Search results for " Nanotubes"
showing 10 items of 289 documents
Mechanical properties of carbon nanotube reinforced nanocomposites
2013
One way to take advantage of the marvelous properties of the carbon nanotubes consists in incorporating them into a matrix to build composite materials. The best candidates for this task are undoubtedly polymers thanks to their strength, toughness, low weight, and easy processing. A mixed model, numerical-analytical, is presented that allows one to predict the elastic properties of carbon nanotube (CNT)/polymer composites containing a random distribution of CNTs, while taking account of the curvature that they show when immersed in the polymer. A three-dimensional model, using a single CNT immersed in an infinite matrix, allows us to numerically evaluate the concentration tensor by evaluati…
Influence of post formation proceses on electrochemical and photoelectrochemical behaviour of TiO2 nanotubes
2011
Electrochemical Synthesis of an Organic Thermoelectric Power Generator.
2020
[EN] Energy harvesting through residual heat is considered one of the most promising ways to power wearable devices. In this work, thermoelectric textiles were prepared by coating the fabrics, first with multiple-wall carbon nanotubes (MWCNTs) by using the layer-by-layer technique and second with poly(3,4-ethylenedioxythiophene) (PEDOT) deposited by electrochemical polymerization. Sodium deoxycholate and poly(diallyldimethylammonium chloride) were used as stabilizers to prepare the aqueous dispersions of MWCNTs. The electrochemical deposition of PEDOT on the MWCNT-coated fabric was carried out in a three-electrode electrochemical cell. The polymerization of PEDOT on the fabric increased the…
Conjugation with carbon nanotubes improves the performance of mesoporous silicon as Li-ion battery anode
2020
Carbon nanotubes can be utilized in several ways to enhance the performance of silicon-based anodes. In the present work, thermally carbonized mesoporous silicon (TCPSi) microparticles and single-walled carbon nanotubes (CNTs) are conjugated to create a hybrid material that performs as the Li-ion battery anode better than the physical mixture of TCPSi and CNTs. It is found out that the way the conjugation is done has an essential role in the performance of the anode. The conjugation should be made between negatively charged TCPSi and positively charged CNTs. Based on the electrochemical experiments it is concluded that the positive charges, i.e., excess amine groups of the hybrid material i…
Supramolecular Association of Halochromic Switches and Halloysite Nanotubes in Fluorescent Nanoprobes for Tumor Detection
2022
Fluorescence imaging has become an indispensable tool in the biomedical laboratory to elucidate the fundamental dynamic and structural factors regulating cellular processes. The development of fluorescent nanoprobes represents a challenge to detect any cellular process under a microscope. Herein, a fluorescent nanomaterial was synthesized by exploiting the supramolecular interaction between a halochromic switch (1Cl) and halloysite nanotubes (HNTs). The successful synthesis of a HNTs/1Cl nanomaterial was confirmed by thermogravimetric analysis and Fourier transform infrared. The aqueous mobility was investigated by dynamic light scattering and ζ-potential measurements as well. Furthermore, …
Understanding the Effects of Crosslinking and Reinforcement Agents on the Performance and Durability of Biopolymer Films for Cultural Heritage Protec…
2021
In the last two decades, the naturally occurring polysaccharides, such as chitosan and pectin, have gained great attention having potential applications in different sectors, from biomedical to new generation packaging. Currently, the chitosan and pectic have been proposed as suitable materials also for the formulation of films and coatings for cultural heritage protection, as well as packaging films. Therefore, the formulation of biopolymer films, considering only naturally occurring polymers and additives, is a current challenging trend. This work reports on the formulation of chitosan (CS), pectin (PC), and chitosan:pectin (CS:PC) films, also containing natural crosslinking and reinforce…
Bionanocomposite films containing halloysite nanotubes and natural antioxidants with enhanced performance and durability as promising materials for c…
2020
In the last decade, the interest toward the formulation of polymer films for cultural heritage protection continuously grew, and these films must be imperatively transparent, removable, and should not react/interact with surface of the artworks. In this research, bionanocomposite films, based on chitosan (Ch) and pectin (P) and containing naturally occurring fillers and antioxidants, were formulated by solvent casting methods and were accurately characterized. The natural halloysite nanotubes (HNT) have a two-fold role, specifically, physical compatibilizer and antioxidant carrier. Therefore, the theoretical solubility between Ch and P was estimated considering Hoy&rsquo
Humidity-enhanced sub-ppm sensitivity to ammonia of covalently functionalized single-wall carbon nanotube bundle layers
2017
International audience; A low-cost method for carbon nanotubes (CNTs) network production from solutions on flexible polyethylene naphthalate substrates has been adopted to prepare high quality and well characterized SWCNT bundle layers to be used as the active layer in chemiresistor gas sensors. Two types of SWCNTs have been tested: pristine SWCNTs, deposited from a surfactant solution, and covalently functionalized SWCNTs, deposited from a dimethyl-acetamide solution. The humidity effects on the sensitivity of the SWCNTs network to NH3 have been investigated. The results show that relative humidity favors the response to NH3, confirming recent theoretical predictions. The COOH-functionaliz…
A synergic nanoantioxidant based on covalently modified halloysite–trolox nanotubes with intra-lumen loaded quercetin
2016
We describe the preparation and properties of the first example of a synergic nanoantioxidant, obtained by different functionalizations of the external surface and the inner lumen of halloysite nanotubes (HNTs). Trolox, a mimic of natural α-tocopherol, was selectively grafted on the HNT external surface; while quercetin, a natural polyphenolic antioxidant, was loaded into the inner lumen to afford a bi-functional nanoantioxidant, HNT–Trolox/Que, which was investigated for its reactivity with transient peroxyl radicals and a persistent 1,1-diphenyl-2-picrylhydrazyl (DPPH˙) radical in comparison with the corresponding mono-functional analogues HNT–Trolox and HNT/Que. Both HNT–Trolox and HNT/Q…