Effect of airborne contaminants on the wettability of supported graphene and graphite

Li, Zhiting; Wang, Yongjin; Kozbial, Andrew; Shenoy, Ganesh J.; Zhou, Feng; McGinley, Rebecca; Ireland, Patrick R.; Morganstein, Brittni; Kunkel, Alyssa; Surwade, Sumedh P.; Li, Lei; Liu, Haitao

doi:10.1038/nmat3709

Cited by 763 publications

(957 citation statements)

References 53 publications

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“…Recent studies on graphitic surfaces indicate that their affinity can change from hydrophobic to hydrophillic within minutes of exposure to ambient due to adsorption of volatile hydrocarbon species in ambient air. [76] Future work should explore the presence of hydrocarbon species on the CNT surface in ambient conditions, and the influence of defects, which are known to act as nucleation hotspots, [39,77,78] on the kinetics and energetics of hydrocarbon adsorption on CNTs.…”

Section: Discussionmentioning

confidence: 99%

Exohedral Physisorption of Ambient Moisture Scales Non-monotonically with Fiber Proximity in Aligned Carbon Nanotube Arrays

et al. 2014

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Here we present a study on the presence of physisorbed water on the surface of aligned carbon nanotubes (CNTs) in ambient conditions, where the wet CNT array mass can be more than 200% larger than that of dry CNTs, and modeling indicates that a water layer > 5 nm thick can be present on the outer CNT surface. The experimentally observed non-linear and non-monotonic dependence of the mass of adsorbed water on the CNT packing (volume fraction) originates from two competing modes. Physisorbed water cannot be neglected in the design and fabrication of materials and devices using nanowires/nanofibers, especially CNTs, and further experimental and ab initio studies on the influence of defects on the surface energies of CNTs, and nanowires/nanofibers in general, are necessary to understand the underlying physics and chemistry that govern this system.One dimensional nanoscale systems, such as nanowires, nanofibers, and nanotubes, are well known for their phenomenal electrical, [1][2][3][4] thermal, [5][6][7][8] and mechanical properties, [9][10][11] which could enable the design and manufacture of next-generation materials with unprecedented properties. [12][13][14][15][16][17][18] However, while many studies have previously explored the synthesis of new architectures and devices using one dimensional nanomaterials, specifically carbon nanotubes (CNTs), the properties they reported were far lower than the properties of predicted using current theory.[12] Some of the main reasons why existing models cannot accurately predict the behavior of CNTs in scalable architectures, such as aligned CNT arrays, are the various CNT morphology and proximity effects, [13][14][15]19] which can strongly impact properties, but are not well understood and cannot be properly integrated into theoretical frameworks. Here we report the presence of a commonly neglected morphological effect, an unexpectedly large (compared to the CNT mass) amount of moisture located on the surface of CNTs in aligned CNT (A-CNT) arrays at ambient conditions; show the non-linear and non-monotonic dependence of this effect on array porosity, which suggests two competing mechanisms; and discuss the strong impact such an effect can have on the structure and properties of nanocomposite architectures composed of A-CNTs.Previous studies on how water interacts with the outer surface of a CNT illustrated that the water molecules form a layer-like shell surrounding the CNTs, [20][21][22][23] and that the water layer density varies greatly and non- * wardle@mit.edu.monotonically with its thickness. [21,22] A recent study on the physisorption of water onto the external surface of a suspended ∼ 1.1 − 1.2 nm diameter single walled CNT showed that more than one layer of water is present on the CNT surface in water vapor, and that water molecules more easily adsorb onto larger diameter CNTs.[24] However, this study was limited to isolated and defect-free CNTs, [24,25] meaning that the interaction of moisture present in ambient air with multiwalled CNTs, which normally have nativ...

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Section: Discussionmentioning

confidence: 99%

Exohedral Physisorption of Ambient Moisture Scales Non-monotonically with Fiber Proximity in Aligned Carbon Nanotube Arrays

et al. 2014

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“…This is in line with theoretical studies showing that the contact angle of water on suspended graphene is higher than on Cu-supported graphene. 29,[62][63][64] To further investigate the wettability of the suspended graphene membrane, approach and retract experiments were carried out in which the meniscus of an SECCM pipet was pushed further against the graphene with the precise control of the z-piezo, while iDC against z-piezo displacement was recorded, and the reverse (pull-off) of the meniscus was also measured. An example of these approach and retract curves (with ion conductance current iDC normalized to the initial value of the approach iIni, iDC/iIni) is presented in Figure 7 (which is typical of 3 different experiments).…”

Section: Wetting and Electrochemistry Of Supported And Suspended Grapmentioning

confidence: 99%

Versatile Polymer-Free Graphene Transfer Method and Applications

Zhang

Güell

Kirkman

et al. 2016

ACS Appl. Mater. Interfaces

106

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A new method for transferring chemical vapor deposition (CVD)-grown monolayer graphene, to a variety of substrates is described. The method makes use of an organic/aqueous biphasic configuration, avoiding the use of any polymeric materials that can cause severe contamination problems. The graphene-coated copper foil sample (on which graphene was grown) sits at the interface between hexane and an aqueous etching solution of ammonium persulfate to remove the copper. With the aid of an Si/SiO2 substrate, the graphene layer is then transferred to a second hexane/water interface, to remove etching products. From this new location, CVD graphene is readily transferred to arbitrary substrates, including three dimensional architectures as represented by atomic force microscopy (AFM) tips and transmission electron microscopy (TEM) grids. Graphene produces a conformal layer on AFM tips, to the very end, allowing the easy production of tips for conductive AFM imaging. Graphene transferred to copper TEM grids provides large area, highly electrontransparent substrates for TEM imaging. These substrates can also be used as working electrodes for electrochemistry and high resolution wetting studies. By using scanning electrochemical cell microscopy, it is possible to make electrochemical and wetting measurements at either a free-standing graphene film or a copper-supported graphene area, and readily determine any differences in behavior.3

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“…Indeed thanks to remarkable advances in combining boron, nitrogen, and carbon atoms in a cyclic aromatic arrangement it is now possible to create two-dimensional sheets with carefully structured regions of carbon and boron nitride. [17][18][19] Despite the growing number of studies for water on h-BN [20][21][22] and graphene 15,16,[23][24][25][26][27] there are no direct measurements of adsorption energies for the water monomer, and the theoretical adsorption energies for these systems vary significantly across different high accuracy methods. 25,[27][28][29] One can use smaller model systems for graphene 25,[29][30][31][32] and h-BN, such as benzene and the inorganic counterpart borazine (B 3 N 3 H 6 ), to help understand the interaction with water.…”

Section: Introductionmentioning

confidence: 99%

Water on BN doped benzene: A hard test for exchange-correlation functionals and the impact of exact exchange on weak binding

Al-Hamdani

Alfè

Lilienfeld

et al. 2014

The Journal of Chemical Physics

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Density functional theory (DFT) studies of weakly interacting complexes have recently focused on the importance of van der Waals dispersion forces, whereas the role of exchange has received far less attention. Here, by exploiting the subtle binding between water and a boron and nitrogen doped benzene derivative (1,2-azaborine) we show how exact exchange can alter the binding conformation within a complex. Benchmark values have been calculated for three orientations of the water monomer on 1,2-azaborine from explicitly correlated quantum chemical methods, and we have also used diffusion quantum Monte Carlo. For a host of popular DFT exchange-correlation functionals we show that the lack of exact exchange leads to the wrong lowest energy orientation of water on 1,2-azaborine. As such, we suggest that a high proportion of exact exchange and the associated improvement in the electronic structure could be needed for the accurate prediction of physisorption sites on doped surfaces and in complex organic molecules. Meanwhile to predict correct absolute interaction energies an accurate description of exchange needs to be augmented by dispersion inclusive functionals, and certain non-local van der Waals functionals (optB88- and optB86b-vdW) perform very well for absolute interaction energies. Through a comparison with water on benzene and borazine (B3N3H6) we show that these results could have implications for the interaction of water with doped graphene surfaces, and suggest a possible way of tuning the interaction energy.

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Effect of airborne contaminants on the wettability of supported graphene and graphite

Cited by 763 publications

References 53 publications

Exohedral Physisorption of Ambient Moisture Scales Non-monotonically with Fiber Proximity in Aligned Carbon Nanotube Arrays

Exohedral Physisorption of Ambient Moisture Scales Non-monotonically with Fiber Proximity in Aligned Carbon Nanotube Arrays

Versatile Polymer-Free Graphene Transfer Method and Applications

Water on BN doped benzene: A hard test for exchange-correlation functionals and the impact of exact exchange on weak binding

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