Fabrication of Composite Carbon Nanotubes With Different Oxidation Levels by a Self-Assembly Surface Modification

2006 ◽  
Author(s):  
Chien-Te Hsieh ◽  
Kuen-Song Lin ◽  
Shih Hung Chan ◽  
Ay Su
Keyword(s):  
Carbon Nanotubes ◽  
Metal Oxide ◽  
Metal Ions ◽  
Self Assembly ◽  
Carbon Composite ◽  
Atomic Ratio ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Hydroxyl Group ◽  
Surface Oxides

An efficient technique to fabricate metal-oxide/carbon composite nanotubes has been developed through a self-assembly processing that includes implantation of acidic groups and interaction between surface oxides and metal ions or hydration molecules. To functionalize carbon nanotubes, gaseous oxidation at 300 °C was firstly employed to build functional oxygen groups including carboxyl, carbonyl and hydroxyl group, on the ends or sidewalls of the nanotubes. It revealed that the oxidized nanotubes express a slight improvement of surface hydrophilicity, which was demonstrated by contact angle measurement. X-ray photoelectron spectroscope investigation indicated that the ratio of attached metal-oxide onto the oxidized nanotubes gradually increases with oxidation level, i.e., surface O/C atomic ratio. This evidence reflected that the surface oxides act as an adsorption center that strongly interacts with metal ions or hydration molecules in aqueous phase. Applying this method, SnO2, RuO2, NiO and PtRu nanoparticles having an average size of 5 nm were assembled on the oxidized carbon nanotubes.

Attachment of Metal Oxide Nanoparticles on Carbon Nanotubes with Different Oxidation Levels

2008 ◽  
Vol 55-57 ◽  
pp. 545-548 ◽  
Author(s):  
Chien Te Hsieh ◽  
J.Y. Lin
Keyword(s):  
Carbon Nanotubes ◽  
Metal Ions ◽  
Photoelectron Spectroscopy ◽  
Tin Dioxide ◽  
Metal Oxide Nanoparticles ◽  
Carbon Composite ◽  
Atomic Ratio ◽  
Hydroxyl Group ◽  
Surface Oxides ◽  
Oxygen Groups

An efficient surface modification technique for fabricating tin dioxide/carbon composite nanotubes has been developed. This technique combines with implantation of acidic groups, interaction between surface oxides and metal ions or hydration molecules, and thermal. To functionalize multi-layered carbon nanotubes (CNTs), gaseous oxidation at 300°C was used to build functional oxygen groups including carboxyl, carbonyl and hydroxyl group, on ends or sidewalls of CNTs. X-ray photoelectron spectroscopy clearly indicated that the atomic ratio of attached tin-oxide on the oxidized CNTs gradually increases with the oxidation level, i.e., surface O/C atomic ratio. This evidence reflected that the surface oxides act as an adsorption center that strongly interacts with metal ions or hydration molecules in aqueous phase.

Directed self-assembly of dual metal ions with ligands: towards the synthesis of noble metal/metal oxide composites with controlled facets

2018 ◽  
Vol 54 (16) ◽  
pp. 2044-2047 ◽  
Author(s):  
Fang Cui ◽  
Jiajia Zhang ◽  
Qing Shao ◽  
Linxu Xu ◽  
Xinzi Pan ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Metal Ions ◽  
Noble Metal ◽  
Self Assembly ◽  
Large Scale ◽  
Assembly Strategy ◽  
Metal Metal ◽  
Exposed Facet ◽  
Dual Metal ◽  
Oxide Composites

Despite numerous reports on noble metal/metal oxide composites, the control of the exposed facet is still a great challenge. Here, the large-scale synthesis of noble metal/metal oxide spheres with controlled facets is enabled by making use of a bottom-up self-assembly strategy.

scholarly journals Concentration-driven phase transition and self-assembly in drying droplets of diluting whole blood

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Anusuya Pal ◽  
Amalesh Gope ◽  
John D. Obayemi ◽  
Germano S. Iannacchione
Keyword(s):  
Phase Transition ◽  
Self Assembly ◽  
Whole Blood ◽  
Morphological Analysis ◽  
Hierarchical Structures ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Colloidal Systems ◽  
Functional Complexity ◽  
Sharp Phase Transition

Abstract Multi-colloidal systems exhibit a variety of structural and functional complexity owing to their ability to interact amongst different components into self-assembled structures. This paper presents experimental confirmations that reveal an interesting sharp phase transition during the drying state and in the dried film as a function of diluting concentrations ranging from 100% (undiluted whole blood) to 12.5% (diluted concentrations). An additional complementary contact angle measurement exhibits a monotonic decrease with a peak as a function of drying. This peak is related to a change in visco-elasticity that decreases with dilution, and disappears at the dilution concentration for the observed phase transition equivalent to 62% (v/v). This unique behavior is clearly commensurate with the optical image statistics and morphological analysis; and it is driven by the decrease in the interactions between various components within this bio-colloid. The implications of these phenomenal systems may address many open-ended questions of complex hierarchical structures.

Fabrication of mesoporous metal oxide coated-nanocarbon hybrid materials via a polyol-mediated self-assembly process

Nanoscale ◽  
2014 ◽  
Vol 6 (23) ◽  
pp. 14371-14379 ◽  
Author(s):  
Bingmei Feng ◽  
Huixin Wang ◽  
Dongniu Wang ◽  
Huilong Yu ◽  
Yi Chu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Hydrogen Bonding ◽  
Metal Oxide ◽  
Hybrid Materials ◽  
Self Assembly ◽  
Polymer Chains ◽  
Carboxyl Groups ◽  
Graphene Sheets ◽  
Assembly Process ◽  
Mesoporous Metal

The hydrogen bonding between the carboxyl groups of carbon nanotubes (CNTs) and the polymer chains of metal oxide precursors can initiate the deposition in a self-assembly manner. Then metal oxide coated-carboxylated CNTs or coated-carboxylated graphene sheets hybrid materials are obtained by pyrolysis or hydrolysis.

Sustainable synthesis of alkaline metal oxide-mesoporous carbons via mechanochemical coordination self-assembly

2017 ◽  
Vol 5 (45) ◽  
pp. 23446-23452 ◽  
Author(s):  
Weida Shan ◽  
Pengfei Zhang ◽  
Shize Yang ◽  
Huiyuan Zhu ◽  
Peiwen Wu ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Metal Ions ◽  
Self Assembly ◽  
Solvent Free ◽  
Mesoporous Carbons ◽  
Alkaline Metal ◽  
Assembly Strategy ◽  
Metal Doped ◽  
Alkaline Metal Oxide

A solvent-free self-assembly strategy for the synthesis of alkaline-metal-doped mesoporous carbons (MCs) is developed through mechanochemical coordination assembly between polyphenols and various metal ions.

Critical Surface Tension of HSF54 Carbon Composite Electrodes on Paper Substrate

2015 ◽  
Vol 1109 ◽  
pp. 214-218
Author(s):  
R. Mohamad Zin ◽  
Fauziahanim Che Seman ◽  
Chin Fhong Soon
Keyword(s):  
Surface Tension ◽  
Carbon Composite ◽  
Contact Angle Measurement ◽  
Contact Angles ◽  
Angle Measurement ◽  
Critical Surface ◽  
Composite Electrodes ◽  
Paper Substrate ◽  
Critical Surface Tension ◽  
Image Acquisition System

The wettability of the carbon composite electrode on paper substrate was studied using contact angle measurement. Y-Shield HSF54 carbon composite material were coated on paper substrates with a mask using squeegee coating technique. Contact angles of the ten polar probe liquids with the HSF54 electrodes were measured using a customed-built image acquisition system. With the contact angles obtained for each probe liquid placed on the electrodes, the surface tension of the electrodes was determined using Fox-Zisman theory. The result showed that the critical surface tension of HSF54 carbon composite electrodes was 37.2 mN/m which is considered to be moderately hydrophobic.

A Novel Formulation for the Modification of Transition Metal Oxide Surfaces for Antifogging Optical Application

2006 ◽  
Vol 510-511 ◽  
pp. 42-45 ◽  
Author(s):  
Yamini Asthana ◽  
Dong Pyo Kim
Keyword(s):  
Metal Oxide ◽  
Dip Coating ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Coupling Agents ◽  
Oxide Surface ◽  
Inorganic Component ◽  
Metal Oxide Surfaces ◽  
Metal Oxide Surface ◽  
Strong Adhesion

Formation of coatings with combined properties of being superhydrophilic / superhydrophobic is of immense applications in the field of optics. In our present work, we developed a hydrophilic, antifogging, transparent, and stable coating by employing an anionic electrolyte, Tiron and dip-coating of organic-inorganic mixture. One of the attempts was to adhere Tiron on metal oxide surface by chelating effect, and the other one was to apply an organicinorganic coating on glass or lens substrate. The latter was formulated by mixing appropriate ratios of organic silanol coupling agents and diacrylates component for strong adhesion to the substrate, and inorganic component of a hybrid mixture of silica, titania and Tiron for the antifogging behavior. The surface chemistry of the coated films was studied by taking ATR-IR measurements, and the wetting behavior was characterised by contact angle measurement

scholarly journals Hydrophobic poly(azomethine-urethane) Film for Detection of Fe3+ Ions in Aqueous Media

2017 ◽  
Author(s):  
Musa Kamacı ◽  
İsmet Kaya
Keyword(s):  
Metal Ions ◽  
Aqueous Media ◽  
Dip Coating ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Excitation Wavelength ◽  
Hydrophobic Property ◽  
Film Sensor ◽  
Dual Emissions ◽  
Dip Coating Technique

A new and easy-to-make polymer film sensor was prepared by dip-coating technique and this film used as fluorescent chemosensor for the detection of metal ions in aqueous solution. The proposed film sensor exhibited dual emissions at 540 and 582 nm under a single excitation wavelength. The fluorescence behavior of this film sensor toward metal ions has been investigated using these two wavelengths. The proposed sensor was found to show selectivity and sensitive to Fe3+ ion when compared the other metal ions in deionized water with excellent photostability. Detection limit of the polymeric film sensor was calculated as 86.15 and 28.90 μM. The results showed that the sensor can be successfully applied to the determination of Fe3+ ions in aqueous media. Contact angle measurement of PAZU film probe was also investigated and the result showed that the proposed film probe has hydrophobic property.

Effects of Surface Treatments of Polycaprolactone Scaffolds on their Properties

2013 ◽  
Vol 747 ◽  
pp. 178-181 ◽  
Author(s):  
Wasana Kosorn ◽  
Boonlom Thavornyutikarn ◽  
Wanida Janvikul
Keyword(s):  
Contact Angle ◽  
Plasma Treatment ◽  
Alkaline Hydrolysis ◽  
Photoelectron Spectroscopy ◽  
Atomic Ratio ◽  
Contact Angle Measurement ◽  
Contact Angles ◽  
Angle Measurement ◽  
Water Contact ◽  
Oh Groups

Polycaprolactone (PCL) was surface modified with alkaline hydrolysis by NaOH and/or low pressure oxygen (O2) plasma treatment. The hydrolysis was conducted in two different stages: one was performed prior to PCL scaffold fabrication by a high pressure supercritical CO2 technique; the other was carried out after the fabrication. The resulting hydrolyzed PCL scaffolds, with pore sizes in the range of 150-250 μm, were denoted as pre-HPCL and post-HPCL, respectively. Both non-hydrolyzed and hydrolyzed PCL scaffolds were subsequently subjected to the plasma treatment, to further enhance the hydrophilicity of the scaffolds. The surface morphology, wettability and chemical composition of all PCL scaffolds were analyzed by scanning electron microscopy (SEM), water contact angle measurement, and X-ray photoelectron spectroscopy (XPS), respectively. It was found that the surface of the scaffolds turned from fairly smooth to highly rough after the hydrolysis and plasma treatment, particularly when both treatments were in use. The post-hydrolysis induced more surface roughness, compared to the pre-hydrolysis. In addition, the water contact angles on the scaffolds enormously reduced after the treatments; plasma treatment, however, showed a more prominent effect than the alkaline hydrolysis. Although expressing a zero-degree contact angle, the plasma-treated pre-HPCL scaffold was wetted more readily than the plasma-treated post-HPCL. These were in good agreement with the XPS results; interestingly, the plasma-treated pre-HPCL scaffold exhibited the greatest O/C atomic ratio among the PCL scaffolds. This indicated its highest extent of PCL chain oxidation, a degradation of ester groups into-COOH and-OH groups.

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