Stable aqueous dispersions of graphitic nanoplatelets via the reduction of exfoliated graphite oxide in the presence of poly sodium 4styrenesulfonate. Mechanical and electrical properties of graphene nanoplates. Functionalized exfoliated graphene oxide ego for supercapacitor electrodes have been synthesized by simple chemical methods from the exfoliated graphite eg as precursor. Surfactantbased graphene dispersion in aqueous medium above 1 mgml has not. The colloidal stability of chemically converted graphene in aqueous media was also found to be similar to that of graphene oxide colloids. Trgo based nonaqueous symmetric supercapacitor is constructed and shown to deliver maximum energy and power densities of 60. Synthesis of graphenebased nanosheets via chemical. The direct dispersion of hydrophobic graphite or graphene sheets in water without the assistance of dispersing agents has generally been considered to be an insurmountable challenge. At the end processable aqueous dispersions of graphene nanosheets the day you get an aqueous dispersion of graphene oxide sheets, which can then applied to a substrate in a variety of ways before or after reduction to graphene. Fewlayer graphene flg sheets with sizes exceeding several micrometers have been synthesized by exfoliation of expanded graphite in aqueous solution of ammonia under microwave irradiation, with an overall yield approaching 8 wt. Processable aqueous dispersion of graphene nanosheets request. The bulk of the oxygencontaining functional groups were removed from graphene oxide.
Abstract graphene sheets offer extraordinary electronic, thermal and mechanical properties and are expected t dan li, marc b. Graphene nanosheets toward printable energy storage nan wei 1,2, lianghao yu 1, zhongti sun 1, yingze song 1, menglei wang 1, zhengnan tian 1, yu xia 3, jingsheng cai 1, yayun li 3, liang zhao 1, qiucheng li 1, mark h. To that end, topdown colloidal approaches such as the exfoliation of powdered graphite in the liquid phase is a very promising route due to its simplicity, utilization of lowcost and readily available graphite, highthroughput potential, possibility of. Request pdf processable aqueous dispersion of graphene nanosheets graphene sheets offer extraordinary electronic, thermal and mechanical properties. The zeta potentials of rgo and gnms aqueous dispersions with various ph values were measured by the use of a zeta sizer nanosystem malvern instruments. The dispersion and aggregation of graphene oxide in aqueous. High resolution transmission electron microscope images of graphene nanosheets obtained with the aqueous phase dispersion technique and. Accordingly, the key step towards the production of processable aqueous dispersions of go is. Aqueous colloidal stability of graphene oxide and chemically. Exfoliation of graphite oxide in propylene carbonate and thermal reduction of the resulting graphene oxide platelets by yanwu zhu, meryl d.
Producing processable graphene flakes in large quantities remains an ongoing challenge for largescale applications. Mos2reduced graphene oxidebased 2d nancomposites for. The latter is one of the highest values reported for a dispersion of graphene obtained by any method. The structure and catalytic activity of samples in the photooxidation of phenol were characterized in line with their separability by controlled settling experiments at different phs, irradiation times and mechanical exposure.
Dec, 2012 the dispersions, which exhibit the tyndall effect, were characterized by tem and raman spectroscopy to confirm the presence of fewlayer graphene. Highconcentration aqueous dispersions of graphene produced. Exfoliation of graphite oxide in propylene carbonate and. Toward high production of graphene flakes hal univ. Highlights a stable aqueous graphene nanosheets was prepared by the reduction of graphene oxide in the potassium hydroxide solution. The production of concentrated dispersions of fewlayer. Synthesis and characterization of stable aqueous dispersions. Aqueous dispersions of graphene from electrochemically.
Wallace1 1arc centre of excellence for electromaterials science, intelligent polymer research institute, university of wollongong, nsw 2522, australia, and. Microwave synthesis of large fewlayer graphene sheets in. The asprepared graphene exhibits better electrochemical performance than graphite and graphene oxide. Effect of concentration of surfactant on the exfoliation of graphite to.
Request pdf processable aqueous dispersion of graphene nanosheets graphene sheets offer extraordinary electronic, thermal and mechanical properties and are expected to find a variety of. Processable aqueous dispersions of graphene stabilized by. A prerequisite for exploiting most proposed applications for graphene is the availability of processable graphene sheets in large quantities. Nanotribology studies of reduced graphene oxide films in air. Malvern zetasizer nanozs90 was used to measure zeta potential of the nanosheets in the dispersions. Nature nanotechnology, 3 2 tuesday, march 11, processable aqueous dispersions of graphene nanosheets. Dispersing graphene in various solvents is one of the key technologies toward the practical applications of graphene. A waterbased green approach to largescale production of aqueous. Herein, using graphene quantum dots gqds as stabilizer, aqueous dispersions of graphene with good stability were demonstrated by directly dispersing commercialized graphene powder into water. Functionalization of graphene nanosheets affects the totalfree energy of mixture systems, which consists of enthalpic and entropic contributions. Processable aqueous dispersions of graphene nanosheets of graphene synthesis introduction.
Request pdf processable aqueous dispersions of graphene stabilized by graphene quantum dots dispersing of graphene in various solvents is one of the key technology towards the practical. Synthesis and characterization of stable aqueous dispersions of graphene ujjal kumar sur1. Processable aqueous dispersions of graphene nanosheets. Exfoliated go sheets form stable aqueous dispersions largely owing to the. In this study, nacl was chosen to neutralize the excessive negative charges and decrease the electrostatic repulsion to accomplish go. Processable aqueous dispersion of graphene nanosheets. Photocatalyst separation from aqueous dispersion using. Jan 27, 2020 gramscale bottomup flash graphene synthesis. Prosthodontic treatment for edentulous patients, th. Wallace, processable aqueous dispersions of graphene nanosheets. Facile and green production of aqueous graphene dispersions.
Na2so4 salt to produce graphene nanosheets in the size range of hundreds square. Graphene sheets offer extraordinary electronic, thermal and mechanical properties and are expected to find a variety of applications. Flash joule heating of inexpensive carbon sources is used to produce gramscale quantities of highquality graphene in under a second, without the need for a furnace, solvents or reactive gases. This opens a significant strategy for the preparation of graphene based. Our study on the surface charge zeta potential of asprepared go sheets shows that. Muller m b, gilje s, kaner r b and wallace g g 2008 processable aqueous dispersions of graphene nanosheets. Amazingly, 100 mg of graphene powder could be stabilized by an average of merely 7.
Processable aqueous dispersions of graphene nanosheets dan li,1 marc b. Nonaqueous energy storage devices using graphene nanosheets. The aqueous dispersion of graphene was prepared through twostep route. Processable aqueous dispersions of graphene nanosheets the university of melbourne. Supporting information exfoliation of graphite oxide in propylene carbonate and thermal reduction of the resulting graphene oxide platelets by yanwu zhu, meryl d.
Functionalized exfoliated graphene oxide as supercapacitor. Sizedependent aggregation of graphene oxide sciencedirect. In order to improve the yield of the resulting graphene material, several different approaches have recently been proposed. Gramscale bottomup flash graphene synthesis nature. The dispersion and aggregation of graphene oxide in aqueous media meng wang, a yang niu, a jihan zhou, b hao wen, b zhenyu zhang, a da luo, a dongliang gao, a juan yang, a dehai liang b and yan li a. Aqueous dispersions of graphene oxide were found to be stable in the ph range of 412, with excellent dispersibility in the range of 711, as evidenced by highly negative zeta potential. Processable aqueous dispersions of graphene nanosheets dan li 1, marc b. However, i can not get this paper, could you kindly sent a pdf format of this. This can be attributed to oxygendefect scattering, and also due to the dispersoons conduction through the thickness of the sample by way of contact between adjacent flakes. Structural and morphological characterizations of ego have been carried out using xray diffraction xrd, scanning electron microscopy sem, ftir and raman. The hrtem image of a typical nanopore of gnms was examined by using an annulardarkfield scanning transmission electron microscope adfstem fei tecnai f20 field emission gun, 200 kv, with. A method for synthesizing and structuring 2dmos 2 rgo molybdenum disulfidereduced graphene oxide nanocompositebased electric double layer capacitor edlc that has a slower discharge rate and higher energy density than rgobased edlc rgedlc is reported. Jan 27, 2015 another approach for preparing aqueous graphene dispersions involves reducing thermally or chemically waterdispersible graphene oxide. Pdf processable aqueous dispersions of graphene nanosheets.
Adsorption and determination of polycyclic aromatic. The main goal of this work is the confinement of graphene nanosheets in an individual polymeric nanofiber and the study of their vibrational and thermal properties in one dimension. Processable aqueous dispersions of graphene nanosheets pdf. A series of nanocomposite photocatalysts was prepared from aqueous dispersions of degussa p25 tio 2 and exfoliated graphite oxide go by heterocoagulation. These data are also presented in figure 4 in histogram format in order to show the number of layers of graphene after 96. Preparation of stable aqueous dispersion of graphene. Synthesis and characterization of nanocomposites based on. Processable aqueous dispersions of graphene stabilized by graphene quantum dots. In a mixture of water and alcohol could yield graphene nanosheets, which formed a highly stable suspension in printing pdf from vba the.
In this paper we report the use of triethylene glycol reduced graphene oxide trgo as an electrode material for nonaqueous energy storage devices such as supercapacitors and liion batteries. Introduction carbon nanomaterials such as carbon nanotubes cnts and graphene nanoplatelets gnps can be used as a nanofillers in polymer nanocomposites because of their excellent mechanical and electrical properties 1, 2 and their high aspect ratio 3, 4. Files available from the acs website may be downloaded for personal use only. Solutionprocessable graphene nanomeshes with controlled pore. Herein, using graphene quantum dots gqds as stabilizer, aqueous. This discovery has enabled us to develop a facile approach to largescale production of aqueous graphene dispersions without the need for polymeric or surfactant stabilizers. After their preparation, graphene sheets were mixed with polyethylene oxide peo solution to be electrospinned. Assisted tip sonication approach for graphene synthesis in. Processable aqueous dispersions of graphene nanosheets abstract graphene sheets offer extraordinary electronic, thermal and mechanical properties and are expected to. The dispersiondeposited on the glass slide was left untouched to obtain a dry and homogenous graphene substrate. A surfactantfree waterprocessable allcarbon composite. Morphological, vibrational and thermal properties of confined. Processable aqueous dispersion of graphene nanosheets article in nature nanotechnology 32. Supporting information graphene nanosheets toward printable.
Files available from the acs website may be downloaded for. An aqueous dispersion formed by graphene sheets was easily obtained through the insitu reduction of the dispersed og layers by applying the procedure reported by li et al. Surfacefunctionalized highly solutionprocessable graphene nanosheets. Such the water soluble graphene can be stored in the form of dispersion 0. Fabrication of graphene substrates 100 l of a graphenecontaining0. It is found that these stable colloids can remain for several days, or even longer time for those gopg composites in which pg content is lower than gos. Aqueous dispersion of graphene sheets stabilized by. Here we report that chemically converted graphene sheets obtained from graphite can readily form stable aqueous colloids through electrostatic stabilization. This file contains supplementary text and data, supplementary figures. Jan 27, 2008 it is well known that exfoliated graphite oxide or go can form welldispersed aqueous colloids 8,9,10,11,12. G processable aqueous dispersions of graphene nanosheets.
Graphene nanomeshes gnms which can be cheaply produced on a large scale. Covalent polymer functionalization of graphene nanosheets and. G g 2008 processable aqueous dispersions of graphene nanosheets. Aqueous colloids and dispersions are stabilized via electrostatic repulsion. Gyoung hwa jeong, haemin lee, jigoo kang, heewoong lee, changkoo kim, jaehyeok lee, jaeho kim, and sangwook kim. Structural and morphological characterizations of ego have been carried out using xray diffraction xrd, scanning electron microscopy sem, ftir and raman spectroscopy. Prosthodontic treatment for edentulous patients pdf download. I am also doing work in the field of graphene,i want to read dispetsions paper processable aqueous dispersions of graphene nanosheets my best knowladge but i can not get graphenee paper,could you kindly sent a pdf format of this paper to me. While the colors of aqueous gopg dispersions are all as dark as black inks. Unfortunately, only limited amounts of singlelayered gnms can be produced by these methods at high costs, and the resulting gnms are not solutionprocessable, for example, by spin or dipcoating, filtration and printing. S1 supporting information scalable salttemplated synthesis of nitrogendoped graphene nanosheets toward printable energy storage nan wei1,2, lianghao yu1, zhongti sun1, yingze song1, menglei wang1, zhengnan tian1, yu xia3, jingsheng cai1, yayun li3, liang zhao1, qiucheng li1, mark h. Processable aqueous dispersions of graphene nanosheets by d.
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