Relationship between specific surface area and pore dimension of high porosity nanoporous silicon - Model and experiment

2007 ◽  
Vol 204 (7) ◽  
pp. 2319-2328 ◽  
Author(s):  
Monuko du Plessis
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Porosity ◽  
Nanoporous Silicon ◽  
Pore Dimension

In-situ controlled synthesis of NiFe MOF materials with excellent electrocatalytic performances for water splitting

2021 ◽  
Vol 14 (02) ◽  
pp. 2151011
Author(s):  
Jingwen Jia ◽  
Longfu Wei ◽  
Ziting Guo ◽  
Fang Li ◽  
Changlin Yu ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Water Splitting ◽  
Specific Surface Area ◽  
High Performance ◽  
Alkaline Condition ◽  
High Porosity ◽  
Large Specific Surface Area ◽  
Electrocatalytic Performance

Metal–organic frameworks (MOFs) are the electrocatalytic materials with large specific surface area, high porosity, controllable structure and monodisperse active center, which is a promising candidate for the application of electrochemical energy conversion. However, the electrocatalytic performance of pure MOFs is seriously limited its poor conductivity and stability. In this work, high-performance electrocatalyst was fabricated through combining NiFe/MOF on nickel foam (NF) via in-situ growth strategy. Through rational control of the time and ratio in reaction precursors, we realized the effective manipulation of the growth behavior, and further investigated the electrocatalytic performance in water splitting. The catalyst presented excellent electrocatalytic performance for water splitting, with low overpotential of 260 mV in alkaline condition at a current density of 50 mA[Formula: see text], which is benefited from the large specific surface area and active sites. This study demonstrates that the rational design of NiFe MOF/NF plays a significant role in high-performance electrocatalyst.

Using Activated Diatomite as Adsorbent for Treatment of Arsenic Contaminated Water

2020 ◽  
Vol 850 ◽  
pp. 16-21
Author(s):  
Hoc Thang Nguyen ◽  
Phong Thanh Dang
Keyword(s):  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Contaminated Water ◽  
Viet Nam ◽  
High Porosity ◽  
Room Condition ◽  
Main Chemical Composition ◽  
Adsorbent Capacity

Diatomite or diatomaceous earth (DE) is one of materials which can be used as an adsorbent to treat heavy metal ions from waste water, even there are many factories used it to clean the water for drinking. However, natural DE (raw DE) has very low adsorption capacity because of low specific surface area. In this work, natural DE from Lam Dong province, Viet Nam was demagnetized to remove iron and activated by HCl solution for 90 minutes with concentration of 10% at room condition. Adsorbent capacity was evaluated using As solution and the results show that the activated diatomite has adsorption capacity three times higher than that of raw DE, and the specific surface area of activated diatomite was increased 47.5% with the main chemical composition of 90.8% SiO2 and high porosity

scholarly journals Manufacture of Fine-Pored Ceramics by the Gelcasting Method

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Bronisław Psiuk ◽  
Anna Gerle ◽  
Małgorzata Osadnik ◽  
Andrzej Śliwa
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Design Theory ◽  
Nanoporous Materials ◽  
Silica Sol ◽  
High Porosity ◽  
Simple Method ◽  
Fine Grained ◽  
Wide Range

The fine-pored materials represent a wide range of applications and searches are being continued to develop methods of their manufacturing. In the article, based on measurements on fine-grained powders of Al2O3, TiO2, and SiO2, it has been demonstrated that gelcasting can be relatively simple method of obtaining of nanoporous materials with high values of both specific surface area and open porosity. The powders were dispersed in silica sol, and the gelling initiator was NH4Cl. The usefulness of experiment design theory for developing of fine-pored materials with high porosity and specific surface area was also shown.

scholarly journals Preparation of Electrospun Active Molecular Membrane and Atmospheric Free Radicals Capture

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3037 ◽  
Author(s):  
Wang ◽  
Su ◽  
Yu ◽  
Li ◽  
Ma ◽  
...  
Keyword(s):  
Free Radicals ◽  
Impact Strength ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Porosity ◽  
Large Specific Surface Area ◽  
Optimal Parameters ◽  
Electrospun Membranes ◽  
Reaction Capacity

We load the natural active molecules onto the spin film in an array using electrospinning techniques. The electrospun active molecular membranes we obtain in optimal parameters exhibit excellent capacity for scavenging radical. The reaction capacity of three different membranes for free radicals are shown as follow, glycyrrhizin acid membrane > quercetin membrane > α-mangostin membrane. The prepared active molecular electrospun membranes with a large specific surface area and high porosity could increase the interaction area between active molecules and free radicals. Additionally, it also has improved anti-airflow impact strength, anti-contaminant air molecular interference ability, and the ability to capture free radicals.

scholarly journals Porosity model and pore evolution of transitional shales: an example from the Southern North China Basin

2020 ◽  
Vol 17 (6) ◽  
pp. 1512-1526
Author(s):  
Xiao-Guang Yang ◽  
Shao-Bin Guo
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Specific Surface Area ◽  
Mineral Content ◽  
High Specific Surface Area ◽  
High Porosity ◽  
Mechanical Compaction ◽  
Pore Evolution

AbstractThe evolution of shale reservoirs is mainly related to two functions: mechanical compaction controlled by ground stress and chemical compaction controlled by thermal effect. Thermal simulation experiments were conducted to simulate the chemical compaction of marine-continental transitional shale, and X-ray diffraction (XRD), CO2 adsorption, N2 adsorption and high-pressure mercury injection (MIP) were then used to characterize shale diagenesis and porosity. Moreover, simulations of mechanical compaction adhering to mathematical models were performed, and a shale compaction model was proposed considering clay content and kaolinite proportions. The advantage of this model is that the change in shale compressibility, which is caused by the transformation of clay minerals during thermal evolution, may be considered. The combination of the thermal simulation and compaction model may depict the interactions between chemical and mechanical compaction. Such interactions may then express the pore evolution of shale in actual conditions of formation. Accordingly, the obtained results demonstrated that shales having low kaolinite possess higher porosity at the same burial depth and clay mineral content, proving that other clay minerals such as illite–smectite mixed layers (I/S) and illite are conducive to the development of pores. Shales possessing a high clay mineral content have a higher porosity in shallow layers (< 3500 m) and a lower porosity in deep layers (> 3500 m). Both the amount and location of the increase in porosity differ at different geothermal gradients. High geothermal gradients favor the preservation of high porosity in shale at an appropriate Ro. The pore evolution of the marine-continental transitional shale is divided into five stages. Stage 2 possesses an Ro of 1.0%–1.6% and has high porosity along with a high specific surface area. Stage 3 has an Ro of 1.6%–2.0% and contains a higher porosity with a low specific surface area. Finally, Stage 4 has an Ro of 2.0%–2.9% with a low porosity and high specific surface area.

scholarly journals Influence of Structure-Directing Additives on the Properties of Poly(methylsilsesquioxane) Aerogel-Like Materials

Gels ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 6 ◽  
Author(s):  
Marta Ochoa ◽  
Alyne Lamy-Mendes ◽  
Ana Maia ◽  
António Portugal ◽  
Luísa Durães
Keyword(s):  
Specific Surface ◽  
Bulk Density ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Porosity ◽  
Poly Ethylene Glycol ◽  
Optimum Amount ◽  
Molar Ratios ◽  
Fine Control ◽  
Poly Ethylene

The effect of glycerol (GLY) and poly(ethylene glycol) (PEG) additives on the properties of silica aerogel-like monoliths obtained from methyltrimethoxysilane (MTMS) precursor was assessed. The tested molar ratios of additive/precursor were from 0 to 0.1 and the lowest bulk densities were obtained with a ratio of 0.025. When a washing step was performed in the sample containing the optimum PEG ratio, the bulk density could be reduced even further. The analysis of the material’s microstructure allowed us to conclude that GLY, if added in an optimum amount, originates a narrower pore size distribution with a higher volume of mesopores and specific surface area. The PEG additive played a binder effect, leading to the filling of micropores and the appearance of large pores (macropores), which caused a reduction in the specific surface area. The reduction of the bulk density and the microstructural changes in the aerogels induced by adding a small amount of these additives confirm the possibility of fine control of properties of these lightweight materials. The achieved high porosity (97%) and low thermal conductivity (~35 mW·m−1·K−1) makes them suitable to be used as thermal insulators.

Preparation and characterization of porous cordierite for potential use in cellular ceramics

2009 ◽  
Vol 63 (4) ◽  
Author(s):  
Marta Valášková ◽  
Gražyna Martynková
Keyword(s):  
Specific Surface ◽  
Size Distribution ◽  
Surface Area ◽  
Aluminum Hydroxide ◽  
Specific Surface Area ◽  
Porous Ceramics ◽  
High Porosity ◽  
Cordierite Ceramics ◽  
Potential Use

AbstractCordierite porous ceramics Z, X, and K were prepared using three mixtures of clay minerals: Z from kaolinite, talc, and aluminum hydroxide, X from kaolinite, talc, vermiculite, and aluminum hydroxide, and K from kaolinite, talc, and magnesium oxide. Ceramics were different in porosity, specific surface area, cordierite polymorphs, and secondary crystalline phases. Vermiculite influenced textural architecture of calcined cordierite ceramics X and predestinated crystallization of the high-temperature hexagonal α-cordierite with secondary minerals enstatite, spinel and corundum. Ceramics Z contained low-temperature orthorhombic β-cordierite, enstatite, and corundum, K was diphase of β-cordierite and forsterite. Total pore area (TPA) and specific surface area (SSA) of X, in spite of the higher porosity and the pore size distribution in the range of 300–1000 nm, were smaller in comparison with TPA and SSA of Z. Ceramics K retained high porosity, two maxima at 300–1000 nm and 50–200 nm in the pores size distribution, and the highest TPA and SSA compared to those observed in ceramics Z and X.

Enhanced Air Filtration Performances by Coating Aramid Nanofibres on a Melt-blown Nonwoven

Nanoscale ◽  
2021 ◽  
Author(s):  
Kangli Xu ◽  
Lei Zhan ◽  
Rui Yan ◽  
Qinfei Ke ◽  
Anlin Yin ◽  
...  
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Small Diameter ◽  
High Porosity ◽  
Large Specific Surface Area ◽  
Air Filtration ◽  
Small Pore Size ◽  
Small Pore

Nanofibre membranes with small diameter and large specific surface area are widely used in filtration fields due to their small pore size and high porosity. To date, aramid nanofibres (ANFs)...

scholarly journals Porous Carrageenan-Derived Carbons for Efficient Ciprofloxacin Removal from Water

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1004 ◽  
Author(s):  
João Nogueira ◽  
Maria António ◽  
Sergey Mikhalev ◽  
Sara Fateixa ◽  
Tito Trindade ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Porous Carbon ◽  
Carbon Materials ◽  
Activated Carbons ◽  
Chemical Activation ◽  
High Specific Surface Area ◽  
High Porosity ◽  
Porous Carbon Materials

Porous carbon materials derived from biopolymers are attractive sorbents for the removal of emerging pollutants from water, due to their high specific surface area, high porosity, tunable surface chemistry, and reasonable cost. However, carrageenan biopolymers were scarcely investigated as a carbon source to prepare porous carbon materials. Herein, hydrochars (HCs) and porous activated carbons (ACs) derived from natural occurring polysaccharides with variable sulfate content (κ-, ι- and λ-carrageenan) were prepared and investigated in the uptake of ciprofloxacin, which is an antibiotic detected in water sources and that poses serious hazards to public health. The materials were prepared using hydrothermal carbonization and subsequent chemical activation with KOH to increase the available surface area. The activated carbons were markedly microporous, presenting high specific surface area, up to 2800 m2/g. Activated carbons derived from κ- and λ-carrageenan showed high adsorption capacity (422 and 459 mg/g, respectively) for ciprofloxacin and fast adsorption kinetics, reaching the sorption equilibrium in approximately 5 min. These features place the ACs investigated here among the best systems reported in the literature for the removal of ciprofloxacin from water.

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