Papers by Keyword: P123

Abstract: In this paper, a series of mesoporous TiO₂ photocatalyst were prepared by hydrothermal method using block copolymer P123 as template and Ti (OBu)₄ as titanium source. The microstructure and spectroscopy performance of the prepared TiO₂ were characterized by means of XRD, SEM, TEM, BET, and BJH analysis, and the photocatalytic activity of mesoporous TiO₂ were examined by measuring the photodegradation of methyl orange , then discussed the best prepared conditions of mesoporous TiO₂ photocatalyst. The results showed that the products were all anatase mesoporous TiO₂ nanopowder, the average particle size is about 7nm and all have the Langmuir type IV pore structure. The best prepared condition: hydrothermal temperature is 160°C, hydrothermal time is 24h, mesoporous TiO₂ photocatalyst has the BET surface area of 146m²/g , it’s photocatalytic degradation rate is 97.07% in an hour.

Abstract: This paper presents the preparation of bimodal crystalline macro-/mesoporous titania powders by using a pluronic polymer (EO20PO70EO20, P123) as a template through a hydrothermal treatment. The as-prepared powders were characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption, scanning electron microscope (SEM) and transmission electron microscope (TEM). The results reveal that the amount of P123 has a significant effect on the surface area of the mesoporous titania. When the mass ratio of P123:TBOT is 1:14, the crystalline macro-/mesoporous titania has the largest surface area (120.96 m2/g), the average pore diameter of this sample reaches a minimum of 6.67 nm.

Abstract: NiO-doped Al₂O₃ was synthesized with 20 wt% of nickel nitrate using the sol-gel process. P123 as an organic additive added to increase surface area of powder. The phase transformation, thermal evolution and surface morphology of the powder were characterized by XRD, TG-DTA and FE-SEM. The 20 wt% NiO-doped Al₂O₃ /10 wt% Ni composite membrane was prepared by hot press sintering (HPS) following with a mechanical alloying process. Hydrogen permeation flux for 20 wt% NiO-doped Al₂O₃ /10 wt% Ni membrane was obtained as 0.1 mol/m² s at 673K.

Abstract: Phase behavior of ternary systems involving PEO-PPO-PEO block copolymer (Pluronic P123), room-temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [Bmim]PF6, and glycerol is investigated at 25 °C by using small-angle X-ray scattering (SAXS) techniques. In this ternary system, the structures formed in the binary P123/[Bmim]PF6 system, hexagonal phase (H1) and lamellar phase (Lα), are still obtained. At lower P123/[Bmim]PF6 ratio, the H1 phase can accommodate more than 30 % glycerol. At higher P123/[Bmim]PF6 ratio, the Lα phase only accommodates less than 2 % glycerol and Lα changes to H1 with increasing the glycerol content. Moreover, a phase separation takes place at a higher glycerol content. Solvatophobic interactions between hydrophobic groups of [Bmim]PF6 and P123, coulombic force existing in the polyoxyethylene chain and imidazolium cation, H-bond between P123 and glycerol, accompanying with the force ascribe to the nitrogen of the imidazole ring and the oxygen of alcohol are helpful for the formation of long-range ordered structure.

Abstract: Polyvinglpyrrolidone (PVP), cetyltrimethylammonium bromide (CTAB), and poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (P123) were used as templates, respectively. The morphology, structure and luminescent properties of the products were characterized and studied. The results show that all the products are pure LaPO4 with hexagonal structure. Comparing with the morphologies of LaPO4:Eu3+ nanocrystals prepared with PVP and CTAB as templates, the LaPO4:Eu3+ nanocrystals with P123 as template present regular spherical structure. The sizes of all products are in the range of 50–120 nm. When ultrasonic time was 2 h, the tendency, intensity and stability of fluorescent irradiation is obviously difference with different templates. In addition, the luminescent intensity of the LaPO4:Eu3+ nanocrystals using PVP as template is the strongest and using P123 as template is the weakest. All above results indicate that the template kinds have played an important role in the morphology and luminescent properties of the LaPO4:Eu3+ nanocrystals.

Abstract: Cuprous oxide and related materials in nanosizes are of much interest and investigated extensively recently. It is reported here that cubic Cu2O nanocubes were synthesized successfully in aqueous solutions at room temperature in air condition. Copper (II) salts in water were reduced with ascorbate acid in air, using the nonionic pluronic amphiphilic triblock copolymer EO20PO70EO20 (P123) as the template-directing and protecting agent. The average edge length of the cubes varied from 50 to 100 nm. Transmission electron microscopy (TEM) has been used for the shape and structural characterization of the obtained Cu2O nanocubes. The UV-Vis spectra showed an obvious blue-shift (0.53 eV), compared to the band gap of the bulk Cu2O crystal, which makes it a promising candidate in solar energy conversion since this sample can make use of higher energy visible rays of solar spectrum. In the FT-IR spectra the peak of Cu-O bond for the Cu2O is clearly distinguished and several weak peaks of the C-H, C-C and C=O bonds for the organic species can also be detectable, implying a little P123 residua in the products. The effect of the triblock copolymer P123 on the growth of the Cu2O nanocubes is discussed.