RESUMO
Recyclable, non-toxic, and degradable biological substrates contribute significantly to super-wetting surfaces. In this work, we prepared magnetic micro-nano super-hydrophobic surfaces through a robust solution with magnetic modified lignin particles as the supporting structure. A novel PDMS (polydimethylsiloxane)/magnetic lignin particle (lignin@Fe3O4)/PDA sponge composite was fabricated. Through dopamine (DA) self-polymerization, covalent deposition of magnetic lignin (ML), and PDMS silane modification, the magnetic super-hydrophobic polyurethane sponge composite (Sponge-P) was synthesized so that the Fe3O4 nanoscale microspheres wrapped with microscale lignin magnetic particles adhered to the sponge surface tighter and were barely dislodged. The as-prepared Sponge-P displayed excellent flexibility and a water contact angle of up to 152.2°. The super-hydrophobic sponge prepared with the proposed method was acid-base stable (pH = 2-12), self-cleaning, and suitable for high-salinity seawater. The magnetic super-hydrophobic sponge has good oil-water separation ability and can absorb 43 times its own weight of oil. In the meantime, due to the introduction of magnetic materials into lignin, we not only constructed micro-nanostructures to improve the surface super-hydrophobicity, but also made Sponge-P have the function of magnetic recovery, which has a unique advantage in treating oily wastewater.
Assuntos
Bandagens , Lignina , Fenômenos Físicos , Dopamina , Fenômenos MagnéticosRESUMO
Designing interfacial coating with tailored characteristics is a crucial step in regulating the wetting properties of oil/water separation materials; however, the controllable fabrication of multifunctional layer with long-term durability in harsh environments remains challenging. Fabrication of raised dots based on magnetic Fe3O4 particles on micro-nanometer units, inspired by mussel chemistry, under the adhesion behavior of dopamine (DA) self-polymerization covalent deposition of Fe3O4 particles and hydrophobic polydimethylsiloxane (PDMS) modification to synthesize magnetic superhydrophobic cotton composites (Cotton-P). Due to the unique magnetic and superhydrophobic surface composition, the synthetic Cotton-P possesses superhydrophobic (155.4°) and magnetic properties and still exhibits these excellent properties after 10 cycles. In addition, the hydrophobicity of magnetic monolithic cotton is virtually unaffected in harsh environments. The chemical/thermal stability of the Cotton-P composite is improved due to the rigid silane coating on the skeleton. Moreover, the Cotton-P revealed excellent oil/water separation efficiency of over 98 % after 10 cycles. Based on these outstanding properties, Cotton-P has the potential to develop in the treatment of oil-water mixtures.
Assuntos
Silanos , Purificação da Água , Dimetilpolisiloxanos , Dopamina , Interações Hidrofóbicas e Hidrofílicas , Óleos/químicaRESUMO
Here, we have developed a novel bilayer hollow amphiphilic biosorbent (BHAB-3) with large adsorption capacity, rapid adsorption kinetics, and cost-effective for the removal of Cr(VI) and Cu(II) from aqueous solutions. The synthesis was based on the clever use of freeze-drying to fix the structure, secondary modification of the carboxymethyl cellulose microspheres with polyethyleneimine and cross-linking by glutaraldehyde. The consequences of pH, initial concentration, contact time and temperature on adsorption were investigated. The Langmuir model fits showed that the maximum adsorption capacities of the two target heavy metal ions reached 835.91 and 294.79 mg/g, respectively. Moreover, BHAB-3 was characterized by SEM, FT-IR, TGA, and XPS synergistically, showing that it exhibits a strong complexation ability for Cu(II) and a strong electrostatic effect for Cr(VI). Adsorption and desorption experiments showed only a slight decrease in the adsorption capacity of the BHAB-3 for Cr(VI) and Cu(II) ions after 5 and 26 cycles, respectively. Given the excellent properties of this adsorbent, it is a promising candidate for heavy metal ion removal.
Assuntos
Poluentes Químicos da Água , Cátions , Cromo , Concentração de Íons de Hidrogênio , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
A separable spherical bio-adsorbent (CMC-Cr) was prepared for capturing heavy metal ions by simple coordination and cross-linking between targeted ions of Cr3+ and carboxymethyl cellulose (CMC). A simple alternation of the CMC incorporation allowed the interconnected networks within the microspheres of preformed solid CMC to be adjusted. The excellent network structure could achieve the maximum collision between the adsorbent and the heavy metal cations in the wastewater. Through investigations, CMC-Cr-2 beads were determined as the optimal adsorbent. The adsorption performance of novel materials was evaluated by examining their adsorption behavior on Pb(II) and Co(II) under both static and dynamic conditions. The results showed that the adsorption behavior of CMC-Cr-2 beads on both two heavy metal cations could be fully reflected by the Freundlich model. Under the theoretical conditions, the maximum adsorption capacities were 97.26 and 144.74 mg/g. The kinetic results for the adsorption of two heavy metal cations on CMC-Cr-2 beads were consistent with the Pseudo-second-order kinetic model. Moreover, the correlation coefficient of the Thomas model was significant in the dynamic adsorption performance tests. Five regeneration cycle studies were successfully carried out on CMC-Cr-2 beads to evaluate reusability and stability. The applicability of CMC-Cr-2 beads in authentic aqueous solutions (both the single and binary pollutant systems) was also studied, and the results indicated that CMC-Cr-2 beads had a high potential for practical implementation. Furthermore, by analyzing the surface interactions of two heavy metal cations with the CMC-Cr-2 beads based on FTIR and XPS characterization, a basic understanding of the interaction between bio-sorbents and pollutants in wastewater can be obtained.
Assuntos
Metais Pesados , Poluentes Químicos da Água , Adsorção , Carboximetilcelulose Sódica/química , Cátions , Concentração de Íons de Hidrogênio , Íons , Cinética , Águas ResiduáriasRESUMO
Superior mechanical properties, high adsorption capacity, and excellent regeneration property are crucial design criterions to develop a new-type aerogel for adsorptive applications towards heavy metal removal from water. Herein, chitosan and melamine not only introduced abundant functional groups to increase adsorbing sites for lead ions, but also reinforced the three-dimensional network skeleton structure of absorbents to improve the service life in adsorption applications. As-fabricated alginate/melamine/chitosan aerogel can extract Pb (II) from aqueous solution efficiently, i.e., the optimum adsorption quantity of 1331.6 mg/g at pH 5.5, which exhibited excellent and selective adsorption capacity for Pb (II) against the competition of coexisting divalent metal ions. More importantly, alginate/melamine/chitosan aerogel could be regenerated using dilute acidic solution and recovered well after eight adsorption-desorption cycles. This work might offer a new idea for design and preparation of biomass-based aerogel sorbents with promising prospect in the remediation of Pb (II)-contaminated wastewater.
Assuntos
Alginatos/química , Quitosana/química , Íons , Chumbo/química , Triazinas/química , Adsorção , Materiais Biocompatíveis/química , Biomassa , Géis , Concentração de Íons de Hidrogênio , Cinética , Metais , Metais Pesados , Sódio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Estresse Mecânico , Temperatura , Águas Residuárias/química , Poluentes Químicos da Água/química , Purificação da ÁguaRESUMO
Novel millimeter hollow microspheres were fabricated from carboxymethyl cellulose microspheres and polyethyleneimine using glutaraldehyde as a crosslinking agent. The hollow microspheres prepared with different polyethyleneimine usages and different polyethyleneimine treatment time were investigated deeply and characterized via SEM-EDX, FT-IR, and BET surface area analysis. It was shown that polyethyleneimine could break the coordination bonds between the carboxyl and Al (III) in carboxymethyl cellulose microspheres, leading to the formation of hollow structures. Most importantly, the usage and treatment time of polyethyleneimine can distinctly tailor the structure of the carboxymethyl cellulose microspheres, resulting in the formation of different hollow microspheres with varied shell thickness and size. Most importantly, we found that the prepared hollow microspheres have excellent adsorption performance toward targeted methyl blue under testing conditions. By virtue of the large accessible amount of -NH2 groups and its unique hollow structure, this type of millimeter hollow microspheres have broad application prospects in the treatment of emerging contaminants in wastewater.
Assuntos
Carboximetilcelulose Sódica/química , Corantes/isolamento & purificação , Microesferas , Adsorção , Cinética , Nitrogênio/química , Polietilenoimina/química , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , TemperaturaRESUMO
Noble metal-based catalytic material with maximum utilization is of prime attraction for conserving rare metal resources. Herein, highly dispersion Ni nanoparticles (NPs)-modified N-doped mesoporous carbon material (Ni-N@C) was fabricated by pyrolysis of Ni2+/Histidine cross-linked alginate hydrogels. In a step forward, the obtained Ni-N@C nanocatalyst was treated by the solution of Pd2+, and tiny amount of Pd NPs were deposited on the surface of Ni via the reducibility of Ni to achieve the high dispersion of precious metals material. In the degradation of highly-concentration p-nitrophenol, the catalyst presents excellent performance which could completely degrade pollutants within a very short period. It was demonstrated that pre-embedded Ni NPs could not only increase the efficiency of Pd NPs but also endow the facile separation characteristic to the catalyst. Besides, the catalyst maintained favorable catalytic capacity even after five reaction cycles. In brief, this work may provide novel guidance for the maximum utilization of noble metal-modified mesoporous N-doped carbon-supported catalysts in practical applications of industrial and the treatment highly-concentration p-nitrophenol.
Assuntos
Nanopartículas Metálicas/química , Níquel/química , Nitrofenóis/química , Paládio/química , Poluentes Químicos da Água/química , Alginatos/química , Carbono/química , Catálise , Cátions Bivalentes , Humanos , Hidrogéis/química , Nanopartículas Metálicas/ultraestrutura , Oxirredução , Porosidade , Águas Residuárias/químicaRESUMO
Considering that the hazardous heavy metal ions like Cd(II) and Cr(VI) are widely present in the environment, nowadays employing easy-to-handle adsorption-oriented processes are feasible choices towards efficient remediation of Cd(II) and Cr(VI) from aqueous systems. Herein we developed a novel amino-functionalized bead with cost-effectiveness, high sorption capacity and fast sorption kinetics to remove Cd(II) and Cr(VI) from aqueous solution. The carboxyl methylcellulose and chitosan-derived nanostructured sorbents synthesis were mainly through chitosan and dopamine self-polymerization, doped in sodium carboxymethyl cellulose, and glutaraldehyde cross-linking. The pH value, initial concentration and contact time were investigated. Experimental data were commendably described by Freundlich isotherm and Pseudo-second-order model. The maximum adsorption capacities of Cd(II) and Cr(VI) obtained from the experimental data were 470.0 mg/g and 347.0 mg/g, respectively. The adsorbents were collaboratively characterized by FT-IR, SEM, TGA, XPS, etc., and the adsorbent basically exhibited high complexation ability to Cd(II) and showed strong electrostatic effect with Cr(VI) under acidic conditions. The recycling characteristics suggested that it possesses an outstanding recyclability. The adsorbent may have a potential as high-value biological adsorbent to remove heavy metals and it deserves further research into the practical application.
Assuntos
Cádmio/isolamento & purificação , Carboximetilcelulose Sódica/química , Quitosana/química , Cromo/isolamento & purificação , Nanoestruturas/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Concentração de Íons de Hidrogênio , Indóis/química , Cinética , Nitrogênio/química , Espectroscopia Fotoeletrônica , Polietilenoimina/química , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , TermogravimetriaRESUMO
The removal of heavy metal ions is of great significance to the friendly development of the environment. Herein, alginate modified graphitic carbon nitride composite hydrogels (g-C3N4/SA) were successfully synthesized through a facile cross-linking polymerization method. This novel composite hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS). The effects of different conditions were examined such as pH, initial concentration and contact time. It demonstrated that this integration process significantly improved the adsorption capacity of each component to targeted metal ions and solved the recycling and separation problem of g-C3N4, which is powdery sorbent and hard to recycle after adsorption. The calculated maximum adsorption capacity of Pb(II), Ni(II) and Cu(II) were 383.4, 306.3 and 168.2 mg g-1, respectively. Adsorption isotherms studies showed that the equilibrium adsorption data fitted well to the Langmuir model and the adsorption kinetic data described well with the pseudo-second-order model according to kinetics studies. More significantly, g-C3N4/SA showed excellent regeneration ability and repeatedly utilized at least five cycles without obvious adsorption capacity loss. As-fabricated g-C3N4/SA can be considered as a potential sorbent for highly effective adsorption of Pb(II), Ni(II) and Cu(II) ions from contaminated water.
Assuntos
Alginatos/química , Grafite/química , Hidrogéis/química , Metais Pesados/química , Compostos de Nitrogênio/química , Poluentes Químicos da Água/química , Técnicas de Química Sintética , Cobre/química , Concentração de Íons de Hidrogênio , Cinética , Chumbo/química , Espectroscopia Fotoeletrônica , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral , Temperatura , Purificação da Água/métodosRESUMO
Designing desirable adsorbent for highly efficient removal of heavy metal ions is of practical significance, given the cost-effectiveness, environmental benign, natural abundance and easy-handling collection features. Herein, a bead-like adsorbent with high adsorption capacity was prepared by modifying alginate beads using polyacrylate with high density of carboxyl groups. The developed alginate/polyacrylate beads were collaboratively characterized by FT-IR, TGA, SEM, XPS, etc., and various adsorption conditions were tested including the pH of the solution, contact time and the initial concentration. The experimental data were fitted well by the Freundlich isotherm model, and the maximum adsorption capacity was obtained from the Langmuir model was 611.0 mg/g, and adsorption process followed the Pseudo-second-order kinetic model. The adsorption mechanisms conformed to multi-layer adsorption, and mainly dominated by chemical interactions. The bead-like adsorbent exhibited excellent reusability after eight sequential cycles and displayed higher adsorption capacity towards lead ions. This type of adsorbent might possess promising role in treating heavy metals from water by virtue of degradable, cost-effective component and high adsorption efficiency.
RESUMO
Heavy metal ions pollution is a terrible issue that needs to be efficiently treated as a matter of priority to construct our sustainable society. However, the easy-to-handling of high-performance biomass-derived sorbents with fascinating features like high sorption capacity, favorable separation and recycling remain challenging. Herein, the development of a novel bead-like adsorbent with above features, that is, Al(III)-assembled carboxymethyl cellulose beads were used for the removal of Pb(II), Ni(II) and Co(II) from aqueous solution. Characterization methods like FT-IR, SEM, XPS and TGA were employed to confirm its physicochemical properties. Removal of the three heavy metal ions at different pH values, initial concentration and contact time were discussed at batch adsorption experiments. Meanwhile, regeneration was also discussed deeply. The results revealed that the adsorption capacity of the sorbents for three heavy metals increases with increasing pH and the initial concentration. The adsorption isotherm could be described well by the Freundlich model, and the maximum adsorption capacity for Pb(II), Ni(II) and Co(II) were 550, 620 and 760 mg/g, respectively. Kinetics study indicated that the Pseudo-second-order model described the best correlation with experimental data, this suggested that the complexation may participated in the adsorption process. More significantly, this type of bead-like adsorbents displayed excellent reusability after four sequential cycles.
Assuntos
Carboximetilcelulose Sódica/química , Metais Pesados/isolamento & purificação , Purificação da Água/métodos , Adsorção , Alumínio/química , Celulose/química , Criogéis/química , Concentração de Íons de Hidrogênio , Íons , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Temperatura , Termodinâmica , Água/química , Poluentes Químicos da Água/químicaRESUMO
The recovery of noble metals from aqueous systems is of great significance for constructing sustainable framework of modern industry yet remains challenging. Herein, CuxSy/Carbon composites with superior thermal stability and adsorption capacity were successfully synthesized via one-pot hydrothermal method using lignosulfonate as dual role of raw materials. The optimal synthesis conditions were investigated via tailoring the temperature and the mass ratio of reagents. The morphologies and physical properties of the composites were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The surface chemistry was analyzed by Zeta potential analysis, Brunauer-Emmet-Teller (BET), and X-ray photoelectron spectroscopy (XPS). The Langmuir model and the pseudo-second-order model well described the adsorption of Pd(II) and Pd(IV) delivered by fabricated composites. The adsorption capacity obtained from Langmuir isotherm model towards Pd(IV) was 114 mg/g and Pd(II) was 101 mg/g, respectively. More importantly, the adsorbed palladium species could be desorbed with hydrochloric acid and thiourea, which suggested good durability and recycling performance of the typical composite. This work might provide a new guidance for the utilization of lignin or its derivatives and enriched the research in the field of noble metal recovery.
RESUMO
To significantly enhance the adsorption efficacy of hexavalent chromium from aqueous medium, a novel and non-toxic chitosan-based composite beads were prepared by integrating task-specific components into one sample, namely ß-cyclodextrin/chitosan/hexamethylenetetramine (ß-CD-CS@HMTA). The pseudo- second-order kinetic and Langmuir isotherm model was used to describe the adsorption process. The maximum capacity Cr(VI) removal reached 333.8â¯mg/g which was superior to most of reported CS derivative adsorbents. The sorption mechanism of composite was investigated by employing FT-IR, SEM-EDS and XPS techniques. It showed that the reason for efficient removal of Cr(VI) onto resultant sample including chemisorption and reduction of Cr(VI) to the non-toxic Cr(III), and the two components of ß-CD and HMTA with task-specific had played a crucial role during the adsorption process. Most importantly, for fixed-bed column sorption testing, the breakthrough curves were well fitted by Thomas model under different flow rates (1, 2 and 3â¯mL/min). Moreover, the ß-CD-CS@HMTA had also manifested perfect adsorption capability towards anionic dyes in initial concentration 500â¯mg/L. This research indicated that as-fabricated chitosan-based composite beads are promising adsorbents for Cr(VI) and anionic dyes because of its superiority of low-cost, easy regeneration and environmental friendly.
Assuntos
Ânions/química , Quitosana/química , Cromo/química , Corantes/química , Géis/química , Metenamina/química , beta-Ciclodextrinas/química , Adsorção , Algoritmos , Poluentes Ambientais/química , Concentração de Íons de Hidrogênio , Modelos Teóricos , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios XRESUMO
Short, surface rough carbon rods, which were derived from natural sisal fiber and went through two different modifications, with excellent electromagnetic wave absorption performance, were studied in this work for the first time. The structure-property relationship was clearly established here. It was shown that these green, cheap and easily obtained carbon rods with mass preparation possibility presented eye-catching absorbing behaviors towards electromagnetic wave. Based on the natural structure of sisal fiber, the minimum reflection loss of KOH activated product reached -51.1 dB and the maximum effective absorbing bandwidth achieved 7.88 GHz. The magnetically modified sample presented -48.6 dB of minimum reflection loss and 4.32 GHz of optimal absorbing bandwidth. Its pioneering application in this field not only opens a new road for this traditional textile sisal fiber but also would possibly make a referable contribution to the design and synthesis of superior carbonaceous electromagnetic wave absorption materials based on bioresource.
RESUMO
Dopamine-derived cavities/Fe3O4 nanoparticles-encapsulated carbonaceous composites with self-generating three-dimensional (3D) network structure were successfully fabricated by a facile synthetic method, in which sodium alginate provided carbon matrix pores and excellent microwave absorption performance was established. The hollow cavities derived from the core-shell-like CaCO3@polydopamine were creatively introduced into the 3D absorber to significantly improve the absorption performance. The sample calcined at 700 °C exhibited the most outstanding microwave absorption performance, with minimal reflection loss up to -50.80 dB at 17.52 GHz with a rare thickness of only 1.5 mm when filler loading was 35% in paraffin matrix. The effective absorption bandwidth of reflection loss < -10 dB reached 3.52 GHz from 14.48 GHz to 18 GHz, corresponding to the same thickness of 1.5 mm. In contrast, the sample without hollow dopamine-derived cavities showed poor performance due to poor impedance matching, and this highlights the role of hollow cavities brought into the 3D structure, which led to a difference in interfacial polarization, multiple reflections and scattering. The novel dopamine-derived cavities/Fe3O4 nanoparticles-encapsulated carbonaceous composites with 3D network structure can be regarded as a promising candidate for application as a microwave absorber with strong absorption.
RESUMO
Chitosan is highly suitable for removing metal ions and dyes from water; however, the sorption performance, stability and recycling are still critical issues in practical applications. Herein, polydopamine-modified-chitosan (CS-PDA) aerogels were synthesized through dopamine self-polymerization and glutaraldehyde cross-linking reactions to enhance the adsorption capacity and acid resistance of chitosan. The self-polymerization of dopamine and gelation of chitosan were accomplished simultaneously, simplifying the synthesis process of CS-PDA aerogels, which is meaningful for the popularization and industrial application of adsorbent. CS-PDA exhibited superior adsorption performances in the removal of Cr(VI), Pb(II) and organic dyes. Adsorption isotherms and kinetic data were well fitted by Langmuir and pseudo-second-order kinetic models. The maximum adsorption capacities of CS-PDA for Cr(VI) and Pb(II) were 374.4 and 441.2 mg g-1, respectively. After eight cycles, adsorption capacity of CS-PDA showed no obvious decline. These superiorities make CS-PDA a promising multifunctional adsorbent for the purification of metal ions and dyes.
RESUMO
Different classes of lipids and phospholipids (PL) as well as fatty acid (FA) compositions, and glycerophospholipid (GP) molecular species in edible parts (adductor muscles) and by-products (gonads and mantles) of scallops Patinopecten yessoensis and Chlamys farreri were characterized. The lipids contained high levels of polyunsaturated FA (PUFA) (20.44-58.81% of total FAs) and PL (54.99-78.26% of total lipids). Among PL, phosphatidylcholine (41.39-51.86 mol%) was dominant. More than 230 GP species belonging to glycerophosphocholine, glycerophosphoethanolamine, glycerophosphoserine, glycerophosphoinositol, lysoglycerophosphocholine, lysoglycerophosphoethanolamine and lysoglycerophosphoinositol were characterized. Individual GP molecular species in different body parts of scallops were also partially quantified. Most of the dominant GP species contained PUFA, especially eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). Considering the high level of PUFA enriched GP, edible parts and by-products (gonads and mantles) of scallops Patinopecten yessoensis and Chlamys farreri provide great potential as health-promoting food for human consumption.
Assuntos
Lipídeos/análise , Pectinidae/química , Frutos do Mar/análise , Animais , Ácidos Docosa-Hexaenoicos/análise , Ácido Eicosapentaenoico/análise , Ácidos Graxos/análise , Ácidos Graxos Insaturados , Gônadas/química , Lipídeos/química , Fosfolipídeos/análise , Fosfolipídeos/química , Especificidade da EspécieRESUMO
A new kind of manganeseporphyrin/vanadium-substituted polyoxometalate coordination compound was synthesized by meso-tetrakis(4-trimethylamidiophenyl) manganeseporphyrin and vanadium-substituted polyoxometalate H5 PMo10 V2O4 reacting in water solution at room temperature, and its structures were studied by IR spectrometry and UV-Vis spectrometry. The results show that metalloporphyrin ring structure and polyoxometalate cage structure still exist in the coordination compound, and these two parts connect with each other by chemical bond. As an excellent catalyst, its effects on benzene hydroxylation and catalytic capabilities were studied with H2O2 solution as an oxidant under mild reaction condition, meanwhile the catalytic active centre in the benzene hydroxylation reaction was discussed. The results indicated that V atom in polyoxometalate is the main centre of catalytic activity, while the presence of manganeseporphyrin could improve its catalytic activity greatly.
RESUMO
A new kind of iron-porphyrin/vanadium-substituted polyoxometalate coordination compound was synthesized by the ion exchange reaction of FeTTMAPPI and H5PMo10V2o40 in solution. The new catalyst was characterized by IR spectrometry and UV-Vis spectrometry. As an excellent catalyst, its effects on benzene hydroxylation and catalytic capabilities were studied with H2O2 solution as the oxidant. The results indicated that the products contained the conjugated structure of porphyrin and the cage structure of polyoxometalate, the V atom in polyoxometalate is the main centre of catalytic activity, meanwhile the presence of iron-porphyrin could increase its catalytic activity greatly.
Assuntos
Ferro/química , Porfirinas/síntese química , Compostos de Tungstênio/química , Vanádio/química , Catálise , Porfirinas/químicaRESUMO
The effects of vitamin C, vitamin E and vitamin B12 on the noise-induced acute change in hepatic glycogen content in rats were investigated. The exposure of rats to 95 dB and 110 dB of noise acutely reduced their hepatic glycogens. Vitamin C (ascorbic acid) and vitamin E (alpha-tocopherol) attenuated the noise-induced acute reduction in the hepatic glycogen contents. This result suggests that antioxidants could reduce the change via reactive oxygen species. Vitamin B12 (cobalamin) delayed the noise-induced change, a finding that suggests that vitamin B12 could postpone the acute change via compensating for vitamin B12 deficiency.