Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 59
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Environ Res ; 259: 119504, 2024 Oct 15.
Article in English | MEDLINE | ID: mdl-38945514

ABSTRACT

While treating zinc-containing wastewater, recovering zinc for reuse as a secondary resource has significant environmental and economic benefits. Herein, based on the alkali-activated tourmaline tailings geopolymers (TTG) after adsorption of zinc ions (Zn (II)), a series of new composites with in-situ construction ZnS nanoparticles on TTG (ZnS/TTG) were synthesized, and used as photocatalysts for the photodegradation of tetracycline hydrochloride (TCH) in solution. Specifically, ZnS nanoparticles were uniformly and stably distributed in the layered structure of TTG, interweaving with each other to generate an interfacial electric field, which could induce more photocarrier generation. Meanwhile, TTG acted as an electron acceptor to accelerate the electron transfer at the interface, thus enhancing the photodegradation activity for TCH. The active radical quenching experiments combined with the ESR indicated that the active species produced during the photocatalytic degradation of TCH by ZnS/TTG composites were •O2- and photogenerated h+. When the initial concentration of Zn (II) was 60 mg/L, the synthesized 60-ZnS/TTG composites (0.5 g/L) reached 91.53% degradation efficiency of TCH (10 mg/L) at pH = 6. Furthermore, the possible pathways and mechanism of 60-ZnS/TTG composites photodegraded TCH were revealed with the aid of degraded intermediates. This report not only proposed valuable references for reusing heavy metal ions and removing TCH from wastewater, but also provided promising ideas for realizing the conversion of used adsorbents into high-efficiency photocatalysts.


Subject(s)
Photolysis , Tetracycline , Wastewater , Water Pollutants, Chemical , Zinc Compounds , Zinc , Tetracycline/chemistry , Wastewater/chemistry , Zinc/chemistry , Water Pollutants, Chemical/chemistry , Zinc Compounds/chemistry , Sulfides/chemistry , Polymers/chemistry , Waste Disposal, Fluid/methods
2.
Langmuir ; 39(7): 2797-2807, 2023 02 21.
Article in English | MEDLINE | ID: mdl-36763007

ABSTRACT

In view of the animal feeds inevitably contaminated by multiple mycotoxins, eco-friendly and efficient palygorskite-montmorillonite (Pal-Mt) materials were prepared to remove polar aflatoxin B1 (AFB1) and weak polar zearalenone (ZEN) from mixed mycotoxins aqueous solution. The adsorption properties and bonding mechanisms between Pal-Mt materials and mycotoxins (AFB1 and ZEN) were investigated systematically. The as-prepared Pal-Mt showed excellent adsorption capacity for AFB1 and ZEN in single- and binary-mycotoxin systems, indicating the effectiveness of Pal-Mt acting as multiple mycotoxin adsorbents. The kinetics of adsorption for ZEN was fast due to the adsorption on the external surface (film and intraparticle diffusion), while AFB1 molecules permeated into mesopores after the external adsorption for the more planar structure. Adsorption isotherms demonstrated that heterogeneous surface adsorption appeared between Pal-Mt and AFB1, and monolayer adsorption occurred on Pal-Mt and ZEN for different polarities of mycotoxins. Thermodynamic parameters illustrated that the adsorption process of both AFB1 and ZEN onto Pal-Mt was spontaneous and endothermic. The adsorption mechanism studies suggested that hydrogen bonding, electrostatic attraction, calcium bridging linkage, and ion-dipole played fundamental roles in the interaction between Pal-Mt and these two mycotoxins.


Subject(s)
Mycotoxins , Zearalenone , Animals , Zearalenone/chemistry , Aflatoxin B1/chemistry , Bentonite/chemistry , Mycotoxins/chemistry , Adsorption
3.
Funct Integr Genomics ; 19(1): 191-204, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30251028

ABSTRACT

Transcription factors are recognized as the key regulators of gene expression. However, the changes in the correlation of transcription factors and their target genes between normal and tumor tissues are usually ignored. In this research, we used mRNA expression profile data from The Cancer Genome Atlas which included 5726 samples across 11 major human cancers to perform co-expression analysis by the Pearson correlation coefficients. Then, integrating 81,357 pairs of transcription factors and target genes from transcription factors databases to find out the changes in the co-expression correlation of these gene pairs from normal to tumor tissues. Based on the changes in the number of co-expressed TF-TG pairs and changes in the level of co-expression, we found the generally reduced correlation between transcription factors and their target genes in cancer. Additionally, we screened out universal and specific transcription factors-target genes pairs which may significant influence particular cancer. Then, we obtained 423 cancer cell line expression profiles from Broad Institute Cancer Cell Line Encyclopedia to verify our results. Some of these pairs like XRCC5-XRCC6 have been reported to involve in multiple cancers, while pairs like IRF1-PSMB9 without any previous articles related to tumor but involve in the biological processes of cancer, which are of great potential to be therapeutic targets. Our research may provide insights to better understand the tumor development mechanisms and find potential therapeutic targets.


Subject(s)
Carcinogenesis/genetics , Gene Expression Regulation, Neoplastic , Neoplasm Proteins/genetics , Neoplasms/genetics , Transcription Factors/genetics , Atlases as Topic , Carcinogenesis/metabolism , Carcinogenesis/pathology , Cell Line, Tumor , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Databases, Genetic , Gene Ontology , Gene Regulatory Networks , Genome, Human , Humans , Interferon Regulatory Factor-1/genetics , Interferon Regulatory Factor-1/metabolism , Ku Autoantigen/genetics , Ku Autoantigen/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , Molecular Sequence Annotation , Neoplasm Proteins/metabolism , Neoplasms/classification , Neoplasms/metabolism , Neoplasms/pathology , Protein Binding , RNA, Messenger/genetics , RNA, Messenger/metabolism , Transcription Factors/metabolism
4.
Environ Sci Technol ; 53(12): 6989-6996, 2019 06 18.
Article in English | MEDLINE | ID: mdl-31184128

ABSTRACT

Low temperature NH3 selective catalytic reduction (NH3-SCR) technology is an efficient and economical strategy for cutting NO x emissions from power-generating equipment. In this study, a novel and highly efficient NH3-SCR catalyst, tourmaline-modified FeMnTiO x is presented, which was synthesized by a simple one-step sol-gel method. We found that the amount of tourmaline has an important impact on the catalytic performance of the modified FeMnTiO x-based catalysts, and the NO x conversion exceeded 80% from 160 to 380 °C with the addition of 5 wt % tourmaline. Compared with the pure FeMnTiO x, the catalytic efficiency at a temperature below 100 °C was increased by nearly 18.9%, and the operation temperature window was broadened significantly. The enhanced catalytic performance of the FeMnTiO x catalyst was mainly attributed to the small spherical nanoparticles structure around the tourmaline powders, resulting in the increased content of Mn3+, Mn4+, and chemical oxygen on the catalytic surface. These as-developed tourmaline-modified FeMnTiO x materials have been demonstrated to be promising as a new type highly efficient low temperature NH3-SCR catalyst.


Subject(s)
Ammonia , Cold Temperature , Catalysis , Silicates , Temperature
5.
J Nanosci Nanotechnol ; 16(4): 3977-80, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27451750

ABSTRACT

Under modern and, intensive feeding livestock and poultry density has increased, and brought a deterioration of the farm environment. The livestock and their excrement generate harmful gases such as ammonia, etc. which restricted the sustainable development and improvement of production efficiency of animal husbandry. In this paper, a new kind of far infrared porous ceramics was prepared to activate, the animal drinking water. The activated water and common water were then supplied to pigs, and the fresh pig feces of experimental group and:control group were collected on a regular basis. The residual protein content in feces was tested by Kjeldahl nitrogen method to study the influence law of the porous ceramics on absorbing nitrogen element in animal feces. The results showed that compared with the control group, the protein content in the experimental group decreased on average by 39.2%. The activated drinking water was conducive to the absorption of nitrogen in pig feed. The clusters of water molecules became smaller under the action of the porous ceramics. Hence, they were easy to pass through the water protein channel on the cell membrane for speeding up the metabolism.


Subject(s)
Animal Feed/analysis , Ceramics/chemistry , Drinking Water/chemistry , Nitrogen/isolation & purification , Swine/metabolism , Water/chemistry , Absorption, Physicochemical , Animals , Materials Testing , Nanoparticles/chemistry , Nanoparticles/ultrastructure , Nanopores/ultrastructure , Porosity , Water Purification/methods
6.
J Nanosci Nanotechnol ; 14(5): 3822-6, 2014 May.
Article in English | MEDLINE | ID: mdl-24734644

ABSTRACT

The cleanability of easy-to-clean ceramic glazes doped with nanometer far-infrared materials was compared with that of some high-quality household ceramic glazes from the market. The cleanability was evaluated by the contact angle measurement using a sessile drop method with a Dataphysics OCA-30 contact angle analyzer. The results showed that the difference of contact angles of water on the glazes before soiling and after cleaning could be used as a parameter for evaluating the cleanability of the glazes. The relationship between cleanability and surface properties, such as surface free energy and surface topography, was investigated. The surface free energy of the samples and their components were calculated using van Oss acid-base approach. By measuring advancing and receding contact angles, the contact angle hysteresis of the ceramic glazes due to the surface topography was investigated. It was shown that the cleanability of ceramic glazes containing nanometer far-infrared materials (NFIM) is better than that of household ceramic glazes from market, due to a higher ratio of electron-acceptor parameter to electron-donor parameter, which led to the effect of water hydration as well as better hydrophilic property and increased smoothness. The contact angle measurement not only accurately evaluates the cleanability of the ceramic glazes, but also has a contribution to the study of cleanability theory. Moreover, this method is simple, convenient and less sample-consumption.

7.
J Nanosci Nanotechnol ; 14(5): 3515-20, 2014 May.
Article in English | MEDLINE | ID: mdl-24734580

ABSTRACT

Surface modification is used to regulate surface free energy of sepiolite with 3-glycidoxypropyltrimethoxysilanes (3-GPTMS), 3-methacryloxypropyltrimethoxysilanes (3-MAPTMS) and 3-mercaptopropyltrimethoxysilane (3-MPTMS). Through characterization by Fourier transform infrared spectroscopy, surface free energy, zeta potential and sedimentation measurements and infrared emissivity, it is found that the surface free energy of 3-MPTMS modified sepiolite decreases to 31.72 mJ/m2 and the percentage of polar component increases to 89.75%, thus leading to that the infrared emissivity of 3-MPTMS modified sepiolite increase to be higher than 0.8 and the dispersion of sepiolite has been improved. The excellent thermal insulation property of coating is prepared with 10% additive amount of 3-MPTMS modified sepiolite and the temperature difference between upper and lower box of modified sepiolite coatings is 10 degrees C which is higher than the untreated sepiolite.

8.
J Nanosci Nanotechnol ; 14(5): 3607-11, 2014 May.
Article in English | MEDLINE | ID: mdl-24734598

ABSTRACT

Mineral black tourmaline powders were heat-treated at different temperatures. Their crystal structure was studied by X-ray diffractometer. Their infrared absorption and emission spectra before and after the heat treatment were analyzed by the Fourier transform infrared spectrometer. The corresponding fine structures were discussed in detail. The results showed that the powders possessed higher infrared emissivity at the band where they showed stronger infrared absorption. However, there is no certain correlation between the peak intensity of infrared absorption and emissivity values at the same frequency. Because of the crystal shrinkage of c-axis, the electronic transitions were stimulated between different energy levels, and the abilities of infrared absorption and emission were enhanced with increasing the temperature of heat treatment.


Subject(s)
Hot Temperature , Minerals/chemistry , Spectroscopy, Fourier Transform Infrared/methods , Crystallography, X-Ray , Molecular Structure
9.
J Nanosci Nanotechnol ; 14(5): 3817-21, 2014 May.
Article in English | MEDLINE | ID: mdl-24734643

ABSTRACT

Rare earth (RE)/tourmaline composite materials prepared by the precipitation method are added to the ceramic raw materials at a certain percentage and sintered into RE functional ceramics with high far infrared emission features. Then the far infrared functional ceramics are used to interact with water. The influence of the ceramics on the physical parameters of water is investigated, and the effect of the activated water on the growth of Bel-7402 hepatoma cells cultured in vitro is further studied. The results indicate that, compared with the raw water, the water activated by the ceramics can inhibit the proliferation of hepatoma cells, with statistical probability P < 0.01, which means that the effect is significant. It can be explained that the water activated by the ceramics has a higher concentration of H+, which decreases the potential difference across the cell membrane to release the apoptosis inducing factor (AIF). After entering the cells, the activated water stimulates the mitochondria to produce immune substances that lead tumor cells to apoptosis.


Subject(s)
Carcinoma, Hepatocellular/pathology , Cell Proliferation , Ceramics , Liver Neoplasms/pathology , Water/chemistry , Humans , Microscopy, Electron, Scanning
10.
J Nanosci Nanotechnol ; 14(5): 3861-7, 2014 May.
Article in English | MEDLINE | ID: mdl-24734652

ABSTRACT

Nano zinc oxide with a high refractive index has good thermal reflection performance, hollow glass microspheres have good thermal reflection and insulation performance, and sepiolite nanofibers with many nanostructural pores have good thermal insulation performance. The dispensability of nano zinc oxide in coating materials was improved by optimizing surface silane coupling agent modification process, leading to the good thermal reflection performance. The thermal insulation performance was improved by hollow glass microspheres and sepiolite nanofibers. On this basis, the thermal insulation coating materials were prepared by exploring the effect of amount, complex mode, and other factors of the above three kinds of functional fillers on the thermal reflection and insulation performance of coating materials. The results showed that the surface modification effect of nano zinc oxide was the best when the silane coupling agent addition was 6%. The reflection and insulation performance of the coatings were the best when the additions of modified nano zinc oxide, hollow glass microspheres, and sepiolite nanofibers were 3%, 4%, and 4%, respectively. Compared with the control coating materials, the thermal insulation effect was improved obviously, which was evaluated by the -13.5 degrees C increase of maximum temperature difference between the upper and the lower surfaces.

11.
J Nanosci Nanotechnol ; 14(5): 3937-42, 2014 May.
Article in English | MEDLINE | ID: mdl-24734668

ABSTRACT

The longitudinal and cross sectional TEM images of sepiolite mineral nanofibers were prepared by cutting in the direction parallel and perpendicular to nanofibers, and the channel microstructure of sepiolite nanofibers was studied. The thermal insulation mechanism of sepiolite nanofibers was analyzed according to the diagrammatic sketch obtained from the above experimental method. The results showed that many discontinuously connected bending shape channels with about 23-26 nm in diameter existed in the center region of nanofibers, and many discontinuously connected irregular micropores and mesopores with the size of about 1-9 nm existed on the wall of nanofibers. The main reasons for the formation of channel microstructure in sepiolite nanofibers were their minerogenetic conditions and the interaction between acid and high-speed airflow in the process of nanofibers preparation, and bubbles in the hydrotherm played a significant role in the microstructure formation. The thermal insulation performance of sepiolite nanofibers could be attributed to obstructive and infrared radiative thermal insulation.

12.
J Nanosci Nanotechnol ; 14(5): 3943-7, 2014 May.
Article in English | MEDLINE | ID: mdl-24734669

ABSTRACT

Tourmaline nano-particles were successfully prepared via a hydrothermal process using HCl as an additive. The reaction temperature (T) and the concentration of HCI (C(HCl)) had effects on the size and morphology of the tourmaline nano-particles. The optimum reaction condition was that: T = 180 degrees C and C(HCl) = 0.1 mol/l. The obtained nano-particles were spherical with the diameter of 48 nm. The far-infrared emissivity of the product was 0.923. The formation mechnism of the tourmaline nano-particles might come from the corrosion of grain boundary between the tourmaline crystals in acidic hydrothermal conditions and then the asymmetric contraction of the crystals.

13.
Se Pu ; 42(1): 99-105, 2024 Jan 08.
Article in Zh | MEDLINE | ID: mdl-38197211

ABSTRACT

Significant developments have recently been achieved in the field of N-lauryl amino acid (NLAA) surfactants derived from renewable resources. Compared with conventional surfactants, NLAAs exhibit remarkable surfactant properties, exceptional biodegradability, good biocompatibility, and high safety profiles. These attributes have led to the widespread use of NLAAs in personal-care products. The detection methods employed for NLAAs include two-phase titration (TT), spectrophotometric analysis (SA), and high performance liquid chromatography (HPLC). However, because both TT and SA measure the total concentration of anionic active matter, identifying and quantifying individual compounds in a sample containing multiple anionic surfactants is impossible. The presence of cationic surfactants in the sample also introduces interferences, which lead to significant errors. Compared with TT and SA, HPLC offers direct and rapid testing procedures. However, compounds with no or weak UV-visible light absorption exhibit low sensitivity when detected by UV, necessitating the use of detectors such as differential refractive index detectors (RIDs), evaporative light scattering detectors (ELSDs), or charged aerosol detectors (CADs). Most HPLC users consider UV light as the fundamental configuration of the instrument, and other detectors are less commonly employed. Therefore, establishing a new HPLC method suitable for the UV detection of NLAAs is of practical significance. In this study, a novel HPLC-UV method was developed for the simultaneous detection of N-lauryl glutamine (LG), N-lauryl glycine (LC), N-lauryl alanine (LA), and N-lauryl sarcosine (LS) by optimizing the mobile-phase composition and selecting an appropriate chromatographic column and detection wavelength. The samples were mixed with acetonitrile-0.10% H3PO4 aqueous solution (60∶40, v/v) and sonicated for 10 min, then stayed at room temperature for 5 min. Subsequently, the mixture was filtered through a 0.22 µm filter membrane and separated on an Agilent Eclipse Plus C18 column (150 mm×4.6 mm, 5 µm). The mobile phase used for separation consisted of acetonitrile-0.10% H3PO4 aqueous solution at a flow rate of 1.0 mL/min. The detection wavelength was set at 205 nm, and the injection volume was 10 µL. The results demonstrated that the four NLAAs exhibited good linearity in the range of 2.0-800.0 mg/L, with correlation coefficients (r)≥0.9995. The limits of detection (LODs) ranged from 0.17 to 0.49 mg/L, and limits of quantification (LOQs) ranged from 0.57 to 1.63 mg/L. The relative standard deviations (RSDs) for precision, repeatability, and stability over 24 h were all below 2.0%. Using this method, the NLAA contents of five facial-cleanser products were determined. The results demonstrated that all five samples contained one or more NLAAs, and the total NLAA contents ranged from 64.58 to 97.01 mg/g. The five spiked-sample recoveries of the NLAAs at four different spiked levels (0.60, 4.50, 15.00, 24.00 mg/g) ranged from 94.3% to 107.4%, indicating satisfactory accuracy. However, the actual NLAA composition and label for one facial-cleanser product were not consistent with our test results. This finding demonstrates the necessity of strengthening market monitoring through testing. The proposed method has the advantages of simple pretreatment, rapid testing, good precision, high accuracy, and appropriate stability. Thus, it is suitable for the determination of NLAA contents in facial cleansers and provides an effective technical reference for the raw-material purity assessment, synthetic yield detection, and product quality control of this type of surfactant.


Subject(s)
Amino Acids , Surface-Active Agents , Chromatography, High Pressure Liquid , Glycine , Acetonitriles
14.
ACS Omega ; 9(32): 34787-34798, 2024 Aug 13.
Article in English | MEDLINE | ID: mdl-39157090

ABSTRACT

Adding an appropriate amount and the stable precipitation of surfactant on the inner surface of agricultural plastic greenhouse films can prevent the formation of water droplets on the inner surface of the film to reduce its harmful effects in the process of plant cultivation and production. In this work, for the stable precipitation of the surfactant glycerol monostearate, diatomite minerals from three origins in China were compared through structural analysis and adsorption performance. The effects of acid treatments and alkali treatments on the mineral structure were studied, and the adsorption mechanism of glycerol monostearate was further investigated. The results show that the structural characteristics of Jilin diatomite are more suitable as adsorbents for glyceryl monostearate adsorption. Because diatomite is resistant to acids but not alkalis, when diatomite is treated with an alkali, impurities on its surface can be removed and the hydroxyl group and specific surface area can be greatly increased. The adsorption capacity of glycerol stearate was increased to 218.4 mg/g, or 32.08%, over its pretreatment level. The results show that this is mainly the result of physical adsorption caused by van der Waals force imbalance and chemisorption caused by a small number of hydrogen bonds. In addition, the dripping performance of this composite dripping film with mineral diatomite was better than that of the commercial dripping film, which provided a theoretical basis for efficient mineral slow-release drip irrigation composite film.

15.
J Hazard Mater ; 475: 134774, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38870850

ABSTRACT

Currently, the low cost and effective purification toward heavy metal ions in wastewater has garnered global attention. Herein, we used hydrothermal method to prepare highly dispersed calcium silicate hydrate in fluorite tailings. And the stacking thickness of calcium silicate hydrate layered morphology was less than 5 nm. For high concentration Cu2+ purification investigation in wastewater, we found that the equilibrium adsorption capacity reached 797.92 mg/g via the CSH with 3:2 Ca/Si molar ratio, be 1.43-21.8 times than that of reported data. Therein, the metal-metal exchange and deposition are the primary pathways for Cu2+ adsorption, and electrostatic attraction is the secondary pathway. And the relative ∼100 % removal rate of high-concentration Ni2+ and Cr3+ ions were confirmed via CSH prepared from different tailings. This method offers a cost-effective way to utilize tailings for preparing highly efficient adsorbents toward HMIs removal in wastewater.

16.
Materials (Basel) ; 15(5)2022 Feb 25.
Article in English | MEDLINE | ID: mdl-35268987

ABSTRACT

In order to realize the high value-added resource utilization of solid waste and reduce the cost of rubber manufacturing, iron ore tailings (IOTs) were used as raw material to prepare a reinforcing filler of rubber through ultrafine grinding and surface organic modification techniques. We studied the effects of ball mill grinding conditions on the particle size and distribution of grinded iron ore tailings (G-IOTs). The effects of bis-(triethoxy-silyl-propyl)-tetrasulfide (Si69)-modified G-IOT (Si69-G-IOT) loading levels on the cure characteristics, static mechanical and dynamic mechanical properties of the styrene butadiene rubber (SBR) composites were also explored in this paper. The grinding and modification mechanism of IOTs and the combination of filler and SBR matrix were explored by grinding simulation of population balance model, X-ray diffraction analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. The results showed that when grinding IOTs at 2000 r/min for 150 min, the particle size distribution of the resulting G-IOTs was the narrowest, with a D90 value of 4.42 µm. The tensile strength and elongation at break of SBR filled with 120 phr Si69-G-IOT were 14.97 MPa and 596.36%, respectively.

17.
Mar Pollut Bull ; 183: 114087, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36084612

ABSTRACT

In the past three decades, nuclear energy has gained much attention as carbon-free electricity. Due to the supply of cooling water in nuclear power plant, large amount of waste heat will increase the water temperature, promote the microalgae and cyanobacteria propagation and increase the chance of red tide. Excess phytoplankton of cool source will result in abnormal operation of cooling system, even core overheating and nuclear leakage. Consequently, it is very important to remove microalgae and cyanobacteria from cold source of nuclear power plants. This review summarizes the formation mechanism and monitoring methods of red tide, compares the advantages and disadvantages of traditional microalgae removal technology including physical, chemical and biological methods. Furthermore, the improved electrochemical method and micro-nano bubble method are introduced in detail. Their combination is considered to be a low-cost, efficient and environmentally-friendly technology to prevent and control red tides for cold source of nuclear power plant.


Subject(s)
Cyanobacteria , Microalgae , Nuclear Power Plants , Phytoplankton , Technology , Water
18.
Nanoscale ; 14(11): 4089-4097, 2022 Mar 17.
Article in English | MEDLINE | ID: mdl-35075465

ABSTRACT

Atmosphere-related atom migration and phase reconstruction are an easy way for optimizing the catalytic activity of a bimetallic catalyst. Herein, the structure evolutions of NiAu nanoparticles under oxidative and reductive environments are investigated via combining identical location and in situ environmental scanning transmission electron microscopy. During oxidation, a NiO layer first forms and the redispersion of Ni and Au atoms yields a Ni@Au@NiO multi-shell structure at 350 °C. Further, Ni and Au segregate into an Au-NiO hybrid structure at 600 °C. During reduction, Au atoms disperse over the particle surface forming a NiAu alloy shell with scattered Au atoms/clusters. In situ observation further discloses that the reduction changes the local structural ordering from Ni3Au to NiAu alloy. Very interestingly, the reduced NiAu exhibits promoted activity over oxidized ones for the CO-NO reaction. Density functional theory calculations further reveal the structure-property relationships of CO, NO, and O adsorbates on NiAu alloy surfaces. This study is beneficial for understanding the atmosphere-related evolution behaviors of bimetallic systems, thereby inspiring the catalytic surface optimization.

19.
Materials (Basel) ; 15(12)2022 Jun 15.
Article in English | MEDLINE | ID: mdl-35744293

ABSTRACT

In this study, ball mill pretreated iron ore tailings were modified with tetraethoxysilane (TEOS) and hexadecyltrimethoxysilane (HDTMS) to obtain iron ore tailings/polysiloxane (IOT/POS) superhydrophobic powders, which were subsequently mixed with chloroprene rubber solution (CRS) to prepare durable superhydrophobic composite coatings. The effect of HDTMS amount and reaction time on the wettability of the superhydrophobic powder was investigated. The influence of the superhydrophobic powders concentration on the wettability of the composite coatings as well as the degree of damage of the superhydrophobicity of the composite coating was analyzed by using the sandpaper abrasion and tape peeling tests. Further, SEM and FTIR were used to analyze the formation mechanism of the IOT/POS superhydrophobic powders and coatings. The results showed for an HDTMS amount of 2.5 mmol and reaction time of 4 h, the contact angle of the IOT/POS powder was 157.3 ± 0.6°, whereas the slide angle was determined to be 5.9 ± 0.8°. For an IOT/POS powder content of 0.06 g/mL in CRS, the contact angle value of the superhydrophobic composite coating was 159.2 ± 0.5°, whereas the slide angle value was 5.5 ± 0.8°. The superhydrophobic composite coating still maintained the superhydrophobicity after the sandpaper abrasion and tape peeling tests, which indicated the iron ore tailings solid waste has the potential to prepare superhydrophobic coatings.

20.
J Nanosci Nanotechnol ; 11(11): 9594-9, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22413254

ABSTRACT

Dispersed nano-CeO2 successfully grew on the surface of natural tourmaline powders by a precipitation method. The results of Fourier transform infrared spectroscopy (FTIR) showed that CeO2 (111) nanospots could apparently enhance the far infrared emission property of tourmaline in relation to CeO2 nanoparticles. This is the first report regarding the effect of the morphology of nano-CeO2 on the far infrared emission property of natural tourmaline. The results of the characterization by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) showed that CeO2 (111) nanospots have much more chemisorbed oxygen than CeO2 nanoparticles, which is beneficial to the unit cell volume shrinkage of tourmaline, thus increasing its far infrared emissivity.

SELECTION OF CITATIONS
SEARCH DETAIL