A novel approach to prevent graphene oxide re-aggregation during the melt compounding with polymers

Fucarino, Roberto; Khatibi, Reza; Rosselli, Sergio; Bruno, Maurizio; Scaffaro, Roberto

doi:10.1016/j.compscitech.2015.10.006

Cited by 84 publications

(50 citation statements)

References 27 publications

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“…However, despite its good mechanical properties and its potential affinity to PA6, GO lamellae present several drawbacks in terms of dispersion and processability [4,5]. When GO is melt processed together with polymers, in fact, pleating and crumpling phenomena occur due to several reasons, such as the thermally-driven formation of intramolecular and intermolecular reactions occurring between oxygen moieties of GO, the mechanical cleavage or distortion of lamellae under shear stress, promoted by the presence of several structural defects, the volatilization of the water integrated within GO structure [5].…”

Section: Introductionmentioning

confidence: 99%

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A green method to prepare nanosilica modified graphene oxide to inhibit nanoparticles re-aggregation during melt processing

Scaffaro

2017

Chemical Engineering Journal

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A graphene oxide-silica nanohybrid (GOS), self-assembled into a lasagna-like structure, was prepared in water and used as a filler for the melt preparation of polyamide 6 (PA6)-based nanocomposites. For sake of comparison, PA6-based materials were prepared under the same processing conditions by adding GO only or a physical mixture of GO and silica (GO+S). All the materials were characterized from a morphological, spectroscopic, thermal, dynamic-mechanical (DMA) and mechanical point of view. For all the nanocomposites, the interphase was studied either by analyzing loss factor plots coming from DMA measurements and by implementing a novel approach, i.e. combining solvent extraction, SEM and EDX measurements. While GO and GO+S showed an almost negligible effect on the macroscopic features of PA6, due to lack of dispersion, PA6-GOS ternary nanocomposites displayed an outstanding enhancement of mechanical and thermo-mechanical performance. This feature is likely due to the formation of an extended and strong interphase. In fact, the silica layers intercalated between GO lamellae played as an exfoliating agent, thus proving to be particularly efficient in avoiding self-aggregation of GO sheets, while those covalently attached to basal planes of GO acted as a rivet, capable to interlock the surrounding polymer chains. Finally, with respect to other techniques commonly adopted for the fabrication of polymer-graphene nanocomposites, the green route herein proposed does not involve any toxic solvent nor time-consuming protocols, and allows achieving remarkable improvements in stiffening (up to +180%), strengthening (up to +210%) and toughening (up to +210%) at extremely low filler contents (0.25% or 0.5%).

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Section: Introductionmentioning

confidence: 99%

“…Email address: roberto.scaffaro@unipa.it (R. Scaffaro) Up to date, several strategies have been adopted to prepare PA6-GO nanocomposites with adequate levels of dispersion [3][4][5]. Basically, all of these approaches can be classified into three categories, each of them presenting their own positive and negative features:…”

Section: Introductionmentioning

confidence: 99%

A green method to prepare nanosilica modified graphene oxide to inhibit nanoparticles re-aggregation during melt processing

Scaffaro

2017

Chemical Engineering Journal

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“…Scaffaro and Maio [24] has reported that direct melt mixing of PA6 with GO can cause pleating and crumpling, leading to the formation of stacked clusters and poor dispersion in the polymer matrix. This occurs as a result of the presence of several structural defects, volatilization/ evaporation of water within the GO structure, intermolecular reactions between oxygen, moieties of GO, and mechanical distortion of the lamella structure under shear stress [23,24]. It is important to notice that the TRGO 600 ( Fig.…”

Section: Characterization Of Graphene Nanoparticlesmentioning

confidence: 99%

Effect of thermally reduced graphene oxides obtained at different temperatures on the barrier and mechanical properties of polypropylene/TRGO and polyamide‐6/TRGO nanocomposites

et al. 2018

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Polypropylene (PP) and polyamide‐6 (PA6) nanocomposites containing thermally reduced graphene oxide (TRGO), obtained either at 600°C (TRGO600) or 800°C (TRGO800), were prepared by melt mixing in order to study the effect of the thermal treatments on their barrier and mechanical properties. Transmission electron microscopy images of nanocomposites showed a relative good dispersion of TRGO in polymer matrices with some agglomerations. Differential scanning calorimetry analyses showed a slight reduction in crystallinity for both polymers in the presence of TRGO. The permeability to oxygen and water vapor was decreased in almost all nanocomposites due to a more tortuous path to gas permeation, being more evident for PP/TRGO800. Tensile stress–strain tests showed that all nanocomposites had higher elastic modulus, but PA6/TRGO600 nanocomposites showed better mechanical properties. These findings indicated that TRGO obtained at a higher temperature imparts better barrier and mechanical properties to PP, while TRGO obtained at a lower temperature imparts better barrier and mechanical properties to PA6. POLYM. COMPOS., 40:E1746–E1756, 2019. © 2018 Society of Plastics Engineers

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“…3 (a) di-vacancy or to 5-7-7-5 Stone Wales defects. 32 The pictorial representation of these contributions is provided in Fig. 3b, together with an exemplicative multi-peak tting of a GO sample.…”

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confidence: 99%

“…The D/G intensity ratio (I D /I G ), which gives information about the size of sp 2 graphenic domains, 15,31,32,[40][41][42] was found to be practically constant (for GOS) or slightly increased (from 1.12 to 1.15 for GOSF) aer functionalization step, whereas the ratio between the integrated areas of D and G (A D /A G ) was equal to 2 for GO, 1.91 for GOS and 1.94 for GOSF. These features can be explained by considering that the size of graphenic crystals remains practically unaltered, since the immobilization of silica and uorotails onto GO planes involves only oxygen moieties, as suggested by the depletion of B mode detected for GOSF and especially GOS, with respect to that of pristine GO.…”

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confidence: 99%

Synthesis of a fluorinated graphene oxide–silica nanohybrid: improving oxygen affinity

2016

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An easy method to achieve a fluorinated graphene oxide-silica nanohybrid (GOSF) is presented. Graphene oxide (GO) was synthesized by Hummer's modified method, the GO-silica nanohybrid (GOS) was obtained via Fischer esterification, the fluorinated moiety (3-pentadecafluoroheptyl-5-perfluorophenyl-1,2,4-oxadiazole) was introduced by nucleophilic substitution operated by the hydroxyl functionalities onto the GOS surface. Full characterization of the new materials confirmed the formation of covalent bonds between the graphene oxide/silica hybrid matrix and the fluorinated moieties. The proposed methodology offers an easy way to get fluorinated carbon/silica hybrid nanomaterials avoiding the harsh reaction conditions usually involved in the preparation of fluorinated materials, and allowing the selective immobilization of specific fluorotails. Moreover, performed oxygen uptake and release kinetics showed that the introduction of fluorinated moieties increases the oxygen exchange, making the material interesting for prospective applications in the biomedical field, as oxygen delivery system, as filler for biocompatible materials, and in the preparation of membranes for the purification of water.

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A novel approach to prevent graphene oxide re-aggregation during the melt compounding with polymers

Cited by 84 publications

References 27 publications

A green method to prepare nanosilica modified graphene oxide to inhibit nanoparticles re-aggregation during melt processing

A green method to prepare nanosilica modified graphene oxide to inhibit nanoparticles re-aggregation during melt processing

Effect of thermally reduced graphene oxides obtained at different temperatures on the barrier and mechanical properties of polypropylene/TRGO and polyamide‐6/TRGO nanocomposites

Synthesis of a fluorinated graphene oxide–silica nanohybrid: improving oxygen affinity

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