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Cano-Casanova L, Ansón-Casaos A, Hernández-Ferrer J, Benito AM, Maser WK, Garro N, Lillo-Ródenas MA, Román-Martínez MC. Surface-Enriched Boron-Doped TiO 2 Nanoparticles as Photocatalysts for Propene Oxidation. ACS Appl Nano Mater 2022; 5:12527-12539. [PMID: 36185169 PMCID: PMC9513816 DOI: 10.1021/acsanm.2c02217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 07/18/2022] [Indexed: 06/16/2023]
Abstract
A series of nanostructured boron-TiO2 photocatalysts (B-X-TiO2-T) were prepared by sol-gel synthesis using titanium tetraisopropoxide and boric acid. The effects of the synthesis variables, boric acid amount (X) and crystallization temperature (T), on structural and electronic properties and on the photocatalytic performance for propene oxidation, are studied. This reaction accounts for the remediation of pollution caused by volatile organic compounds, and it is carried out at low concentrations, a case in which efficient removal techniques are difficult and costly to implement. The presence of boric acid during the TiO2 synthesis hinders the development of rutile without affecting the textural properties. X-ray photoelectron spectroscopy analysis reveals the interstitial incorporation of boron into the surface lattice of the TiO2 nanostructure, while segregation of B2O3 occurs in samples with high boron loading, also confirmed by X-ray diffraction. The best-performing photocatalysts are those with the lowest boron loading. Their high activity, outperforming the equivalent sample without boron, can be attributed to a high anatase and surface hydroxyl group content and efficient photo-charge separation (photoelectrochemical characterization, PEC), which can explain the suppression of visible photoluminescence (PL). Crystallization at 450 °C renders the most active sample, likely due to the development of a pure anatase structure with a large surface boron enrichment. A shift in the wavelength-dependent activity profile (PEC data) and the lowest electron-hole recombination rate (PL data) are also observed for this sample.
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Affiliation(s)
- L. Cano-Casanova
- Grupo
Materiales Carbonosos y Medio Ambiente, Departamento de Química
Inorgánica e Instituto Universitario de Materiales (IUMA),
Facultad de Ciencias, Universidad de Alicante, Ap.99, E-03080 Alicante, Spain
| | - A. Ansón-Casaos
- Instituto
de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
| | - J. Hernández-Ferrer
- Instituto
de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
| | - A. M. Benito
- Instituto
de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
| | - W. K. Maser
- Instituto
de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
| | - N. Garro
- Institut
de Ciència dels Materials (ICMUV), Universitat de València, 46980 Paterna, València, Spain
| | - M. A. Lillo-Ródenas
- Grupo
Materiales Carbonosos y Medio Ambiente, Departamento de Química
Inorgánica e Instituto Universitario de Materiales (IUMA),
Facultad de Ciencias, Universidad de Alicante, Ap.99, E-03080 Alicante, Spain
| | - M. C. Román-Martínez
- Grupo
Materiales Carbonosos y Medio Ambiente, Departamento de Química
Inorgánica e Instituto Universitario de Materiales (IUMA),
Facultad de Ciencias, Universidad de Alicante, Ap.99, E-03080 Alicante, Spain
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Garcia-Bordejé E, Benito AM, Maser WK. Graphene aerogels via hydrothermal gelation of graphene oxide colloids: Fine-tuning of its porous and chemical properties and catalytic applications. Adv Colloid Interface Sci 2021; 292:102420. [PMID: 33934004 DOI: 10.1016/j.cis.2021.102420] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/12/2021] [Accepted: 04/12/2021] [Indexed: 02/07/2023]
Abstract
Recently, 3D graphene aerogel has garnered a high interest aiming at benefiting of the excellent properties of graphene in devices for energy storage or environmental remediation. Hydrothermal gelation of GO dispersion is a straightforward method that offers many opportunities for tuning its properties and for processing it to devices. By adjusting hydrothermal gelation and drying conditions, it is possible to tune the density (from ~3 mg cm-3 to ~2 g cm-3), pore volume, pores size (micro to macropores), pore distribution, surface chemical polarity (hydrophobic or hydrophilic), and electrical conductivity (from ~0.5 S m-1 to S cm-1). Besides other well explored applications in energy storage or environmental remediation, graphene aerogels have excellent prospects as support for catalysis since they combine the advantages of graphene sheets (high surface area, high electrical conductivity, surface chemistry tunability, high adsorption capacity…) while circumventing their drawbacks such as difficult separation from reaction media or tendency to stacking. Compared to other 3D porous carbon materials used as catalyst support, graphene aerogels have unique porous structure. The pore walls are the thinnest to be expected for a carbon material (the thickness of monolayer graphene is 0.335 nm), hence leading to the highest exposed surface area per weight and even per volume for compacted aerogels. This has the potential to maximize the catalytic site density per reactor mass and volume while minimizing the pressure drop for continuous reactions in flow. Herein, different strategies to control the porous texture, chemical and physical properties are revised along with their processability and scalability for the implementation into different morphologies and devices. Finally, the application of graphene aerogels in the catalysis field are overviewed, giving a perspective about future directions needing further research.
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Affiliation(s)
| | - A M Benito
- Instituto de Carboquímica (ICB-CSIC), Miguel Luesma Castán 4, E-50018 Zaragoza, Spain
| | - W K Maser
- Instituto de Carboquímica (ICB-CSIC), Miguel Luesma Castán 4, E-50018 Zaragoza, Spain
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3
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Ansón-Casaos A, Ciria JC, Sanahuja-Parejo O, Víctor-Román S, González-Domínguez JM, García-Bordejé E, Benito AM, Maser WK. The viscosity of dilute carbon nanotube (1D) and graphene oxide (2D) nanofluids. Phys Chem Chem Phys 2020; 22:11474-11484. [PMID: 32391541 DOI: 10.1039/d0cp00468e] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Controlling the physicochemical properties of nanoparticles in fluids directly impacts on their liquid phase processing and applications in nanofluidics, thermal engineering, biomedicine and printed electronics. In this work, the temperature dependent viscosity of various aqueous nanofluids containing carbon nanotubes (CNTs) or graphene oxide (GO), i.e. 1D and 2D nanoparticles with extreme aspect ratios, is analyzed by empirical and predictive physical models. The focus is to understand how the nanoparticle shape, concentration, motion degrees and surface chemistry affect the viscosity of diluted dispersions. To this end, experimental results from capillary viscosimeters are first examined in terms of the energy of viscous flow and the maximum packing fraction applying the Maron-Pierce model. Next, a comparison of the experimental data with predictive physical models is carried out in terms of nanoparticle characteristics that affect the viscosity of the fluid, mostly their aspect ratio. The analysis of intrinsic viscosity data leads to a general understanding of motion modes for carbon nanoparticles, including those with extreme aspect ratios, in a flowing liquid. The resulting universal curve might be extended to the prediction of the viscosity for any kind of 1D and 2D nanoparticles in dilute suspensions.
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Affiliation(s)
- A Ansón-Casaos
- Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain.
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Vallan L, Hernández-Ferrer J, Grasa L, González-Domínguez JM, Martínez MT, Ballesteros B, Urriolabeitia EP, Ansón-Casaos A, Benito AM, Maser WK. Differential properties and effects of fluorescent carbon nanoparticles towards intestinal theranostics. Colloids Surf B Biointerfaces 2020; 185:110612. [PMID: 31740327 DOI: 10.1016/j.colsurfb.2019.110612] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 10/18/2019] [Accepted: 10/24/2019] [Indexed: 12/01/2022]
Abstract
Given the potential applications of fluorescent carbon nanoparticles in biomedicine, the relationship between their chemical structure, optical properties and biocompatibility has to be investigated in detail. In this work, different types of fluorescent carbon nanoparticles are synthesized by acid treatment, sonochemical treatment, electrochemical cleavage and polycondensation. The particle size ranges from 1 to 6 nm, depending on the synthesis method. Nanoparticles that were prepared by acid or sonochemical treatments from graphite keep a crystalline core and can be classified as graphene quantum dots. The electrochemically produced nanoparticles do not clearly show the graphene core, but it is made of heterogeneous aromatic structures with limited size. The polycondensation nanoparticles do not have CC double bonds. The type of functional groups on the carbon backbone and the optical properties, both absorbance and photoluminescence, strongly depend on the nanoparticle origin. The selected types of nanoparticles are compatible with human intestinal cells, while three of them also show activity against colon cancer cells. The widely different properties of the nanoparticle types need to be considered for their use as diagnosis markers and therapeutic vehicles, specifically in the digestive system.
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Affiliation(s)
- L Vallan
- Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
| | - J Hernández-Ferrer
- Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
| | - L Grasa
- Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Miguel Servet, 177, Zaragoza, 50013, Spain; Instituto de Investigación Sanitaria de Aragón (IIS), Zaragoza, Spain; Instituto Agroalimentario de Aragón - IA2 -, (Universidad de Zaragoza - CITA), Zaragoza, Spain
| | | | - M T Martínez
- Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
| | - B Ballesteros
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and the Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, Barcelona, 08193, Spain
| | - E P Urriolabeitia
- Instituto de Síntesis Química y Catálisis Homogénea, ISQCH, CSIC, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain
| | - A Ansón-Casaos
- Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain.
| | - A M Benito
- Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
| | - W K Maser
- Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
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Ansón-Casaos A, Rubio-Muñoz C, Hernández-Ferrer J, Santidrian A, Benito AM, Maser WK. Capacitive and Charge Transfer Effects of Single-Walled Carbon Nanotubes in TiO 2 Electrodes. Chemphyschem 2019; 20:838-847. [PMID: 30768829 DOI: 10.1002/cphc.201900066] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 01/30/2019] [Indexed: 11/08/2022]
Abstract
The transfer of nanoscale properties from single-walled carbon nanotubes (SWCNTs) to macroscopic systems is a topic of intense research. In particular, inorganic composites of SWCNTs and metal oxide semiconductors are being investigated for applications in electronics, energy devices, photocatalysis, and electroanalysis. In this work, a commercial SWCNT material is separated into fractions containing different conformations. The liquid fractions show clear variations in their optical absorbance spectra, indicating differences in the metallic/semiconducting character and the diameter of the SWCNTs. Also, changes in the surface chemistry and the electrical resistance are evidenced in SWCNT solid films. The starting SWCNT sample and the fractions as well are used to prepare hybrid electrodes with titanium dioxide (SWCNT/TiO2 ). Raman spectroscopy reflects the optoelectronic properties of SWCNTs in the SWCNT/TiO2 electrodes, while the electrochemical behavior is studied by cyclic voltammetry. A selective development of charge transfer characteristics and double-layer behavior is achieved through the suitable choice of SWCNT fractions.
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Affiliation(s)
- A Ansón-Casaos
- Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018, Zaragoza, Spain
| | - C Rubio-Muñoz
- Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018, Zaragoza, Spain
| | - J Hernández-Ferrer
- Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018, Zaragoza, Spain
| | - A Santidrian
- Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018, Zaragoza, Spain
| | - A M Benito
- Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018, Zaragoza, Spain
| | - W K Maser
- Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018, Zaragoza, Spain
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Serrano-Luján L, Víctor-Román S, Toledo C, Sanahuja-Parejo O, Mansour AE, Abad J, Amassian A, Benito AM, Maser WK, Urbina A. Environmental impact of the production of graphene oxide and reduced graphene oxide. SN Appl Sci 2019. [DOI: 10.1007/s42452-019-0193-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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García-Bordejé E, Víctor-Román S, Sanahuja-Parejo O, Benito AM, Maser WK. Control of the microstructure and surface chemistry of graphene aerogels via pH and time manipulation by a hydrothermal method. Nanoscale 2018; 10:3526-3539. [PMID: 29410999 DOI: 10.1039/c7nr08732b] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Three-dimensional graphene aerogels of controlled pore size have emerged as an important platform for several applications such as energy storage or oil-water separation. The aerogels of reduced graphene oxide are mouldable and light weight, with a porosity up to 99.9%, consisting mainly of macropores. Graphene aerogel preparation by self-assembly in the liquid phase is a promising strategy due to its tunability and sustainability. For graphene aerogels prepared by a hydrothermal method, it is known that the pH value has an impact on their properties but it is unclear how pH affects the auto-assembly process leading to the final properties. We have monitored the time evolution of the chemical and morphological properties of aerogels as a function of the initial pH value. In the hydrothermal treatment process, the hydrogel is precipitated earlier and with lower oxygen content for basic pH values (∼13 wt% O) than for acidic pH values (∼20 wt% O). Moreover, ∼7 wt% of nitrogen is incorporated on the graphene nanosheets at basic pH generated by NH3 addition. To our knowledge, there is no precedent showing that the pH value affects the microstructure of graphene nanosheets, which become more twisted and bent for the more intensive deoxygenation occurring at basic pH. The bent nanosheets attained at pH = 11 reduce the stacking by the basal planes and they connect via the borders, hence leading eventually to higher pore volumes. In contrast, the flatter graphene nanosheets attained under acidic pH entail more stacking and higher oxygen content after a long hydrothermal treatment. The gravimetric absorption capacity of non-polar solvents scales directly with the pore volume. The aerogels have proved to be highly selective, recyclable and robust for the absorption of nonpolar solvents in water. The control of the porous structure and surface chemistry by manipulation of pH and time will also pave the way for other applications such as supercapacitors or batteries.
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Affiliation(s)
- E García-Bordejé
- Instituto de Carboquímica (ICB-CSIC), Miguel Luesma Castán 4, E-50018 Zaragoza, Spain.
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8
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Núñez JD, Benito AM, Rouzière S, Launois P, Arenal R, Ajayan PM, Maser WK. Graphene oxide-carbon nanotube hybrid assemblies: cooperatively strengthened OH···O 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 C hydrogen bonds and the removal of chemisorbed water. Chem Sci 2017; 8:4987-4995. [PMID: 28989597 PMCID: PMC5625303 DOI: 10.1039/c7sc00223h] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 05/01/2017] [Indexed: 12/05/2022] Open
Abstract
The effective removal of chemisorbed water in graphene oxide by oxidized carbon nanotubes via cooperatively strengthened OH···OC hydrogen bonds.
Owing to their great significance for energy storage and sensing applications, multi-layer papers consisting of graphene oxide–carbon nanotube (GO–CNT) hybrid sheets were prepared by in situ exfoliation of graphite oxide in the presence of oxidized CNTs (oCNTs). For the first time we elucidate the influence of oCNTs on chemisorbed water (CW), i.e. the water molecules inherently bound to the oxygen functional groups (OFGs) of graphene oxide (GO) and responsible for irreversible structural damage upon thermal reduction processes. We show that oCNTs self-assemble onto GO sheets during the liquid phase processing steps by forming cooperatively strengthened OH···OC hydrogen bonds between the carboxylic groups of the oCNTs and OFGs of GO. At oCNT amounts of about 10 to 15 wt% this leads to the displacement of considerable amounts of CW without altering the original chemical composition of GO. The thermally reduced GO–CNT (rGO–CNT) papers reveal improved sp2 character and an enhancement of the specific capacitance by 75% with respect to thermally reduced GO (rGO), largely due to the effective removal of CW by oxidized CNTs. These findings disclose the relevance of the cooperative hydrogen bonding phenomena in graphene oxide paper/film electrodes for the development of improved electrochemical energy storage and sensing devices.
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Affiliation(s)
- J D Núñez
- Instituto de Carboquímica (ICB-CSIC) , E-50018 Zaragoza , Spain . ; Tel: +34 976 73 39 77
| | - A M Benito
- Instituto de Carboquímica (ICB-CSIC) , E-50018 Zaragoza , Spain . ; Tel: +34 976 73 39 77
| | - S Rouzière
- Laboratoire de Physique des Solides , CNRS , Univ. Paris-Sud , Univ. Paris Saclay , F-91405 Orsay Cedex , France
| | - P Launois
- Laboratoire de Physique des Solides , CNRS , Univ. Paris-Sud , Univ. Paris Saclay , F-91405 Orsay Cedex , France
| | - R Arenal
- Laboratorio de Microscopias Avanzadas , Instituto de Nanociencias de Aragón , Univ. Zaragoza , E-50018 Zaragoza , Spain.,ARAID Foundation , E-50018 Zaragoza , Spain
| | - P M Ajayan
- Department of Materials Science and NanoEngineering , Rice University , Houston , Texas 77005 , USA
| | - W K Maser
- Instituto de Carboquímica (ICB-CSIC) , E-50018 Zaragoza , Spain . ; Tel: +34 976 73 39 77
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González-Domínguez JM, Castell P, Bespín-Gascón S, Ansón-Casaos A, Díez-Pascual AM, Gómez-Fatou MA, Benito AM, Maser WK, Martínez MT. Covalent functionalization of MWCNTs with poly(p-phenylene sulphide) oligomers: a route to the efficient integration through a chemical approach. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm35272a] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Naffakh M, Marco C, Gómez MA, Ellis G, Maser WK, Benito A, Martínez MT. Crystalline transformations in nylon-6/single-walled carbon nanotube nanocomposites. J Nanosci Nanotechnol 2009; 9:6120-6126. [PMID: 19908503 DOI: 10.1166/jnn.2009.1558] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Nylon-6/single-walled carbon nanotube (SWNT) nanocomposites with different SWNTs loadings were prepared by melt-blending. An efficient dispersion of SWNTs into the nylon-6 matrix was confirmed by scanning electron microscopy. DSC and time-resolved synchrotron X-ray diffraction were used to provide detailed information on the effect of SWNTs on the crystalline phase transition of nylon-6 in the nanocomposites. The incorporation of SWNTs accelerated the crystallization rate of nylon-6 due to a nucleating effect. The variable-temperature WAXS experiments, in both neat nylon-6 and nylon-6 nanocomposites, showed that the crystallization from the melt occured through the formation of the pseudo-hexagonal crystal form (gamma) and its transformation to the monoclinic form (alpha) on cooling. Additionally, this crystalline transition was reversible as observed upon heating. The alpha-gamma crystalline transformation temperature of nylon-6 was dependent on heating rate and, more importantly, on the SWNT content.
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Affiliation(s)
- M Naffakh
- Departamento de Física e Ingeniería de Polímeros, Instituto de Ciencia y Tecnología de Polímeros, CSIC, c/Juan de la Cierva, 3, 28006, Madrid, Spain
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González-Domínguez JM, Castell P, Ansón A, Maser WK, Benito AM, Martinez MT. Block copolymer assisted dispersion of single walled carbon nanotubes and integration into a trifunctional epoxy. J Nanosci Nanotechnol 2009; 9:6104-6112. [PMID: 19908501 DOI: 10.1166/jnn.2009.1575] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Arc discharge single walled carbon nanotubes were processed by acid treatment, dispersion in a Pluronic F68 block copolymer aqueous solution and centrifugation. The as-prepared material was characterized by transmission electron microscopy, X-ray diffraction and Raman spectroscopy, showing an important degree of debundling as well as the removal of most of the graphitic and metallic impurities from pristine nanotubes. The nanotube-Pluronic material was integrated into an advanced trifunctional epoxy resin, triglycidyl p-aminophenol, using 4,4'-diaminodiphenylsulfone as the curing agent. The material was incorporated into the epoxy system (0.1, 0.25, 0.50, 1.0, 2.0 wt%) throughout hot magnetic stirring and ultrasonication. Curing kinetics was studied using differential scanning calorimetry, applying the Vyazovkin's isoconversional method. In the early stages of curing, the kinetic study revealed a decrease in the activation energy for samples containing Pluronic, suggesting that Pluronic induced an improvement in the mobility of reactants. The cured composites were characterized by Raman spectroscopy, thermogravimetric analysis and scanning electron microscopy. Micrographs revealed successful integration and homogeneous distribution of the nanotube-Pluronic material in the epoxy matrix, while direct integration of bare nanotubes originated aggregates and inhomogeneity.
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12
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Belmonte M, Vallés C, Maser WK, Benito AM, Martinez MT, Miranzo P, Osendi MI. Processing route to disentangle multi-walled carbon nanotube towards ceramic composite. J Nanosci Nanotechnol 2009; 9:6164-6170. [PMID: 19908510 DOI: 10.1166/jnn.2009.1552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Multi-walled carbon nanotubes were highly aggregated into ropes after their synthesis by chemical vapour deposition and, therefore, two different methods for disentangling the bundles of nanotubes were studied. One method compared the use of mild and vigorous mechanical treatments in ethanol and the other one employed dispersants in aqueous media. For comparison purposes and according to their different exfoliating behaviour, sodium dodecyl sulphate and gum arabic were selected as dispersants. The results evidenced that mechanical sonication was insufficient for disentangling the ropes, whereas, the combined action of mild sonication in an ultrasonic bath with the addition of gum arabic to an aqueous suspension containing nanotubes improved the exfoliating performance. Stable suspensions of unbundled multi-walled carbon nanotubes were obtained adding only 0.05 wt% of gum arabic with a dispersant/MWNTs concentration ratio of 0.25. These values corresponded to a reduction in the dispersant concentration between 1 to 2 orders of magnitude compared to those commonly employed. In addition, a processing route for manufacturing dense and homogenous silicon nitride composites using spark plasma sintering with 1.8 vol% of multi-walled carbon nanotubes almost free of organics was developed without nanotubes degradation and aggregation.
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Affiliation(s)
- M Belmonte
- Institute of Ceramics and Glass (CSIC), Kelsen 5, 28049 Madrid, Spain
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Sayago I, Terrado E, Aleixandre M, Horrillo MC, Fernandez MJ, Lafuente E, Maser WK, Benito AM, Urriolabeitia EP, Navarro R, Martinez MT, Gutierrez J, Muñoz E. Novel gas sensors based on carbon nanotube networks. ACTA ACUST UNITED AC 2008. [DOI: 10.1088/1742-6596/127/1/012012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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14
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Lefrant S, de la Chapelle ML, Baltog I, Journet C, Bernier P, Munoz E, Benito A, Maser WK, Martinez MT, de la Fuente GF, Laplaze D, Loiseau A. Raman Investigation of Singlewalled Carbon Nanotubes. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259808030202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- S. Lefrant
- a Laboratoire de Physique Cristalline , IMN, BP 32229 44322, Nantes cedex , 3 , France
| | - M. Lamy de la Chapelle
- a Laboratoire de Physique Cristalline , IMN, BP 32229 44322, Nantes cedex , 3 , France
- b Trinity College , Dublin , Ireland
| | - I. Baltog
- a Laboratoire de Physique Cristalline , IMN, BP 32229 44322, Nantes cedex , 3 , France
| | - C. Journet
- c GDPC, Université Montpellier II , 34095 , Montpellier cedex , France
| | - P. Bernier
- c GDPC, Université Montpellier II , 34095 , Montpellier cedex , France
| | - E. Munoz
- d Instituto de Carboquimica CSIC , Zaragoza , Spain
| | - A. Benito
- d Instituto de Carboquimica CSIC , Zaragoza , Spain
| | - W. K. Maser
- d Instituto de Carboquimica CSIC , Zaragoza , Spain
| | | | | | - D. Laplaze
- c GDPC, Université Montpellier II , 34095 , Montpellier cedex , France
| | - A. Loiseau
- f Laboratoire de Physique du Solide , ONERA, BP 72, 92322 , Chǎtillon cedex , France
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Martínez MT, Callejas MA, Benito AM, Maser WK, Cochet M, Andrés JM, Schreiber J, Chauvet O, Fierro JLG. Microwave single walled carbon nanotubes purification. Chem Commun (Camb) 2002:1000-1. [PMID: 12123043 DOI: 10.1039/b201593e] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new single walled carbon nanotubes (SWCNTs) purification procedure has been developed; it consists in a combination of air treatment and acid microwave digestion leading to a high purity SWCNTs material; the procedure reaches high metal removal percentages and the operation time is drastically reduced compared to conventional acid reflux treatments.
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Affiliation(s)
- M T Martínez
- Instituto de Carboquímica (CSIC), C/Miguel Luesma Castán, 4, 50015 Zaragoza, Spain.
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