scholarly journals STABILIZATION OF LEACHATE IN AGGREGATES MADE WITH PLASTIC FROM WEEE

2021 ◽  
Author(s):  
Ariel Cappelletti ◽  
Lucas Peisino ◽  
Rosana Gaggino ◽  
Paula Marina Uberman ◽  
Lucas Colman ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Activated Carbon ◽  
Bisphenol A ◽  
Organic Solvent ◽  
Iodine Number ◽  
Tetrabromobisphenol A ◽  
Cement Matrix ◽  
Core Shell ◽  
Brominated Flame Retardant ◽  
The Core

A recycled plastic aggregate (RPA) was developed using the core-shell strategy, where the core is the plastic fraction of Waste of Electrical and Electronic Equipment (WEEE) and a cement matrix with stabilizing additives acts as the shell. The amount of brominated flame retardant (mainly tetrabromobisphenol-A) leached in curing water of RPAs was quantified using extraction with an organic solvent and gas chromatography methods (CG-FID). A clear relationship can be established between the characteristics of the stabilizing additive used and the amount of tetrabromobisphenol-A and bisphenol-A leached. The additive used was activated carbon, which in a manufacture scale may be provided by different suppliers with different mesoporous characteristics, which can be easily determined by the iodine number. The analysis proposed can be an effective way to determine if a particular activated carbon can be used as stabilizing additive in the production of RPAs with the developed technology.

scholarly journals Application of the nanoindentation method in assessing of properties of cement composites modified with silica-magnetite nanostructures

2018 ◽  
Vol 163 ◽  
pp. 02002 ◽  
Author(s):  
Elzbieta Horszczaruk ◽  
Roman Jedrzejewski ◽  
Jolanta Baranowska ◽  
Ewa Mijowska
Keyword(s):  
Mechanical Properties ◽  
Magnetite Nanoparticles ◽  
Positive Influence ◽  
Cement Matrix ◽  
Core Shell ◽  
Indentation Modulus ◽  
Cement Composites ◽  
Interfacial Zone ◽  
Berkovich Indenter ◽  
The Core

The results of investigation of the cement composites modified with 5% of silica-magnetite nanostructures of the core-shell type are presented in the paper. The nanoindentation method employing three-sided pyramidal Berkovich indenter was used in the research. The mechanical properties and microstructure of the modified cement composites were evaluated on the basis of the values of hardness and indentation modulus measured inside the cement matrix and in the aggregate-paste interfacial zone. The results were compared with those obtained for the reference composites without nanostructures. The positive influence of the presence of silica-magnetite nanoparticles on the tested properties was found out.

Magnetic Properties of Fe3O4/CoFe2O4 Composite Nanoparticles with Core/Shell Architecture

2020 ◽  
Vol 65 (10) ◽  
pp. 904
Author(s):  
V. O. Zamorskyi ◽  
Ya. M. Lytvynenko ◽  
A. M. Pogorily ◽  
A. I. Tovstolytkin ◽  
S. O. Solopan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Spinel Ferrite ◽  
Composite Nanoparticles ◽  
Core Shell ◽  
Cofe2o4 Nanoparticles ◽  
Core Diameter ◽  
The Core ◽  
Shell Particles ◽  
Interface Parameters ◽  
Shell Composite

Magnetic properties of the sets of Fe3O4(core)/CoFe2O4(shell) composite nanoparticles with a core diameter of about 6.3 nm and various shell thicknesses (0, 1.0, and 2.5 nm), as well as the mixtures of Fe3O4 and CoFe2O4 nanoparticles taken in the ratios corresponding to the core/shell material contents in the former case, have been studied. The results of magnetic research showed that the coating of magnetic nanoparticles with a shell gives rise to the appearance of two simultaneous effects: the modification of the core/shell interface parameters and the parameter change in both the nanoparticle’s core and shell themselves. As a result, the core/shell particles acquire new characteristics that are inherent neither to Fe3O4 nor to CoFe2O4. The obtained results open the way to the optimization and adaptation of the parameters of the core/shell spinel-ferrite-based nanoparticles for their application in various technological and biomedical domains.

Effect of Polyphosphate on Removal of Endocrine-Disrupting Chemicals of Nonylphenol and Bisphenol-A by Activated Carbons

2005 ◽  
Vol 40 (4) ◽  
pp. 484-490 ◽  
Author(s):  
Keun J. Choi ◽  
Sang G. Kim ◽  
Chang W. Kim ◽  
Seung H. Kim
Keyword(s):  
Activated Carbon ◽  
Bisphenol A ◽  
Surface Charge ◽  
Activated Carbons ◽  
Endocrine Disrupting Chemicals ◽  
Dipole Interaction ◽  
High Affinity ◽  
Calcium Polyphosphate ◽  
Endocrine Disrupting ◽  
Positively Charged

Abstract This study examined the effect of polyphosphate on removal of endocrine-disrupting chemicals (EDCs) such as nonylphenol and bisphenol-A by activated carbons. It was found that polyphosphate aided in the removal of nonylphenol and bisphenol- A. Polyphosphate reacted with nonylphenol, likely through dipole-dipole interaction, which then improved the nonylphenol removal. Calcium interfered with this reaction by causing competition. It was found that polyphosphate could accumulate on carbon while treating a river. The accumulated polyphosphate then aided nonylphenol removal. The extent of accumulation was dependent on the type of carbon. The accumulation occurred more extensively with the wood-based used carbon than with the coal-based used carbon due to the surface charge of the carbon. The negatively charged wood-based carbon attracted the positively charged calcium-polyphosphate complex more strongly than the uncharged coal-based carbon. The polyphosphate-coated activated carbon was also effective in nonylphenol removal. The effect was different depending on the type of carbon. Polyphosphate readily attached onto the wood-based carbon due to its high affinity for polyphosphate. The attached polyphosphate then improved the nonylphenol removal. However, the coating failed to attach polyphosphate onto the coal-based carbon. The nonylphenol removal performance of the coal-based carbon remained unchanged after the polyphosphate coating.

scholarly journals Iron Based Core-Shell Structures as Versatile Materials: Magnetic Support and Solid Catalyst

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 72
Author(s):  
Christian Zambrzycki ◽  
Runbang Shao ◽  
Archismita Misra ◽  
Carsten Streb ◽  
Ulrich Herr ◽  
...  
Keyword(s):  
Water Purification ◽  
Functional Materials ◽  
Core Material ◽  
Solid Catalyst ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
The Core ◽  
Shell Nanostructures ◽  
Sio2 Shell ◽  
Iron Based

Core-shell materials are promising functional materials for fundamental research and industrial application, as their properties can be adapted for specific applications. In particular, particles featuring iron or iron oxide as core material are relevant since they combine magnetic and catalytic properties. The addition of an SiO2 shell around the core particles introduces additional design aspects, such as a pore structure and surface functionalization. Herein, we describe the synthesis and application of iron-based core-shell nanoparticles for two different fields of research that is heterogeneous catalysis and water purification. The iron-based core shell materials were characterized by transmission electron microscopy, as well as N2-physisorption, X-ray diffraction, and vibrating-sample magnetometer measurements in order to correlate their properties with the performance in the target applications. Investigations of these materials in CO2 hydrogenation and water purification show their versatility and applicability in different fields of research and application, after suitable individual functionalization of the core-shell precursor. For design and application of magnetically separable particles, the SiO2 shell is surface-functionalized with an ionic liquid in order to bind water pollutants selectively. The core requires no functionalization, as it provides suitable magnetic properties in the as-made state. For catalytic application in synthesis gas reactions, the SiO2-stabilized core nanoparticles are reductively functionalized to provide the catalytically active metallic iron sites. Therefore, Fe@SiO2 core-shell nanostructures are shown to provide platform materials for various fields of application, after a specific functionalization.

scholarly journals Light-Scattering Simulations from Spherical Bimetallic Core–Shell Nanoparticles

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 359
Author(s):  
Francesco Ruffino
Keyword(s):  
Optical Properties ◽  
Light Scattering ◽  
Bimetallic Nanoparticles ◽  
Dominant Role ◽  
Scattered Light ◽  
Specific Interaction ◽  
Surface Enhanced Raman Spectroscopy ◽  
Localized Surface Plasmon ◽  
Core Shell ◽  
The Core

Bimetallic nanoparticles show novel electronic, optical, catalytic or photocatalytic properties different from those of monometallic nanoparticles and arising from the combination of the properties related to the presence of two individual metals but also from the synergy between the two metals. In this regard, bimetallic nanoparticles find applications in several technological areas ranging from energy production and storage to sensing. Often, these applications are based on optical properties of the bimetallic nanoparticles, for example, in plasmonic solar cells or in surface-enhanced Raman spectroscopy-based sensors. Hence, in these applications, the specific interaction between the bimetallic nanoparticles and the electromagnetic radiation plays the dominant role: properties as localized surface plasmon resonances and light-scattering efficiency are determined by the structure and shape of the bimetallic nanoparticles. In particular, for example, concerning core-shell bimetallic nanoparticles, the optical properties are strongly affected by the core/shell sizes ratio. On the basis of these considerations, in the present work, the Mie theory is used to analyze the light-scattering properties of bimetallic core–shell spherical nanoparticles (Au/Ag, AuPd, AuPt, CuAg, PdPt). By changing the core and shell sizes, calculations of the intensity of scattered light from these nanoparticles are reported in polar diagrams, and a comparison between the resulting scattering efficiencies is carried out so as to set a general framework useful to design light-scattering-based devices for desired applications.

Tuning and understanding the electronic effect of Co-Mo-O sties in bifunctional electrocatalysts for ultralong-lasting rechargable zinc-air battery

2021 ◽  
Author(s):  
Yi Guan ◽  
Nan Li ◽  
Jiao He ◽  
Yongliang Li ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Electronic Effect ◽  
Metal Organic Frameworks ◽  
Core Shell ◽  
Zeolitic Imidazolate Frameworks ◽  
Assembly Strategy ◽  
The Core ◽  
Bifunctional Electrocatalysts ◽  
Metal Organic ◽  
Air Battery

Herein, we report a post-assembly strategy by growing the bimetallic Co/Zn zeolitic imidazolate frameworks (BIMZIF) on the surface of the customized Mo metal-organic frameworks (MOFs) (Mo-MOF) to prepare the core-shell...

Sign in / Sign up

Export Citation Format

Share Document