scholarly journals One-step preparation of a novel SrCO3/g-C3N4 nano-composite and its application in selective adsorption of crystal violet

RSC Advances ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 6315-6325 ◽  
Author(s):  
Peng Lu ◽  
Xueli Hu ◽  
Yujie Li ◽  
Meng Zhang ◽  
Xiaoping Liu ◽  
...  

A novel kind of nanoparticle SrCO3/g-C3N4 was prepared using strontium carbonate (SrCO3) and melamine as raw materials via one-step calcination.

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1556 ◽  
Author(s):  
Zhao ◽  
Liu ◽  
Zhang ◽  
Zhang ◽  
Liao ◽  
...  

The adjustment of the emitting wavelength of carbon dots (CDs) is usually realized by changing the raw materials, reaction temperature, or time. This paper reported the effective synthesis of multicolor photoluminescent CDs only by changing the solvent in a one-step solvothermal method, with 1,2,4,5-tetraaminobenzene as both the novel carbon source and nitrogen source. The emission wavelengths of the as-prepared CDs ranged from 527 to 605 nm, with quantum yields (QYs) reaching 10.0% to 47.6%, and it was successfully employed as fluorescence ink. The prepared red-emitting CDs (R-CDs, λem = 605 nm) and yellow-emitting CDs (Y-CDs, λem = 543 nm) were compared through multiple characterization methods, and their luminescence mechanism was studied. It was discovered that the large particle size, the existence of graphite Ns, and oxygen-containing functional groups are beneficial to the formation of long wavelength-emitting CDs. Y-CDs responded to crystal violet, and its fluorescence could be quenched. This phenomenon was thus employed to develop a detection method for crystal violet with a linear range from 0.1 to 11 µM and a detection limit of 20 nM.


2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Lorenzo Comba ◽  
Fabrizio Dabbene ◽  
Paolo Gay ◽  
Cristina Tortia

Even though the main EU regulations concerning food traceability have already entered to force since many years, we still remark very wide and impacting product recalls, which often involve simultaneously large territories and many countries. This is a clear sign that current traceability procedures and systems, when implemented with the only aim of respecting mandatory policies, are not effective, and that there are some aspects that are at present underestimated, and therefore should be attentively reconsidered. In particular, the sole adoption of the so-called “one step back-one step forward traceability” to comply the EC Regulation 178/2002, where every actor in the chain handles merely the data coming from his supplier and those sent to his client, is in fact not sufficient to control and to limit the impact of a recall action after a risk notification. Recent studies on lots dispersion and routing demonstrate that each stakeholder has to plan his activities (production, transformation or distribution) according to specific criteria that allow pre-emptively estimating and limiting the range action of a possible recall. Moreover, these new and very recently proposed techniques still present some limits; first of all the problem of traceability of bulk products (e.g. liquids, powders, grains, crystals) during production phases that involve mixing operations of several lots of different/same materials. In fact, current traceability practices are in most cases unable to deal efficiently with this kind of products, and, in order to compensate the lack of knowledge about lot composition, typically resort to the adoption of very large lots, based for instance on a considered production period. Aim of this paper is to present recent advances in the design of supply chain traceability systems, discussing problems that are still open and are nowadays subject of research.


2012 ◽  
Vol 476-478 ◽  
pp. 194-198 ◽  
Author(s):  
Zhi Chao Chen ◽  
Zheng Liang Xue ◽  
Wei Wang ◽  
Yue Yu ◽  
Qiang Liu ◽  
...  

Keywords: vanadium pentoxide;carbon black;reduction and nitridation;vanadium nitrogen alloy. Abstract. The V2O5 extracted from low vanadium shale and carbon black are used as raw materials to prepare briquetting samples through mixing, grinding and pressing. The samples are prereduced, final reduced and nitrated to produce vanadium nitrogen alloy with high nitrogen content. Thermodynamic analysis and experiment results show that:(1)In order to avoid V2O5 volatilization loss during reduction, the briquetting samples should be pre-reduced for 4 hours below the melting point 670°C of V2O5, which can transform V2O5 into low valence vanadium oxide.(2)During V2O5 being self-reduction under N2 atmosphere, if the final reduction temperature is below 1271°C, the VN is preferential formation; if more than 1271°C, the reduced product forms V4C3.(3)To make a product with high nitrogen and low carbon content, the final reduction and nitride temperature should be controlled below 1300°C.


Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 954 ◽  
Author(s):  
Brenda Antoinette Barnard ◽  
Frederick Johannes Willem Jacobus Labuschagné

The synthesis of Mg-Al, Ca-Al, Zn-Al and Cu-Al layered double hydroxides (LDHs) was investigated with a one-step wet mechanochemical route. The research aims to expand on the mechanochemical synthesis of LDH using a mill designed for wet grinding application. A 10% slurry of solids was added to a Netzsch LME 1 horizontal bead mill and milled for 1 h at 2000 rpm. Milling conditions were selected according to machine limitations and as an initial exploratory starting point. Precursor materials selected consisted of a mixture of oxides, hydroxides and basic carbonates. Samples obtained were divided such that half was filtered and dried at 60 °C for 12 h. The remaining half of the samples were further subjected to ageing at 80 °C for 24 h as a possible second step to the synthesis procedure. Synthesis conditions, such as selected precursor materials and the MII:MIII ratio, were adapted from existing mechanochemical methods. LDH synthesis prior to ageing was successful with precursor materials observably present within each sample. No Cu-Al LDH was clearly identifiable. Ageing of samples resulted in an increase in the conversion of raw materials to LDH product. The research offers a promising ‘green’ method for LDH synthesis without the production of environmentally harmful salt effluent. The synthesis technique warrants further exploration with potential for future commercial up-scaling.


e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Bernd Bruchmann ◽  
Wolfgang Schrepp

Abstract Synthesizing hyperbranched polyurethanes in a one step process using commercially available raw materials: these were the primary conditions for this work. By taking advantage of intramolecular reactivity differences of isocyanate groups in diisocyanates in combination with reactivity differences of OH and NH groups in alkanolamines, it is possible to generate in situ AB2 molecules by controlling reactions of specific functional groups towards each other. This AA* + B*B2 approach works without protecting groups and opens up a simple and versatile strategy towards hyperbranched aromatic as well as aliphatic polyureaurethanes. Preferential diisocyanates for this synthesis were 2,4-toluylene diisocyanate and isophorone diisocyanate, whereas diethanolamine and diisopropanolamine were used as isocyanate-reactive counterparts.


2019 ◽  
Vol 6 (1) ◽  
pp. 184-191 ◽  
Author(s):  
Satyanarayana K. Konavarapu ◽  
Anindita Goswami ◽  
Anaparthi Ganesh Kumar ◽  
Susanta Banerjee ◽  
Kumar Biradha

Four new MOFs were shown to have appreciable proton conductivities, selective adsorption of water vapor over nitrogen and a tendency to selectively adsorb cationic dyes such as methylene blue and crystal violet.


2011 ◽  
Vol 110-116 ◽  
pp. 1928-1933 ◽  
Author(s):  
Yan Xiang Wang ◽  
Xiao Yan Li ◽  
Jian Sun ◽  
Yao Hui Hu

In the paper, ZnO nanopowders were synthesized by one-step hydrothermal synthesis using zinc acetate and sodium hydroxide as raw materials. The influences of molar concentration of NaOH and synthesis temperature on the properties of ZnO nanopowders were investigated. XRD and FSEM were used to characterize ZnO nanopowders. The results showed that; when the molar concentration of NaOH was 0.05 mol/L, 1mol/L and 2mol/L, ZnO micrometer powders were obtained. When the molar concentration of NaOH was 4mol/L, ZnO nanorods or nanosheets were obtained with different reaction temperature. When the temperature was 220°C, ZnO nanorods with the length of 500nm and diameter of 100nm, were synthesised. Pure ZnO nanopowders can be obtained at lower temperature of 100°C by using one-step hydrothermal synthesis. When the synthesis temperature was 100°C and the molar concentration of NaOH was 4mol/L, ZnO nanosheets were produced. The length, width and thickness of ZnO nanosheets were about 800 nm, 500nm and 80nm, respectively.


2013 ◽  
Vol 721 ◽  
pp. 173-176
Author(s):  
Mei Li ◽  
Jian Chun Jiang ◽  
Shou Hai Li ◽  
Kun Huang ◽  
Jian Ling Xia

Calcium zinc monomer salts were prepared via simple one-step double decomposition reaction with the aid of DA and PR as raw materials. FTIR analysis demonstrated that calcium zinc monomer salts of DA and PR have been successfully synthesized. The synergistic effect between DA-based and PR-based calcium zinc monomer salts, the effects of addition amount of DOP and the synergistic effects between epoxidized soybean oil (ESO) and calcium/zinc stabilizers on thermal stability of PVC were analyzed by means of the Congo-red paper, torque rheometer and thermogravimetric analysis methods. The results showed that preferable synergistic stabilizing effects were observed when DA calcium/zinc salt and polymerized rosin calcium/zinc salt were used together. In addition, appropriate dosage of DOP could inhibit the thermal degradation of PVC, and ESO also have certain synergetic effect with prepared novel calcium/zinc stabilizers.


2014 ◽  
Vol 1081 ◽  
pp. 313-317
Author(s):  
Yan Wen Lu ◽  
Yu Ge ◽  
Yue Feng Tang

A one-step carbon thermal method was used to prepare LiFePO4/C particles by using normal Fe2O3, LiH2PO4and sucrose as raw materials. The effect of H2content in the sintering atmosphere of N2on the morphology and the electrochemical performance were investigated. LiFePO4/C materials were characterized by X-ray diffraction, scanning electron microscopy and the elemental analyzer. The results show that the precursor sintering under the atmosphere of 8%H2+N2exhibits the highest electrochemical capacity (162.3 mAh/g at 0.1C) .


Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1463 ◽  
Author(s):  
Juliette Normand ◽  
Rocío Moriche ◽  
Cristina García-Garrido ◽  
Ranier Enrique Sepúlveda Ferrer ◽  
Ernesto Chicardi

In this work, an equiatomic TiNbTaMoZr-based high-entropy alloy (HEA) has been developed by a powder metallurgy route, which consists of a process of combined one-step low-temperature mechanical milling starting from the transition metals as raw materials and a subsequent pressureless sintering. In this way, the optimized synthesized specimen, after 10 h of milling time, showed two different body-centered cubic (bcc) TiNbTaMoZr alloys, which, after sintering at 1450 °C, 1 h of dwell time and a heating and cooling rate of 5 °C min−1, it remained formed as two bcc TiNbTaMoZr-based HEAs. This material, with micrometric and equiaxed particles, and with homogeneously distributed phases, presented a Young’s modulus that was significantly higher (5.8 GPa) and lower (62.1 GPa) than that of the usual commercially pure (cp) Ti and Ti6Al4V alloy used for bone-replacement implants. It also presented similar values to those of the HEAs developed for the same purpose. These interesting properties would enable this TiNbTaMoZr-based HEA to be used as a potential biomaterial for bulk or porous bone implants with high hardness and low Young´s modulus, thereby preventing the appearance of stress-shielding phenomena.


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