scholarly journals Application of Functionalized Multi-Walled Carbon Nanotubes for Growth Enhancement of Mustard Seed Germination

2019 ◽  
Vol 20 (1) ◽  
pp. 120
Author(s):  
Agus Subagio ◽  
Erma Prihastanti ◽  
Ngadiwiyana Ngadiwiyana

Multi-walled carbon nanotubes (MWCNTs) are one of the nanomaterials that can be applied to agriculture. This work investigates the beneficial effects of MWCNT function on mustard plants. In this study, the material of MWCNTs is functionalized with nitric acid to attach the carboxylic group onto the tube wall. The functionalized MWCNTs were characterized by SEM, TEM, XRD, and FTIR. The MWCNT diameter produced ranges from 20 to 50 nm and the inner diameter is 5 to 10 nm at the pyrolysis temperature of 900 °C. It was found that crystallites of the MWCNTs have (002) and (100) directions. There is a weak peak in MWCNTs prior to the functionalization process due to the presence of metal carbide (Fe3C), which serves as an active catalyst. FTIR results clearly indicate the presence of hydroxyl and carboxylic groups. These functionalized MWCNTs were dispersed into distilled water with various concentrations at 25, 50 and 75 µg/mL. By utilizing an immersion time of 24 h, mustard (Brassica juncea) seeds were soaked in each functionalized and non-functionalized MWCNT solution. Functionalized MWCNT solution at a concentration of 50 µg/mL was found to affect the growth of mustard seeds more significantly.

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.


Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1099 ◽  
Author(s):  
Qiuping Li

Ionogels refer to an emerging composite material made from the confinement of ionic liquids within some specific cross-linked network matrices. They have potential applications in areas such as electrochemical and optical-electric materials. Incorporation of lanthanide (Eu3+, Tb3+) complexes covalently functionalized multi-walled carbon nanotubes (MWCNTs) in ionogels provide new ideas to design and synthesize novel luminescent hybrid materials that have excellent characteristics of luminescence and ionic conductivity. Here, the multifunctional ionogels were synthesized by confining an ionic liquid and the rare earth functionalized MWCNTs in the cross-linked polymethyl methacrylate (PMMA) networks, resulting in a novel optical/electric multifunctional hybrid material. The SEM images and digital photographs suggest that the lanthanide functionalized MWCNTs are evenly dispersed in the hybrid matrices, thus leading to a certain transparency bulky gel. The resulting ionogels exhibit certain viscosity and flexibility, and display an intense red/green emission under UV-light irradiation. The intrinsic conductibility of the embedded ionic liquids and carbon nanotubes in conjunction with the outstanding photoluminescent properties of lanthanide complexes makes the soft hybrid gels a material with great potential and valuable application in the field of optical-electric materials.


2017 ◽  
Vol 5 (36) ◽  
pp. 19467-19475 ◽  
Author(s):  
Jing-Jing Fan ◽  
You-Jun Fan ◽  
Rui-Xiang Wang ◽  
Sheng Xiang ◽  
Hua-Guo Tang ◽  
...  

Sulfur-doped multi-walled carbon nanotubes (S-MWCNTs) derived from PEDOT-functionalized MWCNTs can significantly improve the dispersion of supported Pt nanoparticles and enhance their electrocatalytic performance for the MOR.


2019 ◽  
Vol 98 (4) ◽  
pp. 455-460
Author(s):  
Lyudmila V. Akhaltseva ◽  
V. S. Zhurkov ◽  
L. P. Sycheva ◽  
O. N. Savostikova ◽  
A. V. Alekseeva

Introduction. One of the important steps in assessing the nanoparticles (NP) safety is the analysis of mutagenic activity, including the evaluation of gene, chromosomal, and genomic mutations. Material and methods. The purpose of this investigation is to study the ability of different NP aqueus suspensions and the same compounds in microforms to unduce gene mutations in Salmonella/microsome test (Ames test). Anatase titanium dioxide NP coated with simethicone (33.16 ± 16.7 nm, 5-50000 μg/ml), magnetite NP coated with silicate (10 nm, 0.92-575 μg/ml), silver NP coated with аrabian gum (14 ± 0.2 nm, 5-50000 μg/ml), aluminum hydroxide nanofibres (50-70 nm, 24-3000 μg/ml) and multi-walled carbon nanotubes (Taunit MWСNTs, outer diameter 15-40 nm, inner diameter 3-8 nm, length 2 and more microns, 5-50000 μg/ml). In parallel, the mutagenic activity of equivalent microparticles was evaluated in experiments. Ames test (Salmonella/microsomes) registers gene mutations induced by a different mechanism of action, in the variant with preincubation. A set of Salmonella typhimurium indicator strains: TA 100 (base pair substitution mutations), TA 98 and TA 97 (mutations of the frameshift type of the genetic code) were used. Using addition the S9 microsomal activating mixture during the experiment makes it is possible to determine the effect not only of the substances themselves, but also of their metabolites. Conclusion. The investigated nanomaterials as well as their micro analogs in the studied dose range did not induce gene mutations in the Ames test both in presence and absence microsomal activating mixture.


Author(s):  
Shafinaz Shahir ◽  
Boon Kai Tai ◽  
Zaiton Abdul Majid ◽  
Nor Aziah Buang

The possibility of modifying the surface properties of multi-walled carbon nanotubes (MWCNTs) has stimulated increasing interest in their application as components in biosensors. In this sense, it is possible to employ surface modified MWCNTs as support to immobilize biomaterials such as enzymes. In this study the enzyme tyrosinase was immobilized onto functionalized MWCNTs (fMWCNTs) via covalent bonding and activity of immobilized tyrosinase was measured via electrochemical detection of phenol. MWCNTs were first treated with sulphuric acid and nitric acid with ratio 1 : 3 at 70ºC to introduce carboxylated groups (-COOH). The carboxyl moieties were then activated by treatment with a cross-linker, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) to enable tyrosinase immobilization via amide bonding. FTIR spectra of tyrosinase immobilized fMWCNTs showed the presence of peaks attributing to aliphatic C-N (1382 cm-1) and amide carbonyl (1639 cm-1) vibrations which confirmed successful covalent immobilization of tyrosinase onto fMWCNTs. Electrochemical measurements using tyrosinase-fMWCNTS-CPE revealed increasing limiting current values of reduction peak with increasing phenol concentrations at -200mV. The appearance of the reduction current indicates that the immobilization process retained the biological activity of the covalently bonded tyrosinase on fMWCNTs surface. This study has demonstrated the potential of using MWCNTs as support for enzyme immobilization and their application in biosensor technology.


2010 ◽  
Vol 447-448 ◽  
pp. 634-638 ◽  
Author(s):  
Henry Kuo Feng Cheng ◽  
Nanda Gopal Sahoo ◽  
Lin Li ◽  
Siew Hwa Chan ◽  
Jian Hong Zhao

Multi-walled carbon nanotubes (MWCNTs) were functionalized with a carboxyl group (-COOH) to improve their dispersion in a nylon6 (PA6) matrix, a liquid crystal polymer (LCP) and their blend. This functionalized MWCNTs also achieved better interfacial adhesions with both polymer matrices and with both phases in the blend. The dispersion of MWCNT-COOH in the polymer matrices and their interfacial interactions with polymer molecules were found to be the most important factors affecting the properties of composites. Moreover, studies on morphological, rheological, and mechanical properties confirmed that a better miscibility between PA6 and LCP had been constituted in the presence of MWCNT-COOH. Therefore, it is observed that the functionalized MWCNTs not only played the traditional role as reinforcing fillers in the polymer matrices, but also performed a novel role as compatibilizers for their blend.


2011 ◽  
Vol 298 ◽  
pp. 121-127 ◽  
Author(s):  
Xing Sheng Wang ◽  
Pu Liu ◽  
Hai Tao Zheng ◽  
Hui Hu ◽  
Wen Juan Zheng ◽  
...  

Coenzyme, nicotinamide adenine dinucle-otide (NAD+) functionalized multi-walled carbon-nanotubes (MWCNTs) were prepared in this work. Carboxylic groups were firstly introduced to MWCNTs by oxidation in a mixture of sulfuric acid and nitric acid, and the NAD moistures were further attached by the formation of amide bonds with carboxylic groups under the help of 1-ethyl-3-(3-dimethyl-aminopropyl)carbodiimidehydrochloride and N-hydroxysuccinimide, which resulted in the coenzyme functionalized materials, MWCNTs-NAD. The MWCNTs-NAD was characterized by UV-Vis, FT-IR and TEM, and it was found clearly that the MWCNTs-NAD exhibited coenzyme activity compared with native NAD+ in reaction catalyzed by NAD-dependent alcohol dehydrogenase. The application of MWCNTs-NAD on the construction of dehydrogenase biosensor was further investigated.


2019 ◽  
Vol 54 (14) ◽  
pp. 1847-1861
Author(s):  
Alireza Bagherzade ◽  
Masoud Jamshidi

In this study, multi-walled carbon nanotubes (MWCNTs) were functionalized by both sulfuric/nitric acids and amino acids to form COOH and NH2/COOH/OH groups on their surface, respectively. The functionalized MWCNTs were characterized by Fourier Transform Infrared Spectroscopy, titration test, thermal gravimetric analysis, and solvent stability test. The results revealed that in each method, the functional groups were successfully attached to the surface of nanotubes. Acid treatment grafted more oxygen-containing groups compared to commercial carboxylated MWCNTs. The amino acid functionalized MWCNTs indicated improved stability in different solvents compared to raw and acid treated MWCNTs. These functionalized MWCNTs were incorporated into epoxy resin and the properties of the nanocomposites were evaluated by scanning electron microscopy, tensile test, dynamic mechanical thermal analysis, differential scanning calorimetry, and thermogravimetric analysis. The morphology of the nanocomposites revealed that acid and amino acid treated samples had better interaction with the epoxy resin. Compared to epoxy sample contained raw MWCNT (control) and commercial carboxylated MWCNTs, the addition of functionalized MWCNTs to the epoxy resin improved the tensile strength by 39% and 25% (for acid treated) and 46% and 33% (for amino acid treated), respectively. The best tensile properties for acid and amino acid treated samples were reached by MWCNTs acid treated at 110℃ for 15 min and MWCNTs treated in a 50 g/L aqueous solution of amino acid, respectively. Storage modulus of the epoxy samples which contained acid and amino acid treated MWCNTs were 1560 and 1900 MPa, respectively. The glass rubber transition temperature ( Tg) of the epoxy samples containing acid and amino acid treated nanotubes were increased by 1.1℃ and 5.9℃, respectively, compared to the control sample. Therefore, based on these mechanical properties, the epoxy samples containing nanotubes functionalized by amino acid exhibited the highest performance in the epoxy nanocomposite. Incorporating acid and amino acid treated MWCNTs accelerated the curing process of epoxy where the curing temperature decreased by 9.1℃ and 13.3℃, respectively. Because of the reaction between amine groups grafted on MWCNTs in the amino acid treatment and epoxide groups of the epoxy resin, this acceleration was more significant in the case of amino acid sample. Note that addition of functionalized MWCNTs to epoxy resin did not lead to increased thermal stability.


2015 ◽  
Vol 754-755 ◽  
pp. 1146-1150
Author(s):  
Muhammad Mahyiddin Ramli ◽  
Siti Salwa Mat Isa ◽  
Mohd Nazrin Md Isa ◽  
Shahrir Rizal Kasjoo ◽  
Simon J. Henley

Langmuir-Blodgett technique was applied to build optically homogeneous film of functionalized multi-walled carbon nanotubes (MWCNTs) on paper substrate. The palladium (Pd) nanoparticles were drop-casted onto MWCNTs network films before being exposed in hydrogen (H2) gas molecules environment under vacuum and atmospheric pressure at room temperature. The results demonstrate that the functionalized MWCNTs dispersed with Pd nanoparticles show good H2sensing response on paper substrate where the sensitivity of around 10 % was recorded at only 2 minutes exposure time.


2011 ◽  
Vol 65 (23-24) ◽  
pp. 3362-3364 ◽  
Author(s):  
Yan Pan ◽  
Yunfang Liu ◽  
Weidong Chi ◽  
Zengmin Shen

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