A systemic investigation on the hydroxylation behavior of caustic magnesia and magnesia sinter

Salomão, R.; Arruda, Cezar C.; Kawamura, Mirian A.

doi:10.1016/j.ceramint.2015.07.012

Cited by 18 publications

(20 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Knowledge about the chemical and physical stability of MgO‐based nanostructures is of key interest for their processing, for example, for the production of ceramics, and for their use as materials components at elevated temperatures, such as in catalysis . The interaction of MgO particles with pristine, adsorbate free surfaces with gaseous or liquid water has been studied on particle ensembles in different size regimes .…”

Section: Introductionmentioning

confidence: 99%

“…processing, for example, for the production of ceramics, [13][14][15][16] and for their use as materials components at elevated temperatures, such as in catalysis. [17][18][19][20][21][22][23][24] The interaction of MgO particles with pristine, adsorbate free surfaces with gaseous or liquid water has been studied on particle ensembles in different size regimes.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Thin water films and particle morphology evolution in nanocrystalline MgO

et al. 2018

View full text Add to dashboard Cite

A key question in the field of ceramics and catalysis is how and to what extent residual water in the reactive environment of a metal oxide particle powder affects particle coarsening and morphology. With X‐ray Diffraction (XRD) and Transmission Electron Microscopy (TEM), we investigated annealing‐induced morphology changes on powders of MgO nanocubes in different gaseous H2O environments. The use of such a model system for particle powders enabled us to describe how adsorbed water that originates from short exposure to air determines the evolution of MgO grain size, morphology, and microstructure. While cubic nanoparticles with a predominant abundance of (100) surface planes retain their shape after annealing to T = 1173 K under continuous pumping with a base pressure of water p(H2O) = 10−5 mbar, higher water partial pressures promote mass transport on the surfaces and across interfaces of such particle systems. This leads to substantial growth and intergrowth of particles and simultaneously favors the formation of step edges and shallow protrusions on terraces. The mass transfer is promoted by thin films of water providing a two‐dimensional solvent for Mg2+ ion hydration. In addition, we obtained direct evidence for hydroxylation‐induced stabilization of (110) faces and step edges of the grain surfaces.

show abstract

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Thin water films and particle morphology evolution in nanocrystalline MgO

et al. 2018

View full text Add to dashboard Cite

show abstract

“…[1] While self-assembly driven by specific recognition between molecular ligands can provide programmable structures with high yield, the spontaneous organization of nanoparticles via the so-called oriented attachment process is more interesting because of its simplicity. [7] Herein, we describe the spontaneous assembly of monodisperse sub-10 nm MgO nanocubes mediated by the adsorp-tion of water molecules from the gas phase.A tr oom temperature and in the absence of any structure directing organic ligand, the particles spontaneously orient themselves to form one-dimensional arrays.Strikingly,instead of forming perfect stacked cube assemblies,s uch as observed for metal nanocubes in solution, [8] the MgO nanocubes form staggered assemblies,where the cubes are offset from each other. [7] Herein, we describe the spontaneous assembly of monodisperse sub-10 nm MgO nanocubes mediated by the adsorp-tion of water molecules from the gas phase.A tr oom temperature and in the absence of any structure directing organic ligand, the particles spontaneously orient themselves to form one-dimensional arrays.Strikingly,instead of forming perfect stacked cube assemblies,s uch as observed for metal nanocubes in solution, [8] the MgO nanocubes form staggered assemblies,where the cubes are offset from each other.…”

mentioning

confidence: 99%

“…[2,3] Such as elforganization proceeds via repeated attachment events of crystalline particles on specific crystal faces [3] and produces uncontaminated and chemically pure nanostructures,c rucial for fundamental studies in surface science and catalysis [4][5][6] and also for the organization and integration of nanoparticles into mesoscale building blocks and ceramic microstructures. [7] Herein, we describe the spontaneous assembly of monodisperse sub-10 nm MgO nanocubes mediated by the adsorp-tion of water molecules from the gas phase.A tr oom temperature and in the absence of any structure directing organic ligand, the particles spontaneously orient themselves to form one-dimensional arrays.Strikingly,instead of forming perfect stacked cube assemblies,s uch as observed for metal nanocubes in solution, [8] the MgO nanocubes form staggered assemblies,where the cubes are offset from each other.…”

mentioning

confidence: 99%

Hydroxylation Induced Alignment of Metal Oxide Nanocubes

et al. 2016

View full text Add to dashboard Cite

Water vapor is ubiquitous under ambient conditions and may alter the shape of nanoparticles. How to utilize water adsorption for nanomaterial functionality and structure formation, however, is a yet unexplored field. Herein, we report the use of water vapor to induce the self-organization of MgO nanocubes into regularly staggered one-dimensional structures. This transformation evolves via an initial alignment of the MgO cubes, the formation of intermediate elongated Mg(OH) structures, and their reconversion into MgO cubes arranged in staggered structures. Ab initio DFT modelling identifies surface-energy changes associated with the cube surface hydration and hydroxylation to promote the uncommon staggered stacked assembly of the cubes. This first observation of metal oxide nanoparticle self-organization occurring outside a bulk solution may pave novel routes for inducing texture in ceramics and represents a great test-bed for new surface-science concepts.

show abstract

“…Conversion of the reaction was calculated based on the weight lost by sample calcination at 500°C, carried out in triplicate, considering the MH decomposition temperature (400°C) (Equation 2) [34], [35] [36] [37]. This analysis ignored the possible hydroxylation of magnesite, because this happens only at high temperatures, at least 150°C [38].…”

Section: Methodsmentioning

confidence: 99%

Kinetic study of photocatalytic degradation of Ifos famide in a microchannel and simulation

Corbel¹,

Donat²,

Schneider³

2019

SDRP-JNMS

View full text Add to dashboard Cite

This paper aims to evaluate the kinetics of hydroxylation for two distinct magnesias from Brazilian mineral sources regarding their purity: A -92.44wt% and B -98.20wt% of MgO. The magnesias were characterized and hydroxylated in a CSTR (1,0L) under: 80°C, stirring rate of 950rpm and 30%w/w of solids, in triplicate. The results showed that the presence of natural impurities in caustic magnesia (Fe, Mn, Al, Ca) hindered the advance of the reaction, but not at the beginning, when the hydroxylation was similar for both samples, what is associated with the similar values of their surface area. The reaction stabilization was observed after two hours for both samples: Sample A -35.15%; Sample B -46.43%. The natural impurities of caustic magnesia influenced the development of hydroxylation after 30 minutes, causing a retardant effect probably due to their behavior as a physical-chemical barrier, hindering the ions diffusion though the solid matrix.

show abstract

A systemic investigation on the hydroxylation behavior of caustic magnesia and magnesia sinter

Cited by 18 publications

References 40 publications

Thin water films and particle morphology evolution in nanocrystalline MgO

Thin water films and particle morphology evolution in nanocrystalline MgO

Hydroxylation Induced Alignment of Metal Oxide Nanocubes

Kinetic study of photocatalytic degradation of Ifos famide in a microchannel and simulation

Contact Info

Product

Resources

About