scholarly journals Inorganic cation-tailored “trapdoor” effect of the silicoaluminophosphate zeolite for highly selective CO2 separation

2021 ◽  
Author(s):  
Xiaohe Wang ◽  
Nana Yan ◽  
Miao Xie ◽  
Puxu Liu ◽  
Pu Bai ◽  
...  
Keyword(s):  
Nanoporous Materials ◽  
Co2 Separation ◽  
Inorganic Cation ◽  
Small Pore

Functional nanoporous materials are widely explored for CO2 separation, in particular small-pore aluminosilicate zeolites having “trapdoor” effect. Such effect allows the specific adsorbate to push away the sited cations inside...

Revisiting the Thermal Conductivity of Nanoporous Materials

2009 ◽  
Author(s):  
Chandan Bera ◽  
Natalio Mingo ◽  
S. Volz
Keyword(s):  
Thermal Conductivity ◽  
Monte Carlo ◽  
Monte Carlo Calculation ◽  
Nanoporous Materials ◽  
The Past ◽  
Small Pore ◽  
Spurious Effect ◽  
Phonon Boltzmann Equation ◽  
Boundary Geometry ◽  
Correct Boundary Conditions

Although the thermal conductivity of nanoporous materials has been investigated in the past, previous models have overestimated the small pore limit. Various authors had proposed a cylindrical boundary geometry to mimic the pore’s environment. This permits to solve the phonon Boltzmann equation analytically [1] or numerically [2], but for fixed porosity it leads to a saturation of the thermal conductivity at small pore diameters. We show that such saturation is a spurious effect of the cylindrical boundary approximation. By implementing a Monte Carlo calculation with correct boundary conditions, we obtain considerably different thermal conductivities than predicted by the cylindrical boundary geometry. The approach is illustrated in the case of Si and SiGe nanoporous materials.

Time-resolved operando DRIFTS-MS study of the moisture tolerance of small-pore SAPO-34 molecular sieves during CH4/CO2 separation

2020 ◽  
Vol 298 ◽  
pp. 110071 ◽  
Author(s):  
Marta Romero ◽  
Juan C. Navarro ◽  
Luis F. Bobadilla ◽  
María I. Domínguez ◽  
Svetlana Ivanova ◽  
...  
Keyword(s):  
Molecular Sieves ◽  
Co2 Separation ◽  
Time Resolved ◽  
Small Pore

scholarly journals Stability of Zeolitic-imidazolate Frameworks in Humid Environments: Disentangling the Roles of Confined vs. Surface Water

2020 ◽  
Author(s):  
Mohammad R. Momeni ◽  
Farnaz A. Shakib
Keyword(s):  
Water Adsorption ◽  
Bulk Water ◽  
Nanoporous Materials ◽  
Mechanistic Study ◽  
Quantum Mechanical ◽  
Particle Sizes ◽  
Zeolitic Imidazolate Frameworks ◽  
Small Pore ◽  
Dynamics Simulations ◽  
Unsaturated Metal Sites

<div>Most of the chemistry in nanoporous materials with small pore sizes and windows are known to occur on the surface of the material which is in immediate contact with substrate/solvent, rather than inside the pores and channels. Experimentally, it is not straightforward to distinguish the chemistry of confinement from the surface. Comprehensive molecular dynamics simulations coupled with quantum mechanical calculations are employed to decipher stability of zeolitic-imidazolate frameworks in aqueous solutions. Water adsorption properties are compared and contrasted in crystalline bulk vs. nanopoarticles of ZIF-8 as a representative of the ZIF family in order to fully disentangle how water interacts with the surface of the material which contains coordinatively unsaturated metal sites compared to the pristine bulk. </div><div>Our following detailed mechanistic study reveals the significantly higher propensity of the surface with coordinatively unsaturated Zn$^{2+}$ sites toward water attack and hydrolysis. Our results presented in this work are general and are applicable to other nanoporous materials with small particle sizes, pores and windows and are useful in devising plans for synthesis of more robust water stable materials for applications that involve atmospheric and/or bulk water.</div>

scholarly journals Stability of Zeolitic-imidazolate Frameworks in Humid Environments: Disentangling the Roles of Confined vs. Surface Water

2020 ◽  
Author(s):  
Mohammad R. Momeni ◽  
Farnaz A. Shakib
Keyword(s):  
Water Adsorption ◽  
Bulk Water ◽  
Nanoporous Materials ◽  
Mechanistic Study ◽  
Quantum Mechanical ◽  
Particle Sizes ◽  
Zeolitic Imidazolate Frameworks ◽  
Small Pore ◽  
Dynamics Simulations ◽  
Unsaturated Metal Sites

<div>Most of the chemistry in nanoporous materials with small pore sizes and windows are known to occur on the surface of the material which is in immediate contact with substrate/solvent, rather than inside the pores and channels. Experimentally, it is not straightforward to distinguish the chemistry of confinement from the surface. Comprehensive molecular dynamics simulations coupled with quantum mechanical calculations are employed to decipher stability of zeolitic-imidazolate frameworks in aqueous solutions. Water adsorption properties are compared and contrasted in crystalline bulk vs. nanopoarticles of ZIF-8 as a representative of the ZIF family in order to fully disentangle how water interacts with the surface of the material which contains coordinatively unsaturated metal sites compared to the pristine bulk. </div><div>Our following detailed mechanistic study reveals the significantly higher propensity of the surface with coordinatively unsaturated Zn$^{2+}$ sites toward water attack and hydrolysis. Our results presented in this work are general and are applicable to other nanoporous materials with small particle sizes, pores and windows and are useful in devising plans for synthesis of more robust water stable materials for applications that involve atmospheric and/or bulk water.</div>

Surface modification to suppress small pore clogging in resistive pulse sensing

2020 ◽  
Vol 13 (11) ◽  
pp. 115002
Author(s):  
Yukichi Horiguchi ◽  
Yuji Miyahara
Keyword(s):  
Surface Modification ◽  
Resistive Pulse ◽  
Small Pore ◽  
Resistive Pulse Sensing ◽  
Pore Clogging

Design of Stratified Functional Nanoporous Materials for CO2 Capture and Conversion

2017 ◽  
Author(s):  
J. Karl Johnson ◽  
Jingyun Ye
Keyword(s):  
Nanoporous Materials

scholarly journals A case of pleuroperitoneal communication in which establishing a laparoscopic pneumoperitoneum was useful for the detection of a fistula

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Takehiko Manabe ◽  
Kenji Ono ◽  
Soichi Oka ◽  
Yuichiro Kawamura ◽  
Toshihiro Osaki
Keyword(s):  
Thoracic Surgery ◽  
Surgical Repair ◽  
Abdominal Cavity ◽  
Case Presentation ◽  
X Ray ◽  
Video Assisted Thoracic Surgery ◽  
Video Assisted ◽  
Pleuroperitoneal Communication ◽  
Small Pore ◽  
Chest X Ray

Abstract Background Pleuroperitoneal communication (PPC) is rarely observed, accounting for 1.6% of all patients who undergo continuous ambulatory peritoneal dialysis (CAPD). Although there have been several reports concerning the management of this condition, we have encountered several cases in which control failed. We herein report a valuable case of PPC in which laparoscopic pneumoperitoneum with video-assisted thoracic surgery (VATS) was useful for supporting the diagnosis and treatment. Case presentation The patient was a 58-year-old woman with chronic renal failure due to chronic renal inflammation who was referred to a nephrologist in our hospital to undergo an operation for the induction of CAPD. Post-operatively, she had respiratory failure, and chest X-ray and computed tomography (CT) showed right-sided hydrothorax that decreased when the injection of peritoneal dialysate was interrupted. Therefore, PPC was suspected, and she was referred to our department for surgical repair. We planned surgical treatment via video-assisted thoracic surgery. During the surgery, we failed to detect any lesions with thoracoscopy alone; we therefore added a laparoscopic port at her right-sided abdomen near the navel and infused CO2 gas into the abdominal cavity. On thoracoscopy, bubbles were observed emanating from a small pore at the central tendon of the diaphragm, which was considered to be the lesion responsible for the PPC. We closed it by suturing directly. Conclusions VATS with laparoscopic pneumoperitoneum should be considered as an effective method for inspecting tiny pores of the diaphragm, especially when the lesions responsible for PPC are difficult to detect.

scholarly journals Adsorbed xenon propellant storage: are nanoporous materials worth the weight?

2021 ◽  
Author(s):  
Melanie T Huynh ◽  
Nickolas Gantzler ◽  
Samuel Hough ◽  
David Roundy ◽  
Praveen Kumar Thallapally ◽  
...  
Keyword(s):  
High Pressures ◽  
Storage System ◽  
Nanoporous Materials ◽  
Bulk Storage

Xenon is used as a propellant for spacecraft. Conventionally, xenon is compressed to high pressures (75-300 bar) for bulk storage onboard the spacecraft. An adsorbed xenon storage system based on...

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