scholarly journals Oxidation of Sodium Deoxycholate Catalyzed by Gold Nanoparticles and Chiral Recognition Performances of Bile Salt Micelles

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4508
Author(s):  
Jing Wang ◽  
Xu Xu ◽  
Hao Chen ◽  
Shuai-Shuai Zhang ◽  
Yin-Xian Peng
Keyword(s):  
Oxidation Product ◽  
Mass Spectra ◽  
Uv Light ◽  
Sodium Deoxycholate ◽  
Chiral Discrimination ◽  
Alkaline Condition ◽  
Chiral Model ◽  
Mixed Solution ◽  
Gold Nps ◽  
The Difference

Au nanoparticles (NPs) were prepared by UV light irradiation of a mixed solution of HAuCl4 and sodium deoxycholate (NaDC) under alkaline condition, in which NaDC served as both reducing agent and capping agent. The reaction was monitored by circular dichroism (CD) spectra, and it was found that the formed gold NPs could catalyze the oxidation of NaDC. A CD signal at ~283 nm in the UV region was observed for the oxidation product of NaDC. The intensity of the CD signal of the oxidation product was enhanced gradually with the reaction time. Electrospray ionization (ESI) mass spectra and nuclear magnetic resonance (NMR) spectra were carried out to determine the chemical composition of the oxidation product, revealing that NaDC was selectively oxidized to sodium 3-keto-12-hydroxy-cholanate (3-KHC). The chiral discrimination abilities of the micelles of NaDC and its oxidation product, 3-KHC, were investigated by using chiral model molecules R,S-1,1′-Binaphthyl-2,2′-diyl hydrogenphosphate (R,S-BNDHP). Compared with NaDC, the micelles of 3-KHC displayed higher binding ability to the chiral model molecules. In addition, the difference in binding affinity of 3-KHC micelles towards R,S-isomer was observed, and S-isomer was shown to preferentially bind to the micelles.

Research on Some Novel Functional Azobenzene Derivatives with Alkyl Chains and Different Substituted Groups

2011 ◽  
Vol 474-476 ◽  
pp. 537-542
Author(s):  
Ti Feng Jiao ◽  
Xu Hui Li ◽  
Jing Xin Zhou ◽  
Yuan Yuan Xing ◽  
Jing Ren
Keyword(s):  
Alkyl Chain ◽  
Uv Light ◽  
Molecular Structures ◽  
Functional Material ◽  
Alkyl Chains ◽  
Temperature Ranges ◽  
The Difference ◽  
Structural Influence ◽  
Azobenzene Derivatives ◽  
Base Group

Two functional azobenzene derivatives with alkyl chains and different substituted groups have been synthesized and their photoisomerization have also been investigated. It has been found that depending on the alkyl chain and different substituted groups, the formed azobenzene derivatives showed different properties, indicating distinct regulation of molecular skeletons. UV and IR data confirmed commonly the characteristic absorption of alkyl chain and aromatic segments in molecular structures. Thermal analysis demonstrated that the structural influence of both compounds in different temperature ranges. The difference of thermal stability is mainly attributed to the formation of Schiff base group and different substituent groups in molecular structure. The photoisomerization of these compounds both in solution and in cast film can undergo trans-to-cis isomerization by UV light irradiation, depending on different substituted groups. The present results have demonstrated that the special properties of azobenzene derivatives can be effectively turned by modifying molecular structures of objective compounds with proper substituted groups, which show potential application in functional material field.

Comparison of Salt and Ester Formulations of Picloram

Weed Science ◽  
1970 ◽  
Vol 18 (4) ◽  
pp. 447-451 ◽  
Author(s):  
R. W. Bovey ◽  
M. L. Ketchersid ◽  
M. G. Merkle
Keyword(s):  
Potassium Salt ◽  
Uv Light ◽  
Diesel Oil ◽  
Acacia Farnesiana ◽  
Quercus Virginiana ◽  
Live Oak ◽  
Petri Dishes ◽  
The Difference ◽  
Extensive Degradation ◽  
Ulmus Alata

Under Texas conditions, the potassium salt of 4-amino-3,5,6-trichloropicolinic acid (picloram) usually was more effective than the isooctyl ester formulation for control of live oak (Quercus virginianaMill.), yaupon(Ilex vomitoriaAit.), winged elm(Ulmus alataMichx.), huisache (Acacia farnesiana(L.) Willd.), and honey mesquite(Prosopis juliflora(Swartz) DC. var.glandulosa(Torr.) Cockerell). Possible reasons for the difference in effectiveness of picloram formulations were studied in the laboratory. Extensive degradation of the ester of picloram (96%) occurred in open Petri dishes after 72 hr exposure to ultraviolet (uv) light, compared to a loss of 26% for the salt of picloram. Forty-five percent of the isooctyl ester of picloram was lost at high temperatures (60 C), whereas only 2% of the potassium salt of picloram was lost after 1 week at 60 C from open Petri dishes in a dark oven. Application of the ester to soils reduced thermal and ultraviolet light degradation losses compared to losses from open Petri dishes. Loss of the ester was greater when applied in diesel oil to Petri dishes than in either water or paraffin oil. The salt of picloram leached most after 12.5 cm simulated rainfall in soil columns to the 17.5 to 30-cm level (907 μg), followed by the acid (360 μg), and last the isooctyl ester (0 μg). However, considerable acid (161 μg) was recovered at the 32.5 to 45-cm depth from the isooctyl ester treatment exposed to wet soils for 3 days, indicating hydrolysis of the ester to acid.

Optical Property and Photoisomerization of Some Functional Azobenzene Derivatives with Aromatic Substituted Groups

2011 ◽  
Vol 121-126 ◽  
pp. 1009-1013
Author(s):  
Ti Feng Jiao ◽  
Xu Hui Li ◽  
Qiu Rong Li ◽  
Jing Xin Zhou
Keyword(s):  
Molecular Structure ◽  
Optical Property ◽  
Potential Application ◽  
Uv Light ◽  
Molecular Structures ◽  
Functional Material ◽  
Methyl Group ◽  
Uv Light Irradiation ◽  
The Difference ◽  
Azobenzene Derivatives

Some functional azobenzene derivatives with aromatic substituted groups have been synthesized and their photoisomerization have also been investigated. It has been found that depending on different substituted groups, such as phenyl or naphthyl segments, the formed azobenzene derivatives showed different properties, indicating distinct regulation of molecular skeletons. Spectral data confirmed commonly the characteristic absorption of substituted groups and aromatic segments in molecular structures. In addition, the photoisomerization of all compounds in solution can show trans-to-cis photoisomerization by UV light irradiation, and demonstrate distinct isomerization ratio depending on effect of different substituted headgroups. The difference is mainly attributed to the aromatic substituted headgroups and methyl group in molecular structure. The present results have showed that the special properties of azobenzene derivatives could be effectively turned by modifying molecular structures of objective compounds with proper substituted groups, which show potential application in sensor and functional material field.

PHOTOCATALYTIC ACTIVITY OF NITROGEN AND FLUORINE CO-DOPED TITANIUM DIOXIDE PREPARED USING OF VARIOUS PH SOLUTIONS

2010 ◽  
Vol 24 (15n16) ◽  
pp. 3242-3247 ◽  
Author(s):  
MASAHIRO KATOH ◽  
AKIHIRO IMAYAMA ◽  
NARISUKE MORI ◽  
TOSHIHIDE HORIKAWA ◽  
TAHEI TOMIDA
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Uv Light ◽  
Anatase Phase ◽  
Wave Length ◽  
Green Light ◽  
Light Irradiation ◽  
Mixed Solution ◽  
Co Doped

Introducing different atoms into TiO 2 crystal lattice is a famous method to improve photocatalytic activity of TiO 2 under visible-light irradiation. In this paper, Nitrogen ( N ) and fluorine ( F ) co -doped TiO 2 powders were prepared by mixing TiCl 3 solutions with ammonium fluoride ( NH 4 F ). In preparation, we used NH 3- H 2 O solution for adjustment of pH values (pH 2, 7, and 9) of mixed solution. X-ray diffraction (XRD) indicated N , F - TiO 2 powders prepared at pH7 and pH9 contained only anatase phase, but the powders prepared at pH2 contained both anatase and rutile phase. The result of XRD also indicated N , F - TiO 2 powders prepared at pH7 had the smallest crystallite size. We measured photocatalytic activity of prepared N , F - TiO 2 powders by the decomposition of methylene blue. N , F - TiO 2 powder prepared at pH7 and pH9 showed same high photocatalytic activity under ultraviolet light irradiation (peak wave length = 352 nm). Furthermore, under green light LED irradiation (wave length = 525 nm), a sample prepared at pH7 decomposed methylene blue more quickly than any other samples. As the result, N , F - TiO 2 prepared at pH7 had the best catalytic activity under both UV-light and visible light in the all of N , F - TiO 2 prepared and reference TiO 2 photocatalyst (ST-01 produced by Ishihara Co. Ltd).

Color Tunability of Blue Phosphors by Changing Cations for Near-UV InGaN-Based Light-Emitting Diode

2014 ◽  
Vol 986-987 ◽  
pp. 156-159
Author(s):  
Yi Wen Zhu ◽  
Fen Fen Hu ◽  
Mei Li Zhou ◽  
Ping Chen ◽  
Zheng Liang Wang
Keyword(s):  
Uv Light ◽  
Light Emitting Diode ◽  
Blue Emission ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Blue Shift ◽  
Ionic Radii ◽  
Light Emitting ◽  
Triclinic Structure ◽  
The Difference

The serials of blue phosphors, CaAl2Si2O8: Eu2+ doped with different content Sr2+ and Mg2+ ions, were prepared by solid-state reaction at high temperature. And their structure and photo-luminescent properties were investigated. In Ca0.96-ySryAl2Si2O8: 0.04Eu2+ (y = 0.10, 0.30, 0.50, 0.70, 0.90) system, for y ≦ 0.03, all the compositions crystallize in triclinic structure of CaAl2Si2O8, and on further increase of y, the system undergoes a compositionally induced phase transition from triclinic to monoclinic structure. For Ca0.96-yMgyAl2Si2O8: 0.04Eu2+ (y = 0.10, 0.30, 0.50, 0.70, 0.90) system, for z ≦ 0.03, all the compositions are of triclinic structure of CaAl2Si2O8. With the further increase of z, other phase appears. The emission spectra of these phosphors show blue shift with the introduction of Sr2+ ions, and red shift with Mg2+ ions. The reason may be due to the difference ionic radii of Mg2+, Ca2+, Sr2+. These phosphors show excellent blue emission and broad excitation band in near-UV (ultraviolet) range. They may be potential phosphors for near-UV light-emitting diodes (LEDs).

scholarly journals Manufacturing of Polymer-based 1×2 Y-branch Symmetric and Asymmetric Waveguide Coupler through Moulding Technique

2021 ◽  
Vol 18 (3) ◽  
pp. 8998-9005
Author(s):  
Mohd Shafiq Ghazali ◽  
Fadhlur Rahman Mohd Romlay ◽  
Abang Annuar Ehsan
Keyword(s):  
Soft Lithography ◽  
Uv Light ◽  
Optical Devices ◽  
Production Equipment ◽  
Cnc Machining ◽  
Replication Process ◽  
Waveguide Coupler ◽  
Optical Polymer ◽  
The Difference ◽  
Good Agreement

Manufacturing of Y-branch coupler depends on high technology production equipment and in-factory accuracy assembly tools. The manufacturing of a 1×2 Y-branch symmetric and asymmetric waveguide coupler based on the mould replication process and Epoxy OG142 as an optical core is presented; an alternative to provide a less complex technique. The polymer optical waveguide adopted two basic designs: the 1×2 Y-branch symmetric coupler as the core structure and the 1×2 asymmetric coupler that allows non-symmetric optical splitting. This paper focused on the main structure fabrication of the 1×2 symmetric and asymmetric waveguide coupler that produces a power output. The fabrication was done by engraving acrylic to produce a master mould using CNC machining tools for optical devices. Both 1×2 devices were made via soft lithography, which duplicated the pattern from the master mould onto a second mould to produce an actual device. Optical polymer epoxy OG142 was injected into the second mould, of which the product was then put on top of acrylic. The device was completed after curing the optical polymer glue, epoxy OG142, by exposing the assembly on the second mould under UV light until both parts bonded. The difference between the simulation and design TOFR value was only ±2%. This showed that the simulation and design are in good agreement, which provides similar performance.

scholarly journals Removal of Sulfamethoxazole, Sulfathiazole and Sulfamethazine in their Mixed Solution by UV/H2O2 Process

2019 ◽  
Vol 16 (10) ◽  
pp. 1797 ◽  
Author(s):  
Guangcan Zhu ◽  
Qi Sun ◽  
Chuya Wang ◽  
Zhonglian Yang ◽  
Qi Xue
Keyword(s):  
Uv Light ◽  
Degradation Pathway ◽  
Photochemical Oxidation ◽  
Order Kinetic ◽  
Mixed Solution ◽  
Initial Concentration ◽  
Aqueous Environments ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Acidic Conditions

Sulfamethoxazole (SMZ), sulfathiazole (STZ) and sulfamethazine (SMT) are typical sulfonamides, which are widespread in aqueous environments and have aroused great concern in recent years. In this study, the photochemical oxidation of SMZ, STZ and SMT in their mixed solution using UV/H2O2 process was innovatively investigated. The result showed that the sulfonamides could be completely decomposed in the UV/H2O2 system, and each contaminant in the co-existence system fitted the pseudo-first-order kinetic model. The removal of sulfonamides was influenced by the initial concentration of the mixed solution, the intensity of UV light irradiation, the dosage of H2O2 and the initial pH of the solution. The increase of UV light intensity and H2O2 dosage substantially enhanced the decomposition efficiency, while a higher initial concentration of mixed solution heavily suppressed the decomposition rate. The decomposition of SMZ and SMT during the UV/H2O2 process was favorable under neutral and acidic conditions. Moreover, the generated intermediates of SMZ, STZ and SMT during the UV/H2O2 process were identified in depth, and a corresponding degradation pathway was proposed.

NO2 gas sensing properties of bilayer graphene by CVD method

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hui Li ◽  
Zengwen Zhang ◽  
Ruiyang Fang ◽  
Zhihui Gao ◽  
Wei He
Keyword(s):  
Recovery Time ◽  
Gas Sensing ◽  
Uv Light ◽  
Bilayer Graphene ◽  
Monolayer Graphene ◽  
Content Type ◽  
Desorption Time ◽  
The Difference ◽  
Cu Foil ◽  
Difference Effect

Purpose The authors designed those experiments to test the sensitivity of graphene when it is exposed to NO2 gas, to find a way to decrease the recovery time of graphene and to find the difference effect between monolayer and bilayer graphene in the experiments. Design/methodology/approach The authors transferred graphene from film on Cu foil to NO2 sensor sample and measured the resistances of on monolayer and bilayer graphene when they were exposed to NO2 gas under different concentration; then, the authors obtained the results. Findings The results show that monolayer graphene exhibits a linear response when the NO2 concentration is below 20 ppm. But the monolayer graphene will not be so sensitive to NO2 gas when the concentration continues to reduce. The desorption time of monolayer graphene is longer when compared with bilayer graphene. It shows faster recovery time and higher response of bilayer graphene under low NO2 concentration. And the limit detectable NO2 concentration of bilayer graphene is 50 ppb. Desorption time of bilayer graphene is shortened to below 20 s under UV light. Originality/value The authors found a reliable way to decrease the recovery time of graphene when it is exposed NO2 gas and got the concrete data.

scholarly journals Influence of relative humidity on the heterogeneous oxidation of secondary organic aerosol

2018 ◽  
Vol 18 (19) ◽  
pp. 14585-14608 ◽  
Author(s):  
Ziyue Li ◽  
Katherine A. Smith ◽  
Christopher D. Cappa
Keyword(s):  
Relative Humidity ◽  
Mass Loss ◽  
Mass Spectra ◽  
Secondary Organic Aerosol ◽  
Complex Mixture ◽  
Organic Aerosol ◽  
Oh Radicals ◽  
Heterogeneous Oxidation ◽  
Substantial Impact ◽  
The Difference

Abstract. Secondary organic aerosol (SOA) is a complex mixture of hundreds of semi-volatile to extremely low-volatility organic compounds that are chemically processed in the atmosphere, including via heterogeneous oxidation by gas-phase radicals. Relative humidity (RH) has a substantial impact on particle phase, which can affect how SOA evolves in the atmosphere. In this study, SOA from dark α-pinene ozonolysis is heterogeneously aged by OH radicals in a flow tube at low and high RH. At high RH (RH =89 %) there is substantial loss of particle volume (∼60 %) at an equivalent atmospheric OH exposure of 3 weeks. In contrast, at low RH (RH =25 %) there is little mass loss (<20 %) at the same OH exposure. Mass spectra of the SOA particles were measured as a function of OH exposure using a vacuum ultraviolet aerosol mass spectrometer (VUV-AMS). The mass spectra observed at low RH overall exhibit minor changes with oxidation and negligible further changes above an OH exposure =2×1012 molecule cm−3 s suggesting limited impact of oxidation on the particle composition. In contrast, the mass spectra observed at high RH exhibit substantial and continuous changes as a function of OH exposure. Further, at high RH clusters of peaks in the mass spectra exhibit unique decay patterns, suggesting different responses of various species to oxidation. A model of heterogeneous oxidation has been developed to understand the origin of the difference in aging between the low- and high-RH experiments. Differences in diffusivity of the SOA between the low- and high-RH experiments alone can explain the difference in compositional change but cannot explain the difference in mass loss. Instead, the difference in mass loss is attributable to RH-dependent differences in the OH uptake coefficient and/or the net probability of fragmentation, with either or both larger at high RH compared to low RH. These results illustrate the important impact of relative humidity on the fate of SOA in the atmosphere.

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