1
|
Li X, Jamali M, Fielding LA. Pyrene-functionalized poly(methacrylic acid) acts as an efficient stabilizer for graphene nanoplatelets and facilitates their use in waterborne latex formulations. J Colloid Interface Sci 2024; 676:396-407. [PMID: 39033674 DOI: 10.1016/j.jcis.2024.07.116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 07/10/2024] [Accepted: 07/13/2024] [Indexed: 07/23/2024]
Abstract
HYPOTHESIS Pyrene derivatives are effective motifs when designing graphene-philic surfactants, enabling the use of hydrophobic graphene-based nanomaterials in waterborne formulations. Hence, novel pyrene end-functionalized polymeric stabilizers show promise for stabilizing aqueous graphene nanomaterial dispersions, and offer benefits over traditional small molecule surfactants. EXPERIMENTS Pyrene end-functionalized poly(methacrylic acid) (Py-PMAAn, where n = 68 to 128) was synthesized by reversible addition-fragmentation chain-transfer (RAFT) polymerization of MAA using a pyrene-containing RAFT chain-transfer agent. These polymers were evaluated as aqueous graphene nanoplatelet (GNP) stabilizers. Subsequently, polymer-stabilized GNPs were formulated into film-forming polymer latex dispersions and the properties of the resulting GNP-containing films measured. FINDINGS Py-PMAAn homopolymers with well-defined molecular weights were prepared via RAFT solution polymerization. They served as efficient stabilizers for aqueous GNP dispersions and performed better than a traditional small molecule surfactant and non-functionalized PMAA, especially at higher pH and with higher molecular weight polymers. The use of Py-PMAAn allowed GNPs to be readily formulated into waterborne latex coatings. When compared to controls, the resulting films were significantly reinforced due to the improved homogeneity of dried nanocomposite films and chain entanglement between the polymer matrix and stabilizers. Thus, the ability to readily incorporate GNPs into aqueous formulations and enhance GNP/polymer matrix interfaces was demonstrated for these novel amphiphilic stabilizers.
Collapse
Affiliation(s)
- Xueyuan Li
- Department of Materials, School of Natural Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK; Henry Royce Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Mohammed Jamali
- Department of Materials, School of Natural Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK; Henry Royce Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Lee A Fielding
- Department of Materials, School of Natural Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK; Henry Royce Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| |
Collapse
|
2
|
Adenine derived reactive dispersant and the enhancement of graphene based composites. J Colloid Interface Sci 2023; 640:91-99. [PMID: 36842421 DOI: 10.1016/j.jcis.2023.02.069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/11/2023] [Accepted: 02/12/2023] [Indexed: 02/17/2023]
Abstract
HYPOTHESIS Homogeneous dispersion of graphene is the precondition for constructing high performance graphene based composites. However, most of the current dispersants reported in literature still suffer excess usage to reach a desired graphene concentration. Residual of dispersant in composite may seriously affect its properties. Hence, it is expected to obtain effective dispersant with high reactivity to diminish its adverse impacts on graphene composites. EXPERIMENTS A highly reactive graphene dispersant (DSiA) was synthesized by grafting silanol groups (Si-OH) onto adenine. Molecular structure and the performance of the dispersant were systematically characterized. Composites were fabricated by direct writing of the graphene dispersion on various substrates, and their features were evaluated by resistance, solvent erosion and tensile testing. FINDINGS Graphene concentration can reach up to 6 mg mL-1 in the presents of DSiA at the weight ratio of 1:1 (DSiA: graphene). DSiA also exhibited good performance for stabilizing multi-walled carbon nanotubes (MWCNTs). Moreover, the dispersant is highly reactive. The graphene based composites showed good mechanical strength and excellent solvent resistance. Overall, the new dispersant provides an ideal choice to uniformly disperse graphene and suitable for fabricating high performance nanocarbon based composites.
Collapse
|
3
|
Coreas R, Castillo C, Li Z, Yan D, Gao Z, Chen J, Bitounis D, Parviz D, Strano MS, Demokritou P, Zhong W. Biological Impacts of Reduced Graphene Oxide Affected by Protein Corona Formation. Chem Res Toxicol 2022; 35:1244-1256. [PMID: 35706338 PMCID: PMC9842398 DOI: 10.1021/acs.chemrestox.2c00042] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Applications of reduced graphene oxide (rGO) in many different areas have been gradually increasing owing to its unique physicochemical characteristics, demanding more understanding of their biological impacts. Herein, we assessed the toxicological effects of rGO in mammary epithelial cells. Because the as-synthesized rGO was dissolved in sodium cholate to maintain a stable aqueous dispersion, we hypothesize that changing the cholate concentration in the dispersion may alter the surface property of rGO and subsequently affect its cellular toxicity. Thus, four types of rGO were prepared and compared: rGO dispersed in 4 and 2 mg/mL sodium cholate, labeled as rGO and concentrated-rGO (c-rGO), respectively, and rGO and c-rGO coated with a protein corona through 1 h incubation in culture media, correspondingly named pro-rGO and pro-c-rGO. Notably, c-rGO and pro-c-rGO exhibited higher toxicity than rGO and pro-rGO and also caused higher reactive oxygen species production, more lipid membrane peroxidation, and more significant disruption of mitochondrial-based ATP synthesis. In all toxicological assessments, pro-c-rGO induced more severe adverse impacts than c-rGO. Further examination of the material surface, protein adsorption, and cellular uptake showed that the surface of c-rGO was coated with a lower content of surfactant and adsorbed more proteins, which may result in the higher cellular uptake observed with pro-c-rGO than pro-rGO. Several proteins involved in cellular redox mediation were also more enriched in pro-c-rGO. These results support the strong correlation between dispersant coating and corona formation and their subsequent cellular impacts. Future studies in this direction could reveal a deeper understanding of the correlation and the specific cellular pathways involved and help gain knowledge on how the toxicity of rGO could be modulated through surface modification, guiding the sustainable applications of rGO.
Collapse
Affiliation(s)
- Roxana Coreas
- Environmental Toxicology Graduate Program, University of California – Riverside, California 92521, United States
| | - Carmen Castillo
- Department of Biochemistry, University of California – Riverside, California 92521, United States
| | - Zongbo Li
- Department of Chemistry, University of California – Riverside, California 92521, United States
| | - Dong Yan
- Nanofabrication Facility, University of California – Riverside, California 92521, United States
| | - Ziting Gao
- Department of Chemistry, University of California – Riverside, California 92521, United States
| | - Junyi Chen
- Environmental Toxicology Graduate Program, University of California – Riverside, California 92521, United States
| | - Dimitrios Bitounis
- Center for Nanotechnology and Nanotoxicology, HSPH-NIEHS Nanosafety Center, Department of Environmental Health, Harvard T. H. Chan School of Public Health Initiative for Sustainable Nanotechnology, Harvard University, Boston, Massachusetts 02115, United States
| | - Dorsa Parviz
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Michael S Strano
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Philip Demokritou
- Center for Nanotechnology and Nanotoxicology, HSPH-NIEHS Nanosafety Center, Department of Environmental Health, Harvard T. H. Chan School of Public Health Initiative for Sustainable Nanotechnology, Harvard University, Boston, Massachusetts 02115, United States
| | - Wenwan Zhong
- Environmental Toxicology Graduate Program, University of California – Riverside, California 92521, United States,Department of Chemistry, University of California – Riverside, California 92521, United States
| |
Collapse
|
4
|
Loh H, Marchi C, Magagnin L, Sierros KA. Graphene Flake Self-Assembly Enhancement via Stretchable Platforms and External Mechanical Stimuli. ACS OMEGA 2021; 6:30607-30617. [PMID: 34805689 PMCID: PMC8600623 DOI: 10.1021/acsomega.1c04368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 10/14/2021] [Indexed: 06/13/2023]
Abstract
While the green production and application of 2D functional nanomaterials, such as graphene flakes, in films for stretchable and wearable technologies is a promising platform for advanced technologies, there are still challenges involved in the processing of the deposited material to improve properties such as electrical conductivity. In applications such as wearable biomedical and flexible energy devices, the widely used flexible and stretchable substrate materials are incompatible with high-temperature processing traditionally employed to improve the electrical properties, which necessitates alternative manufacturing approaches and new steps for enhancing the film functionality. We hypothesize that a mechanical stimulus, in the form of substrate straining, may provide such a low-energy approach for modifying deposited film properties through increased flake packing and reorientation. To this end, graphene flakes were exfoliated using an unexplored combination of ethanol and cellulose acetate butyrate for morphological and percolative electrical characterization prior to application on polydimethylsiloxane (PDMS) substrates as a flexible and stretchable electrically conductive platform. The deposited percolative free-standing films on PDMS were characterized via in situ resistance strain monitoring and surface morphology measurements over numerous strain cycles, with parameters extracted describing the dynamic modulation of the film's electrical properties. A reduction in the film resistance and strain gauge factor was found to correlate with the surface roughness and densification of a sample's (sub)surface and the applied strain. High surface roughness samples exhibited enhanced reduction in resistance as well as increased sensitivity to strain compared to samples with low surface roughness, corresponding to surface smoothing, which is related to the dynamic settling of graphene flakes on the substrate surface. This procedure of incorporating strain as a mechanical stimulus may find application as a manufacturing tool/step for the routine fabrication of stretchable and wearable devices, as a low energy and compatible approach, for enhancing the properties of such devices for either high sensitivity or low sensitivity of electrical resistance to substrate strain.
Collapse
Affiliation(s)
- Harrison
A. Loh
- Statler
College of Engineering and Mineral Resources, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Claudio Marchi
- Department
of Chemistry, Materials and Chemical Engineering Giulio Natta, Politecnico di Milano, Via Mancinelli 7, 20131 Milano, Italy
| | - Luca Magagnin
- Department
of Chemistry, Materials and Chemical Engineering Giulio Natta, Politecnico di Milano, Via Mancinelli 7, 20131 Milano, Italy
| | - Konstantinos A. Sierros
- Statler
College of Engineering and Mineral Resources, West Virginia University, Morgantown, West Virginia 26506, United States
| |
Collapse
|
5
|
González-Domínguez JM, León V, Lucío MI, Prato M, Vázquez E. Production of ready-to-use few-layer graphene in aqueous suspensions. Nat Protoc 2018; 13:495-506. [PMID: 29446772 DOI: 10.1038/nprot.2017.142] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Graphene has promising physical and chemical properties such as high strength and flexibility, coupled with high electrical and thermal conductivities. It is therefore being incorporated into polymer-based composites for use in electronics and photonics applications. A main constraint related to the graphene development is that, being of a strongly hydrophobic nature, almost all dispersions (usually required for its handling and processing toward the desired application) are prepared in poisonous organic solvents such as N-methyl pyrrolidone or N,N-dimethyl formamide. Here, we describe how to prepare exfoliated graphite using a ball mill. The graphene produced is three to four layers thick and ∼500 nm in diameter on average, as measured by electron microscopy and Raman spectroscopy; can be stored in the form of light solid; and is easily dispersed in aqueous media. Our methodology consists of four main steps: (i) the mechanochemical intercalation of organic molecules (melamine) into graphite, followed by suspension in water; (ii) the washing of suspended graphene to eliminate most of the melamine; (iii) the isolation of stable graphene sheets; and (iv) freeze-drying to obtain graphene powder. This process takes 6-7 or 9-10 d for aqueous suspensions and dry powders, respectively. The product has well-defined properties and can be used for many science and technology applications, including toxicology impact assessment and the production of innovative medical devices.
Collapse
Affiliation(s)
- Jose M González-Domínguez
- Department of Organic Chemistry, Faculty of Chemical Science and Technology-IRICA, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Verónica León
- Department of Organic Chemistry, Faculty of Chemical Science and Technology-IRICA, University of Castilla-La Mancha, Ciudad Real, Spain
| | - María Isabel Lucío
- Department of Organic Chemistry, Faculty of Chemical Science and Technology-IRICA, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Maurizio Prato
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Trieste, Italy.,Carbon Nanobiotechnology Laboratory CIC BiomaGUNE, Donostia-San Sebastián, Spain.,Basque Foundation for Science (IKERBASQUE), Bilbao, Spain
| | - Ester Vázquez
- Department of Organic Chemistry, Faculty of Chemical Science and Technology-IRICA, University of Castilla-La Mancha, Ciudad Real, Spain
| |
Collapse
|
6
|
Rodríguez AM, Muñoz-García AB, Crescenzi O, Vázquez E, Pavone M. Stability of melamine-exfoliated graphene in aqueous media: quantum-mechanical insights at the nanoscale. Phys Chem Chem Phys 2018; 18:22203-9. [PMID: 27452832 DOI: 10.1039/c6cp04213a] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In recent experiments, melamine (1,3,5-triazine-2,4,6-triamine) has been proposed as an effective exfoliating agent to obtain high quality graphene from graphite. After washing out the melamine in excess, small amounts (ppm) are still needed to stabilize the dispersion of graphene flakes in aqueous media. To understand the origin of this behaviour, we investigated the melamine-graphene-water system and the fundamental interactions that determine its structure and energetics. To disentangle the subtle interplay of hydrogen-bonding and dispersive forces we used state-of-the-art ab initio calculations based on density functional theory. First, we focused on the case of water molecules interacting with melamine-graphene assemblies at different melamine coverages. We found that water-melamine interactions provide the driving force for washing off the melamine from graphene. Then, we addressed the interaction of single and double layers of water molecules with the graphene surface in the presence of an adsorbed melamine molecule. We found that this melamine acts as a non-covalent anchor for keeping a number of water molecules conveniently close to the graphene surface, thus helping its stabilization in aqueous media. Our analysis helps understanding how competing weak forces can lead to a stable graphene water suspension thanks to small amounts of adsorbed melamine. From our results, we derive simple indications on how the water-graphene interfacial properties can be tuned via non-covalent adsorption of small functional molecules with H-bond donor/acceptor groups. These new hints can be helpful to prepare stable graphene dispersions in water and so to unlock graphene potential in aqueous environments.
Collapse
Affiliation(s)
- Antonio M Rodríguez
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Comp. Univ. Monte Sant'Angelo Via Cintia 21, 80126 Naples, Italy.
| | - Ana B Muñoz-García
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Comp. Univ. Monte Sant'Angelo Via Cintia 21, 80126 Naples, Italy.
| | - Orlando Crescenzi
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Comp. Univ. Monte Sant'Angelo Via Cintia 21, 80126 Naples, Italy.
| | - Ester Vázquez
- Departamento de Química Orgánica, Facultad de Ciencias y Tecnologías Químicas-IRICA, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain.
| | - Michele Pavone
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Comp. Univ. Monte Sant'Angelo Via Cintia 21, 80126 Naples, Italy.
| |
Collapse
|
7
|
A study on amphiphilic fluorinated block copolymer in graphite exfoliation using supercritical CO 2 for stable graphene dispersion. J Colloid Interface Sci 2018; 510:162-171. [PMID: 28942166 DOI: 10.1016/j.jcis.2017.09.065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 09/11/2017] [Accepted: 09/15/2017] [Indexed: 11/24/2022]
Abstract
In this study, poly(2,2,2-trifluoroethyl methacrylate)-block-poly(4-vinylpyridine) (PTFEMA-b-PVP) was synthesized by stepwise reversible addition-fragmentation chain transfer (RAFT) polymerization for the preparation of graphene by the exfoliation of graphite nanoplatelets (GPs) in supercritical CO2 (SCCO2). Two different block copolymers (low and high molecular weights) were prepared with the same block ratio and used at different concentrations in the SCCO2 process. The amount of PTFEMA-b-PVP adsorbed on the GPs and the electrical conductivity of the SCCO2-treated GP samples were evaluated using thermogravimetric analysis (TGA) and four-point probe method, respectively. All GP samples treated with SCCO2 were then dispersed in methanol and the dispersion stability was investigated using online turbidity measurements. The concentration and morphology of few-layer graphene stabilized with PTFEMA-b-PVP in the supernatant solution were investigated by gravimetry, scanning electron microscopy, and Raman spectroscopy. Destabilization study of the graphene dispersions revealed that the longer block copolymer exhibited better affinity for graphene, resulting in a higher yield of stable graphene with minimal defects.
Collapse
|
8
|
León V, Castañeda G, Herrero MA, Vázquez E. Gold nanoparticles as analytical tools for the quantification of small quantities of triazine derivatives anchored on graphene in water dispersions. RSC Adv 2017. [DOI: 10.1039/c7ra02358h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
A fast, simple and sensitive method develops to detect ppm levels of melamine anchored on graphene in aqueous graphene dispersions.
Collapse
Affiliation(s)
- Verónica León
- Departamento de Química Orgánica
- Inorgánica y Bioquímica
- Facultad de Ciencias y Tecnologías Químicas-IRICA
- Universidad de Castilla–La Mancha
- 13071 Ciudad Real
| | - Gregorio Castañeda
- Departamento de Química Analítica y Tecnología de Alimentos
- Facultad de Ciencias y Tecnologías Químicas-IRICA
- Universidad de Castilla–La Mancha
- 13071 Ciudad Real
- Spain
| | - María Antonia Herrero
- Departamento de Química Orgánica
- Inorgánica y Bioquímica
- Facultad de Ciencias y Tecnologías Químicas-IRICA
- Universidad de Castilla–La Mancha
- 13071 Ciudad Real
| | - Ester Vázquez
- Departamento de Química Orgánica
- Inorgánica y Bioquímica
- Facultad de Ciencias y Tecnologías Químicas-IRICA
- Universidad de Castilla–La Mancha
- 13071 Ciudad Real
| |
Collapse
|
9
|
Varenik M, Green MJ, Regev O. Distinguishing Self-Assembled Pyrene Structures from Exfoliated Graphene. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10699-10704. [PMID: 27723350 DOI: 10.1021/acs.langmuir.6b03379] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Sonication-assisted graphene production from graphite is a popular lab-scale approach in which ultrasound energy breaks down graphite sheets into graphene flakes in aqueous medium. Dispersants (surfactant molecules) are incorporated into the solution to prevent individual graphene flakes from reaggregating. However, in solution these dispersants self-assemble into various structures, which can interfere with the characterization of the graphene produced. In this study, we characterized graphene dispersions stabilized by a family of pyrene-based surfactants that facilitate a high exfoliation yield. These surfactants self-assembled to form flakes and ribbons-shapes very similar to those of graphene structures. The dispersant structures were present both in the graphene dispersion and in the precipitate after the solvent had been evaporated and could therefore have been mistakenly identified as graphene by electron microscopy techniques and other characterization techniques, such as Raman and X-ray photoelectron spectroscopy. Contrary to previous reports, we showed-by removing the dispersants by filtration and washing-that the surfactants did not affect the shape of the graphene prepared by sonication.
Collapse
Affiliation(s)
| | - Micah J Green
- Artie McFerrin Department of Chemical Engineering, Texas A&M University , College Station, Texas 77843-3122, United States
| | | |
Collapse
|
10
|
Parviz D, Irin F, Shah SA, Das S, Sweeney CB, Green MJ. Challenges in Liquid-Phase Exfoliation, Processing, and Assembly of Pristine Graphene. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:8796-8818. [PMID: 27546380 DOI: 10.1002/adma.201601889] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 06/28/2016] [Indexed: 05/08/2023]
Abstract
Recent developments in the exfoliation, dispersion, and processing of pristine graphene (i.e., non-oxidized graphene) are described. General metrics are outlined that can be used to assess the quality and processability of various "graphene" products, as well as metrics that determine the potential for industrial scale-up. The pristine graphene production process is categorized from a chemical engineering point of view with three key steps: i) pretreatment, ii) exfoliation, and iii) separation. How pristine graphene colloidal stability is distinct from the exfoliation step and is dependent upon graphene interactions with solvents and dispersants are extensively reviewed. Finally, the challenges and opportunities of using pristine graphene as nanofillers in polymer composites, as well as as building blocks for macrostructure assemblies are summarized in the context of large-scale production.
Collapse
Affiliation(s)
- Dorsa Parviz
- Artie McFerrin Department of Chemical Engineering, College Station, TX, 77843, USA
| | - Fahmida Irin
- Artie McFerrin Department of Chemical Engineering, College Station, TX, 77843, USA
| | - Smit A Shah
- Artie McFerrin Department of Chemical Engineering, College Station, TX, 77843, USA
| | - Sriya Das
- Artie McFerrin Department of Chemical Engineering, College Station, TX, 77843, USA
| | - Charles B Sweeney
- Artie McFerrin Department of Chemical Engineering, College Station, TX, 77843, USA
| | - Micah J Green
- Artie McFerrin Department of Chemical Engineering, College Station, TX, 77843, USA.
| |
Collapse
|
11
|
Stevens B, Guin T, Sarwar O, John A, Paton KR, Coleman JN, Grunlan JC. Highly Conductive Graphene and Polyelectrolyte Multilayer Thin Films Produced From Aqueous Suspension. Macromol Rapid Commun 2016; 37:1790-1794. [DOI: 10.1002/marc.201600413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/29/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Bart Stevens
- Department of Mechanical Engineering Texas A&M University College Station TX 77843 USA
| | - Tyler Guin
- Department of Mechanical Engineering Texas A&M University College Station TX 77843 USA
| | - Owais Sarwar
- Department of Mechanical Engineering Texas A&M University College Station TX 77843 USA
| | - Alyssa John
- Department of Mechanical Engineering Texas A&M University College Station TX 77843 USA
| | - Keith R. Paton
- School of Physics University of Dublin Trinity College Dublin 2 Ireland
| | | | - Jaime C. Grunlan
- Department of Mechanical Engineering Texas A&M University College Station TX 77843 USA
| |
Collapse
|
12
|
León V, González-Domínguez JM, Fierro JLG, Prato M, Vázquez E. Production and stability of mechanochemically exfoliated graphene in water and culture media. NANOSCALE 2016; 8:14548-55. [PMID: 27411953 DOI: 10.1039/c6nr03246j] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The preparation of graphene suspensions in water, without detergents or any other additives is achieved using freeze-dried graphene powders, produced by mechanochemical exfoliation of graphite. These powders of graphene can be safely stored or shipped, and promptly dissolved in aqueous media. The suspensions are relatively stable in terms of time, with a maximum loss of ∼25% of the initial concentration at 2 h. This work provides an easy and general access to aqueous graphene suspensions of chemically non-modified graphene samples, an otherwise (almost) impossible task to achieve by other means. A detailed study of the stability of the relative dispersions is also reported.
Collapse
Affiliation(s)
- V León
- Organic Chemistry area, Faculty of Chemical Science and Technology - IRICA, University of Castilla-La Mancha, Avda. Camilo José Cela 10, 13071,, Ciudad Real, Spain.
| | | | | | | | | |
Collapse
|
13
|
Hansen MJ, Rountree KS, Irin F, Sweeney CB, Klaassen CD, Green MJ. Photodegradation of dispersants in colloidal suspensions of pristine graphene. J Colloid Interface Sci 2016; 466:425-31. [DOI: 10.1016/j.jcis.2015.10.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 10/09/2015] [Accepted: 10/12/2015] [Indexed: 10/22/2022]
|
14
|
|