Nanomaterials

1250 KiB

Open AccessArticle

Nano-Electrochemistry and Nano-Electrografting with an Original Combined AFM-SECM

by Achraf Ghorbal, Federico Grisotto, Julienne Charlier, Serge Palacin, Cédric Goyer, Christophe Demaille and Ammar Ben Brahim

Nanomaterials 2013, 3(2), 303-316; https://doi.org/10.3390/nano3020303 - 17 May 2013

Cited by 12 | Viewed by 10221

Abstract

This study demonstrates the advantages of the combination between atomic force microscopy and scanning electrochemical microscopy. The combined technique can perform nano-electrochemical measurements onto agarose surface and nano-electrografting of non-conducting polymers onto conducting surfaces. This work was achieved by manufacturing an original Atomic [...] Read more.

This study demonstrates the advantages of the combination between atomic force microscopy and scanning electrochemical microscopy. The combined technique can perform nano-electrochemical measurements onto agarose surface and nano-electrografting of non-conducting polymers onto conducting surfaces. This work was achieved by manufacturing an original Atomic Force Microscopy-Scanning ElectroChemical Microscopy (AFM-SECM) electrode. The capabilities of the AFM-SECM-electrode were tested with the nano-electrografting of vinylic monomers initiated by aryl diazonium salts. Nano-electrochemical and technical processes were thoroughly described, so as to allow experiments reproducing. A plausible explanation of chemical and electrochemical mechanisms, leading to the nano-grafting process, was reported. This combined technique represents the first step towards improved nano-processes for the nano-electrografting. Full article

(This article belongs to the Special Issue New Developments in Nanomaterial Analysis)

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733 KiB

Open AccessArticle

Desorption of 1,3,5-Trichlorobenzene from Multi-Walled Carbon Nanotubes: Impact of Solution Chemistry and Surface Chemistry

by Xingmao Ma and Sheikh Uddin

Nanomaterials 2013, 3(2), 289-302; https://doi.org/10.3390/nano3020289 - 17 May 2013

Cited by 11 | Viewed by 6701

Abstract

The strong affinity of carbon nanotubes (CNTs) to environmental contaminants has raised serious concern that CNTs may function as a carrier of environmental pollutants and lead to contamination in places where the environmental pollutants are not expected. However, this concern will not be [...] Read more.

The strong affinity of carbon nanotubes (CNTs) to environmental contaminants has raised serious concern that CNTs may function as a carrier of environmental pollutants and lead to contamination in places where the environmental pollutants are not expected. However, this concern will not be realized until the contaminants are desorbed from CNTs. It is well recognized that the desorption of environmental pollutants from pre-laden CNTs varies with the environmental conditions, such as the solution pH and ionic strength. However, comprehensive investigation on the influence of solution chemistry on the desorption process has not been carried out, even though numerous investigations have been conducted to investigate the impact of solution chemistry on the adsorption of environmental pollutants on CNTs. The main objective of this study was to determine the influence of solution chemistry (e.g., pH, ionic strength) and surface functionalization on the desorption of preloaded 1,3,5-trichlorobenzene (1,3,5-TCB) from multi-walled carbon nanotubes (MWNTs). The results suggested that higher pH, ionic strength and natural organic matter in solution generally led to higher desorption of 1,3,5-TCB from MWNTs. However, the extent of change varied at different values of the tested parameters (e.g., pH < 7 vs. pH > 7). In addition, the impact of these parameters varied with MWNTs possessing different surface functional groups, suggesting that surface functionalization could considerably alter the environmental behaviors and impact of MWNTs. Full article

(This article belongs to the Special Issue CNT based Nanomaterials)

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4303 KiB

Open AccessArticle

Electrophoretic Deposition of Carbon Nanotubes on 3-Amino-Propyl-Triethoxysilane (APTES) Surface Functionalized Silicon Substrates

by Anirban Sarkar and Theda Daniels-Race

Nanomaterials 2013, 3(2), 272-288; https://doi.org/10.3390/nano3020272 - 13 May 2013

Cited by 63 | Viewed by 21921

Abstract

Fabrication of uniform thin coatings of multi-walled carbon nanotubes (MWCNTs) by electrophoretic deposition (EPD) on semiconductor (silicon) substrates with 3-aminopropyl-triethoxysilane (APTES) surface functionalization has been studied extensively in this report. The gradual deposition and eventual film formation of the carbon nanotubes (CNTs) is [...] Read more.

Fabrication of uniform thin coatings of multi-walled carbon nanotubes (MWCNTs) by electrophoretic deposition (EPD) on semiconductor (silicon) substrates with 3-aminopropyl-triethoxysilane (APTES) surface functionalization has been studied extensively in this report. The gradual deposition and eventual film formation of the carbon nanotubes (CNTs) is greatly assisted by the Coulombic force of attraction existing between the positively charged –NH₂ surface groups of APTES and the acid treated, negatively charged nanotubes migrating towards the deposition surfaces. The remarkable deposition characteristics of the CNT coatings by EPD in comparison to the dip coating method and the influence of isopropyl (IPA)-based CNT suspension in the fabricated film quality has also been revealed in this study. The effect of varying APTES concentration (5%–100%) on the Raman spectroscopy and thickness of the deposited CNT film has been discussed in details, as well. The deposition approach has eliminated the need of metal deposition in the electrophoretic deposition approach and, therefore, establishes a cost-effective, fast and entirely room temperature-based fabrication strategy of CNT thin films for a wide range of next generation electronic applications. Full article

(This article belongs to the Special Issue CNT based Nanomaterials)

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1870 KiB

Open AccessReview

Nanostructured Biomaterials and Their Applications

by Kirsten Parratt and Nan Yao

Nanomaterials 2013, 3(2), 242-271; https://doi.org/10.3390/nano3020242 - 10 May 2013

Cited by 19 | Viewed by 10635

Abstract

Some of the most important advances in the life sciences have come from transitioning to thinking of materials and their properties on the nanoscale rather than the macro or even microscale. Improvements in imaging technology have allowed us to see nanofeatures that directly [...] Read more.

Some of the most important advances in the life sciences have come from transitioning to thinking of materials and their properties on the nanoscale rather than the macro or even microscale. Improvements in imaging technology have allowed us to see nanofeatures that directly impact chemical and mechanical properties of natural and man-made materials. Now that these can be imaged and quantified, substantial advances have been made in the fields of biomimetics, tissue engineering, and drug delivery. For the first time, scientists can determine the importance of nanograins and nanoasperities in nacre, direct the nucleation of apatite and the growth of cells on nanostructured scaffolds, and pass drugs tethered to nanoparticles through the blood-brain barrier. This review examines some of the most interesting materials whose nanostructure and hierarchical organization have been shown to correlate directly with favorable properties and their resulting applications. Full article

(This article belongs to the Special Issue Trends of Nanomaterials in Life Sciences)

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277 KiB

Open AccessArticle

A Thermal Model for Carbon Nanotube Interconnects

by Kaji Muhammad Mohsin, Ashok Srivastava, Ashwani K. Sharma and Clay Mayberry

Nanomaterials 2013, 3(2), 229-241; https://doi.org/10.3390/nano3020229 - 26 Apr 2013

Cited by 26 | Viewed by 7006

Abstract

In this work, we have studied Joule heating in carbon nanotube based very large scale integration (VLSI) interconnects and incorporated Joule heating influenced scattering in our previously developed current transport model. The theoretical model explains breakdown in carbon nanotube resistance which limits the [...] Read more.

In this work, we have studied Joule heating in carbon nanotube based very large scale integration (VLSI) interconnects and incorporated Joule heating influenced scattering in our previously developed current transport model. The theoretical model explains breakdown in carbon nanotube resistance which limits the current density. We have also studied scattering parameters of carbon nanotube (CNT) interconnects and compared with the earlier work. For 1 µm length single-wall carbon nanotube, 3 dB frequency in S₁₂ parameter reduces to ~120 GHz from 1 THz considering Joule heating. It has been found that bias voltage has little effect on scattering parameters, while length has very strong effect on scattering parameters. Full article

(This article belongs to the Special Issue CNT based Nanomaterials)

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196 KiB

Open AccessCommunication

Separation of Short Single- and Double-Stranded DNA Based on Their Adsorption Kinetics Difference on Graphene Oxide

by Po-Jung Jimmy Huang and Juewen Liu

Nanomaterials 2013, 3(2), 221-228; https://doi.org/10.3390/nano3020221 - 4 Apr 2013

Cited by 54 | Viewed by 11241

Abstract

Separation of short single- and double-stranded DNA typically requires gel electrophoresis followed by DNA extraction, which is a time consuming process. Graphene oxide adsorbs single-stranded DNA more quickly than double-stranded ones, allowing for selective removal of the former with a simple mixing and [...] Read more.

Separation of short single- and double-stranded DNA typically requires gel electrophoresis followed by DNA extraction, which is a time consuming process. Graphene oxide adsorbs single-stranded DNA more quickly than double-stranded ones, allowing for selective removal of the former with a simple mixing and centrifugation operation. The effect of DNA length and salt on adsorption selectivity has been characterized and its application in DNA melting curve measurement has been demonstrated. Full article

(This article belongs to the Special Issue Nanomaterials in Sensors)

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3163 KiB

Open AccessArticle

Effects of Microstructure on Electrode Properties of Nanosheet-Derived H_x(Ni_1/3Co_1/3Mn_1/3)O₂ for Electrochemical Capacitors

by Masato Yano, Shinya Suzuki, Masaru Miyayama and Masataka Ohgaki

Nanomaterials 2013, 3(2), 204-220; https://doi.org/10.3390/nano3020204 - 25 Mar 2013

Cited by 9 | Viewed by 7610

Abstract

Nanosheet-derived H_x(Ni_1/3Co_1/3Mn_1/3)O₂ was prepared by restacking (Ni_1/3Co_1/3Mn_1/3)O₂ nanosheets with large or small lateral sizes and their electrochemical properties in a 1 M KOH aqueous solution; microstructural factors [...] Read more.

Nanosheet-derived H_x(Ni_1/3Co_1/3Mn_1/3)O₂ was prepared by restacking (Ni_1/3Co_1/3Mn_1/3)O₂ nanosheets with large or small lateral sizes and their electrochemical properties in a 1 M KOH aqueous solution; microstructural factors were compared with those of bulk H_x(Ni_1/3Co_1/3Mn_1/3)O₂ (HNCM). The electrodes composed of small nanosheets exhibited very large capacitances of 1241 F·g⁻¹ (395 mAh·g⁻¹) at a current density of 50 mA·g⁻¹, and 430 F·g⁻¹ (100 mAh·g⁻¹) at a large current density of 1000 mA·g⁻¹. These large capacitances resulted from a heterogeneous layer structure with a large surface area and pore volume. The electrodes of large nanosheets, with a strongly interconnected microstructure and a surface area slightly larger than that of HNCM, exhibited good cycle stability and capacitances larger than that of HNCM. Microstructural control through the restacking of (Ni_1/3Co_1/3Mn_1/3)O₂ nanosheets improved the electrochemical properties of H_x(Ni, Co, Mn)O₂. Full article

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Nanomaterials, Volume 3, Issue 2 (June 2013) – 7 articles , Pages 204-316

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