Effects of carboxylated multi-walled carbon nanotubes having different outer diameters on hollow fiber ultrafiltration membrane fabrication and characterization by electrochemical impedance spectroscopy

2017 ◽  
Vol 75 (6) ◽  
pp. 2431-2457 ◽  
Author(s):  
Esra A. Genceli ◽  
Reyhan Sengur-Tasdemir ◽  
Gulsum Melike Urper ◽  
Selin Gumrukcu ◽  
Zeliha Guler-Gokce ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Hollow Fiber ◽  
Electrochemical Impedance ◽  
Ultrafiltration Membrane ◽  
Membrane Fabrication ◽  
Multi Walled Carbon Nanotubes ◽  
Fabrication And Characterization ◽  
Walled Carbon Nanotubes

scholarly journals Multi-walled carbon nanotubes/nano-Ag-TiO2 membrane DNA electrochemical biosensor

2019 ◽  
Author(s):  
Zhongguo Zheng ◽  
Lisa Schultz ◽  
John Smith
Keyword(s):  
Carbon Nanotubes ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Biosensor ◽  
Electrochemical Impedance ◽  
Carbon Paste ◽  
Dna Electrochemical Biosensor ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Paste Electrode

AbstractA highly sensitive DNA electrochemical biosensor was prepared based on multi-walled carbon nanotube/nano-Ag-TiO2 composite membrane. The Ag-TiO2 composite is mixed with a suitable amount of multi-walled carbon nanotubes (MWNT) dispersed in N,N-dimethylformamide to form a uniform and stable mixed solution, which is applied onto the surface of the bare carbon paste electrode. A MWNT/Ag-TiO2 modified carbon paste electrode was prepared. The large specific surface area and good electron transport properties of carbon nanotubes have a good synergistic effect on the good biocompatibility of Ag-TiO2 nanocomposites and excellent adsorption capacity of DNA, which significantly improves the immobilization and DNA hybridization of DNA probes. Detection sensitivity. The preparation of the sensing membrane and the immobilization and hybridization of DNA were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The exogenous glufosinate acetyltransferase gene fragment of transgenic plants was detected by electrochemical impedance spectroscopy. The linear range was 1. 0 × 10 - 11 ∼1. 0 × 10 - 6 mol / L. The detection limit was 3. 12 × 10 - 12 mol / L.

scholarly journals Disposable Multi-Walled Carbon Nanotubes-Based Plasticizer-Free Solid-Contact Pb2+-Selective Electrodes with a Sub-PPB Detection Limit †

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2550 ◽  
Author(s):  
Yueling Liu ◽  
Yingying Gao ◽  
Rui Yan ◽  
Haobo Huang ◽  
Ping Wang
Keyword(s):  
Carbon Nanotubes ◽  
Electrochemical Impedance Spectroscopy ◽  
Detection Limit ◽  
Electrochemical Impedance ◽  
Solid Contact ◽  
Water Films ◽  
Multi Walled Carbon Nanotubes ◽  
Nernstian Slope ◽  
Disk Electrodes ◽  
Walled Carbon Nanotubes

Potentiometric plasticizer-free solid-contact Pb2+-selective electrodes based on copolymer methyl methacrylate-n-butyl acrylate (MMA-BA) as membrane matrix and multi-walled carbon nanotubes (MWCNTs) as intermediate ion-to-electron transducing layer have been developed. The disposable electrodes were prepared by drop-casting the copolymer membrane onto a layer of MWCNTs, which deposited on golden disk electrodes. The obtained electrodes exhibited a sub-ppb level detection limit of 10−10 mol·L−1. The proposed electrodes demonstrated a Nernstian slope of 29.1 ± 0.5 mV/decade in the linear range from 2.0 × 10−10 to 1.5 × 10−3 mol·L−1. No interference from gases (O2 and CO2) or water films was observed. The electrochemical impedance spectroscopy of the fabricated electrodes was compared to that of plasticizer-free Pb2+-selective electrodes without MWCNTs as intermediated layers. The plasticizer-free MWCNTs-based Pb2+-selective electrodes can provide a promising platform for Pb(II) detection in environmental and clinical application.

Multi-walled Carbon Nanotubes Reinforced into Hollow Fiber by Chitosan Sol-gel for Solid/Liquid Phase Microextraction of NSAIDs from Urine Prior to HPLC-DAD Analysis

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
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Phase ◽  
Hollow Fiber ◽  
Sol Gel ◽  
Liquid Phase Microextraction ◽  
Extraction Device ◽  
Multi Walled Carbon Nanotubes ◽  
Solid Liquid ◽  
Walled Carbon Nanotubes

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.

Development of a Polymeric Carbon Nanocomposite Hollow-Fiber Membrane for Wastewater Treatment

2021 ◽  
Vol 21 (7) ◽  
pp. 3711-3715
Author(s):  
Jeongdong Choi ◽  
Eun-Sik Kim
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Hollow Fiber ◽  
Hollow Fiber Membranes ◽  
Permeate Flux ◽  
Fiber Membranes ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Polymeric Carbon ◽  
Carbon Nanocomposite

This study investigated experimental parameters to fabricate polymeric carbon nanocomposite hollow-fiber membranes with graphene oxide and multi-walled carbon nanotubes. This case was different from that of flat-sheet type membranes in that the characteristics of the hollow-fiber type membranes were affected by the structure of the spinneret, the flow rate of the injected polymer and draw solution, and the mixing ratio. The membranes were characterized in terms of mechanical strength, porosity, hydrophilicity, and permeate flux using different solutions. The results reveal a mechanical strength of the carbon nanocomposite hollow-fiber membranes that is about 47.8% higher than that of hollow-fiber membranes without carbon nanomaterials. The porosity and surface hydrophilicity changed to produce more applicable membranes for water and wastewater treatment. As for the permeate flux, the nanocomposite membrane with graphene oxide showed a higher flux compared to the multi-walled carbon nanotubes membrane, which could be influenced by structural effects of the carbon materials.

scholarly journals Electrodeposition of Sn and Sn Composites with Carbon Materials Using Choline Chloride-Based Ionic Liquids

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 798
Author(s):  
Ana T. S. C. Brandão ◽  
Liana Anicai ◽  
Oana Andreea Lazar ◽  
Sabrina Rosoiu ◽  
Aida Pantazi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Materials ◽  
Electrochemical Impedance ◽  
Choline Chloride ◽  
Composite Films ◽  
Growth Stages ◽  
Initial Growth ◽  
Sem Images ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Nano carbons, such as graphene and carbon nanotubes, show very interesting electrochemical properties and are becoming a focus of interest in many areas, including electrodeposition of carbon–metal composites for battery application. The aim of this study was to incorporate carbon materials (namely oxidized multi-walled carbon nanotubes (ox-MWCNT), pristine multi-walled carbon nanotubes (P-MWCNT), and reduced graphene oxide (rGO)) into a metallic tin matrix. Formation of the carbon–tin composite materials was achieved by electrodeposition from a choline chloride-based ionic solvent. The different structures and treatments of the carbon materials will create metallic composites with different characteristics. The electrochemical characterization of Sn and Sn composites was performed using chronoamperometry, potentiometry, electrochemical impedance, and cyclic voltammetry. The initial growth stages of Sn and Sn composites were characterized by a glassy-carbon (GC) electrode surface. Nucleation studies were carried out, and the effect of the carbon materials was characterized using the Scharifker and Hills (SH) and Scharifker and Mostany (SM) models. Through a non-linear fitting method, it was shown that the nucleation of Sn and Sn composites on a GC surface occurred through a 3D instantaneous process with growth controlled by diffusion. According to Raman and XRD analysis, carbon materials were successfully incorporated at the Sn matrix. AFM and SEM images showed that the carbon incorporation influences the coverage of the surface as well as the size and shape of the agglomerate. From the analysis of the corrosion tests, it is possible to say that Sn-composite films exhibit a comparable or slightly better corrosion performance as compared to pure Sn films.

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