Carbon Nanotube Nanocomposites (carbon + nanotube_nanocomposite)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

Signal-On Electrochemiluminescence Biosensors Based on CdS,Carbon Nanotube Nanocomposite for the Sensitive Detection of Choline and Acetylcholine

ADVANCED FUNCTIONAL MATERIALS, Issue 9 2009
Xiao-Fei Wang
Abstract This work describes for the first time signal-on electrochemiluminescence (ECL) enzyme biosensors based on cadmium sulfide nanocrystals (CdS NCs) formed in situ on the surface of multi-walled carbon nanotubes (MWCNTs). The MWCNT,CdS can react with H2O2 to generate strong and stable ECL emission in neutral solution. Compared with pure CdS NCs, the MWCNT,CdS can enhance the ECL intensity by 5.3-fold and move the onset ECL potential more positively for about 400,mV, which reduces H2O2 decomposition at the electrode surface and increases detection sensitivity of H2O2. Furthermore, the ECL intensity is less influenced by the presence of oxygen in solution. Benefiting from these properties, signal-on enzyme-based biosensors are fabricated by cross-linking choline oxidase and/or acetylcholine esterase with glutaraldehyde on MWCNT,CdS modified electrodes for detection of choline and acetylcholine. The resulting ECL biosensors show wide linear ranges from 1.7 to 332,µM and 3.3 to 216,µM with lower detection limit of 0.8 and 1.7,µM for choline and acetylcholine, respectively. The common interferents such as ascorbic acid and uric acid in electrochemical enzyme-based biosensors do not interfere with the ECL detection of choline and acetylcholine. Furthermore, both ECL biosensors possess satisfying reproducibility and acceptable stability. [source]

Synthesis and properties of poly(butylene terephthalate)/multiwalled carbon nanotube nanocomposites prepared by in situ polymerization and in situ compatibilization

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010
Fangjuan Wu
Abstract A novel cyclic initiator was synthesized from dibutyl tin(IV) oxide and hydroxyl-functionalized multiwalled carbon nanotubes (MWNTs) and was used to initiate the ring-opening polymerization of cyclic butylene terephthalate oligomers to prepare poly(butylene terephthalate) (PBT)/MWNT nanocomposites. The results of Fourier transform infrared and NMR spectroscopy confirmed that a graft structure of PBT on the MWNTs was formed during the in situ polymerization; this structure acted as an in situ compatibilizer in the nanocomposites. The PBT covalently attached to the MWNT surface enhanced the interface adhesion between the MWNTs and PBT matrix and, thus, improved the compatibility. The morphologies of the nanocomposites were observed by field emission scanning electron microscopy and transmission electron microscopy, which showed that the nanotubes were homogeneously dispersed in the PBT matrix when the MWNT content was lower than 0.75 wt %. Differential scanning calorimetry and thermogravimetric analysis were used to investigate the thermal properties of the nanocomposites. The results indicate that the MWNTs acted as nucleation sites in the matrix, and the efficiency of nucleation was closely related to the dispersion of the MWNTs in the matrix. Additionally, the thermal stability of PBT was improved by the addition of the MWNTs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

Isothermal crystallization behavior of polyamide 6,6/multiwalled carbon nanotube nanocomposites

POLYMER ENGINEERING & SCIENCE, Issue 12 2009
Shi-Ya Lin
The good dispersion of functionalized multiwalled carbon nanotube (f-MWCNT) in polyamide 6,6 (PA 6,6) matrix was prepared by solution mixing techniques. The crystalline structure and crystallization behaviors of PA 6,6 and PA 6,6/f-MWCNT nanocomposites were studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and polarized optical microscopy (POM) analysis. DSC isothermal results revealed that the overall isothermal crystallization rates of PA 6,6 increased as well as the activation energy of PA 6,6 extensively decreased by adding f-MWCNT into PA 6,6, suggesting that the addition of f-MWCNT probably induces the heterogeneous nucleation. The effect of f-MWCNT on the chain arrangement for the crystallization of PA 6,6/f-MWCNT nanocomposites was also discussed. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers [source]

Morphology, thermal, and rheological behavior of nylon 11/multi-walled carbon nanotube nanocomposites prepared by melt compounding

POLYMER ENGINEERING & SCIENCE, Issue 6 2009
Shu Huang
Nylon 11 (PA11) nanocomposites with different loadings of multi-walled carbon nanotubes (MWNTs) were prepared by melt compounding. Scanning electron microscopy images on the fracture surfaces of the composites showed a uniform dispersion of MWNTs throughout the matrix. The presence of the MWNTs significantly improved the thermal stability and enhanced the storage modulus (G,) of the polymer matrix. Melt rheology studies showed that, compared with neat PA11, the incorporation of MWNT into the matrix resulted in higher complex viscosities (|,*|), storage modulus (G,), loss modulus (G,), and lower loss factor (tan,). PA11 and its nanocomposites containing less than 1 wt% MWNTs showed similar frequency dependencies and reached a Newtonian plateau at low frequencies. For the nanocomposite with 2 wt% MWNTs, the regional network was destroyed and the orientation of the MWNTs during shearing exhibited a very strong shear thinning effect. The complex viscosities (|,*|) of the nanocomposites are larger than that of neat PA11 and decreased with increasing the temperature. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers [source]