scholarly journals Synthesis of Mesoporous MWCNT/HKUST-1 Composite for Wastewater Treatment

2019 ◽  
Vol 9 (20) ◽  
pp. 4407 ◽  
Author(s):  
Rasidi Sule ◽  
Ajay K. Mishra
Keyword(s):  
Carbon Nanotubes ◽  
Surface Area ◽  
Multiwalled Carbon Nanotubes ◽  
Particle Diameter ◽  
Pollutant Removal ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Average Particle ◽  
Multiwalled Carbon ◽  
Composite Surface

Metal–organic frameworks (MOFs) (Hong Kong University of Science and Technology (HKUST)-1) have been widely studied using the hydrothermal method. Recently, efforts have also been geared toward the incorporation of multiwalled carbon nanotubes (MWCNTs) into the HKUST-1 MOF to advance its applications for gas storage as well as pollutant removal in wastewater. However, a significant reduction in the MWCNT/HKUST-1 composite surface area has limited its applications. We therefore synthesized HKUST-1 and HKUST-1 impregnated with acid-treated multiwalled carbon nanotubes (FMWCNTs). A large surface area of 1131.2 m2g−1 was obtained after acid treatment of the as-received MWCNTs. HKUST-1 was found to have an average particle diameter of 6.5 to 8 µm with a BET surface area of 1176.66 m2g−1. The FMWCNT/HKUST-1 composites had a BET surface area of 1108.85 m2/g. The addition of FMWCNTs was found to increase the parent MOF pore volume from 0.76 to 1.93 cm3g−1. A BJH desorption cumulative pore size of 6.97 nm was obtained in a composite sample. The maximum adsorption capacity of the composites was found to be greater than 100 mg/g at 298 K. The results obtained indicate that FMWCNT/HKUST-1 nanocomposites are a potential adsorbent for methylene blue (MB) removal in dye synthetic water.

scholarly journals Synthesis and Physicochemical Behaviour of Polyurethane-Multiwalled Carbon Nanotubes Nanocomposites Based on Renewable Castor Oil Polyols

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Alaa Ali ◽  
Kamal Yusoh ◽  
S. F. Hasany
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Surface Area ◽  
Multiwalled Carbon Nanotubes ◽  
Castor Oil ◽  
Multiwalled Carbon ◽  
Area Studies ◽  
Composite Surface ◽  
Scanning Electron

Polyurethanes (PUs) are high performance materials, with vast industrial and engineering applications. In this research, effects of Multiwalled Carbon Nanotubes (MWCNTs) on physicochemical properties of Castor Oil based Polyurethanes (COPUs) were studied. MWCNTs were added in different weight percentages (0% to 1% wt) in a castor oil based polyurethane (COPUs-MWCNTs) nanocomposites. The composition, structure, and morphology of polyurethanes were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), and element detection by energy dispersive spectroscopy (EDX) analysis, respectively. Thermal stability was studied by thermogravimetric analysis (TGA). Barrier properties and surface area studies were investigated by nitrogen permeability machine and BET technique. Mechanical properties were calculated by tensile universal testing machine. Results showed well dispersed MWCNTs in polyurethane matrix at different weight percentages. The best results were obtained with 0.3 wt% of MWCNTs in the composite. Surface area studies revealed presence of very few pores which is in a good agreement with barrier permeability, reduced up to ~68% in 1 wt% and ~70% in 0.5 wt% of MWCNTs in polymer matrix, with respect to pure COPUs samples.

scholarly journals Comparison of Single-Walled and Multiwalled Carbon Nanotubes Durability as Pt Support in Gas Diffusion Electrodes

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mehdi Asgari ◽  
Elaheh Lohrasbi
Keyword(s):  
Carbon Nanotubes ◽  
Fuel Cell ◽  
Surface Area ◽  
Multiwalled Carbon Nanotubes ◽  
Gas Diffusion ◽  
Support Surface ◽  
Gas Diffusion Electrodes ◽  
Potential Cycling ◽  
Multiwalled Carbon ◽  
Area Loss

Durability of single-walled (SWCNT) and multiwalled carbon nanotubes (MWCNT) as Pt supports was studied using two accelerated durability tests (ADTs), potential cycling and potentiostatic treatment. ADT of gas diffusion electrodes (GDEs) was once studied during the potential cycling. Pt surface area loss with increasing the potential cycling numbers for GDE using SWCNT was shown to be higher than that for GDE using MWCNT. In addition, equilibrium concentrations of dissolved Pt species from GDEs in 1.0 M H2SO4 were found to be increased with increasing the potential cycling numbers. Both findings suggest that Pt detachment from support surface plays an important role in Pt surface loss in proton exchange membrane fuel cell electrodes. ADT of GDEs was also studied following the potentiostatic treatments up to 24 h under the following conditions: argon purged, 1.0 M H2SO4, 60°C, and a constant potential of 0.9 V. The subsequent electrochemical characterization suggests that GDE that uses MWCNT/Pt is electrochemically more stable than other GDE using SWCNT/Pt. As a result of high corrosion resistance, GDE that uses MWCNT/Pt shows lower loss of Pt surface area and oxygen reduction reaction activity when used as fuel cell catalyst. The results also showed that potential cycling accelerates the rate of surface area loss.

The Effect of Surface Area, Pore Volume, and Pore Size Distribution on the Modified Multiwalled Carbon Nanotubes

2014 ◽  
Vol 625 ◽  
pp. 148-151 ◽  
Author(s):  
Rahmam Syuhaidah ◽  
Muti Mohamed Norani ◽  
Suriati Sufian
Keyword(s):  
Carbon Nanotubes ◽  
Surface Treatment ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Multiwalled Carbon Nanotubes ◽  
Pore Volume ◽  
Multiwalled Carbon ◽  
Effect Of Surface

Carbon Nanotubes (CNT) have emerged and gained great interest for research in many applications because of their unique specific characteristics such as having high porosity, high surface area and the existence of a wide spectrum of surface functional groups through chemical modification. Multiwalled carbon nanotubes (MWCNT) is a type of CNT that comprises of multiple layers of concentric cylinders. The overall study of this research work is to modify MWCNT to become a good adsorbent that can adsorb CO2 at its optimum capacity. In order to make MWCNT as an efficient adsorbent, surface treatment on pristine MWCNT is necessary to overcome the hydrophobicity issue by the introduction of carboxyl group. Upon the surface treatment, functionalization of MWCNT with 3-Aminopropyl triethoxysilane (APTS) was conducted to obtain the attachment of amine group that will assist MWCNT in adsorbing CO2. The surface treatment and functionalization process undergone by MWCNT changed the physical properties of MWCNT such as the surface area, pore volume, and pore size distribution. These properties can be determined using surface area and pore analyzer (SAP). Sample that treated with the mixture of nitric and sulfuric acid (HNO3/H2SO4) and functionalized with APTS gives the lowest surface area (22.07 m2/g) and pore volume (0.06 cm3/g). The pore size distribution also decreases due to the most presence of functional group onto the surface of modified MWCNT. This research paper is focusing on the effect of surface area, pore volume, and pore size distribution on the modified MWCNT.

Characterization of Nano-Sized Particles for Propulsion Applications

2003 ◽  
Vol 800 ◽  
Author(s):  
Grant A. Risha ◽  
Eric Boyer ◽  
Brian Evans ◽  
Kenneth K. Kuo ◽  
Rafaat Malek
Keyword(s):  
Surface Area ◽  
Rapid Development ◽  
Particle Diameter ◽  
Nano Particles ◽  
Bet Surface Area ◽  
Solid Fuels ◽  
Average Particle ◽  
Hybrid Rocket ◽  
Combustion Properties ◽  
Active Content

ABSTRACTEnergetic nano-sized particles have been shown to have a great potential for use in the aerospace propulsion applications. Some of the unique combustion properties of nano-particles such as very rapid ignition and short combustion times make them particularly valuable for propulsion systems; they can be included in solid fuels, solid propellants, or even as energetic gellant in liquid systems. However, due to the novelty of the application and rapid development of production techniques, there is no comprehensive understanding of what characteristics of a nano-sized particle are important in contributing to desirable performance and ease of processing into a final usable form. Previous studies have shown that HTPB-based solid fuels containing various types of nano-sized particles showed differing performance results when tested in the same hybrid rocket motor under identical conditions. Many of these particles have data available only on the basic composition (aluminum, boron, boron carbide, etc.), average diameter, and/or BET surface area. In order to better understand and correlate observed combustion behavior with intrinsic material properties, the particles of interest need to be better characterized. A variety of standard particle characterization techniques were applied to the fifteen types of particles examined in this study and the results tabulated. Some of the parameters measured were average particle diameter, specific surface area, amount of active content, and oxide layer thickness. Trends in propulsion performance measured using a parameter of great interest to the hybrid rocket community (fuel mass burning rate) in general matched trends in particle characteristics (i.e. active content, surface area), but there were some noticeable exceptions. This study indicates that there is still much more to learn about the correlation between physical and chemical properties and measured combustion performance. Other parameters that should be examined in the future include particle size distribution, degree of agglomeration, reactivity and thermal effects (oxidation rate, onset temperature for oxidation exotherm, heat release associated with any excess stored energy), etc.

scholarly journals Removal of atenolol from aqueous solutions by multiwalled carbon nanotubes modified with ozone: kinetic and equilibrium study

2018 ◽  
Vol 2017 (3) ◽  
pp. 636-649 ◽  
Author(s):  
Bahare Dehdashti ◽  
Mohammad Mehdi Amin ◽  
Hamidreza Pourzamani ◽  
Lida Rafati ◽  
Mehdi Mokhtari
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solutions ◽  
Multiwalled Carbon Nanotubes ◽  
Removal Efficiency ◽  
Contact Time ◽  
Maximum Adsorption Capacity ◽  
Multiwall Carbon Nanotube ◽  
Multiwalled Carbon ◽  
Initial Concentration ◽  
Multiwall Carbon

Abstract The aim of study is removal of atenolol from aqueous solutions by multiwalled carbon nanotubes modified with ozone. The design of the experiment was adopted across four levels with the L16 matrix arrangement. The factors influencing atenolol adsorption include changes in the pH value, contact time, the dose of the modified multiwall carbon nanotube, and the initial concentration of atenolol in the solution; these factors were evaluated along with the extent of their influence on removal efficiency. Data analyses were performed by the Design Expert 6 software. The results indicated that the pH, contact time, adsorbent dose, and the initial concentration were 7, 20 min, 0.15 g/L and 1 mg/L, respectively. In this state, the removal efficiency was calculated to be 75.79%. The maximum adsorption capacity was obtained as 5.05 mg/g under optimal conditions. The data were analyzed using adsorption models obtained from the isotherm fitting tool software. The results suggested that the data had a greater congruence with the Freundlich model (corrected Akaike information criterion = 2.58). Furthermore, the kinetics of the reactions followed pseudo second order kinetics (R2 = 0.95). Based on this study, it can be concluded that modified multiwall carbon nanotubes enjoy high potential and efficiency as adsorbents for the removal of atenolol from aqueous solutions.

Effect of Multiwalled Carbon Nanotubes On Mechanical Properties of Concrete

2012 ◽  
Vol 2 (6) ◽  
pp. 166-168 ◽  
Author(s):  
Dr.T.Ch.Madhavi Dr.T.Ch.Madhavi ◽  
◽  
Pavithra.P Pavithra.P ◽  
Sushmita Baban Singh Sushmita Baban Singh ◽  
S.B.Vamsi Raj S.B.Vamsi Raj ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Multiwalled Carbon
Sign in / Sign up

Export Citation Format

Share Document