Synthesis of graphitic carbon nitride-based nanocomposites and their mechanical properties in epoxy compositions.

Thermoset epoxy resins are widely used in research and commercial applications. Zeolite imidazole framework-8 (ZIF-8), graphitic carbon nitride (GCN, g-C3N4), and S-doped graphitic carbon nitride (SCN, S-g-C3N4) composites were synthesized as accelerators and their effects on the physical properties of epoxies were examined. An ultrasound-assisted method was used to prepare ZIF-8/GCN and ZIF-8/SCN nanocomposites while g-C3N4 and S-g-C3N4 were prepared from the calcination of melamine and thiourea, respectively. The surface morphology, and particle size were characterized by scanning electron microscopy, and X-ray diffraction. The properties of synthesized nanocomposites were measured using Fourier-transform infrared spectroscopy. After the accelerator was added to the epoxy composites, their activation energies were calculated using differential scanning calorimetry. The tensile strength and flexural strength were measured using a universal testing machine and impact strength was measured by using an Izod impact strength tester. The impact strength of ZIF-8/SCN nanocomposites was enhanced by 45.2%. The storage stability of the epoxy compositions with different catalysts was evaluated by measuring the variation of viscosity with time at a constant temperature.

Synthesis of Waterborne Polyurethane Using Phosphorus-Modified Rigid Polyol and its Physical Properties.

In this study, a phosphorous-containing polyol (P-polyol) was synthesized and reacted with isophorone diisocyanate (IPDI) to produce water-dispersed polyurethane. To synthesize waterborne polyurethanes (WPUs), mixtures of P-polyol and polycarbonate diol (PCD) were reacted with IPDI, followed by the addition of dimethylol propionic acid, to confer hydrophilicity to the produced polyurethane. An excess amount of water was used to disperse polyurethane in water, and the terminal isocyanate groups of the resulting WPUs were capped with ethylene diamine. P-polyol:PCD molar ratios of 0.1:0.9, 0.2:0.8, and 0.3:0.7 were used to synthesize WPUs. The films prepared by casting and drying the synthesized WPUs in plastic Petri dishes were used to test the changes in physical properties induced by changing the P-polyol:PCD molar ratio. The experimental results revealed that the tensile strength of PU-10, the WPU with a P-polyol:PCD molar ratio of 0.1:0.9, was 16% higher than that of the reference P-polyol-free WPU sample. Moreover, the thermal decomposition temperature of PU-10 was 27 °C higher than that of the reference sample.

Preparation of C60 Nanowhiskers-SnO2 Nanocomposites and Photocatalytic Degradation of Organic Dyes.

C60 nanowhiskers were prepared using a liquid-liquid interfacial precipitation (LLIP) method. Tin oxide (SnO2) nanoparticles were synthesized by a reaction of tin (IV) chloride pentahydrate with ammonium nitrate in an electric furnace. The C60 nanowhiskers-SnO2 nanocomposites were calcined in an electric furnace at 700 °C under an inert argon gas atmosphere for 2 h. The crystallinity, morphology and optical properties of the samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and UV-vis spectrophotometry. The photocatalytic activity of the C60 nanowhiskers-SnO2 nanocomposites in the degradation of the organic dyes, such as methylene blue, methyl orange, rhodamine B, and brilliant green, under ultraviolet light at 254 nm by UV-vis spectrophotometry was evaluated and compared with that of C60 nanowhiskers and SnO2 nanoparticles. The experimental results showed that C60 nanowhiskers-SnO2 nanocomposites exhibited remarkably higher photocatalytic degradation of organic dyes compared to C60 nanowhiskers and SnO2 nanoparticles.

Preparation of ZnS-graphene nanocomposites under electric furnace and photocatalytic degradation of organic dyes.

Zinc sulfide (ZnS) nanoparticles were synthesized from zinc nitrate hexahydrate and thiourea under microwave irradiation. The ZnS-graphene nanocomposites were calcined in an electric furnace at 700 degrees C under an inert argon gas atmosphere for 2 hr. The heated ZnS-graphene nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and UV-vis spectrophotometry. After heat treatment, ZnS-graphene nanocomposites had a more porous and larger surface area, than the unheated ZnS-graphene nanocomposites. The photocatalytic activity of the heated ZnS-graphene nanocomposites in the degradation of organic dyes, such as methylene blue, methyl orange, and rhodamine B, under ultraviolet light at 254 nm by UV- vis spectrophotometer was evaluated and compared with that of the unheated ZnS nanoparticles, heated ZnS nanoparticles, unheated ZnS-graphene nanocomposites. Among the our experimental results as a photocatalyst, the heated ZnS-graphene nanocomposites exhibited remarkably higher photocatalytic degradation of organic dyes as compared to other nanomaterials such as unheated ZnS nanoparticles and heated ZnS-graphene nanocomposites.

Preparation of graphene-ZrO2 nanocomposites by heat treatment and photocatalytic degradation of organic dyes.

ZrO2 nanoparticles were synthesized by combining a solution containing zinconyl chloride in distilled water with a NH4OH solution under microwave irradiation. Graphene and ZrO2 nanocomposites were synthesized in an electric furnace at 700 degrees C for 2 hours. The heated graphene-ZrO2 nanocomposites were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. In addition, UV-vis spectrophotometry was used to evaluate the heated graphene-ZrO2 nanocomposites as a catalyst in the photocatalytic degradation of organic dyes. The photocatalytic effect of the heated graphene-ZrO2 nanocomposites was compared with that of unheated graphene nanoparticles, heated graphene nanoparticles, and unheated graphene-ZrO2 nanocomposites in organic dyes (methylene blue, methyl orange, and rhodamine B) under ultraviolet light at 254 nm.

Preparation of C60(O)n-ZnO nanocomposite under electric furnace and photocatalytic degradation of organic dyes.

Zinc oxide (ZnO) nanoparticles were synthesized sonochemically by applying ultrasonic irradiation to a mixed aqueous-alcoholic solution of zinc nitrate with sodium hydroxide at room temperature. The morphology and optical properties of the ZnO nanoparticles were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-vis spectroscopy. The C60(O)n nanoparticles were synthesized by heating a mixture of C60 and 3-chloroperoxybenzoic acid in a benzene solvent under the reflux system. The heated C60(O)n-ZnO nanocomposite was synthesized in an electric furnace at 700 degrees C for two hours. The heated C60(O)n-ZnO nanocomposite was characterized by XRD, SEM, and TEM, and examined as a catalyst in the photocatalytic degradation of organic dyes by UV-vis spectroscopy. The photocatalytic effect of the heated C60(O)n-ZnO nanocomposite was evaluated by a comparison with that of unheated C60(O)n nanoparticles, heated C60(O)n nanoparticles, and unheated C60(O)n-ZnO in organic dyes, such as methylene blue (MB), methyl orange (MO), and rhodamine B (RhB) under ultraviolet light at 365 nm.

Synthesis of [60]fullerene-ZnO nanocomposite under electric furnace and photocatalytic degradation of organic dyes.

Zinc oxide (ZnO) nanoparticles were synthesized by a reaction between an aqueous-alcoholic solution of zinc nitrate and sodium hydroxide under ultrasonic irradiation at room temperature. The morphology, optical properties of the ZnO nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-vis spectroscopy. The [60]fullerene and zinc oxide nanocomposite were synthesized in an electric furnace at 700 degrees C for two hours. The [60]fullerene-ZnO nanocomposite was characterized by XRD, SEM and TEM. In addition, the [60]fullerene-ZnO nanocomposite was investigated as a catalyst in the photocatalytic degradation of organic dyes using UV-vis spectroscopy. The photocatalytic activity of the [60]fullerene-ZnO nanocomposite was compared with that of ZnO nanoparticles, heated ZnO nanoparticles after synthesis, pure [60]fullerene, and heated pure [60]fullerene in organic dyes such as methylene blue (MB), methyl orange (MO), and rhodamine B (RhB) under ultraviolet light at 254 nm.

Preparation of self-assembled zinc oxide nanoparticles multilayer films under ultrasonic irradiation.

Zinc oxide nanoparticles were synthesized and self-assembled on the reactive surface of a glass slide functionalized with (3-mercaptopropyl)-trimethoxysilane under ultrasonic irradiation. The structure, morphology, and optical property of the zinc oxide nanoparticles were investigated by TEM, XRD, and UV-vis spectroscopy. The functionalized glass slide was soaked in an aqueous solution which dispersed zinc oxide nanoparticles under ultrasonic irradiation. Zinc oxide multilayer films grew up to several layers (up to 5 layers) depending on the immersion time. The self-assembled zinc oxide nanoparticles multilayer films were characterized using UV-vis spectroscopy and SEM. Ultrasonic irradiation was an efficient method to make multilayer films on the functionalized glass slide with zinc oxide nanoparticles.

Synthesis of gold nanoparticles using pluronic F127NF under microwave irradiation and catalytic effects.

This study examined the synthesis of gold nanoparticles with pluronic F127NF and KAuCl4 in water under non-classical conditions. The gold nanoparticle products were well dispersed in water and characterized by ultraviolet-visible spectroscopy and transmission electron microscopy. The reaction time for the synthesis was investigated by monitoring the change in color and the peak of the UV-vis spectra under microwave conditions. The gold nanoparticles were used as a catalyst for the reduction of 4-nitrophenol to 4-aminophenol with NaBH4. The resulting product was confirmed by UV-vis spectroscopy and liquid chromatography-mass spectroscopy.

Sonochemical reaction of fullerene[C60] with several 2'-azidoethyl per-O-acetyl glycosides.

Cycloadditive reaction of fullerene[C60] with various 2'-azidoethyl per-O-acetyl glycopyranoside of D-mannose, D-galactose, D-glucose, D-xylose and D-maltose, respectively gave the glycosyl fullerene[C60] derivatives 2a-2e such as alpha-D-mannosyl fullerene[C60] under ultrasonication. Based on analyses using 1H- and 13C-NMR, UV-vis, FT-IR, and FAB-MS spectroscopies of the glycosyl fullerene[C60] derivatives, the products were composed of a mixture of [5,6]- and [6,6]-junction isomers which were predominantly the closed [5,6]-junction isomer.

Ultrasonic, chemical stability and preparation of self-assembled fullerene[C60]-gold nanoparticle films.

C(60)-functionalized gold nanoparticle films were self-assembled on the reactive surface of glass slides functionalized with 3-aminopropyltrimethoxysilane. The functionalized glass slides were alternately soaked in the solutions containing unmodified C(60) and 4-aminothiophenoxide/hexane thiolate-protected gold nanoparticles. Organic reaction (amination) facilitated the layer-by-layer multilayer film assembly. C(60)-functionalized gold nanoparticle films have grown up to several layers (upto 5 layers were examined) depending on the immersion time. The assembled nanoparticle films were characterized using UV-vis spectroscopy. The chemical stability of C(60)-gold nanoparticle films was studied by monitoring the changes in absorbance after the immersion of the films in acidic solutions. The ultrasonic stability of these nanoparticle films was studied by exposing them to ultrasonic irradiated surrounding, which results in the aggregation of nanoparticles on solid surfaces.

Preparation of a water-soluble fullerene [C70] under ultrasonic irradiation.

A water-soluble fullerene [C(70)] is prepared with fullerene [C(70)] and a mixture of concd. sulfuric acid (H(2)SO(4)) and concd. nitric acid (HNO(3)) at the ratio (v/v) of 3:1 under ultrasonic irradiation at 25-43 degrees C. The MALDI-TOF-MS spectra confirmed that the product of a water-soluble fullerene compound was C(70).

The oxidation of fullerene[C60] with various amine N-oxides under ultrasonic irradiation.

The reaction of C60 with various amine N-oxides such as 3-picoline N-oxide (Aldrich 98.0%), pyridine N-oxide hydrate (Aldrich 95.0%), quinoline N-oxide (Aldrich 97.0%), isoquinoline N-oxide (Aldrich 98.0%) under ultrasonic irradiation in air at 25-43 degrees C causes the oxidation of fullerene[C60(O)n] (n=1-2 or n=1). The MALDI-TOF MS, UV-vis spectra, and HPLC profile confirmed that the products of fullerene oxidation are [C60(O)n] (n=1-2 or n=1).

Synthesis of a water-soluble fullerene [C60] under ultrasonication.

A water-soluble fullerene [C60] is prepared with fullerene [C60] and a mixture of strong inorganic acids at the ratio (v/v) of 3:1 under ultrasonic condition at 25-43 degrees C. The MALDI-TOF MS and 13C-NMR spectra confirmed that the product of a water-soluble fullerene compound was C60.

The oxidation of fullerene [C70] with various oxidants by ultrasonication.

The reaction of C70 by ultrasonication with various oxidants such as 3-chloroperoxy benzoic acid (Fluka 99%), 4-methyl morpholine N-oxide (Aldrich 97%), chromium (VI) oxide (Aldrich 99.9%), and oxone monopersulfate compound, at room temperature causes the oxidation of fullerene [C70(O)n] (n = 1-2 or n = 1). The FAB-MS, UV-visible, FT-IR spectra, and HPLC analysis confirmed that products of fullerene oxidation are [C70(O)n] (n = 1-2 or n = 1).