Metallic and Semiconducting Nanowires from Single Wall Carbon Nanotubes

2004 ◽  
Vol 818 ◽  
Author(s):  
Kousik Sivakumar ◽  
Shaoxin Lu ◽  
Balaji Panchapakesan
Keyword(s):  
Carbon Nanotubes ◽  
Silver Nanowires ◽  
Functional Materials ◽  
Nano Particles ◽  
Single Wall Carbon Nanotubes ◽  
Structure Property ◽  
Semiconducting Nanowires ◽  
Sensing Applications ◽  
Macro Scale ◽  
Different Types

AbstractThe focus of today's research has largely shifted from macro scale to micro scale and further to nano scale. The reason being the desire to realize quantum size effects in devices that has long eluded scientists around the world alike. With the discovery of nanoparticles, nanowires, and nanotubes, the ability to realize these effects practically into devices has increased manifold. Integration of carbon nanotubes with different types of functional materials may become mandatory in the future for electronics and sensing applications and in this sense, nucleation, growth and evolution of the structure of metallic and semiconducting materials on carbon nanotubes may be necessary. Further, it also provides opportunities to do fundamental research on understanding the structure-property relationships of these nanowires using carbon nanotubes. In this paper, we present a technique to form metallic and semiconducting nanowires using carbon nanotubes themselves as templates. Nanowires of silver and platinum have been fabricated by the electric field assisted deposition of nano particles of these metals on single walled carbon nanotubes. SEM and TEM investigations have shown the dimensions of the nanowires to be dependent only on the size of the nanoparticles, 10 - 100 nm in our case. The silver nanowires exhibited linear current – voltage characteristics whereas the platinum nanowires exhibited non-linear characteristics beyond a certain bias. This technique provides a high degree of selectivity by manipulating the charges on the surface of the nanotubes, which enables the deposition of metals only on the nanotubes and not anywhere else. The versatility of this technique allows for the fabrication of different types of metallic and semiconducting nanowires at the same dimensions as carbon nanotubes.

Spectroscopic analysis of different types of single-wall carbon nanotubes

1998 ◽  
Vol 44 (4) ◽  
pp. 518-524 ◽  
Author(s):  
H Kuzmany ◽  
B Burger ◽  
M Hulman ◽  
J Kürti ◽  
A. G Rinzler ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Spectroscopic Analysis ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon ◽  
Different Types

scholarly journals Dispersion of Carbon Nanotubes with Different Types of Superplasticizer as a Dispersing Agent for Self-Sensing Cementitious Materials

2021 ◽  
Vol 11 (18) ◽  
pp. 8452
Author(s):  
Pedro de Almeida Carísio ◽  
Yasmim Gabriela dos Santos Mendonça ◽  
Carlos Fernando Teodósio Soares ◽  
Oscar Aurelio Mendoza Reales ◽  
Eduardo de Moraes Rego Fairbairn ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Cementitious Materials ◽  
Cement Matrix ◽  
Cement Pastes ◽  
Sensing Applications ◽  
Dispersing Agent ◽  
Vis Spectroscopy ◽  
Different Types ◽  
Conductive Fillers ◽  
Dispersing Agents

Due to their exceptional electrical properties, carbon nanotubes (CNTs) can be applied as conductive fillers to develop self-sensing cement-based matrices. In order to obtain an adequate self-sensing response, CNTs must be evenly dispersed through the cement matrix in a volume sufficient enough to create an electric percolation network. This is challenged by the difficulty of dispersing CNTs; therefore, there is a demand for an efficient dispersing agent that can be filled by superplasticiezers, which are products of known compatibility with cement and high availability. This research explores the use of four commercial superplasticizers available in Brazil, both naphthalene and ether polycarboxylate-based, as dispersing agents for CNTs in water. Ultrasonic energy was applied to aqueous solutions containing CNTs and superplasticizers. UV–Vis spectroscopy and ξ-potential measurements were used to investigate which superplasticizer was more effective to disperse the CNTs. Cement pastes were produced with the CNT dispersions and their electrical resistivity was measured. It was found that only superplasticizers without aliphatic groups in their structure were capable of dispersing CNTs in water. It was concluded that second-generation naphthalene-based superplasticizers were more efficient dispersing agents for CNTs than third-generation ether polycarboxylate-based ones for self-sensing applications.

Functionalization of wood/plant-based natural cellulose fibers with nanomaterials: a review

TAPPI Journal ◽  
2018 ◽  
Vol 17 (02) ◽  
pp. 92-111 ◽  
Author(s):  
Charu Agarwal ◽  
Levente Csoka
Keyword(s):  
Noble Metals ◽  
Tin Dioxide ◽  
Carbon Nanomaterials ◽  
Point Of Care ◽  
Functional Materials ◽  
Cellulose Fibers ◽  
Sensing Applications ◽  
Natural Cellulose ◽  
Macro Scale ◽  
Disposable Device

Being the most abundant natural biopolymer on earth, cellulose has been vastly exploited in a range of applications, from writing paper to high-end biosensors. Natural cellulose fibers can be isolated from wood or non-woody plants such as hemp, jute, flax, and bamboo by chemical or mechanical treatments. To make it suitable for targeted applications, cellulose fibers are modified with functional moieties in the nanometer scale. Cellulose has been functionalized with noble metals such as silver and gold nanoparticles for catalysis and antimicrobial applications. A number of metal oxides, such as zinc oxide, titanium dioxide, and tin dioxide have been incorporated into cellulose. The porosity, hydrophilicity, and roughness of cellulose surface makes it an ideal substrate for a plethora of sensing applications. Further, it can be made into a lightweight, portable, foldable, and disposable device, which provides an excellent platform for various point-of-care purposes. Cellulose fibers have also been immobilized with carbon nanomaterials, including carbon nanotubes and graphene oxide. For optical applications, [Fe(hptrz)3](OTs)2 spin-crossover nanoparticles have also been immobilized on cellulose fibers. Likewise, many enzymes, macromolecules, and some polymers have been used to modify natural cellulose for specific end uses. This review focuses on recent developments in the modification or immobilization of functional materials on cellulose fibers, in macro-scale only, obtained from wood or plant sources.

Experimental Study of Thermoelectric Properties of SWCNTs and SiC Nanoparticles and its Composites Doped With Sol-Gels

2013 ◽  
Author(s):  
Mujibur R. Khan ◽  
Miletus Jones ◽  
Luz Bugarin ◽  
Salvador Sandoval
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Seebeck Coefficient ◽  
Sol Gel ◽  
Single Wall Carbon Nanotubes ◽  
Material System ◽  
Structure Property ◽  
Sic Nanoparticles ◽  
Property Relation ◽  
Similar Range

Thermoelectric (TE) properties of Single wall carbon nanotubes (SWCNTs) and Silicon carbide (SiC) nanoparticles after treated with sol-gel dopants at elevated temperature. Different combinations of P and N type sol-gels were used. The combinations were Boron-Antimony, Aluminum-Antimony, Aluminum-Phosphorus and Boron–Phosphorus. The nanoparticles were randomly distributed on a nonconductive glass substrate and hot and cold junctions were created using silver epoxy and Alumel (Ni-Al) wire. The carbon nanotubes used were approximately 60% semiconducting and 40% metallic. Voltage (mV), current (μA) and resistance (Ω) were measured across the distributed nanoparticles within 160° C temperature difference. The Seebeck coefficient for pristine SWCNTs was 0.12 mV/oC. When doped with Boron-Antimony the Seebeck coefficient increased to 0.981 mV/°C. On the hand, SiC nanoparticles showed no TE effect at pristine form, but when infused with SWCNTs substantial TE effect was present. Even though the Seebeck coefficient was in a similar range with different SWCNT concentrations (wt%), current, resistance and Power factor (P.F.) changed with wt% of nanotubes. Resistance of the nanotube samples slightly decreased with the increase in temperature. Finally, the SiC+SWCNT composites were prepared using the sintering process at around 1500° C. Thermoelectric and Mechanical properties of the composites were tested. The structure-property relation was analyzed using SEM (scanning electron microscope) and XRD (X-ray diffraction). It was revealed that fiber like SWCNTs created randomly distributed network with Nano contact junctions inside the SiC matrix and enhance thermoelectric and mechanical properties in the combined SiC+SWCNTs material system. Put abstract text here.

scholarly journals Sensing with Chirality Pure near Infrared Fluorescent Carbon Nanotubes

2020 ◽  
Author(s):  
Robert Nißler ◽  
Larissa Kurth, ◽  
Han Li ◽  
Alexander Spreinat ◽  
Ilyas Kuhlemann ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Dna Sequences ◽  
Near Infrared ◽  
Single Wall Carbon Nanotubes ◽  
Term Stability ◽  
Long Term Stability ◽  
Sensing Applications ◽  
Main Challenge ◽  
The Impact

Semiconducting single wall carbon nanotubes (SWCNTs) fluoresce in the near infrared (NIR) and the emission wavelength depends on their chirality (n,m). Interactions with the environment affect the fluorescence and can be tailored by functionalizing SWCNTs with biopolymers such as DNA, which is the basis for fluorescent biosensors. So far, such biosensors were mainly assembled from mixtures of SWCNT chiralities with large spectral overlap, which affects sensitivity as well as selectivity and prevents multiplexed sensing. The main challenge to gain chirality pure sensors has been to combine approaches to isolate specific SWCNTs and generic (bio)functionalization approaches. Here, we created chirality pure SWCNT-based NIR biosensors for important analytes such as neurotransmitters and investigated the impact of SWCNT chirality/handedness as well as long-term stability and sensitivity. For this purpose, we used aqueous two-phase extraction (ATPE) to gain chirality pure (6,5)-, (7,5)-, (9,4)- and (7,6)- SWCNTs (emission at ~ 990, 1040, 1115 and 1130 nm). Exchange of the surfactant sodium deoxycholate (DOC) to specific singlestranded (ss)DNA sequences yielded monochiral sensors for small analytes (dopamine, riboflavin, ascorbic acid, pH). DOC used in the separation process was completely removed because residues impaired sensing. The assembled monochiral sensors were up to 10 times brighter than their non-purified counterparts and the ssDNA sequence affected absolute fluorescence intensity as well as colloidal (long-term) stability and selectivity for the analytes. (GT)40-(6,5)-SWCNTs displayed the maximum fluorescence response to the neurotransmitter dopamine (+140 %, Kd = 1.9 x10-7 M) and a long-term stability > 14 days. Furthermore, the specific ssDNA sequences imparted selectivity to the analytes independent of SWCNT chirality and handedness of (+/-) (6,5)-SWCNTs. These monochiral/single-color SWCNTs enabled ratiometric/multiplexed sensing of dopamine, riboflavin, H2O2 and pH. In summary, we demonstrated the assembly, characteristics and potential of monochiral (single-color) SWCNTs for multiple NIR fluorescent sensing applications.

scholarly journals Sensing with Chirality Pure near Infrared Fluorescent Carbon Nanotubes

2020 ◽  
Author(s):  
Robert Nißler ◽  
Larissa Kurth, ◽  
Han Li ◽  
Alexander Spreinat ◽  
Ilyas Kuhlemann ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Dna Sequences ◽  
Near Infrared ◽  
Single Wall Carbon Nanotubes ◽  
Term Stability ◽  
Long Term Stability ◽  
Sensing Applications ◽  
Main Challenge ◽  
The Impact

Semiconducting single wall carbon nanotubes (SWCNTs) fluoresce in the near infrared (NIR) and the emission wavelength depends on their chirality (n,m). Interactions with the environment affect the fluorescence and can be tailored by functionalizing SWCNTs with biopolymers such as DNA, which is the basis for fluorescent biosensors. So far, such biosensors were mainly assembled from mixtures of SWCNT chiralities with large spectral overlap, which affects sensitivity as well as selectivity and prevents multiplexed sensing. The main challenge to gain chirality pure sensors has been to combine approaches to isolate specific SWCNTs and generic (bio)functionalization approaches. Here, we created chirality pure SWCNT-based NIR biosensors for important analytes such as neurotransmitters and investigated the impact of SWCNT chirality/handedness as well as long-term stability and sensitivity. For this purpose, we used aqueous two-phase extraction (ATPE) to gain chirality pure (6,5)-, (7,5)-, (9,4)- and (7,6)- SWCNTs (emission at ~ 990, 1040, 1115 and 1130 nm). Exchange of the surfactant sodium deoxycholate (DOC) to specific singlestranded (ss)DNA sequences yielded monochiral sensors for small analytes (dopamine, riboflavin, ascorbic acid, pH). DOC used in the separation process was completely removed because residues impaired sensing. The assembled monochiral sensors were up to 10 times brighter than their non-purified counterparts and the ssDNA sequence affected absolute fluorescence intensity as well as colloidal (long-term) stability and selectivity for the analytes. (GT)40-(6,5)-SWCNTs displayed the maximum fluorescence response to the neurotransmitter dopamine (+140 %, Kd = 1.9 x10-7 M) and a long-term stability > 14 days. Furthermore, the specific ssDNA sequences imparted selectivity to the analytes independent of SWCNT chirality and handedness of (+/-) (6,5)-SWCNTs. These monochiral/single-color SWCNTs enabled ratiometric/multiplexed sensing of dopamine, riboflavin, H2O2 and pH. In summary, we demonstrated the assembly, characteristics and potential of monochiral (single-color) SWCNTs for multiple NIR fluorescent sensing applications.

scholarly journals Application of Functionalized SWCNTs for Increase of Degradation Resistance of Acrylic Paint for Cars

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Osiel Lucas Flores ◽  
Oxana V. Kharissova ◽  
Ubaldo Ortiz Méndez ◽  
Héctor Leija Gutiérrez ◽  
Edgar de Casas Ortiz ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electron Beam ◽  
Physical Properties ◽  
Single Wall Carbon Nanotubes ◽  
Raman Spectrometry ◽  
Single Wall Carbon ◽  
Acrylic Paint ◽  
Different Types ◽  
Acrylic Paints

Physical properties of automotive acrylic paint are improved by incorporation of three different types of carbon nanotubes: single-wall carbon nanotubes (SWCNTs), OH-functionalized single-wall carbon nanotubes (OH-SWCNTs), and aniline-functionalized single-wall carbon nanotubes (aniline-SWCNTs). The formed composites are studied by electron miscroscopy methods and Raman spectrometry. It is found that the acrylic paints with addition of OH-SWCNTs and aniline-SWCNTs show better quality for their applications. In particular, the resistance against degradation by electron beam increased in ~500%.

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