Search results for "Carbon nanotube"
showing 10 items of 422 documents
Carbon Nanotubes. By Stefanie Reich, Christian Thomsen and Janina Maultzsch.
2005
Monofunctional pyrenes at carbon nanotube electrodes for direct electron transfer H2O2 reduction with HRP and HRP-bacterial nanocellulose
2021
Abstract The non-covalent modification of carbon nanotube electrodes with pyrene derivatives is a versatile approach to enhance the electrical wiring of enzymes for biosensors and biofuel cells. We report here a comparative study of five pyrene derivatives adsorbed at multi-walled carbon nanotube electrodes to shed light on their ability to promote direct electron transfer with horseradish peroxidase (HRP) for H2O2 reduction. In all cases, pyrene-modified electrodes enhanced catalytic reduction compared to the unmodified electrodes. The pyrene N-hydroxysuccinimide (NHS) ester derivative provided access to the highest catalytic current of 1.4 mA cm−2 at 6 mmol L−1 H2O2, high onset potential …
Evidence for long-lived, optically generated quenchers of excitons in single-walled carbon nanotubes.
2011
The nonlinear dependence of near-infrared photoluminescence (PL) emission on excitation intensity has been measured for individual nanotubes representing six different (n,m) species. Significant deviations from linearity are observed for intensities as low as ~100 W/cm(2), and an approximate inverse correlation is found between nonlinearity and PL action cross section (brightness). A model in which all PL nonlinearity arises from exciton-exciton annihilation is insufficient to account for the experimental data using realistic parameters. It is proposed that additional nonlinear quenching arises from photoinduced quenching states or species with longer lifetimes than emissive excitons. Evide…
Stress Transfer within CNT Fibres: A FEA Approach
2015
Abstract Carbon nanotube (CNT) fibres are characterized by extreme anisotropy in their structure and physical properties. These fibres have been shown to have high axial strength, but poor shear strength between carbon nanotubes; for this reason it is difficult to transfer stress uniformly acrossthe fibre cross section. Here, Finite Element Analysis (FEA) is used to predict the stress distribution and the stress-strain curves of CNT fibres. The resultsdemonstrate that, in accordance with St. Venant principle,very considerable length-to-diameter ratios (> 10 3 ) are required to obtain a uniform stress distribution within the fibres even in the presence of low applied strain.
Carbon Nanotube-Reinforced Nanocomposites.
CONTROLLING THE FUNCTIONALIZATION OF CARBON NANOTUBES AND GRAPHENE NANOPLATELETS
2013
The functionalization of carbon nanostructures by diazonium chemistry is a versatile strategy to obtain soluble nanomaterials with degrees of functionalization among the highest ever reported.[1,2] Starting from these premises we have studied the functionalization of single, double and multi-walled carbon nanotubes and graphene nanoplatelets by addition of aryl diazonium salts generated in situ by treatment of 4-substituted anilines with isopentylnitrite. Taking advantage of highly controlled flow synthesis [3-5] and following a thorough purification and characterization protocol (UV-vis, TGA, ATR-IR, AFM and other surface tools), we have investigated the key parameters to obtain both funct…
Carbon Nanostructures: Covalent and Macromolecular Chemistry
2012
The aim of this introductory chapter is to bring to the attention of the readers the achievements made in the chemistry of carbon nanostructures and, mostly, in the chemistry of fullerenes, carbon nanotubes (CNTs), and the most recent graphenes. Since the discovery of fullerenes in 1985 and their further preparation in multigram amounts, the chemistry and reactivity of thesemolecular carbon allotropes have been well established. Actually, this chemical reactivity has been used as a benchmark for further studies carried out in the coming carbon nanotubes (single andmultiple wall) and graphenes. Assuming that the fundamental chemistry of fullerenes is known and basically corresponds to that o…
Covalently Supported Ionic Liquid Phases: An Advanced Class of Recyclable Catalytic Systems
2016
In this review, the most recent advances in the synthesis and catalytic applications of covalently supported ionic liquid (IL) phases will be discussed. This class of recyclable catalytic materials is based on the covalent attachment of several types of ammonium salts, usually imidazolium, but also thiazolium, triazolium, and pyrrolidinium salts, on the surface of different supports, for example, silica, periodic mesoporous organosilica, polystyrene, magnetic-based materials, carbon nanotubes (NTs), halloysite NTs, polyhedral oligomeric silsesquioxane (POSS), and fullerenes. Moreover, poly(ionic liquid) materials, in which the IL-based structure also acts as a support, will be considered. T…
Thin-Film Heterojunction by Carbon Nanotube Derivatives with Enhanced Solubility and Optical Properties
2012
Multi-functional hybrid-carbon nanotubes for advanced Ultra-High Molecular Weight Polyethylene-based nanocomposites: a novel approach for stabilizati…
2015
Our results demonstrate that immobilizing stabilizing molecules on nanoparticles, and using the latter as multifunctional filler for nanocomposites, is a viable route towards to produce high-performance polymeric materials