scholarly journals Template-Based Synthesis of Nanoporous Hydroxyapatite

ISRN Ceramics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
E. Salimi ◽  
J. Javadpour ◽  
M. Anbia
Keyword(s):  
Pore Structure ◽  
Nonionic Surfactant ◽  
Surface Area ◽  
Cetyltrimethylammonium Bromide ◽  
Surfactant Concentration ◽  
Nonionic Surfactants ◽  
Bone Substitutes ◽  
Surface Areas ◽  
Desorption Isotherms ◽  
Adsorption Desorption

Hydroxyapatite (HAp) particles, a potential starting material for bone substitutes, with nanopores were synthesized in the presence of cetyltrimethylammonium bromide (CTAB) and P123 as cationic and nonionic surfactants as the structuring units. Effect of nonionic surfactant concentration on surface areas is also investigated. Based on N2 adsorption-desorption isotherms investigation, surface area increased up to 50 m2/g by using P123 and 147 m2/g by using CTAB as porosity agent. Pore structure remained even after the removal of surfactant and calcinations at 400°C.

scholarly journals Synthesis and Characterization of Nanoporous Monetite Which Can Be Applicable for Drug Carrier

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Esmael Salimi ◽  
Jafar Javadpour
Keyword(s):  
Surface Area ◽  
Cetyltrimethylammonium Bromide ◽  
Drug Carrier ◽  
Synthesis And Characterization ◽  
X Ray ◽  
Plate Shape ◽  
Desorption Isotherms ◽  
Adsorption Desorption

Wormhole-like mesostructured monetite was successfully synthesized using cetyltrimethylammonium bromide (C19H42BrN, CTAB), as a porosity agent. X-ray techniques and FTIR reveal that the crystalline grains consist of highly crystalline pure monetite phase. Monetite rods with diameter around 20–40 nm and length in the range of 50–200 nm were confirmed by FESEM and TEM. Based on N2adsorption-desorption isotherms investigation, surface area increased up to 31.5 m2/g due to the removal of surfactant after calcinations at 400°C. The results indicate that CTAB can not only affect monetite crystallization but also change particles morphology from plate shape to rod-like.

scholarly journals Tuning the hierarchical pore structure of graphene oxide through dual thermal activation for high-performance supercapacitor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeongpil Kim ◽  
Jeong-Hyun Eum ◽  
Junhyeok Kang ◽  
Ohchan Kwon ◽  
Hansung Kim ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Pore Structure ◽  
Specific Capacitance ◽  
Surface Area ◽  
Thermal Annealing ◽  
High Performance ◽  
Annealing Process ◽  
Supercapacitor Electrode ◽  
Simple Method ◽  
Surface Areas

AbstractHerein, we introduce a simple method to prepare hierarchical graphene with a tunable pore structure by activating graphene oxide (GO) with a two-step thermal annealing process. First, GO was treated at 600 °C by rapid thermal annealing in air, followed by subsequent thermal annealing in N2. The prepared graphene powder comprised abundant slit nanopores and micropores, showing a large specific surface area of 653.2 m2/g with a microporous surface area of 367.2 m2/g under optimized conditions. The pore structure was easily tunable by controlling the oxidation degree of GO and by the second annealing process. When the graphene powder was used as the supercapacitor electrode, a specific capacitance of 372.1 F/g was achieved at 0.5 A/g in 1 M H2SO4 electrolyte, which is a significantly enhanced value compared to that obtained using activated carbon and commercial reduced GO. The performance of the supercapacitor was highly stable, showing 103.8% retention of specific capacitance after 10,000 cycles at 10 A/g. The influence of pore structure on the supercapacitor performance was systematically investigated by varying the ratio of micro- and external surface areas of graphene.

Structural and surface aspects of thermally treated copper aluminium mixed hydroxides

1991 ◽  
Vol 69 (10) ◽  
pp. 1511-1515 ◽  
Author(s):  
Awad I. Ahmed ◽  
S. E. Samra ◽  
S. A. El-Hakam
Keyword(s):  
Pore Structure ◽  
Copper Content ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Areas ◽  
Structure Surface ◽  
Adsorption Desorption

CuO–Al2O3 catalysts containing various amounts of copper oxide have been prepared by precipitation. The phase changes were studied by X-ray diffraction. The results obtained revealed that the thermal treatment of solid CuO–Al2O3 at 700 °C produced only crystalline CuO. Heating to 900 °C led to the formation of copper alumina spinel together with unreacted CuO and γ-Al2O3. The spinel content was found to increase with increasing copper content. Nitrogen adsorption–desorption isotherms on the calcined samples have been measured. Surface areas have been calculated and the pore structure analysed. The textural properties of the system were found to depend on both the copper content and the calcination temperature. Key words: CuO, Al2O3 catalysts, structure, surface area, pore structure.

Variation in Pore Structure Characteristics with Composition in the High Volatile Bituminous Coal of Binchang Area

2014 ◽  
Vol 962-965 ◽  
pp. 890-898
Author(s):  
Jin Ping Li ◽  
Da Zhen Tang ◽  
Ting Xu Yu ◽  
Gang Sun
Keyword(s):  
Low Temperature ◽  
Pore Structure ◽  
Parallel Plate ◽  
Bituminous Coal ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Test Results ◽  
Structure Characteristics ◽  
Desorption Isotherms ◽  
Adsorption Desorption

Pore structure characteristics and the effect of lithotype and maceral on pore for three types of high-volatile bituminous coals from Binchang area were investigated by combined low-temperature nitrogen adsorption/desorption, nuclear magnetic resonance (NMR), scanning electron microscope (SEM) and maceral analysis. The low temperature N2 adsorption/desorption test results show that: micropores are more abundant than transitional pores with high BET surface area; two types of pore structures can be identified by adsorption/desorption isotherms; Pore morphology is mainly represented by well-connected, ink-bottled, cylindrical and parallel plate pores. NMR T2 distributions at full saturated condition are apparent or less obvious trimodal and three types of T2 distributions are identified; Seepage pores are better developed when compared with the middle-high rank coal. Further research found that the three coal lithotypes are featured by remarkably different pore structure characteristics and maceral contents of coal are linearly correlated to some of pore structure parameters.

scholarly journals Adsorptive removal of antibiotics from water using peanut shells from agricultural waste

RSC Advances ◽  
2018 ◽  
Vol 8 (24) ◽  
pp. 13546-13555 ◽  
Author(s):  
Rui Li ◽  
Yuling Zhang ◽  
Wenlei Chu ◽  
Zaixing Chen ◽  
Jiali Wang
Keyword(s):  
Porous Structure ◽  
Pore Size ◽  
Surface Area ◽  
Agricultural Waste ◽  
Adsorptive Removal ◽  
Peanut Shells ◽  
Desorption Isotherms ◽  
Adsorption Desorption

The porous structure of the materials was determined using the surface area and pore size analyzer (JW-BK132F) by N2 adsorption–desorption isotherms at 77 K.

Influence of Gel Aging Time on the Properties of Various Silica Aerogels Synthesized from Water Glass

2016 ◽  
Vol 866 ◽  
pp. 176-180 ◽  
Author(s):  
Sevil Yücel ◽  
Burcu Karakuzu ◽  
Pınar Terzioğlu ◽  
Tülay Merve Temel
Keyword(s):  
Aging Time ◽  
Water Glass ◽  
Silica Aerogels ◽  
Bet Surface Area ◽  
Porous Network ◽  
Surface Areas ◽  
Calcium Magnesium ◽  
Desorption Isotherms ◽  
Microscopy Techniques ◽  
Adsorption Desorption

In the present paper, water glass was used to synthesize silica aerogels and calcium magnesium silica aerogels. The present research was aimed to investigate the effect of gel aging time (1 and 24 hours) on the physical and surface properties of aerogels. Brunauer-Emmett-Teller, Barrett-Joyner-Halenda, Fourier Transform Infrared spectroscopy and scanning electron microscopy techniques were used to characterize aerogels. Successful formation of nanopores (2.8-4.4 nm) was approved by N2 adsorption/desorption isotherms. The aerogels contained porous network structure with different surface areas (388.9-729.9 m2 g-1). Aging for longer times led to an ability to decrease the density of the aerogels. The bulk density was higher in silica aerogels than in calcium magnesium silica aerogels. The well-tailored network matrix with high BET surface area (729.9 m2 g-1) and low density (0.116 g cm-3) was achieved via 24 hours gel aging of calcium magnesium silica aerogel.

Nitrogen and Water Sorption Properties of Ethyl-Substituted Silica Aerogels and Xerogels

1994 ◽  
Vol 371 ◽  
Author(s):  
Chunling Liu ◽  
Sridhar Komarneni
Keyword(s):  
Pore Structure ◽  
Surface Area ◽  
Water Sorption ◽  
Ph Value ◽  
High Surface ◽  
High Surface Area ◽  
Silica Aerogels ◽  
Modified Silica ◽  
Surface Areas ◽  
Water Sorption Properties

AbstractHigh surface area ethyltrimethoxysilane (ETMS) modified silica aerogels and xerogels were synthesized by cohydrolyzing the mixtures of ETMS and tetramethylorthosilicate (TMOS). The effects of ETMS content, pH value and solvent addition were investigated. The surface area, pore structure and hydrophobicity were studied using nitrogen and water sorption measurements. By ETMS modification of TMOS gels, high surface area, density and hydrophobicity were achieved. The 25 mole% ETMS-75 mole% TMOS was found to be the best composition for both aerogel and xerogel, which are hydrophobic and have surface areas of 1221 and 832 m2/g, respectively.

scholarly journals Structural Study of Microporous Xerogels Prepared by Polycondensation of Pyrogallol with Formaldehyde

2010 ◽  
Vol 6 (1) ◽  
pp. 878-883 ◽  
Author(s):  
Rebeh Moussaoui ◽  
Mongi Ben Mosbah ◽  
Younes Moussaoui ◽  
Elimame Elaloui
Keyword(s):  
Specific Surface ◽  
Aqueous Medium ◽  
Surface Area ◽  
Absorption Spectra ◽  
Structural Study ◽  
Perchloric Acid ◽  
Nitrogen Adsorption ◽  
Desorption Isotherms ◽  
Adsorption Desorption ◽  
Ftir Absorption Spectra

Microporous xerogels were prepared by polycondensation of pyrogallol with formaldehyde catalyzed by perchloric acid in aqueous medium. The samples were characterized by FTIR absorption spectra. The micro-porosity and the specific surface area are characterized by nitrogen adsorption - desorption isotherms. The obtained characteristics depend on the conditions of polycondensation.

scholarly journals Sorption of Methylene Blue for Studying the Specific Surface Properties of Biomass Carbohydrates

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1115
Author(s):  
Tatiana Skripkina ◽  
Ekaterina Podgorbunskikh ◽  
Aleksey Bychkov ◽  
Oleg Lomovsky
Keyword(s):  
Methylene Blue ◽  
Specific Surface ◽  
Surface Area ◽  
Surface Characterization ◽  
Gas Adsorption ◽  
Comparative Method ◽  
Nitrogen Adsorption ◽  
Surface Areas ◽  
Nitrogen Adsorption Isotherms ◽  
Adsorption Desorption

The surface area is an important parameter in setting any biorefining technology. The aim of this study was to investigate the applicability of sorption of methylene blue to characterize the surface of the main biomass carbohydrates: α-cellulose, sigmacell cellulose, natural gum, β-glucan, and starch. The morphology of particles of the model objects was studied by scanning electron microscopy. Nitrogen adsorption isotherms demonstrate that the selected carbohydrates are macroporous adsorbents. The monolayer capacities, the energy constants of the Brunauer–Emmett–Teller (BET) equation, and specific surface areas were calculated using the BET theory, the comparative method proposed by Gregg and Sing, and the Harkins–Jura method. The method of methylene blue sorption onto biomass carbohydrates was adapted and mastered. It was demonstrated that sorption of methylene blue proceeds successfully in ethanol, thus facilitating surface characterization for carbohydrates that are either soluble in water or regain water. It was found that the methylene blue sorption values correlate with specific surface area determined by nitrogen adsorption/desorption and calculated from the granulometric data. As a result of electrostatic attraction, the presence of ion-exchanged groups on the analyte surface has a stronger effect on binding of methylene blue than the surface area does. Sorption of methylene blue can be used in addition to gas adsorption/desorption to assess the accessibility of carbohydrate surface for binding large molecules.

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