scholarly journals CO2-Mineralised Nesquehonite: A New “Green” Building Material

2021 ◽  
Vol 5 (1) ◽  
pp. 60
Author(s):  
Anthony Kastrinakis ◽  
Vasilios Skliros ◽  
Petros Tsakiridis ◽  
Maria Perraki
Keyword(s):  
Building Material ◽  
Building Materials ◽  
Co2 Storage ◽  
Green Building ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Natural Pozzolan ◽  
X Ray ◽  
Co2 Mineralization ◽  
Reactive Magnesia

Synthetic nesquehonite with a Mg(HCO3)OH·2H2O chemical formula is a solid product of CO2 mineralization with cementitious properties. It constitutes an “MHCH” (magnesium hydroxy-carbonate hydrate) phase and, along with dypingite and hydromagnesite, is considered to be a promising permanent and safe solution for CO2 storage with potential utilization as a supplementary material in “green” building materials. In this work, synthetic nesquehonite-based mortars were evaluated in terms of their compressive strengths. Nesquehonite was synthesized by CO2 mineralization under ambient conditions (25 °C and 1 atm). A saturated Mg2+ solution was used at a pH of 9.3. The synthesized nesquehonite was subsequently studied by means of optical microscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Impurity-free nesquehonite formed elongated fibers, often around a centerpiece, creating a rosette-like structure. The synthesized nesquehonite was mixed with reactive magnesia, natural pozzolan, standard aggregate sand and water to create a mortar. The mortar was cast into 5 × 5 × 5 silicone mold and cured in water for 28 days. A compressive strength of up to 22 MPa was achieved. An X-ray diffraction study of the cured mortars revealed the formation of brucite as the main hydration crystalline phase. Carbon dioxide mineralized nesquehonite is a very promising “green” building material with competitive properties that might prove to be an essential part of the circular economy industrial approach.

scholarly journals Magnesium Oxybromides MOB-318 and MOB-518: Brominated Analogues of Magnesium Oxychlorides

2020 ◽  
Vol 10 (11) ◽  
pp. 4032
Author(s):  
Anna-Marie Lauermannová ◽  
Michal Lojka ◽  
Filip Antončík ◽  
David Sedmidubský ◽  
Milena Pavlíková ◽  
...  
Keyword(s):  
Building Materials ◽  
Simultaneous Thermal Analysis ◽  
Heating Process ◽  
X Ray Diffraction ◽  
Sustainable Building ◽  
X Ray ◽  
Environmentally Sustainable ◽  
Transmission Electron ◽  
Magnesium Oxychloride ◽  
Sustainable Building Materials

The search for environmentally sustainable building materials is currently experiencing significant expansion. It is increasingly important to find new materials or reintroduce those that have been set aside to find a good replacement for Portland cement, which is widely used despite being environmentally insufficient and energy-intensive. Magnesium oxybromides, analogues to well-known magnesium oxychloride cements, fit both categories of new and reintroduced materials. In this contribution, two magnesium oxybromide phases were prepared and thoroughly analyzed. The stoichiometries of the prepared phases were 5Mg(OH)2∙MgBr2∙8H2O and 3Mg(OH)2∙MgBr2∙8H2O. The phase analysis was determined using X-ray diffraction. The morphology was analyzed with scanning and transmission electron microscopy. The chemical composition was studied using X-ray fluorescence and energy dispersive spectroscopy. Fourier transform infrared spectroscopy was also used. The thermal stability and the mechanism of the release of gasses linked to the heating process, such as water and hydrobromic acid evaporation, were analyzed using simultaneous thermal analysis combined with mass spectroscopy. The obtained results were compared with the data available for magnesium oxychlorides.

scholarly journals Discovery of Fe7O9: a new iron oxide with a complex monoclinic structure

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ryosuke Sinmyo ◽  
Elena Bykova ◽  
Sergey V. Ovsyannikov ◽  
Catherine McCammon ◽  
Ilya Kupenko ◽  
...  
Keyword(s):  
Applied Sciences ◽  
Crystal Structure ◽  
Iron Oxide ◽  
Iron Oxides ◽  
Industrial Applications ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Insight Into

Abstract Iron oxides are fundamentally important compounds for basic and applied sciences as well as in numerous industrial applications. In this work we report the synthesis and investigation of a new binary iron oxide with the hitherto unknown stoichiometry of Fe7O9. This new oxide was synthesized at high-pressure high-temperature (HP-HT) conditions, and its black single crystals were successfully recovered at ambient conditions. By means of single crystal X-ray diffraction we determined that Fe7O9 adopts a monoclinic C2/m lattice with the most distorted crystal structure among the binary iron oxides known to date. The synthesis of Fe7O9 opens a new portal to exotic iron-rich (M,Fe)7O9 oxides with unusual stoichiometry and distorted crystal structures. Moreover, the crystal structure and phase relations of such new iron oxide groups may provide new insight into the cycling of volatiles in the Earth’s interior.

The Development of Green Building Materials Trend in China

2013 ◽  
Vol 357-360 ◽  
pp. 1070-1073
Author(s):  
Bao Zhu Sheng
Keyword(s):  
Sustainable Development ◽  
Building Material ◽  
Building Materials ◽  
Civil Engineering ◽  
Green Building ◽  
Engineering Construction ◽  
Factors Influencing ◽  
Green Building Materials ◽  
History Of ◽  
Development Tendency

Building material is the base of civil engineering construction, in the history of thousands of years of development, building materials also gradually change and change, and is closely related to the progress of human civilization and the development of science and technology.Green building materials has the vital significance to the construction of a conservation-oriented society and sustainable development, in accordance with China's social development.This paper introduces the importance of the development of green building materials,analyzes some factors influencing the development of green building materials in China,and discusses the development tendency of green building materials in China.

Effect of NABr on the Pore Size and Surface Morphology of Cu Foam Prepared by Hydrogen Bubble Templating

2021 ◽  
Vol 880 ◽  
pp. 83-88
Author(s):  
Mary Donnabelle L. Balela ◽  
Reginald E. Masirag ◽  
Francis O. Pacariem Jr. ◽  
Juicel Marie D. Taguinod
Keyword(s):  
Polyethylene Glycol ◽  
Cuprous Oxide ◽  
Active Material ◽  
Current Collector ◽  
Hydrogen Bubble ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Foam ◽  
Interconnected Pores

Binderless supercapacitor electrodes are currently being employed to increase the surface contact between the active material and current collector, leading to enhanced capacitance. In binderless electrodes, the active material is directly grown on the surface of the current collector, omitting the use of insulative polymer-based binders. In this work, Cu foam was successfully electrodeposited on Cu sheet by dynamic hydrogen bubble templating (DHBT) using polyethylene glycol (PEG) and sodium bromide (NaBr) as additives. The current density was set at 3 A·cm-2 and electrodeposition was performed for 20 s. At 200 mg/L PEG, increasing the NaBr concentration from 0 to 80 mM produced Cu foam with decreasing pores sizes of about 75.15 to 34.10 μm. However, the walls of the interconnected pores became thicker as the pore diameters were reduced. This indicates that NaBr promotes Cu deposition rather than hydrogen evolution reaction (HER), leading to smaller pore sizes. X-ray diffraction confirms the oxidation of the Cu foam under ambient conditions forming cuprous oxide (Cu2O). The Cu2O/Cu foam was then utilized as binderless electrode for supercapacitor, resulting to a specific capacitance of 0.815 F·cm-2 at 5 mV·s-1. Results show the potential of the fabricated Cu2O/Cu foam as binderless electrode for pseudo-type supercapacitors.

scholarly journals X-ray diffraction study on new organic- natural building materials

2018 ◽  
Vol 22 ◽  
pp. 372-379 ◽  
Author(s):  
Raluca Fernea ◽  
Iacob Florea ◽  
Daniela Lucia Manea ◽  
Petru Pășcuță ◽  
Daniela Roxana Tămaș-Gavrea
Keyword(s):  
Diffraction Study ◽  
Building Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Natural Building

Complexes of trimethylsilyl trifluoromethanesulfonate with nitrogen, oxygen, and phosphorus donors

2016 ◽  
Vol 94 (4) ◽  
pp. 424-429 ◽  
Author(s):  
Alasdair P.M. Robertson ◽  
Saurabh S. Chitnis ◽  
Seth Chhina ◽  
Hector J. Cortes S. ◽  
Brian O. Patrick ◽  
...  
Keyword(s):  
Solid Phase ◽  
Donor Ligands ◽  
Solution Stability ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lewis Bases ◽  
Trimethylsilyl Trifluoromethanesulfonate ◽  
Solid State Structures ◽  
Lower Basicity

The Lewis acceptor chemistry of Me3SiOTf with p-block Lewis bases has been explored and a library of complexes has been characterized by spectroscopic and, where possible, crystallographic methods. Compounds with the generic formula [Me3Si(L)][OTf] (L = 4-dmap, pyr, imz, OPMe3, OPCy3, OPPh3, OpyrMe, dmso, PMe3) were isolated from 1:1 mixtures of Me3SiOTf and the respective ligand in CH2Cl2. Characterization by NMR spectroscopy confirmed the solution stability of all but [Me3Si(PMe3)][OTf], with indications that the latter dissociates into PMe3 and Me3SiOTf. Solid-state structures of [Me3Si(4-dmap)][OTf], [Me3Si(pyr)][OTf], [Me3Si(OPCy3)][OTf], [Me3Si(OPPh3)][OTf], [Me3Si(OpyrMe)][OTf], and [Me3Si(PMe3)][OTf] were elucidated by single crystal X-ray diffraction, confirming the envisaged ionic formulations resulting from the displacement of the OTf anion from the silicon center of Me3SiOTf by the incoming ligand. Mixtures of Me3SiOTf with other related donors, including ChPPh3 (Ch = S or Se), NEt3, SMe2, PPh3, 2,2′-bipy, or Me2CO, show no evidence of reaction under ambient conditions, reflecting the lower basicity and (or) greater steric encumbrance of these ligands. Reactions of Me3SiOTf with bis-donor ligands yielded complexes of the generic formulae [Me3Si(L–L)SiMe3][OTf]2 (L–L = 4,4′-bipy, tmeda, dmpe) and [Me3Si(L–L)][OTf] (L–L = 4,4′-bipy, tmeda, dmpe). The tmeda and dmpe complexes, however, were found to dissociate in solution, with complexes only prevailing in the solid phase. X-ray diffraction studies of [Me3Si(4,4′-bipy)SiMe3][OTf]2 and [Me3Si(dmpe)SiMe3][OTf]2 confirmed the expected connectivities and ionic formulations, with Si–ligand bond lengths comparable to those observed in [Me3Si(pyr)][OTf] and [Me3Si(PMe3)][OTf], respectively.

Crystallization of nanostructured cobalt hydroxide carbonate at ambient conditions: a key precursor of Co3O4

2016 ◽  
Vol 80 (6) ◽  
pp. 995-1011 ◽  
Author(s):  
J. González-López ◽  
Á. Fernández-González ◽  
A. Jiménez
Keyword(s):  
Transformation Process ◽  
Cobalt Hydroxide ◽  
Small Range ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Lamellar Crystal ◽  
X Ray ◽  
Platelet Morphology ◽  
Transmission Electron ◽  
Material Sciences

AbstractCrystals of Co2CO3(OH)2have been synthesized under ambient conditions, in contrast to hydrothermal methods reported previously. We have developed a simple but efficient methodology to obtain an initial amorphous phase that evolves to a crystalline cobalt hydroxide carbonate after one week of maturation. X-ray diffraction analysis indicates that this phase crystallizes in the space groupP21/a(a= 12.886(6),b= 9.346(3),c= 3.156(1) Å, β = 110.358(6)°). The platelet morphology of Co2CO3(OH)2agrees with its lamellar crystal structure. High-resolution transmission electron microscopy (HRTEM) reveals that each individual platelet is comprised of nanodomains disoriented with respect to their neighbours. The kinetics and the activation energy (Ea= 6.26 kJ mol–1) of the transformation process have been estimated using the rate constant method. The precipitation of solids leads to a decrease in the cobalt concentration in the solution (∼88%) reaching values of ∼150 ppm, which can be considered a successful reduction from the perspective of water quality. The calcination in air of the synthetized platelets produced exclusively Co3O4. The thermo-X-ray difraction results confirm that Co2CO3(OH)2is transformed over a small range of temperatures (225–235°C) into pure Co3O4. HRTEM images show that the lamellar nanomorphology is preserved in the Co3O4phase. Therefore, understanding the crystallization behaviour of Co2CO3(OH)2can help to minimize environmental problems caused by cobalt pollution and may facilitate the management of methods to obtain phases with specific nanomorphologies used widely in material sciences.

Contributions to the Chemistry of Boron, 204 [1] An Unusual [2+2]-Cycloaddition Reaction of Dicobalt Octacarbonyl

1990 ◽  
Vol 45 (6) ◽  
pp. 828-832 ◽  
Author(s):  
Sreelatha Channareddy ◽  
Gerald Linti ◽  
Heinrich Nöth
Keyword(s):  
Diffraction Analysis ◽  
Cycloaddition Reaction ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dicobalt Octacarbonyl

Dicobalt octacarbonyl reacts with (9-fluorenylidene)(2,2,6,6-tetramethylpiperidino)borane (1) at ambient conditions in an unexpected [2+2]-cycloaddition to yield an oxaboretane derivative (2). The structure of 2 has been determined by X-ray diffraction analysis. Similarities between the complex 2 and other oxaboretanes are discussed.

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