Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
Add more filters










Publication year range
1.
J Nanosci Nanotechnol ; 16(5): 4320-7, 2016 May.
Article in English | MEDLINE | ID: mdl-27483752

ABSTRACT

RGO/Resol carbon composites were prepared from a mixture of reduced GO and a low-molecular-weight phenolic resin (Resol) solution. The effects of the calcination temperature, amount of Resol added and KOH treatment on the electrochemical performance of the RGO/Resol composites were investigated. The physical and electrochemical properties of the composite materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer, Emmett and Teller (BET) surface areas measurements, and cyclic voltammetry (CV). The relationships between their physical properties and their electrochemical performance were examined for use as super-capacitors (SCs). The RGO/Resol composite calcined at 400 degrees C after the KOH loading showed dramatically improved electrochemical properties, showing a high BET surface and capacitance of 2190 m2/g and 220 F/g, respectively. The RGO/Resol composites calcined after the KOH treatment showed much better capacitor performance than those treated only thermally at the same temperature without KOH impregnation. The fabrication of high surface electrodes was essential for improving the SCs properties.

2.
J Nanosci Nanotechnol ; 16(5): 4505-11, 2016 May.
Article in English | MEDLINE | ID: mdl-27483782

ABSTRACT

In this study, the synthesis of porous titania-silica (TiO2-SiO2) composite aerogel at ambient pressure by using non-hazardous chemicals as a source of silica was investigated. TiO2-SiO2 composite aerogels were characterised and their photocatalytic performances were investigated for the removal efficiency of acetaldehyde and NO(x) under UV light. Results showed that porous composite aerogel with aggregated morphology, high surface area and an increased mesoporosity were formed. TiO2-SiO2(1.8) composite, with high Ti/Si ratio, showed the best results in terms of photocatalytic removal of acetaldehyde and nitrogen oxide.

3.
J Nanosci Nanotechnol ; 15(1): 334-8, 2015 Jan.
Article in English | MEDLINE | ID: mdl-26328355

ABSTRACT

The mesoporous monolithic carbon (MMC) foams and carbon tubes were newly fabricated in cm-scale using the mixture of triblock copolymers and phenol/HCHO resin precursors. The regular mesoporosity were formed in the body of MMC foam and carbon fibers. In this work, the organic phases containing chiral ARCA adsorbent and a phase transfer catalyst were coated on the surfaces of mesoporous carbon support, and this ARCA/carbon mixture was adopted for the enantioselective separation of amino acid in the circulation system. (S)-ARCA coated MMC support showed high selcetivity up to 90% for the separation of D-type phenylalanine, serine and tryptophan from racemic mixtures.


Subject(s)
Amino Acids/chemistry , Amino Acids/isolation & purification , Carbon/chemistry , Adsorption , Carbon Fiber , Porosity , Silicon Dioxide , Stereoisomerism
4.
Biomacromolecules ; 16(1): 246-56, 2015 Jan 12.
Article in English | MEDLINE | ID: mdl-25514368

ABSTRACT

Renewable thermoset elastomers were prepared using the plant-based monomer carvomenthide. Controlled ring-opening transesterification polymerization of carvomenthide using diethylene glycol as an initiator gave α,ω-dihydroxyl poly(carvomenthide) (HO-PCM-OH), which was subsequently converted to carboxy-telechelic poly(carvomenthide) (HOOC-PCM-COOH) by esterification with excess succinic anhydride through a one-pot, two-step process, leading to no crystallinity, high viscosity, strong thermal resistance, and low glass transition temperature of the resulting functionalized polyester. Thermal curing processes of the resulting 3, 6, and 12 kg mol(-1) prepolymers were achieved with trifunctional aziridine to give cross-linked PCM elastomers. The thermal properties, mechanical behavior, and biocompatibility of the rubbery thermoset products were investigated by differential scanning calorimetry, thermal gravimetric analysis, dynamic mechanical analysis, tensile tests under static and cyclic loads, and cell adherence. These new materials are useful candidates to satisfy the design objective for the engineering of a variety of soft tissues.


Subject(s)
Biocompatible Materials/chemical synthesis , Elastomers/chemical synthesis , Monoterpenes/chemistry , Plant Extracts/chemistry , Animals , Biocompatible Materials/chemistry , Calorimetry, Differential Scanning , Cyclohexane Monoterpenes , Elastomers/chemistry , Ethylene Glycols , In Vitro Techniques , Mice , NIH 3T3 Cells , Succinic Anhydrides , Transition Temperature
5.
J Nanosci Nanotechnol ; 13(6): 4106-9, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23862456

ABSTRACT

The main drawback of flocculation process with dye wastewater is the large amount of unrecyclable sludge which needs disposal. A novel process using Ti-salt flocculation to purify wastewater was developed to produced sludge that can be calcined to produce titania. In this study, iron-doped TiO2 nanomaterial was successfully produced from sludge obtained by the flocculation of dye wastewater with a composite floculant including TiCl4 and FeSO4. The titania was characterised using scanning electron microscopy (SEM/EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), and the photodecomposition of acetaldehyde. The XDR results showed that the anatase and rutile structures were found after sludge calcination at 550 degrees C and 640 degrees C respectively. The elemental analyses were carried out using EDX. The rutile titania sample consisted of Ti (35.7 wt.%), Fe (14.7 wt.%), O (42.3 wt.%), P (2.6 wt.%) and Ca (4.7 wt.%). The photocatalytic activity was monitored for the photodecomposition of gas acetaldehyde. Iron-doped titania seems to play an important role in increasing the photocatalytic activity under UV light irradiation.

6.
J Nanosci Nanotechnol ; 11(2): 1652-5, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21456259

ABSTRACT

Multiwalled carbon nanotubes (CNTs) were synthesized using Ni loaded mesoporous SBA-15 as a template by reaction of methane and carbon dioxide. The influences of nickel content on the selectivity and crystallinity of CNTs were investigated. It can be seen that the crooked CNTs with a diameter varied from 9.9, 12.5 to 36.5 nm with creasing content of Ni from 5, 15, and 30 wt%/SBA-15. A uniform diameter and good quality CNTs were obtained in our system.

7.
J Nanosci Nanotechnol ; 11(2): 1672-5, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21456264

ABSTRACT

A highly ordered CO3O4 and NiO porous crystals were synthesized using cage-containing SBA-16 silica as a template. The porous crystals were characterized by X-ray powder diffraction (XRD), transition electron microscopy (TEM), N2 adsorption/desorption isotherm and cyclic voltammograms (CV). The porous crystal has a high specific area (138.4 m2/g) and it has show much better electrical properties (CV) than bulk.

8.
J Nanosci Nanotechnol ; 10(5): 3260-5, 2010 May.
Article in English | MEDLINE | ID: mdl-20358935

ABSTRACT

Dye wastewater flocculation using TiCl4 and FeSO4 coagulants was studied for organic removal and precipitation efficiency. Moreover, TiCl4 was assessed in a pilot-scale flocculation process to investigate organic removal and solution pH effect. A large amount of TiO2 was produced from sludge of Ti-salt flocculation in dye wastewater. This flocculation process simultaneously reduces a large amount of sludge produced from wastewater. The TiO2 nanoparticle was characterized in terms of physical and chemical properties. Results showed that 77.6% of organic matter was removed from dye wastewater when using FeSO4 as coagulant, while TiCl4 degraded 75.9% of organic matter. On the other hand, floc precipitation efficiency was better for TiCl4 if compared with FeSO4. The optimum concentration of TiCl4 for pilot-scale flocculation was found to be equal to 2.1 g/L. DWT (Dye wastewater titania) size was 15-20 nm, mainly doped with carbon atoms and exhibited a dominant anatase structure. DWT was similar to P-25 in decomposing acetaldehyde under UV-irradiation and complete photocatalytic degradation was achieved after 140 min.


Subject(s)
Coloring Agents/isolation & purification , Industrial Waste/prevention & control , Nanostructures/chemistry , Titanium/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Water/chemistry , Adsorption , Chemical Fractionation/methods , Coloring Agents/chemistry , Materials Testing , Nanostructures/ultrastructure , Particle Size , Salts/chemistry , Water Pollutants, Chemical/chemistry
9.
Chem Commun (Camb) ; (28): 4296-8, 2009 Jul 28.
Article in English | MEDLINE | ID: mdl-19585052

ABSTRACT

New chiral cobalt(III) salen complexes immobilized via HO3S-linkers on ordered SBA-16 by electrostatic interactions showed very high activity in enantioselective ring-opening reactions of racemic epoxides.

10.
J Nanosci Nanotechnol ; 7(11): 3876-9, 2007 Nov.
Article in English | MEDLINE | ID: mdl-18047078

ABSTRACT

A route to synthesize porous materials with a bimodal macro/mesoscopic pore system has been investigated in this work. Polystyrene with sub-micrometer size was used as a template in the synthesis. The resulting mesoporous silica wall replicated inversely the morphology of polystyrene template and had highly ordered three-dimensional arrays of macro pores. Large and moldable meso/macro porous silica monoliths could be obtained in centimeter scale by using monodispersed polystyrene beads and MCM-41 sol solutions. These bimodal structured porous silicates have been used as supports for asymmetric kinetic resolution of racemic epoxides to synthesize optically pure epoxide.


Subject(s)
Colloids/chemistry , Crystallization/methods , Nanostructures/chemistry , Nanostructures/ultrastructure , Nanotechnology/methods , Silicon Dioxide/chemistry , Macromolecular Substances/chemistry , Materials Testing , Molecular Conformation , Particle Size , Phase Transition , Porosity , Surface Properties
11.
J Nanosci Nanotechnol ; 7(11): 3914-6, 2007 Nov.
Article in English | MEDLINE | ID: mdl-18047087

ABSTRACT

The nanostructured SnO2 gas sensor with Au electrodes and Pt heater has been fabricated as one unit via screen printing process. The gas sensor was tested for CH4 sensing behavior at 350 degrees C in the concentration range of 500-10,000 ppm. Those mesoporous SnO2 sensors exhibited the similar sensoring properties in CH4 and CO detection. The fast speed of response and high sensitivity were obtained for mesoporous tin oxide sensor as compared to non-porous one.


Subject(s)
Crystallization/methods , Electrochemistry/instrumentation , Methane/analysis , Nanostructures/chemistry , Nanotechnology/instrumentation , Tin Compounds/chemistry , Electrochemistry/methods , Equipment Design , Equipment Failure Analysis , Gases/analysis , Macromolecular Substances/chemistry , Materials Testing , Microelectrodes , Molecular Conformation , Nanostructures/ultrastructure , Nanotechnology/methods , Particle Size , Porosity , Surface Properties
SELECTION OF CITATIONS
SEARCH DETAIL
...