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1.
Environ Technol ; 42(3): 479-491, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31219731

RESUMO

In this paper, the catalytic wet peroxide oxidation (CWPO) combined with vacuum ultraviolet (VUV) irradiation was developed to mineralize the wastewater with high concentration of unsymmetrical dimethylhydrazine (UDMH), especially to decompose the main byproduct of UDMH decomposition, N-nitrosodimethylamine (NDMA). CuO-NiO-MgO/γ-Al2O3 was used as the catalyst and H2O2 as the resources of ⋅ O H . Fourier Transform Infrared spectroscopy (FT-IR), X-ray Powder Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray spectroscopy (EDX) were employed to evaluate the structure of the catalyst. The treatment performances such as the UDMH degradation efficiency, chemical oxygen demand (COD) removal efficiency, and the concentration of N-nitrosodimethylamine (NDMA) were investigated in the treating process. The optimal conditions were obtained based on the results of single-factor experiments including parameters such as the initial UDMH concentration, catalyst dosage, initial pH, H2O2 dosage and temperature. The comprehensive results indicated that CWPO/H2O2/VUV process presented remarkable treatment performance to the reaction conditions with about 100% UDMH conversion efficiency, 95.02% COD removal efficiency and approximately 100% UDMH removal within 30 min.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Catálise , Dimetilidrazinas , Peróxido de Hidrogênio , Oxirredução , Peróxidos , Espectroscopia de Infravermelho com Transformada de Fourier , Vácuo
2.
ACS Appl Mater Interfaces ; 11(32): 29242-29254, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31319034

RESUMO

There is a constant drive to develop ultra-high-performance multifunctional coatings for existing construction used in modern engineering technologies. For these materials to be used in unsound infrastructure protections, they are required to present enhanced robustness while bearing functionalities to meet multiple uses. Single-function coating is not smart enough to provide satisfactory protection, and the preparation process of multifunctional materials is complex, costly, and provides poor durability. Thus, existing coatings are not suitable to generate an intelligent closed-loop protection system. Herein, we report an innovative 5S multifunctional intelligent coating (5SC) for existing construction materials with superdurable, superhydrophobic, self-monitoring, self-heating, and self-healing properties. The 5SC material showed highly durable superhydrophobic properties as revealed by the main failure tests of building materials including physical friction (abrasion, scratching), 100% tensile strain, photoaging (3000 h of ultraviolet (UV) aging), acid corrosion (concentrated hydrochloric acid and sulfuric acid), and freeze-thaw aging (salty solution). The coated surface was highly sensitive to pressure, with monitoring thresholds from 1 to 30 000 N per 0.01 m2. It showed an early heating rate as high as 6 °C/min while maintaining very good self-monitoring and ice-melting drainage performance to protect the existing structures. This novel composite material is suitable for constructions in extreme areas where corrosion and freeze-thaw damage can occur. This multifunctional material presents a very broad range of applications and development potential in the construction field.

3.
Anal Sci ; 31(10): 1027-33, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26460367

RESUMO

A novel biosensor was developed by immobilizing hemoglobin (Hb) on a glassy carbon electrode (GCE) modified with a composite of ZnO nano-rods and carbon nanofiber (CNF), a strong reducer, hydrazine, was firstly used to evaluate the electrochemical behavior of Hb on Hb/ZnO/CNF/GCE. UV-vis and circular dichroism (CD) spectra indicated the conformational structure of Hb interaction with ZnO/CNF was predominantly an α-helical structure. The modified electrodes were characterized by scanning electron microscopy (SEM), electron impedance spectroscopy (EIS), and cyclic voltammetry. Electrocatalytic mechanism of Hb to oxidation reaction of hydrazine was suggested. The bioelectrocatalytic activity, kinetic parameters of Michaelis-Menten constant (Km), stability and reproducibility were also investigated. A linear dependence of peak currents to the concentrations of hydrazine was observed in the range from 1.98 × 10(-5) to 1.71 × 10(-3) mol L(-1) with a correlation coefficient of 0.998, and a detection limit (S/N = 3) of 6.60 µmol L(-1) was estimated.


Assuntos
Técnicas Biossensoriais/métodos , Carbono/química , Hemoglobinas/química , Hidrazinas/análise , Nanofibras/química , Nanotubos/química , Óxido de Zinco/química , Biocatálise , Eletroquímica , Eletrodos , Hemoglobinas/metabolismo , Hidrazinas/química , Proteínas Imobilizadas/química , Proteínas Imobilizadas/metabolismo , Oxirredução , Propriedades de Superfície
4.
ACS Appl Mater Interfaces ; 3(9): 3300-7, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21812487

RESUMO

Microfloccules of TiO(2) nanoparticles, on which glycerol-dehydrogenase (GDH), 1,3-propanediol-oxidoreductase (PDOR), and glycerol-dehydratase (GDHt) were coimmobilized, were prepared by adsorption-flocculation with polyacrylamide (PAM). The catalytic activity of immobilized enzyme in the glycerol redox reaction system, the enzyme leakage, stabilities of pH and temperature, as well as catalytic kinetics of immobilized enzymes relative to the free enzymes were evaluated. Enzyme loading on the microfloccules as much as 104.1 mg/g TiO(2) (>90% loading efficiency) was obtained under the optimal conditions. PAM played a key role for the formation of microfloccules with relatively homogeneous distribution of size and reducing the enzyme leakage from the microfloccules during the catalysis reaction. The stabilities of GDH against pH and temperature was significantly higher than that those of free GDH. Kinetic study demonstrated that simultaneous NAD(H) regeneration was feasible in glycerol redox system catalysted by these multienzyme microfloccules and the yield of 1, 3-popanediol (1, 3-PD) was up to 11.62 g/L. These results indicated that the porous and easy-separation microfloccules of TiO(2) nanoparticles with immobilized multienzymes were efficient in term of catalytic activity as much as the free enzymes. Moreover, compared with free enzyme, the immobilized multienzymes system exhibited the broader pH, higher temperature stability.


Assuntos
Enzimas Imobilizadas/metabolismo , Nanopartículas Metálicas/química , Titânio/química , Resinas Acrílicas/química , Adsorção , Álcool Desidrogenase/química , Álcool Desidrogenase/metabolismo , Enzimas Imobilizadas/química , Hidroliases/química , Hidroliases/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Oxirredução , Desidrogenase do Álcool de Açúcar/química , Desidrogenase do Álcool de Açúcar/metabolismo , Temperatura
5.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 2): o322, 2011 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-21523008

RESUMO

In the title compound, C(21)H(23)NO, obtained via a one-pot synthesis, an intra-molecular O-H⋯N hydrogen bond stabilizes the mol-ecular conformation. The dihedral angle between the fused ring system and the phenyl ring is 78.27 (5)°. The crystal packing is characterized by helical chains of mol-ecules linked by C-H⋯O hydrogen bonds.

6.
Inhal Toxicol ; 19 Suppl 1: 251-4, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17886074

RESUMO

It has been proven that administration by inhalation is one of the alternative and effective approaches to dose biomedicines such as insulin for diabetics. Here, we introduce a new approach to fabricate the inhaler, posing the merits of not using volatile solvent, having selectable size of drug particles, and being simple and low cost compared with conventional devices. Creatine particles were prepared by spray-drying, and simultaneously a nanofiber mat of crosslinked poly(vinyl pyrrolidone) (PVP) was used to collect the graduated creatine nanoparticles. The scanning electron microscopy (SEM) photos indicated that the nanoparticles were individually dispersed without any agglomerate on the PVP nanofibers and released after the nitrogen gas flow (10 L/min) passed through the PVP nanofiber mat. This approach is unique and universal for nonagglomerate dispersing of nanoparticles and releasing without using any dispersing solvent.


Assuntos
Desenho de Equipamento/instrumentação , Nanopartículas/administração & dosagem , Nebulizadores e Vaporizadores , Administração por Inalação , Desenho de Equipamento/métodos , Nanopartículas/química
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