Nanoscale Evaluation of Multi-Walled Carbon Nanotube’s Performance on Resisting Oxidization of Asphalt

2020 ◽  
Vol 982 ◽  
pp. 195-200
Author(s):  
Abdullah Al Mamun ◽  
Okan Sirin
Keyword(s):  
Adhesive Force ◽  
Force Microscopy ◽  
Modified Asphalt ◽  
Atomic Force ◽  
Resistance To Oxidation ◽  
Pavement Engineering ◽  
Multi Walled Carbon Nanotubes ◽  
Polymer Modified Asphalt ◽  
Styrene Butadiene ◽  
Walled Carbon Nanotubes

Nanotechnology has contributed significantly to different subfields of the construction industry, including asphalt pavement engineering. The improved properties and new functionalities of the nanomaterials have provided different desired properties of asphalt. In this study, the effectiveness of multi-walled carbon nanotubes (MWCNT) in resisting the oxidation of polymer-modified asphalt was measured. A total of three different percentages (0.5%, 1%, and 1.5%) of MWCNT were used to modify the Styrene-Butadiene (SB) and styrene–butadiene–styrene (SBS) modified asphalt (4% and 5%). The laboratory oxidized asphalt samples were evaluated by an atomic force microscopy machine. The oxidation of the polymer-MWCNT modified asphalt is measured by simulating the existing functional group of the asphalt and as a function of the adhesive force. It is observed that the use of MWCNT in SB and SBS can increase the resistance to oxidation.

Developing an electrochemical immunosensor for early diagnosis of hepatocellular carcinoma

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abdulrahman Al-Shami ◽  
Rami Joseph Oweis ◽  
Mohamed Ghazi Al-Fandi
Keyword(s):  
Hepatocellular Carcinoma ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Electrochemical Immunosensor ◽  
Content Type ◽  
Force Microscopy ◽  
Promising Tool ◽  
Atomic Force ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Purpose This paper aims to report on the development of a novel electrochemical amperometric immunosensor to diagnose early hepatocellular carcinoma (HCC) by detecting the Midkine (MDK) biomarker. Design/methodology/approach Anti-Midkine antibodies were immobilized covalently through carbodiimides chemistry on carbon screen-printed electrodes modified with carboxylated multi-walled carbon nanotubes. The development process was characterized using cyclic voltammetry, electrochemical impedimetric spectroscopy, Fourier transform infrared spectroscopy and atomic force microscopy. Differential pulse voltammetry was used to investigate the immunosensor performance in detecting MDK antigen within the concentration range of 1 pg/ml to 100 ng/ml. Findings MDK immunosensor exhibited high sensitivity and linearity with a detection limit of 0.8 pg/ml and a correlation coefficient of 0.99. The biosensor also demonstrated high selectivity, stability and reproducibility. Originality/value The developed MDK immunosensor could be a promising tool to diagnose HCC and reduce the number of related deaths.

Synthesis of Carbon Nanotubes/Gold Nanoparticles Hybrids for Environmental Applications

2010 ◽  
Vol 71 ◽  
pp. 34-39
Author(s):  
L. Minati ◽  
G. Speranza ◽  
I. Bernagozzi ◽  
S. Torrengo ◽  
L. Toniutti ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Covalently Bonded ◽  
Plasmon Resonances ◽  
Multi Walled Carbon Nanotubes ◽  
Synthesis Of Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi-walled carbon nanotubes were chemically cut by acid treatments and then deposited on 2-aminoethanethiol-modified gold substrate by the application of an external electric field. 2-aminoethanethiol-capped gold nanoparticles were then covalently bonded to the nanotubes to exploit their plasmon resonances. Reaction intermediates as well as the final products were analyzed by X-Ray Photoelectron Spectroscopy, Atomic Force Microscopy and Scanning Electron Microscopy. The synergetic interaction between carbon nanotubes and gold nanoparticles leads to an efficient signal enhancement in Raman spectra. This is of particular interest for the detection of toxic molecules dangerous for the environment.

Investigation of Resiliency of Carbon Nanotubes and Gallium Nitride Nanocircuits to Simulated Space Radiation

2004 ◽  
Vol 851 ◽  
Author(s):  
B. W. Jacobs ◽  
V. M. Ayres ◽  
M. A. Crimp ◽  
R. M. Ronningen ◽  
A. F. Zeller ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Gallium Nitride ◽  
Heavy Ion ◽  
Force Microscopy ◽  
Micro Raman Spectroscopy ◽  
Atomic Force ◽  
Total Ionization ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

ABSTRACTHeavy ion irradiations of single and multi walled carbon nanotubes and total ionization dose of gallium nitride nanowires were investigated. Post irradiation analyses of samples were performed with transmission and scanning electron microscopy, atomic force microscopy and micro Raman spectroscopy.

scholarly journals Influence of MWCNTs Doping on the Structure and Properties of PEDOT:PSS Films

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Jiao Li ◽  
Juncheng Liu ◽  
Congjie Gao ◽  
Jinling Zhang ◽  
Hanbin Sun
Keyword(s):  
Lower Percentage ◽  
Structure And Properties ◽  
Melt Mixing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Fourier Transform Raman Spectroscopy ◽  
Coating Method ◽  
Multi Walled Carbon Nanotubes ◽  
Quartz Substrates ◽  
Walled Carbon Nanotubes

Poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) doped with multi-walled carbon nanotubes (MWCNTs) films is fabricated on quartz substrates by spin coating method. The effects of MWCNTs on the structure and properties of PEDOT:PSS film have been investigated. X-ray diffractometer (XRD) and Fourier transform Raman spectroscopy (FTRM) show that the crystallization behavior and the main chain of PEDOT:PSS are not changed. Atomic force microscopy (AFM) shows that individual nanotubes are well dispersed in the PEDOT:PSS matrix. Moreover, some nanotubes overlap into a net-like structure, forming new conductive channels, which can enhance efficiently the film conductivity. The conductivity of PEDOT:PSS film doped with a lower percentage of MWCNTs (0.2 wt%) is 9.16 S/cm, higher than that of pure PEDOT:PSS film (0.28 S/cm), although the optical transmission of PEDOT:PSS decreases a little after the addition of MWCNTs. The interaction between MWCNTs and PEDOT:PSS during melt mixing is also given a possible explanation.

scholarly journals Effect of Nanoclays on Moisture Susceptibility of SBS-Modified Asphalt Binder

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Han Wang ◽  
Yinchuan Guo ◽  
Aiqin Shen ◽  
Xiaolong Yang ◽  
Peng Li
Keyword(s):  
Asphalt Binder ◽  
Moisture Susceptibility ◽  
Force Microscopy ◽  
Modified Asphalt ◽  
Atomic Force ◽  
Modified Binders ◽  
Modified Asphalt Binder ◽  
Water Damage ◽  
Styrene Butadiene ◽  
Sbs Modified Asphalt

Moisture susceptibility plays an important role in the damage of asphalt pavement. Failure occurs when asphalt is removed from the aggregate particles due to the decreased adhesion between the asphalt and aggregate in comparison with that between water and the aggregate. In recent years, efforts utilizing nanomaterials to improve the diverse properties of asphalt have proven to be effective. In this study, three types of nanoclays were used to modify styrene-butadiene-styrene- (SBS-) modified asphalt. The resistances to water damage of the modified binders were evaluated using the surface free energy (SFE) and atomic force microscopy (AFM). The results revealed that the total SFE decreased and the energy ratio (ER) increased when the asphalt binder was modified with the nanoclays, indicating that the addition of nanoclays can improve the moisture resistance of these aggregate-binder systems. After immersion, a decreased amount of bee structures was observed in both the SBS and nanoclay-modified asphalts due to the interactions between water and bitumen. However, the residual amount of bee structures was higher in the nanoclay-modified asphalts than in the SBS-modified asphalt, indicating that the addition of nanoclay makes the surface morphology of asphalt more resistant to water damage. Finally, freeze-thaw splitting tests were used to verify the results obtained through the SFE and AFM tests.

scholarly journals Identifying the Thermal Storage Stability of Polymer-Modified Asphalt with Carbon Nanotubes Based on Its Macroperformance and Micromorphology

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Xi-yin Liu ◽  
Peng Wang ◽  
Yu Lu ◽  
Tian-tao Zhang ◽  
Li-zhi Wang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Atomic Force Microscopy ◽  
Storage Stability ◽  
Thermal Storage ◽  
Rich Phase ◽  
Force Microscopy ◽  
Modified Asphalt ◽  
Atomic Force ◽  
Polymer Modified Asphalt

The thermal storage stability of polymer-modified asphalt (PMA) is the key to avoid performance attenuation during storage and transportation in pavement engineering. However, phase separation of PMA continuously occurs after long-term thermal storage due to the overlooked influence of the phase interface. Two kinds of carbon nanotubes (CNTs) and styrene-butadiene-styrene triblock copolymer (SBS) were selected in this paper to address the aforementioned issue. The segregation test was used to simulate the long-term storage process from 0 to 10 days. Macroperformance included the softening point difference (△SP), irrecoverable compliance (Jnr), recovery rate (R%), and complex modulus (G∗) measured by the softening point test, multistress creep recovery (MSCR) test, and small strain oscillatory rheological test. Microcharacteristics were obtained by the SBS characteristic peak index, SBS-rich phase distribution, polymer swelling degree, and particle characteristics of the SBS-rich phase. They were measured by Fourier-transformed infrared spectroscopy (FT-IR), fluorescence microscopy (FM), and atomic force microscopy (AFM), respectively. Results showed that the optimum CNT amount necessary to obtain an improved thermal storage stability of PMA was 0.5 wt.%. After 10 days of storage, the largest R% of SBS modified asphalt (SBSMA) decreased to 2.24% and the smallest Jnr increased to 0.069 1/kPa, while R% of SBSMA with CNTs was 62.15% and its Jnr was 0.013 1/kPa. R% and Jnr of SBSMA with CNTs showed almost no change after 6 days of storage, implying an effective antirutting performance. The results from the microperformance investigation showed that phase separation of SBS mainly occurred on day 4, while SBS degradation and base asphalt aging led to the worse macroperformance after 10 days of storage. Additional CNTs restrained the SBS-rich phase from floating upward. Meanwhile, a small size of polymer-rich phase and dense network of SBSMA with CNTs were observed in fluorescence microscopy and atomic force microscopy images, thereby exhibiting improved thermal storage stability. Adding CNTs would retard the segregation due to CNT entanglement with SBS.

TUNING PROPERTIES AND MORPHOLOGY IN HIGH VINYL CONTENT SBS BLOCK COPOLYMER, A THERMOPLASTIC ELASTOMER VIA THIOL-ENE MODIFICATION

2017 ◽  
Vol 90 (3) ◽  
pp. 550-561 ◽  
Author(s):  
Prithwiraj Mandal ◽  
Siva Ponnupandian ◽  
Soumyadip Choudhury ◽  
Nikhil K. Singha
Keyword(s):  
Block Copolymer ◽  
Thermoplastic Elastomer ◽  
Atomic Force Microscopy Analysis ◽  
Ene Reaction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Analysis ◽  
Styrene Butadiene Styrene ◽  
Styrene Butadiene ◽  
Butadiene Styrene

ABSTRACT Thiol-ene modification of high vinyl content thermoplastic elastomeric styrene butadiene styrene (SBS) block copolymer (BCP) was carried out using different thiolating agents in toluene at 70 °C. 1H NMR analysis confirmed the participation of vinyl double bond in the thiol-ene modification reaction of SBS. Surface morphology of the block copolymers evaluated by atomic force microscopy analysis showed higher roughness after the thiol-ene reaction. The thiol-modified SBS block copolymer showed better adhesion strength and oil resistance properties than the pristine SBS.

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