Facile, environmentally friendly, cost effective and scalable production of few-layered graphene

© 2017 Elsevier B.V. Commercialization of graphene is still one the biggest challenges in the carbon field despite the development of several methods for its production. The lack of simple, cost-effective and scalable methods for mass-production of graphene hampers its promotion to the market. Here, we propose a new method for large-scale p roduction of mono- and few-layered graphene via liquid phase exfoliation with the use of wet ball milling in the presence of organic solvents at extremely low temperatures. The wet ball milling combined with the temperature modulated high surface energy solvents affords exfoliation of bulk graphite into graphenes in a fast, scalable, cost effective and environmentally friendly process. The thorough statistical analysis of as-prepared graphene flakes demonstrates that more than 61% of the flakes comprise less than 5 layers, while ∼14% of the flakes were monolayer graphene. Combined with the ∼30% yield of few-layer graphene out of the graphite precursor, this method demonstrates incredible efficiency in just 45 min. In the presence of methanol, our method results in formation of predominantly bi-layer graphene, which is more difficult to obtain in scalable fashion, than mono-layer graphene. The high quality of as-obtained graphenes is fully confirmed by Raman spectroscopy, TEM, SAED, AFM and X-ray photoelectron spectroscopy

Facile, environmentally friendly, cost effective and scalable production of few-layered graphene

© 2017 Elsevier B.V. Commercialization of graphene is still one the biggest challenges in the carbon field despite the development of several methods for its production. The lack of simple, cost-effective and scalable methods for mass-production of graphene hampers its promotion to the market. Here, we propose a new method for large-scale p roduction of mono- and few-layered graphene via liquid phase exfoliation with the use of wet ball milling in the presence of organic solvents at extremely low temperatures. The wet ball milling combined with the temperature modulated high surface energy solvents affords exfoliation of bulk graphite into graphenes in a fast, scalable, cost effective and environmentally friendly process. The thorough statistical analysis of as-prepared graphene flakes demonstrates that more than 61% of the flakes comprise less than 5 layers, while ∼14% of the flakes were monolayer graphene. Combined with the ∼30% yield of few-layer graphene out of the graphite precursor, this method demonstrates incredible efficiency in just 45 min. In the presence of methanol, our method results in formation of predominantly bi-layer graphene, which is more difficult to obtain in scalable fashion, than mono-layer graphene. The high quality of as-obtained graphenes is fully confirmed by Raman spectroscopy, TEM, SAED, AFM and X-ray photoelectron spectroscopy

Heat transfer performance of two-phase closed thermosyphon with oxidized CNT/water nanofluids

In this paper, the effects of different acids on the thermal performance of oxidized carbon nanotubes (CNT)/water nanofluids in a two-phase closed thermosyphon were studied. The structures morphology and functionalization degree were studied concurrently. The results indicated that strong oxidants increased dispersivity of CNT in the nanofluids. In other words, as the number of COOH groups increased in the nanofluids, an upward trend was also observed in the thermal efficiency of the thermosyphon

Microwave-Assisted Synthesis of Highly-Crumpled, Few-Layered Graphene and Nitrogen-Doped Graphene for Use as High-Performance Electrodes in Capacitive Deionization

Capacitive deionization (CDI) is a promising procedure for removing various charged ionic species from brackish water. The performance of graphene-based material in capacitive deionization is lower than the expectation of the industry, so highly-crumpled, few-layered graphene (HCG) and highly-crumpled nitrogen-doped graphene (HCNDG) with high surface area have been introduced as promising candidates for CDI electrodes. Thus, HCG and HCNDG were prepared by exfoliation of graphite in the presence of liquid-phase, microwave-assisted methods. An industrially-scalable, cost-effective, and simple approach was employed to synthesize HCG and HCNDG, resulting in few-layered graphene and nitrogen-doped graphene with large specific surface area. Then, HCG and HCNDG were utilized for manufacturing a new class of carbon nanostructure-based electrodes for use in large-scale CDI equipment. The electrosorption results indicated that both the HCG and HCNDG have fairly large specific surface areas, indicating their huge potential for capacitive deionization applications

Facile, environmentally friendly, cost effective and scalable production of few-layered graphene

© 2017 Elsevier B.V. Commercialization of graphene is still one the biggest challenges in the carbon field despite the development of several methods for its production. The lack of simple, cost-effective and scalable methods for mass-production of graphene hampers its promotion to the market. Here, we propose a new method for large-scale p roduction of mono- and few-layered graphene via liquid phase exfoliation with the use of wet ball milling in the presence of organic solvents at extremely low temperatures. The wet ball milling combined with the temperature modulated high surface energy solvents affords exfoliation of bulk graphite into graphenes in a fast, scalable, cost effective and environmentally friendly process. The thorough statistical analysis of as-prepared graphene flakes demonstrates that more than 61% of the flakes comprise less than 5 layers, while ∼14% of the flakes were monolayer graphene. Combined with the ∼30% yield of few-layer graphene out of the graphite precursor, this method demonstrates incredible efficiency in just 45 min. In the presence of methanol, our method results in formation of predominantly bi-layer graphene, which is more difficult to obtain in scalable fashion, than mono-layer graphene. The high quality of as-obtained graphenes is fully confirmed by Raman spectroscopy, TEM, SAED, AFM and X-ray photoelectron spectroscopy

Facile, environmentally friendly, cost effective and scalable production of few-layered graphene

© 2017 Elsevier B.V. Commercialization of graphene is still one the biggest challenges in the carbon field despite the development of several methods for its production. The lack of simple, cost-effective and scalable methods for mass-production of graphene hampers its promotion to the market. Here, we propose a new method for large-scale p roduction of mono- and few-layered graphene via liquid phase exfoliation with the use of wet ball milling in the presence of organic solvents at extremely low temperatures. The wet ball milling combined with the temperature modulated high surface energy solvents affords exfoliation of bulk graphite into graphenes in a fast, scalable, cost effective and environmentally friendly process. The thorough statistical analysis of as-prepared graphene flakes demonstrates that more than 61% of the flakes comprise less than 5 layers, while ∼14% of the flakes were monolayer graphene. Combined with the ∼30% yield of few-layer graphene out of the graphite precursor, this method demonstrates incredible efficiency in just 45 min. In the presence of methanol, our method results in formation of predominantly bi-layer graphene, which is more difficult to obtain in scalable fashion, than mono-layer graphene. The high quality of as-obtained graphenes is fully confirmed by Raman spectroscopy, TEM, SAED, AFM and X-ray photoelectron spectroscopy

Facile, environmentally friendly, cost effective and scalable production of few-layered graphene

© 2017 Elsevier B.V. Commercialization of graphene is still one the biggest challenges in the carbon field despite the development of several methods for its production. The lack of simple, cost-effective and scalable methods for mass-production of graphene hampers its promotion to the market. Here, we propose a new method for large-scale p roduction of mono- and few-layered graphene via liquid phase exfoliation with the use of wet ball milling in the presence of organic solvents at extremely low temperatures. The wet ball milling combined with the temperature modulated high surface energy solvents affords exfoliation of bulk graphite into graphenes in a fast, scalable, cost effective and environmentally friendly process. The thorough statistical analysis of as-prepared graphene flakes demonstrates that more than 61% of the flakes comprise less than 5 layers, while ∼14% of the flakes were monolayer graphene. Combined with the ∼30% yield of few-layer graphene out of the graphite precursor, this method demonstrates incredible efficiency in just 45 min. In the presence of methanol, our method results in formation of predominantly bi-layer graphene, which is more difficult to obtain in scalable fashion, than mono-layer graphene. The high quality of as-obtained graphenes is fully confirmed by Raman spectroscopy, TEM, SAED, AFM and X-ray photoelectron spectroscopy

Microwave-assisted direct coupling of graphene nanoplatelets with poly ethylene glycol and 4-phenylazophenol molecules for preparing stable-colloidal system

Herein, microwave-assisted direct coupling of Graphene Nanoplatelets (GNP) with polymers including hydroxyl ( OH) groups such as poly ethylene glycol (PEG) and bio-molecules like 4-phenylazophenol (Azo) are investigated. Among different water-soluble polymers, PEG has received unique consideration due to its biocompatibility. Moreover, Azo-treated GNP can easily employ in long-term solar thermal storage. Thus, an electrophilic addition reaction under microwave irradiation is presented as an efficient procedure to functionalize GNP with Azo and PEG. In order to compare the activities of different catalysts under microwave irradiation, the direct coupling of GNP with Azo and PEG were performed in the presence of ZnCl2, FeCl2,TiCl4 and AlCl3, separately. The use of simple Lewis acids loading provides an electrophilic addition reaction in as little as 30 min, which provide a shortcut and prevent time-consuming and multiple steps approaches. Interestingly, PEG-treated GNP has no cross-linking of the flakes, which this allows the production of more dispersed GNP in aqueous media. Investigation of colloidal stability using particle absorbance measurement showed successful results in terms of stability with very low sediment. (C) 2015 Elsevier B.V. All rights reserved