Optimizing Hydrogen Storage in MOFs through Engineering of Crystal Morphology and Control of Crystal Size

2021 ◽  
Author(s):  
Kuthuru Suresh ◽  
Darpandeep Aulakh ◽  
Justin Purewal ◽  
Donald J. Siegel ◽  
Mike Veenstra ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Crystal Size ◽  
Crystal Morphology ◽  
And Control

Investigation of irradiation-induced nucleation processes in silicon and germanium

1995 ◽  
Vol 53 ◽  
pp. 224-225
Author(s):  
Harry A. Atwater ◽  
C.M. Yang ◽  
K.V. Shcheglov
Keyword(s):  
Room Temperature ◽  
Crystal Size ◽  
Initial Distribution ◽  
Engineering Control ◽  
Size Evolution ◽  
Silicon And Germanium ◽  
Ge Quantum Dot ◽  
And Control ◽  
Germanium Quantum Dots ◽  
Kinetics Of

Studies of the initial stages of nucleation of silicon and germanium have yielded insights that point the way to achievement of engineering control over crystal size evolution at the nanometer scale. In addition to their importance in understanding fundamental issues in nucleation, these studies are relevant to efforts to (i) control the size distributions of silicon and germanium “quantum dots𠇍, which will in turn enable control of the optical properties of these materials, (ii) and control the kinetics of crystallization of amorphous silicon and germanium films on amorphous insulating substrates so as to, e.g., produce crystalline grains of essentially arbitrary size.Ge quantum dot nanocrystals with average sizes between 2 nm and 9 nm were formed by room temperature ion implantation into SiO2, followed by precipitation during thermal anneals at temperatures between 30°C and 1200°C[1]. Surprisingly, it was found that Ge nanocrystal nucleation occurs at room temperature as shown in Fig. 1, and that subsequent microstructural evolution occurred via coarsening of the initial distribution.

Microwave Molecular Sieves Synthesis and Capillary Crystal Growth by Geometric Confinement.

2003 ◽  
Vol 782 ◽  
Author(s):  
Steven B. Ogunwumi ◽  
John F. Wight ◽  
James C. Fajardo
Keyword(s):  
Molecular Sieves ◽  
Molecular Sieve ◽  
Crystal Size ◽  
Mesoporous Molecular Sieve ◽  
Guest Molecules ◽  
Microwave Hydrothermal ◽  
Geometric Confinement ◽  
Capillary Bundle ◽  
And Control ◽  
Mcm 41

ABSTRACTMicrowave heating is an alternate means for material processing. The technique is promising for the accelerated synthesis of new materials. Microwave molecular sieves synthesis is combined with capillary confinement as a novel synthetic method. It is successfully demonstrated in the preparation of small ZSM-5 crystals by microwave hydrothermal synthesis within 1–1.7 μm channels of a capillary bundle. The geometric and spatial confinement offered by the capillary is expected to define and control the resulting crystal size distribution and orientation.MCM-41, a mesoporous molecular sieve with a uni-dimensional regular array of hexagonal channels is investigated as a candidate for capillary confinement. The large porous channels of MCM-41(>35 å ) is attractive as a host for promoting inclusions of guest molecules or templates. The successful confinement of MCM-41 represents an important step towards the alignment of molecular sieves in a defined orientation within thin capillaries bundled (less than 5 μm channels). Ultimately, such an approach may be useful for the fabrication of new molecular sieve devices.

Hydrogen Storage in Nanostructured Mg-Base Alloys

2009 ◽  
Vol 5 ◽  
pp. 213-221 ◽  
Author(s):  
A.F. Palacios-Lazcano ◽  
J.L Luna-Sánchez ◽  
J. Jiménez-Gallegos ◽  
Francisco Cruz-Gandarilla ◽  
J. Gerardo Cabañas-Moreno
Keyword(s):  
Hydrogen Storage ◽  
Single Phase ◽  
Crystal Size ◽  
Argon Atmosphere ◽  
Nanocrystalline Alloys ◽  
Nominal Composition ◽  
Alloyed Powder ◽  
Mechanically Alloyed ◽  
Powder Alloys

Powders of elemental Mg, Zn, Al and Ag were milled in order to produce nanocrystalline alloys with nominal composition Mg98M2 (M=Zn, Al and Ag). Pure Mg was also mechanically milled without any additions. Single-phase nanocrystalline (crystal size 24-26 nm) Mg98M2 alloys were produced after 216 ks of milling. A passivity procedure was followed immediately after milling, by gradually exposing the alloy powders to air (~ 12 hrs). After this procedure, the mechanically alloyed powders were kept under argon atmosphere before being hydrided at 200 and 300 °C under 0.5 and 3 MPa P for 10 min. Previously milled (~ 1.5 years before) and passivated powder alloys (stored in air and referred to as “AE” samples) were also hydrided under the same conditions. No hydriding was observed in the as-received Mg powders (crystal size >> 100 nm), but the as-milled, passivated nanocrystalline alloys were partially hydrided (even the AE samples). The amounts of the MgH2 phase in the hydrided samples were larger in the Ar-stored than in the AE samples under all hydriding conditions. The possible role of MgO and Mg hydroxides, as well as of the alloying elements, on the hydriding behavior of the nanostructured, mechanically alloyed powder alloys is discussed.

Assembly of Amelogenin Proteolytic Products and Control of Octacalcium Phosphate Crystal Morphology

2003 ◽  
Vol 44 (1) ◽  
pp. 58-64 ◽  
Author(s):  
J. Moradian-Oldak ◽  
M. Iijima ◽  
N. Bouropoulos ◽  
H. B. Wen
Keyword(s):  
Crystal Morphology ◽  
Octacalcium Phosphate ◽  
And Control

Risk identification and control of stationary high-pressure hydrogen storage vessels

2009 ◽  
Vol 22 (6) ◽  
pp. 950-953 ◽  
Author(s):  
Ping Xu ◽  
Jinyang Zheng ◽  
Pengfei Liu ◽  
Rui Chen ◽  
Fangming Kai ◽  
...  
Keyword(s):  
High Pressure ◽  
Hydrogen Storage ◽  
Risk Identification ◽  
And Control ◽  
Pressure Hydrogen

Research into the Effects of Pour-Point Depressant on Different Wax-Contents Crude Oils

2011 ◽  
Vol 236-238 ◽  
pp. 804-807 ◽  
Author(s):  
Xiao Fei Zhao ◽  
Su Min Liu ◽  
Qing Long She ◽  
Hai Fei Wen ◽  
Jing Ma ◽  
...  
Keyword(s):  
Crystal Size ◽  
Crystal Morphology ◽  
Oil Fields ◽  
Crude Oils ◽  
Pour Point Depressant ◽  
Crystallization Peak ◽  
Point Depressant ◽  
Wax Crystal ◽  
Abnormal Points ◽  
Wax Crystallization

The oils studied in this work were three typical oils, sampled from Daqing, Jilin, Liaohe Oil Fields and marked with 1#, 2#, 3# respectively, with wax contents 20.06%, 26.2%, 32.9% separately. The effects of PPD on WATs, abnormal points, pour points, rheological properties and wax-crystal morphology were studied in detail in this paper. The results of experiments indicated that PPD lowers WATs and abnormal points, and decreases the viscosities of crude oils when they are non-Newtonian fluids. In wax-crystallization peak area, both high shear rate and increase of cooling rate make the effects of PPD decrease and the viscosity of oil increase. When 1# sample is reheated to some temperature below 50°C (for 2#, below 70°C), the effects of PPD reduce. With the increase of PPD’s dosage, the crystal size gets smaller and the dispersibility becomes better.

Modeling and Control of a Renewable Hybrid Energy System With Hydrogen Storage

2014 ◽  
Vol 22 (1) ◽  
pp. 169-179 ◽  
Author(s):  
Milana Trifkovic ◽  
Mehdi Sheikhzadeh ◽  
Khaled Nigim ◽  
Prodromos Daoutidis
Keyword(s):  
Hydrogen Storage ◽  
Energy System ◽  
Hybrid Energy System ◽  
Modeling And Control ◽  
Hybrid Energy ◽  
And Control

scholarly journals Effects of Solid-State Stretching on Microstructure Evolution and Physical Properties of Isotactic Polypropylene Sheets

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 618 ◽  
Author(s):  
Huajian Ji ◽  
Xulin Zhou ◽  
Xin Chen ◽  
Haili Zhao ◽  
Yu Wang ◽  
...  
Keyword(s):  
Solid State ◽  
Yield Point ◽  
Isotactic Polypropylene ◽  
Microstructure Evolution ◽  
Crystal Size ◽  
Crystal Morphology ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering

The microstructure evolution of an isotactic polypropylene (iPP) sheet during solid-state stretching was studied. The transition of the spherulites—cylindrites was evaluated using in-situ two-dimensional wide-angle and small-angle X-ray scattering methods. The crystallinity of stretched iPP sheets was characterized by differential scanning calorimetry. The crystal morphology was observed by means of scanning electron microscopy. It was found that the differences of crystal microstructure of the iPP sheet depended on the stretching strain, which promoted the orientation of molecular chains. Amorphous molecular chains in the spherulites oriented and formed into a mesophase near the yield point, and the partially ordered mesophase was further stretched to form an oriented cylindrite structure after the yield point. The highest relative content of cylindrites appeared at 15% strain. Notably, as the amorphous phase embedded into the lamellae layer, the crystal size decreased with the increase of strain, which indicated that the crystallinity of the stretched iPP sheet was much higher than that of unstretched iPP sheet. The induced cylindrites structure played a more important role in improving the mechanical properties and heat resistance of iPP sheets. Compared with the unstretched iPP sheets, the tensile strength increased by 28%, the notch impact toughness significantly increased by 78%, and the vicat softening point increased from 104 to 112 °C.

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