27][28][29][30] while photocatalyst-free reduction of GO to reduced GO (rGO) has been reported by Ding et al [31] In general, UV-irradiation methods offer advantages such as simplicity, cleanness and low cost.…”

Section: Introductionmentioning

confidence: 99%

Photo-reduction of Graphene Oxide during Photo-polymerization of Graphene Oxide/Epoxy-Novolac Nanocomposite Coatings

Sharif

Pourabas

Fazli

2016

J. Photopol. Sci. Technol.

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In the present study, in-situ UV reduction of graphene oxide (GO) during Photopolymerization of the epoxy-novolac nanocomposite and its effect on the thermal properties of nanocomposite were investigated at different loading level of GO. Chemical structure and structural distortion of GO before and after UV irradiation have been characterized using infrared and Raman spectroscopy as well as scanning electron microscopy (SEM). Obtained results showed that GO has been reduced to graphene (Gr) in effect of UV irradiation. TEM and SEM observations indicated well dispersion of GO sheets within the cured epoxy resin matrix.

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A powerful tool for graphene functionalization: Benzophenone mediated UV-grafting

Cited by 46 publications

References 70 publications

Study of benzophenone grafting on reduced graphene oxide by unconventional techniques

Study of benzophenone grafting on reduced graphene oxide by unconventional techniques

Impedance Hyperbolicity in Inkjet‐Printed Graphene Nanocomposites: Tunable Capacitors for Advanced Devices

Photo-reduction of Graphene Oxide during Photo-polymerization of Graphene Oxide/Epoxy-Novolac Nanocomposite Coatings

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