A dynamic microporous magnet exhibiting room-temperature thermal hysteresis, variable magnetic ordering temperatures and highly selective adsorption for CO2

2019 ◽  
Vol 7 (2) ◽  
pp. 218-222
Author(s):  
Zhong-Yi Liu ◽  
Hong Zhao ◽  
Wei-Chao Song ◽  
Xiu-Guang Wang ◽  
Zheng-Yu Liu ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Room Temperature ◽  
Thermal Hysteresis ◽  
Selective Adsorption ◽  
Magnetic Ordering ◽  
Temperature Hysteresis ◽  
High Adsorption ◽  
Adsorption Selectivity

A dynamic microporous magnet exhibits a room-temperature hysteresis loop, variable magnetic ordering temperatures and high adsorption selectivity for CO2 over N2.

Magnetic, Spectral and Structural Aspects of Spin Transitions in Iron(II) Complexes of 2-(Pyrazol-3-yl)pyridine and 3-(Thiazol-2-yl)pyrazole

1999 ◽  
Vol 52 (2) ◽  
pp. 109 ◽  
Author(s):  
Lucia S. Harimanow ◽  
Kristian H. Sugiyarto ◽  
Donald C. Craig ◽  
Marcia L. Scudder ◽  
Harold A. Goodwin
Keyword(s):  
Hydrogen Bonding ◽  
Hysteresis Loop ◽  
Room Temperature ◽  
Thermal Hysteresis ◽  
Structural Data ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Thermal Hysteresis Loop ◽  
Lower Temperature ◽  
Structural Aspects

Tris(ligand)iron(II) complexes of 2-(pyrazol-3-yl)pyridine (3ppH) and 3-(thiazol-2-yl)pyrazole (3tpH) undergo temperature-induced singlet (1A1) ⇔ quintet (5T2) transitions. The transition in [Fe(3ppH)3] [CF3SO3]2.2H2O is continuous and centred above room temperature while that in the anhydrous triflate salt is discontinuous and is centred below room temperature. The latter transition occurs via a thermal hysteresis loop of width 12 K, Tc↓ and Tc↑ being 229 and 241 K, respectively. The displacement of the transition to lower temperature in the anhydrous salt is believed to be associated with the loss of hydrogen bonding involving the uncoordinated pyrazole >NH group and solvate water. In [Fe(3tpH)2(3tp)] [ClO4].2H2O and [Fe(3tpH)2(3tp)] [BF4].2H2O (3tp is the deprotonated ligand) continuous transitions are observed, centred below room temperature. In these instances the displacement is consistent with the intrinsically weaker field of the bidentate system containing two five-membered heterocycles. Structural data were obtained for [Fe(3ppH)3][CF3SO3]2.2H2O, [Fe(3tpH)3] [BF4]2.1·5H2O and [Ni(3tpH)3] [BF4]2.2(3tpH). The average metal–nitrogen distances in the complexes are 1·97, 2·18 and 2·09 Å, severally. The large difference in the distances for the two iron complexes arises from the different ground states: a singlet for the 3ppH complex and a quintet for the 3tpH complex. In all three salts there is extensive hydrogen bonding involving the pyrazole >NH groups, the anions and the solvate molecules. [Fe(3ppH)3] [CF3SO3]2.2H2O: monoclinic, space group P21/c, a 12·33(1), b 24·44(1), c 12·55(1) Å, β 115·27(4)°, Z 4. [Fe(3tpH)3] [BF4]2.1·5H2O: monoclinic, space group C 2/c, a 41·56(2), b 16·418(3), c 18·154(7) Å, β 106·94(2)°, Z 8. [Ni(3tpH)3] [BF4]2.2(3tpH):P bcn, a 14·928(2), b 15·310 (3), c 17·882 (3) Å, Z 4.

scholarly journals Synthesis and characterization of lead-free ternary component BST–BCT–BZT ceramic capacitors

2014 ◽  
Vol 04 (02) ◽  
pp. 1450014 ◽  
Author(s):  
Venkata Sreenivas Puli ◽  
Dhiren K. Pradhan ◽  
Brian C. Riggs ◽  
Shiva Adireddy ◽  
Ram S. Katiyar ◽  
...  
Keyword(s):  
Phase Transition ◽  
Dielectric Constant ◽  
Energy Density ◽  
Electric Field ◽  
Hysteresis Loop ◽  
Electric Fields ◽  
Room Temperature ◽  
Thermal Hysteresis ◽  
Lead Free ◽  
Maximum Electric Field

Polycrystalline sample of lead-free 1/3( Ba 0.70 Sr 0.30 TiO 3) + 1/3( Ba 0.70 Ca 0.30 TiO 3) + 1/3( BaZr 0.20 Ti 0.80 O 3)( BST - BCT - BZT ) ceramic was synthesized by solid state reaction method. Phase purity and crystal structure of as-synthesized materials was confirmed by X-ray diffraction (XRD). Temperature-dependent dielectric permittivity studies demonstrated frequency-independent behavior, indicating that the studied sample has typical diffuse phase transition behavior with partial thermal hysteresis. A ferroelectric phase transition between cubic and tetragonal phase was noticed near room temperature (~ 330 K). Bulk P–E hysteresis loop showed a saturation polarization of 20.4 μC/cm2 and a coercive field of ~ 12.78 kV/cm at a maximum electric field of ~ 115 kV/cm. High dielectric constant (ε ~ 5773), low dielectric loss (tan δ ~ 0.03) were recorded at room temperature. Discharge energy density of 0.44 J/cm3 and charge energy density of 1.40 J/cm3 were calculated from nonlinear ferroelectric hysteresis loop at maximum electric field. Dielectric constant at variable temperatures and electric fields, ferroelectric to paraelectric phase transition and energy storage properties were thoroughly discussed.

A microporous yttrium metal–organic framework of an unusual nia topology for high adsorption selectivity of C2H2and CO2over CH4at room temperature

2017 ◽  
Vol 1 (10) ◽  
pp. 1982-1988 ◽  
Author(s):  
Kang Liu ◽  
Xu Li ◽  
Dingxuan Ma ◽  
Yi Han ◽  
Baiyan Li ◽  
...  
Keyword(s):  
Room Temperature ◽  
Metal Organic Framework ◽  
High Adsorption ◽  
Adsorption Selectivity ◽  
Basic Sites ◽  
Metal Organic ◽  
Organic Framework

A new microporous yttrium MOF Y-H3TDPAT with Lewis basic sites on the pore surfaces was hydrothermally synthesized and structurally characterized as an unusualniatopology.

An arsenicniobate-based 3D framework with selective adsorption and anion-exchange properties

2016 ◽  
Vol 40 (3) ◽  
pp. 2220-2224 ◽  
Author(s):  
Ning Li ◽  
Yiwei Liu ◽  
Ying Lu ◽  
Danfeng He ◽  
Shumei Liu ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Selective Adsorption ◽  
High Adsorption ◽  
Adsorption Selectivity ◽  
Cationic Framework ◽  
3D Framework ◽  
Exchange Properties

An arsenicniobate-based cationic framework shows a high adsorption selectivity of water and ethanol and effectively removes toxic SCN− anions.

Room temperature study of the optical switching of a spin crossover compound inside its thermal hysteresis loop

2010 ◽  
Vol 96 (4) ◽  
pp. 041907 ◽  
Author(s):  
G. Gallé ◽  
D. Deldicque ◽  
J. Degert ◽  
Th. Forestier ◽  
J.-F. Létard ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Optical Switching ◽  
Room Temperature ◽  
Spin Crossover ◽  
Thermal Hysteresis ◽  
Temperature Study ◽  
Thermal Hysteresis Loop

Core-Shell Molecularly Imprinted Polymer Nanocomposites for Biomedical and Environmental Applications

2019 ◽  
Vol 25 (34) ◽  
pp. 3633-3644
Author(s):  
Nasrullah Shah ◽  
Saba Gul ◽  
Mazhar Ul-Islam
Keyword(s):  
Food Processing ◽  
Selective Adsorption ◽  
Environmental Applications ◽  
Core Shell ◽  
Template Molecule ◽  
Hollow Core ◽  
Imprinted Polymer ◽  
Adsorption Selectivity ◽  
Molecularly Imprinting Polymers ◽  
Relative Adsorption

: Core-shell polymers represent a class of composite particles comprising of minimum two dissimilar constituents, one at the center known as a core which is occupied by the other called shell. Core-shell molecularly imprinting polymers (CSMIPs) are composites prepared via printing a template molecule (analyte) in the coreshell assembly followed by their elimination to provide the everlasting cavities specific to the template molecules. Various other types of CSMIPs with a partial shell, hollow-core and empty-shell are also prepared. Numerous methods have been reported for synthesizing the CSMIPs. CSMIPs composites could develop the ability to identify template molecules, increase the relative adsorption selectivity and offer higher adsorption capacity. Keen features are measured that permits these polymers to be utilized in numerous applications. It has been developed as a modern technique with the probability for an extensive range of uses in selective adsorption, biomedical fields, food processing, environmental applications, in utilizing the plant's extracts for further applications, and sensors. This review covers the approaches of developing the CSMIPs synthetic schemes, and their application with special emphasis on uses in the biomedical field, food care subjects, plant extracts analysis and in environmental studies.

Weak ferromagnetic response in PbZr1−xTixO3 single crystals

2019 ◽  
Vol 7 (36) ◽  
pp. 11085-11089
Author(s):  
Iwona Lazar ◽  
Monika Oboz ◽  
Jerzy Kubacki ◽  
Andrzej Majchrowski ◽  
Julita Piecha ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Single Crystals ◽  
Room Temperature ◽  
Ferromagnetic Hysteresis ◽  
First Time ◽  
Ferromagnetic Hysteresis Loop ◽  
Weak Ferromagnetic

For the first time, a weak ferromagnetic hysteresis loop at room temperature has been observed in PbZr1−xTixO3 (PZT) single crystals.

scholarly journals Solvent-Free Synthesis of Phosphonic Graphene Derivative and Its Application in Mercury Ions Adsorption

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 485
Author(s):  
Robert Olszewski ◽  
Małgorzata Nadolska ◽  
Marcin Łapiński ◽  
Marta Prześniak-Welenc ◽  
Bartłomiej Cieślik ◽  
...  
Keyword(s):  
Adsorption Efficiency ◽  
Mercury Ions ◽  
High Adsorption ◽  
Adsorption Selectivity ◽  
Nickel Ions ◽  
Cadmium Ions ◽  
First Order ◽  
Bivalent Ions ◽  
Pseudo Second Order ◽  
Solvent Free Synthesis

Functionalized graphene was efficiently prepared through ball-milling of graphite in the presence of dry ice. In this way, oxygen functional groups were introduced into material. The material was further chemically functionalized to produce graphene derivative with phosphonic groups. The obtained materials were characterized by spectroscopic and microscopic methods, along with thermogravimetric analysis. The newly developed material was used as an efficient mercury adsorbent, showing high adsorption efficiency. The adsorption isotherms were fitted using Freundlich and Langmuir models. The adsorption kinetics were fitted with pseudo-first order and pseudo-second order models. Adsorption selectivity was determined in the presence of cadmium ions and nickel ions. The presence of mentioned bivalent ions in the solution did not affect mercury adsorption efficiency.

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