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CURATOR

PhD Student at École de technologie supérieure studying Carbon Nanotube MEMS.

PINBOARD SUMMARY

You will be left astounded when you get to know about its potential and uses.

Carbon nanotubes are remarkable materials that are set to supercede silicon-based technologies in the future.

Sci-fi stuff! Do you fancy an elevator ride to space or drive a car powered by hydrogen with no emissions? These are some of the mind-boggling applications possible with carbon nanotubes.

Too good to be true? Of course, one might argue that there is no sign of hydrogen cars (at least commercially) or space elevators, but considering how fast paced scientific advancement is, it is not a distant dream by any standards.

One of the main areas of application of nanotubes is electronics. Miniaturization of microchips is fast approaching its limit and carbon nanotubes are the best hopes for further miniaturization. Carbon nanotube transistors are currently being investigated as a replacement for conventional silicon transistors. Computers powered by nanotubes can be expected to be much faster and more powerful than today's computers with lower power consumption.

So how do they look? As the name suggests, carbon nanotubes are just hollow tubes/cylinders composed of pure carbon. Based on the structure, nanotubes can be further classified into single-walled and multi-walled nanotubes. Multi-walled nanotubes are basically concentric layers of nanotubes inside each other, and can be thought of as a "Russian doll".

Companies like Intel and IBM are now switching their focus to commercializing nanotube products. Carbon fiber, which is used in the automotive industry to reduce weight and improve strength is a very good example of commercialization. DexMat is a company that specializes in nanotube products.

Everything seems good BUT as with any material, there are certain limitations associated with nanotubes, primarily cost. Manufacturing nanotubes requires expensive tools, which lead to higher costs. The other limiting factor is toxicity. Nanotubes are highly toxic and this limits their use in biological applications.

10 ITEMS PINNED

Pseudocapacitive desalination of brackish water and seawater via vanadium pentoxide decorated multi-walled carbon nanotubes.

Abstract: We introduce membrane pseudocapacitive deionization (MPDI) of a hybrid cell consisting of one electrode of hydrated vanadium pentoxide (hV2O5) decorated on multi-walled carbon nanotubes electrode (MWCNT) and one electrode of activated carbon. This hybrid system enables sodium removal by pseudocapacitive intercalation to MWCNT-hV2O5 electrode and chloride removal by non-Faradaic electrosorption of the porous carbon electrode. MWCNT-hV2O5 electrode was synthesized by electrochemical deposition of hydrated vanadium pentoxide on the MWCNT paper. The stable electrochemical operating window for MWCNT-hV2O5 electrode is identified between -0.5 V and +0.4 V vs. Ag/Cl which provides a specific capacity of 44 mAh/g (corresponds with 244 F/g) in aqueous 1 M NaCl. The desalination performance of the MPDI system was investigated in aqueous 200 mM NaCl (brackish water) and 600 mM NaCl (sea water) solutions. With the aid of an anion and a cation exchange membrane, the MPDI hybrid cell was operated from -0.4 V to +0.8 V cell voltage without crossing the reduction and oxidation potential limit of both electrodes. For the 600 mM NaCl solution, the NaCl salt adsorption capacity of the cell was 23.6±2.2 mg/g which is equivalent to 35.7±3.3 mg/g as normalized to the mass of the MWCNT-hV2O5 electrode. Additionally, we propose a normalization method for the electrode material with Faradaic reactions based on sodium uptake capacities.

Pub.: 26 Jul '17, Pinned: 26 Sep '17

Molecularly imprinted electrochemical sensor prepared on a screen printed carbon electrode for naloxone detection

Abstract: Naloxone (NLX) is a pharmaceutical used as opioid antagonist. A molecular imprinted polymer electrochemical sensor for simple and rapid detection of NLX was prepared through the modification of commercial available screen printed carbon electrode (SPCE). The SPCE was modified with multi-walled carbon nanotubes (MWCNT) by drop coating to increase the signal response and improve the sensitivity. The MIP preparation was carried out via in situ electropolymerization using 4-aminobenzoic acid (4-ABA) as functional monomer. The morphology of the obtained sensor was characterized by scanning electron microscopy (SEM). Several parameters controlling the preparation and performance of the MIP sensor were studied and optimized. The electrochemical behavior of NLX at MIP and control non-imprinted (NIP) sensor was evaluated by differential pulse voltammetry (DPV), demonstrating a better MIP response and the success of the imprinting. The proposed MIP/MWCNT/SPCE sensor showed a linear relationship between peak current intensity and NLX concentration in the range between 0.25 and 10.0 μM, with limits of detection (LOD) and quantification (LOQ) of 0.20 μM and 0.67 μM respectively. The repeatability and reproducibility were also tested with relative standard deviations (RSD) of 4.6 and 9.6% respectively. Moreover, the applicability of the method was successfully confirmed with detection of NLX in biological samples (urine and human serum). The sensor is promising to be used for screening NLX in point-of-care people with opioid overdose.

Pub.: 08 Dec '16, Pinned: 12 Apr '17

Synergistic contributions by decreasing overpotential and enhancing electrocatalytic reduction in ONPCNRs/SWCNTs nanocomposite for highly sensitive nonenzymatic detection of hydrogen peroxide

Abstract: In this study, a novel nanocomposite material consisted of oxygen-doped, nitrogen-rich carbon nanoribbons polymer and single-walled carbon nanotubes (ONPCNRs/SWCNTs) has been facilely synthesized through simply electrostatic interaction process using poly(diallyldimethylammonium chloride) polycationic compound (PDDA). During the synthesis, the N-containing of ONPCNRs could undergo protonation to produce protonated compound under pH 6.5 condition, which could improve electrocatalytic activity of the vertically aligned N-containing ONPCNRs/SWCNTs nanocomposite due to the electron withdrawing ability of nitrogen atoms to create net positive charge on the adjacent carbon atoms in the PDDA-modified SWCNTs (PDDA/SWCNTs) plane. Meanwhile, due to the high N-doping ONPCNRs have high adsorption capacity and selectivity toward H2O2 adsorption, the combination of PDDA/SWCNTs and use of high N-doping ONPCNRs overlayer lead to an effective reduction in overpotential, enhanced Faradaic efficiencies and current densities for H2O2 reduction to H2O. As a non-enzymatic amperometric sensor, the resulting ONPCNR/SWCNTs nanocomposite-modified electrode exhibited high sensitivity and selectivity for the detection of H2O2 in the range of 1.0–500 μM with a detection limit of 0.51 μM (S/N = 3). The results indicated that the synergetic effect with ONPCNRs improves the capability of the PDDA/SWCNTs matrix for H2O2 detection. This work demonstrated that ONPCNRs/SWCNTs nanocomposite possesses the feasibility and potential applications in sensing.

Pub.: 24 Feb '17, Pinned: 12 Apr '17