Electrochemical determination of paracetamol by SWCNT-modified carbon paste electrode: a cyclic voltammetric study

Ambika A. V.,Navya N.,Kiran Kumar S. R.,Suresha B. L. 한국탄소학회 2022 Carbon Letters Vol.32 No.5

The central theme of this work is the synthesis of single-walled carbon nanotubes (SWCNTs) through the chemical vapor deposition method (CVD). Single-walled carbon nanotubes are synthesized using catalyst-chemical vapor deposition of acetylene at 750 °C temperature. X-ray diffraction study gives a characteristic peak (002) at 26.55° corresponding to the existence of carbon nanotube confirms that the particles are crystalline in nature and hexagonal phase. An SEM and HR-TEM outcome gives surface morphology of SWCNTs. The elemental composition was confirmed by EDAX. The ideal concentration of single-walled carbon nanotubes was used to design a novel electrochemical sensor for determining paracetamol (PA) using cyclic voltammetry. Electrochemical determination of paracetamol is described using a single-walled carbon nanotube modified carbon paste electrode (SWCNT/MCPE). The SWCNT/MCPE was used in this study to detect paracetamol electrochemically at pH 7.2 in a 0.2 M PBS with a scan rate of 50 mV s−1. A single-walled nanotube modified carbon paste electrode was used to develop a sensitive and selective electrochemical technique for the detection of PA. The SWCNT/MCPE showed excellent electrocatalytic activity towards the oxidation of paracetamol in phosphate buffer solution. Therefore, with increased oxidation currents, the voltammetric responses of paracetamol at the bare carbon paste electrode are organized within cyclic voltammetric peaks.

Effects of oxidized single-walled carbon nano tubes on carbon fiber papers as gas diffusion layers

김익규,박수진 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

In this work, PAN-based carbon fiber papers (CFPs) were prepared with various weight of oxidized single walled-carbon nanotubes. The electric properties, mechanical properties, surface energy and porosity of the resulting CFPs were investigated. The influences of the oxidized single wall carbon nano tubes contents on the electric and mechanical properties were also examined. The morphology of CFPs was observed using scanning electron microscopy and X-ray diffraction. The electric properties of the prepared CFPs were characterized by four-probe point method. The surface free energy was investigated using contact angle measurement of three liquid droplets. The porosity of prepared CPFs was examined by mercury porosimetry. The results indicate that amounts of oxidized single wall carbon nanotubes affect the electric and mechanical properties, and surface free energy of carbon fiber papers.

Selective detection of chlorine at room temperature utilizing single-walled carbon nanotubes functionalized with platinum nanoparticles synthesized via ultraviolet irradiation

Choi, Sun-Woo,Kim, Byung-Moon,Oh, Sang-Hyub,Byun, Young Tae Elsevier Sequoia 2017 Sensors and actuators. B Chemical Vol.249 No.-

<P><B>Abstract</B></P> <P>In this study, photoreduction by an ultraviolet (UV) irradiation method was applied to synthesizing platinum (Pt) nanoparticles into networked single-walled carbon nanotubes (SWCNTs). To investigate the growth behaviour of Pt nanoparticles, we systematically controlled the UV irradiation intensity and exposure time. These processing factors significantly influenced the formation behaviour of Pt nanoparticles regarding diameter and density. Utilizing the photoreduction process, the sidewalls of SWCNTs were uniformly functionalized with Pt nanoparticles synthesized under optimal UV conditions. For application as practical chlorine (Cl<SUB>2</SUB>) sensors, the sensing performances of Pt nanoparticle-functionalized SWCNTs for Cl<SUB>2</SUB> were compared against the injection of other gases such as nitrogen dioxide, ammonia and carbon monoxide. The results indicate that UV irradiation is an effective way to functionalize the sidewalls of SWCNTs with catalytic Pt nanoparticles. In addition, the Cl<SUB>2</SUB> selectivity and response of SWCNT-based gas sensors were enhanced by functionalization with catalytic Pt nanoparticles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Excellent chlorine gas sensors based on single-walled carbon nanotubes functionalized with Pt nanoparticles were fabricated utilizing photo-reduction method. </LI> <LI> The gas sensors based on single-walled carbon nanotubes functionalized with Pt nanoparticles exhibit outstanding and highly selective chlorine detection. </LI> <LI> Conducting channel modulation of single-walled carbon nanotubes by coexistence of Pt/PtO is the responsible mechanism. </LI> </UL> </P>

Effect of post-annealing on single-walled carbon nanotubes synthesized by arc-discharge

Suyoung Park,Sun-Woo Choi,Changhyun Jin 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.4

In this study, high-purity single-walled carbon nanotubes (SWCNTs) were prepared by removing the unreacted metal constituents and amorphous carbon impurities using a post-annealing process. Unlike conventional thermal processing techniques, this technique involved different gas atmospheres for efficient removal of impurities. A heat treatment was conducted in the presence of chlorine, oxygen, and chlorine + oxygen gases. The nanotubes demonstrated the best characteristics, when the heat treatment was conducted in the presence of a mixture of chlorine and oxygen gases. The scanning electron microscopy, transmission electron microscopy, ultraviolet absorbance, and sheet resistance measurements showed that the heat treatment process efficiently removed the unreacted metal and amorphous carbon impurities from the as-synthesized SWCNTs. The high-purity SWCNTs exhibited improved electrical conductivities. Such high-purity SWCNTs can be used in various carbon composites for improving the sensitivity of gas sensors.

SYNTHESIS OF SINGLE-WALLED CARBON NANOTUBES FROM LIQUEFIED PETROLEUM GAS

QIANG ZHANG,YI LIU,JIAQI HUANG,WEIZHONG QIAN,YAO WANG,FEI WEI 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2008 NANO Vol.3 No.2

Hydrocarbons such as methane, ethylene, and CO with high purity (> 99.9%) have been widely used to synthesize single-walled carbon nanotubes (SWCNTs). Here, liquefied petroleum gas (LPG) was used to synthesize SWCNTs by catalytic chemical vapor deposition. The LPG converted into CNTs and other stable hydrocarbons. The BET specific surface area of SWCNT was about 583 m2/g. The as-grown SWCNT showed good graphitization. The graphitization can be further modulated by the growth temperature. Certain amount of sulfur in LPG was a promoter for SWCNT growth. Compared SWCNTs obtained from methane, more semiconductive SWCNTs were synthesized from LPG as carbon source. The LPG is in low price, thus, a methodology to lower the production cost of SWCNTs with hydrocarbon mixtures is realized.

마이크로파 정제에 의한 액정방사용 단일벽 탄소나노튜브의 제조 및 특성

김민지,이동주,구본철,유기현,김대윤,김남동,Kim, Min Ji,Lee, Dongju,Ku, Bon-cheol,Ryu, Ki-Hyun,Kim, Dae-Yoon,Kim, Nam Dong 한국섬유공학회 2021 한국섬유공학회지 Vol.58 No.3

Carbon nanotube fibers (CNTFs) have attracted wide attention owing to their exceptional lightness, electrical conductivity, and mechanical flexibility that make them potential components for applications including carbon composites, nanoelectronics, and optics. CNTFs have been successfully fabricated from carbon nanotubes (CNTs) by liquid-crystal spinning. This spinning method requires low-defect CNTs to form a liquid crystalline phase for making highly-oriented CNTFs. In this study, we conducted microwave purification to effectively remove impurities from CNTs, such as residual metallic catalyst and carbon-based impurities, that are formed during CNT synthesis. We fabricated single-walled carbon nanotube fibers (SWCNTFs) using liquid-crystal spinning purified single-walled carbon nanotubes (SWCNTs) to examine the effect of SWCNTs on the liquid crystal phase and resultant fibers. In conclusion, this method removed impurities from SWCNTs and increased the oxygen-containing functional groups in the SWCNTs, which are capable of forming a liquid crystal phase, thereby enhancing the mechanical performance of fibers.

단일벽 탄소 나노튜브(SWNT) 강화 구리 복합체의 제조 및 기계적 특성에 관한 연구

성병호(Byung-ho Sung),오세영(Seyoung Oh),최지훈(Jee-hoon Choi),심언태(Untae Sim),김범준(Bumjoon Kim),백승현(Seunghyun Baik),임병수(Byengsoo Lim),김철주(Chul-ju Kim) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Carbon nanotubes were coated by nickel to increase interfacial bonding on copper matrix materials. Mixing processes of ultrasonicating single-walled carbon nanotubes and copper powders were carried out in ethanol to obtain the uniform composition of specimens. The nanocomposite materials were fabricated by sintering processes, which consists of mixing carbon nanotubes with matrix powders followed by hot-pressing. The mechanical properties of single walled carbon nanotube reinforced copper matrix nanocomposite materials have been investigated by SP-creep test and wear test. The displacement rate of nickel-coated nanotube-copper composite was found to increase at 200℃ when compared with pure copper or other nanocomposite materials. The incorporation of carbon nanotubes and nickel-coated carbon nanotubes in the copper matrix composites decreased friction coefficients and increased times up to the onset point of scuffing, compared with those of pure copper specimens.

아크 방전법으로 성장된 대면적 단일벽 탄소나노튜브 필름

강영진,오동훈,송혜진,정진연,정혁,조유석,김도진,Kang, Young-Jin,Oh, Dong-Hoon,Song, Hye-Jin,Jung, Jin-Yeun,Jung, Hyuk,Cho, You-Suk,Kim, Do-Jin 한국재료학회 2008 한국재료학회지 Vol.18 No.5

A simple method to deposit carbon nanotube films uniformly on large area substrates using an arc discharge method is reported in this paper. The arc discharge method was modified to deposit carbon nanotube films in situ on the substrates. The substrates were scanned several times over the arcing point for a uniform film thickness. Deposition was carried out under variable dc bias conditions at 600 torr of $H_2$ gas. The thickness uniformity of the single-wall carbon nanotube films as characterized by a four-point probe was within 30% deviation. The morphology and crystal quality of the single-wall carbon nanotube film were also characterized by field emission scanning electron microscopy and Raman spectroscopy.

Highly flexible dielectric composite based on passivated single-wall carbon nanotubes (SWNTs)

Jeong, Hyeon-Taek,Kim, Yong-Ryeol The Korean Society of Applied Science and Technolo 2015 한국응용과학기술학회지 Vol.32 No.1

Single-walled carbon nanotubes (SWNTs) was modified with various length of linear alkyl chains and passivated to form dielectric filler. The modified SWNTs embedded into epoxy matrix to fabricate a flexible composite with high dielectric constant. The dielectric behavior of the composite was significantly changed with various alkyl chain length(n) of pyrene. The dielectric constant of the epoxy/SWNTs composite significantly increased with respect to increase in length of alkyl chain at the frequency range from 10 to 105Hz (n=12and18).We also found that the passivated epoxy/SWNTs composite with high dielectric constant presented low dielectric loss. The resulted dielectric performances corresponded to de-bundling of nanotubes and their distribution behavior in the matrix in terms of tail length of alkyl pyrene in the passivation layer.

Purification and Preparation of Single-Walled Carbon Nanotube Films

박규창,S. Manivannan,정일옥,류재황,이창석,장진,김기서 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5

We describe a simple process for the removal of metal catalysts and the dispersion of single-walled carbon nanotubes (SWNTs) in aqueous and organic solvents without damaging the structure of the nanotubes. The metal catalyst was removed by using a sodium hydroxide (NaOH) - ethyl alcohol (EtOH) solution. Dispersion of purified nanotubes was accomplished by using a polymer wrapping functionalization. Raman and scanning electron microscope analyses were performed to confirm the purity and the dispersion of the treated tubes. The bundle size of the dispersed SWNTs was elucidated using the atomic force microscopy technique and the size was measured as 2 - 5 nm. Transparent and conducting carbon nanotube films were prepared on glass substrates by using a spin-coating method. Optical transmission and sheet resistance measurements showed that the randomly-oriented, dispersed nanotubes film had an average sheet resistance of 974 Ω/□ and a at optical transmission of ∽77 % at 600 nm. In this simple and scalable process, the sheet resistance and the optical transmission of the film were controlled by using the number of coatings and the concentration of the solution. We describe a simple process for the removal of metal catalysts and the dispersion of single-walled carbon nanotubes (SWNTs) in aqueous and organic solvents without damaging the structure of the nanotubes. The metal catalyst was removed by using a sodium hydroxide (NaOH) - ethyl alcohol (EtOH) solution. Dispersion of purified nanotubes was accomplished by using a polymer wrapping functionalization. Raman and scanning electron microscope analyses were performed to confirm the purity and the dispersion of the treated tubes. The bundle size of the dispersed SWNTs was elucidated using the atomic force microscopy technique and the size was measured as 2 - 5 nm. Transparent and conducting carbon nanotube films were prepared on glass substrates by using a spin-coating method. Optical transmission and sheet resistance measurements showed that the randomly-oriented, dispersed nanotubes film had an average sheet resistance of 974 Ω/□ and a at optical transmission of ∽77 % at 600 nm. In this simple and scalable process, the sheet resistance and the optical transmission of the film were controlled by using the number of coatings and the concentration of the solution.