scholarly journals Design of a pH-Responsive Conductive Nanocomposite Based on MWCNTs Stabilized in Water by Amphiphilic Block Copolymers

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1410 ◽  
Author(s):  
den Hoed ◽  
Pucci ◽  
Picchioni ◽  
Raffa
Keyword(s):  
Carbon Nanotubes ◽  
Block Copolymers ◽  
Acrylic Acid ◽  
Zeta Potential ◽  
Amphiphilic Block Copolymers ◽  
Ph Responsive ◽  
Potential Applications ◽  
Multi Walled Carbon Nanotubes ◽  
Responsive Behavior ◽  
Walled Carbon Nanotubes

Homogeneous water dispersions of multi-walled carbon nanotubes (MWCNTs) were prepared by ultrasonication in the presence of an amphiphilic polystyrene-block-poly(acrylic acid) (PS-b-PAA) copolymer. The ability of PS-b-PAA to disperse and stabilize MWCTNs was investigated by UV-vis, SEM and zeta potential. The results show that the addition of a styrene block to PAA enhances the dispersion efficiency of the graphitic filler compared to pure PAA, possibly due to the nanotube affinity with the polystyrene moiety. Notably, the dispersions show an evident pH-responsive behavior, being MWCNTs reaggregation promoted in basic environment. It is worth noting that the responsive character is maintained in solid composites obtained by drop casting, thus indicating potential applications in sensing.

scholarly journals Design of a pH-responsive Conductive Nanocomposite Based on MWCNTs Stabilized in Water by Amphiphilic Block Copolymers

2019 ◽  
Author(s):  
Frank den Hoed ◽  
Andrea Pucci ◽  
Francesco Picchioni ◽  
Patrizio Raffa
Keyword(s):  
Electrical Conductivity ◽  
Block Copolymers ◽  
Acrylic Acid ◽  
Zeta Potential ◽  
Amphiphilic Block Copolymers ◽  
Ph Responsive ◽  
Sensing Applications ◽  
Responsive Behavior ◽  
Ph Variations ◽  
Poly Acrylic Acid

Homogeneous water dispersions of MWCNTs were prepared by ultrasonication in the presence of an amphiphilic polystyrene-block-poly(acrylic acid) (PS-b-PAA) copolymer. The ability of PS-b-PAA to disperse and stabilize MWCTNs was investigated by UV-vis, SEM and zeta potential. It is shown that the copolymer can disperse nanotubes directly by sonication in water. The results show that the addition of a styrene block to PAA enhances the dispersion efficiency compared to pure PAA, possibly due to the nanotube affinity with the polystyrene moiety. Notably, the dispersions show an evident pH-responsive behavior, being MWCNTs reaggregation promoted in basic environment. Furthermore, composites obtained by drop casting display electrical conductivity responsive to pH variations, showing the potential of such materials for sensing applications.

scholarly journals Combining Carbon Nanotubes and Chitosan for the Vectorization of Methotrexate to Lung Cancer Cells

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2889 ◽  
Author(s):  
Giuseppe Cirillo ◽  
Orazio Vittorio ◽  
David Kunhardt ◽  
Emanuele Valli ◽  
Florida Voli ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Ph Responsive ◽  
Carbon Nanostructure ◽  
X Ray ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Responsive Behavior ◽  
Walled Carbon Nanotubes

A hybrid system composed of multi-walled carbon nanotubes coated with chitosan was proposed as a pH-responsive carrier for the vectorization of methotrexate to lung cancer. The effective coating of the carbon nanostructure by chitosan, quantified (20% by weight) by thermogravimetric analysis, was assessed by combined scanning and transmission electron microscopy, and X-ray photoelectron spectroscopy (N1s signal), respectively. Furthermore, Raman spectroscopy was used to characterize the interaction between polysaccharide and carbon counterparts. Methotrexate was physically loaded onto the nanohybrid and the release profiles showed a pH-responsive behavior with higher and faster release in acidic (pH 5.0) vs. neutral (pH 7.4) environments. Empty nanoparticles were found to be highly biocompatible in either healthy (MRC-5) or cancerous (H1299) cells, with the nanocarrier being effective in reducing the drug toxicity on MRC-5 while enhancing the anticancer activity on H1299.

pH Responsive Release of Doxorubicin to the Cancer Cells by Functionalized Multi-Walled Carbon Nanotubes

2015 ◽  
Vol 15 (7) ◽  
pp. 4799-4805 ◽  
Author(s):  
B. Anbarasan ◽  
S. Vignesh Babu ◽  
K. Elango ◽  
B. Shriya ◽  
S. Ramaprabhu
Keyword(s):  
Carbon Nanotubes ◽  
Cancer Cells ◽  
Ph Responsive ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

pH-Switchable electroactive composite films of carboxylated multi-walled carbon nanotubes and Prussian blue

RSC Advances ◽  
2015 ◽  
Vol 5 (125) ◽  
pp. 103184-103188
Author(s):  
Ying Tong ◽  
Yuanyuan Wang ◽  
Bowen Gao ◽  
Lei Su ◽  
Xueji Zhang
Keyword(s):  
Thin Films ◽  
Carbon Nanotubes ◽  
Prussian Blue ◽  
Composite Films ◽  
Ph Responsive ◽  
Composite Thin Films ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Here the combination of carboxylated multi-walled carbon nanotubes (CMWCNTs) and Prussian blue (PB) for fabricating pH-responsive electroactive composite thin films is reported.

scholarly journals The Application of Multi-Walled Carbon Nanotubes in Bone Tissue Repair Hybrid Scaffolds and the Effect on Cell Growth In Vitro

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 230 ◽  
Author(s):  
Jie Xu ◽  
Xueyan Hu ◽  
Siyu Jiang ◽  
Yiwei Wang ◽  
Roxanne Parungao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Bone Tissue ◽  
Optimal Growth ◽  
Bone Tissue Regeneration ◽  
Proliferation And Differentiation ◽  
Potential Applications ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Hybrid Scaffolds

In this study, composite scaffolds with different multi-walled carbon nanotubes (MWCNTs) content were prepared by freeze-drying. These scaffolds were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), porosity, hydrophilicity, mechanical strength, and degradation. The MWCNTs scaffolds were structurally sound and had porous structures that offered ample space for adherence, proliferation, and differentiation of MC3T3-E1 cells, and also supported the transport of nutrients and metabolic waste. CS/Gel/nHAp/0.3%MWCNTs scaffolds provided the best outcomes in terms of scaffold porosity, hydrophilicity, and degradation rate. However, CS/Gel/nHAp/0.6%MWCNTs scaffolds were found to support the optimal growth, homogenous distribution, and biological activity of MC3T3-E1 cells. The excellent properties of CS/Gel/nHAp/0.6%MWCNTs scaffolds for the adhesion, proliferation, and osteogenesis differentiation of MC3T3-E1 cells in vitro highlights the potential applications of this scaffold in bone tissue regeneration.

Nanohybrid Nanoparticles Based on Chitosan/Functionalized Carbon Nanotubes as Anti-HIV Nanocarrier

NANO ◽  
2015 ◽  
Vol 10 (01) ◽  
pp. 1550010 ◽  
Author(s):  
R. Afshari ◽  
S. Mazinani ◽  
M. Abdouss
Keyword(s):  
Carbon Nanotubes ◽  
Drug Delivery ◽  
Carbon Nanotube ◽  
Drug Delivery Systems ◽  
Drug Loading ◽  
Delivery Systems ◽  
Potential Applications ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Carbon nanotube-natural biopolymer nanovectors have important potential applications in delivery system for drugs and biomolecules. In this work, the use of multi-walled carbon nanotubes (MWCNT) as nanoreservoirs for drug loading and controlled release is demonstrated. We synthesized different carbon nanotube-based drug delivery systems including acid and amide-functionalized MWCNT; chitosan (CS) covalently grafted to functionalized MWCNT and MWCNT-CS nanoparticles (NPs) using an ionotropic gelation method as a sustained-release systems for delivery of Tenofovir (hydrophilic anti-retroviral drug). The prepared NPs as different drug delivery systems were characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). As it is shown, in vitro drug release studies indicated that the cumulative release rate of Tenofovir from MWCNT–CS NPs shows the best result and it reaches the maximum value (90%) after about 120 h. Moreover, comparing to ungrafted CNTs, MWCNT–CS shows high dispersability and long-term stability in aqueous medium which approves the effective solubilization of MWCNT followed by grafting with CS.

scholarly journals Construction of Multiple Switchable Sensors and Logic Gates Based on Carboxylated Multi-Walled Carbon Nanotubes/Poly(N,N-Diethylacrylamide)

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3358 ◽  
Author(s):  
Xuemei Wu ◽  
Xiaoqing Bai ◽  
Yang Ma ◽  
Jie Wei ◽  
Juan Peng ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Logic Gate ◽  
Logic Gates ◽  
Present System ◽  
Ph Responsive ◽  
Cyclic Voltammetric ◽  
Computing Systems ◽  
Multi Walled Carbon Nanotubes ◽  
Gate System ◽  
Walled Carbon Nanotubes

In this work, binary hydrogel films based on carboxylated multi-walled carbon nanotubes/poly(N,N-diethylacrylamide) (c-MWCNTs/PDEA) were successfully polymerized and assembled on a glassy carbon (GC) electrode surface. The electroactive drug probes matrine and sophoridine in solution showed reversible thermal-, salt-, methanol- and pH-responsive switchable cyclic voltammetric (CV) behaviors at the film electrodes. The control experiments showed that the pH-responsive property of the system could be ascribed to the drug components of the solutions, whereas the thermal-, salt- and methanol-sensitive behaviors were attributed to the PDEA constituent of the films. The CV signals particularly, of matrine and sophoridine were significantly amplified by the electrocatalysis of c-MWCNTs in the films at 1.02 V and 0.91 V, respectively. Moreover, the addition of esterase, urease, ethyl butyrate, and urea to the solution also changed the pH of the system, and produced similar CV peaks as with dilution by HCl or NaOH. Based on these experiments, a 6-input/5-output logic gate system and 2-to-1 encoder were successfully constructed. The present system may lead to the development of novel types of molecular computing systems.

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