Carbon Nanotubes-Doped Glassy Carbon Ceramic Composite Electrode and its Electrocatalytic Reduction of Nitrite

2011 ◽  
Vol 306-307 ◽  
pp. 1215-1220 ◽  
Author(s):  
Dan Zi Sun

A conductive glassy carbon ceramic composite electrode (GCCE) comprised of multi-walled carbon nanotubes (MWNTs) and glassy carbon microparticles in an organically modified silicate matrix was fabricated using a sol-gel method. The electrode thus prepared exhibits electrocatalytic behavior to the reduction of nitrite and facilitates the detection of nitrite at an applied potential of 0.0 V. A linear range from 2.5×10-5 to 3×10-3 M for the detection of sodium nitrite has been observed at the composite electrode with a sensitivity of 9.6 μA/mM and a detection limit of 9×10-6 M based on a signal-to-noise ratio of 3.

2013 ◽  
Vol 718-720 ◽  
pp. 124-126
Author(s):  
Dan Zi Sun

9, 10-Phenanthrenequinone (PQ) supported on glassy carbon microparticles by adsorption was dispersed in methyltrimethoxysilane (MTMOS) derived gels to yield a conductive composite which was used as electrode material to fabricate a PQ-modified glassy carbon ceramic composite electrode. It shows good electrocatalytic activity toward the reduction of iodate and could be used as an amperometric sensor for the determination of iodate in table warter.


2019 ◽  
Vol 20 (5) ◽  
pp. 390-400 ◽  
Author(s):  
Nabil N. AL-Hashimi ◽  
Amjad H. El-Sheikh ◽  
Rania F. Qawariq ◽  
Majed H. Shtaiwi ◽  
Rowan AlEjielat

Background: The efficient analytical method for the analysis of nonsteroidal antiinflammatory drugs (NSAIDs) in a biological fluid is important for determining the toxicological aspects of such long-term used therapies. Methods: In the present work, multi-walled carbon nanotubes reinforced into a hollow fiber by chitosan sol-gel assisted-solid/ liquid phase microextraction (MWCNTs-HF-CA-SPME) method followed by the high-performance liquid chromatography-diode array detection (HPLC–DAD) was developed for the determination of three NSAIDs, ketoprofen, diclofenac, and ibuprofen in human urine samples. MWCNTs with various dimensions were characterized by various analytical techniques. The extraction device was prepared by immobilizing the MWCNTs in the pores of 2.5 cm microtube via chitosan sol-gel assisted technology while the lumen of the microtube was filled with few microliters of 1-octanol with two ends sealed. The extraction device was operated by direct immersion in the sample solution. Results: The main factors influencing the extraction efficiency of the selected NSAIDs have been examined. The method showed good linearity R2 ≥ 0.997 with RSDs from 1.1 to 12.3%. The limits of detection (LODs) were 2.633, 2.035 and 2.386 µg L-1, for ketoprofen, diclofenac, and ibuprofen, respectively. The developed method demonstrated a satisfactory result for the determination of selected drugs in patient urine samples and comparable results against reference methods. Conclusion: The method is simple, sensitive and can be considered as an alternative for clinical laboratory analysis of selected drugs.


Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 481
Author(s):  
Daniel Polak ◽  
Izabela Zielińska ◽  
Maciej Szwast ◽  
Igor Kogut ◽  
Artur Małolepszy

The aim of this work is to develop a new type of carbon-ceramic membranes for the removal of pharmaceutical substances from water. The membranes were prepared by the chemical modification method using an organosilicon precursor—octadecyltrichlorosilane (ODTS). Graphene oxide, multi-walled carbon nanotubes with carboxylic groups, and single-walled carbon nanotubes were used in the modification process. The filtration properties and adsorption properties of the developed membranes were tested. In order to characterize the membrane, the water permeability, the change of the permeate flux in time, and the adsorbed mass of the substance were determined. Additionally, the surface properties of the membranes were characterized by contact angle measurements and porosimetry. The antibiotic tetracycline was used in the adsorption tests. Based on the results, the improved adsorption properties of the modified membrane in relation to the unmodified membrane were noticed. Novel ceramic membranes modified with MWCNT are characterized by 45.4% removal of tetracycline and permeate flux of 520 L·h·m−2·bar−1. We demonstrated the ability of modified membranes to adsorb pharmaceuticals from water streams that are in contact with the membrane. Novel membranes retain their filtration properties. Therefore, such membranes can be used in an integrated filtration–adsorption process.


Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 224 ◽  
Author(s):  
Jung-Eun Park ◽  
Yong-Seok Jang ◽  
Tae-Sung Bae ◽  
Min-Ho Lee

Multi walled carbon nanotubes-hydroxyapatite (MWCNTs-HA) with various contents of MWCNTs was synthesized using the sol-gel method. MWCNTs-HA composites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). HA particles were generated on the surface of MWCNT. Produced MWCNTs-HA nanocomposites were coated on pure titanium (PT). Characteristic of the titanium coated MWCNTs-HA was evaluated by field-emission scanning electron microscopy (FE-SEM) and XRD. The results show that the titanium surface was covered with MWCNTs-HA nanoparticles and MWCNTs help form the crystalized hydroxyapatite. Furthermore, the MWCNTs-HA coated titanium was investigated for in vitro cellular responses. Cell proliferation and differentiation were improved on the surface of MWCNT-HA coated titanium.


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