scholarly journals Effect of Ethanol on the Morphology and Textual Properties of ZSM-5 Zeolite

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 198
Author(s):  
Xiuru Liu ◽  
Yiqing Sun
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Crystal Size ◽  
Ethanol Concentration ◽  
Textural Properties ◽  
Oh Groups ◽  
And Diffusion

The morphology of ZSM-5 zeolite impacts the adsorption, separation and diffusion of molecules. The morphology and textural properties of ZSM-5 zeolites were adjusted by regulating the content of ethanol in the synthesis gel. When the ratio of ethanol/SiO2 was lower than 2, the obtained crystals were isolated particles. With higher ethanol concentration, the chainlike zeolite was generated due to the condensation of terminal Si-OH groups. The crystals stacked more and more compactly with the increase in ethanol concentration, resulting in decreased specific surface area, total volume and mesoporous volume. The crystal size increased gradually with the increase in the ethanol concentration. Moreover, some other small molecular alcohols could also induce the formation of chainlike morphology of ZSM-5.

scholarly journals Experimental and Simulation Studies on Adsorption and Diffusion Characteristics of Coalbed Methane

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3445 ◽  
Author(s):  
Donghyeon Kim ◽  
Youngjin Seo ◽  
Juhyun Kim ◽  
Jeongmin Han ◽  
Youngsoo Lee
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Coalbed Methane ◽  
Equilibrium Time ◽  
Diffusion Characteristics ◽  
Adsorbed Methane ◽  
Cbm Production ◽  
Lump Coal ◽  
And Diffusion

Coalbed methane (CBM) content is generally estimated using the isotherm theory between pressure and adsorbed amounts of methane. It usually determines the maximum content of adsorbed methane or storage capacity. However, CBM content obtained via laboratory experiment is not consistent with that in the in-situ state because samples are usually ground, which changes the specific surface area. In this study, the effect of the specific surface area relative to CBM content was investigated, and diffusion coefficients were estimated using equilibrium time analysis. The differences in adsorbed content with sample particle size allowed the determination of a specific surface area where gases can adsorb. Also, there was an equilibrium time difference between fine and lump coal, because more time is needed for the gas to diffuse through the coal matrix and adsorb onto the surface in lump coal. Based on this, we constructed a laboratory-scale simulation model, which matched with experimental results. Consequently, the diffusion coefficient, which is usually calculated through canister testing, can be easily obtained. These results stress that lump coal experiments and associated simulations are necessary for more reliable CBM production analysis.

Effect of Crystals Size, Surface Area and Pore Size of Hydroxyapatite Microspheres on the Loading Ability of Bovine Serum Albumin

2011 ◽  
Vol 197-198 ◽  
pp. 17-20
Author(s):  
Jun Ming Li ◽  
Ai Juan Wang ◽  
Yu Peng Lv ◽  
Bai Ling Jiang
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Bovine Serum ◽  
Crystal Size ◽  
Adsorption Ability ◽  
Before And After

Effect of crystals size, surface area, pore size and porosity of hydroxyapatite microspheres on the loading ability of bovine serum albumin was studied in this paper. The surface morphology, specific surface area and porosity of hydroxyapatite microspheres were characterized by scanning electron microscope, specific surface area and pore size analyzer, respectively. The concentration of BSA in aqueous solutions both before and after adsorption was determined by ultraviolet-visible spectrophotometer. The results indicated that the adsorption behavior of bovine serum albumin appeared to obey the Langmuir-type isotherm model. Fast adsorption appeared at the beginning, and then decreased gradually. Hydroxyapatite microspheres calcined at 600°C had the maximum capacity, and those calcined at 800°C showed lower adsorption ability. The loading ability of hydroxyapatite microspheres depended on its crystal size, specific surface area, pore size and porosity, etc.

scholarly journals Textural properties of synthetic clay-ferrihydrite associations

Clay Minerals ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 395-407 ◽  
Author(s):  
R. Celis ◽  
J. Cornejo ◽  
M. C. Hermosin
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mercury Porosimetry ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Fractal Approach ◽  
Adsorption Data ◽  
Synthetic Clay ◽  
Nitrogen Adsorption Data

AbstractKaolinite-ferrihydrite and montmorillonite-ferrihydrite associations were prepared following a procedure based on the Russell method for the synthesis of ferrihydrite and the texture of the clay-ferrihydrite complexes was studied using different techniques. The textural properties of kaolinite were little affected by the Fe association, showing only a slight increase in the specific surface area measured by nitrogen adsorption and a decrease in the largest pores (>10 µm), as measured by mercury porosimetry. In contrast, the nitrogen specific surface area of the montmorillonite complexes was much higher than that of the clay without Fe and the pore structure depended on the amounts of Fe in the complexes. Application of the fractal approach to nitrogen adsorption data indicated that the surface roughness (microporosity) was greater for the complexes prepared from diluted Fe(III) solutions, in agreement with the information obtained from classical interpretation of the adsorption isotherms (shape of the isotherms and t-plots).

Effect of ZnO Particle Size on the Curing of Carboxylated NBR and Carboxylated SBR

2004 ◽  
Vol 77 (2) ◽  
pp. 214-226 ◽  
Author(s):  
G. R. Hamed ◽  
K.-C. Hua
Keyword(s):  
Zinc Oxide ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Cure Rate ◽  
Surface Areas ◽  
Diffusion Limited ◽  
Rate Of Dissolution ◽  
Oxide Particles ◽  
And Diffusion

Abstract A carboxylated nitrile rubber (XNBR) and a carboxylated SBR (XSBR) were mixed with zinc oxide particles of different specific surface areas (“S”, 35 m2/g; “M”, 3.5m2/g; “L”, 0.5 m2/g) and cure behavior at 165 ºC studied using oscillating disc rheometry. Without added zinc oxide, both raw rubbers slowly stiffen over many hours of heating. This is probably due to condensation of carboxyl groups to form anhydride crosslinks. XNBR compositions containing the finely divided “S” crosslink much more rapidly. Full cure is reached after about 10 minutes of heating. Cure rate decreases markedly as the specific surface area of the ZnO decreases. A composition containing “M” at twice stoichiometry requires about an hour to cure well, while with “L”, about 10 hours are required. In contrast, curing of the XSBR depends little on the specific surface area of the ZnO, either with “S” or “L”, curing is essentially complete after 30 minutes. After simply mixing ZnO into either rubber, it remains as a dispersed particulate. With XNBR, curing appears to be controlled by the rate of dissolution and diffusion of ZnO, while, with XSBR, reaction is not diffusion limited and may be confined to regions near particle surfaces.

Annealing of mesoporous silica loaded with silver nanoparticles within its pores from isothermal sorption

1998 ◽  
Vol 13 (10) ◽  
pp. 2888-2895 ◽  
Author(s):  
Weiping Cai ◽  
Lide Zhang ◽  
Huicai Zhong ◽  
Guoliang He
Keyword(s):  
Mesoporous Silica ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ag Nanoparticles ◽  
Porous Silica ◽  
Pore Wall ◽  
Ag Particles ◽  
Real Value ◽  
And Diffusion

Influences of annealing on the structure of mesoporous silica loaded with silver (Ag) nanoparticles, and on the coarsening of Ag particles within pores of the host were investigated from isothermal sorption. Doping a small amount of Ag nanoparticles into pores of silica and subsequent annealing decreases the measured values of specific surface area and pore volume of porous silica significantly. This is attributed to the presence and coarsening of Ag particles within pores or channels between pores, which result in more and more isolated and unmeasured free spaces. The measured value of a specific surface area for the doped samples cannot represent the real value, which is, in fact, unable to be measured directly. During additional annealing, Ag particles within silica coarsen mainly according to the mechanism of formation of Ag adatoms on pore wall and diffusion of the adatoms along with pore walls. Only the larger particles located in the larger pores can continuously grow. The smaller particles and those located in the channels or pores with smaller dimension will disappear. The activation energy of the ripening process was estimated to be about 0.60 eV, and the migration barrier of Ag adatom on the pore wall of silica is about 0.10 eV.

scholarly journals A Case Study of Waste Scrap Tyre-Derived Carbon Black Tested for Nitrogen, Carbon Dioxide, and Cyclohexane Adsorption

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4445 ◽  
Author(s):  
Zuzana Jankovská ◽  
Marek Večeř ◽  
Ivan Koutník ◽  
Lenka Matějová
Keyword(s):  
Activated Carbon ◽  
Carbon Black ◽  
Specific Surface ◽  
Surface Area ◽  
Sorption Capacity ◽  
Specific Surface Area ◽  
Textural Properties ◽  
Pyrolytic Carbon ◽  
Surface Areas ◽  
Wide Range

Waste scrap tyres were thermally decomposed at the temperature of 600 °C and heating rate of 10 °C·min−1. Decomposition was followed by the TG analysis. The resulting pyrolytic carbon black was chemically activated by a KOH solution at 800 °C. Activated and non-activated carbon black were investigated using high pressure thermogravimetry, where adsorption isotherms of N2, CO2, and cyclohexane were determined. Isotherms were determined over a wide range of pressure, 0.03–4.5 MPa for N2 and 0.03–2 MPa for CO2. In non-activated carbon black, for the same pressure and temperature, a five times greater gas uptake of CO2 than N2 was determined. Contrary to non-activated carbon black, activated carbon black showed improved textural properties with a well-developed irregular mesoporous-macroporous structure with a significant amount of micropores. The sorption capacity of pyrolytic carbon black was also increased by activation. The uptake of CO2 was three times and for cyclohexane ten times higher in activated carbon black than in the non-activated one. Specific surface areas evaluated from linearized forms of Langmuir isotherm and the BET isotherm revealed that for both methods, the values are comparable for non-activated carbon black measured by CO2 and for activated carbon black measured by cyclohexane. It was found out that the N2 sorption capacity of carbon black depends only on its specific surface area size, contrary to CO2 sorption capacity, which is affected by both the size of specific surface area and the nature of carbon black.

Valorization of cellulose-doped lignin: application of cellulose-doped lignin-derived activated carbon in capacitors and investigation of its textural properties and electrochemical performance

2021 ◽  
Author(s):  
Liangcai Wang ◽  
Xin Feng ◽  
Huanhuan Ma ◽  
Jielong Wu ◽  
Yu Chen ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
Wall Thickness ◽  
Textural Properties ◽  
Pore Wall ◽  
Surface Areas ◽  
Pore Wall Thickness

Abstract This work provides an idea for efficient and harmless utilization of lignin and further evaluated the textural properties of lignin-derived activated carbon/specific capacitance relationship. The yield of cellulose-doped apricot shell lignin (ASLC) was 30.42%. H3PO4/KOH was used to assist the preparation of ASLC-derived activated carbon (AAC) for capacitors. The specific surface areas of the as-obtained AAC-P-3 and AAC-K-2 were 1475.16 m2/g and 2136.56 m2/g, respectively. The specific capacitances of AAC-P-3 and AAC-K-2 were 169.14 F/g and 236.00 F/g, respectively, upon the current density of 0.50 A/g. In capacitors containing aqueous KOH as the electrolyte, the AR2 (0.983) between specific surface area and specific capacitance was highest, followed by the AR2 (0.978) between Vmicro/Vmeso and specific capacitance, the AR2 (0.975) between pore-wall thickness and specific capacitance. Consequently, the specific capacitances of the AACs depend not only the specific surface area, but also on the Vmicro/Vmeso, pore-wall thickness, and Vmicro.

Alteration of imogolite by dry grinding

Clay Minerals ◽  
1981 ◽  
Vol 16 (2) ◽  
pp. 139-149 ◽  
Author(s):  
Teruo Henmi ◽  
Naganori Yoshinaga
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Layer Silicate ◽  
Oh Groups ◽  
X Ray ◽  
Dry Grinding ◽  
Structure Morphology ◽  
Complete Breakdown ◽  
Water Holding

AbstractThe effects of dry grinding on the structure, morphology and properties of imogolite have been investigated by means of X-ray powder diffraction analysis, IR, DTA, and measurements of CEC and specific surface area. Imogolite is very susceptible to alteration by grinding compared to layer silicate minerals such as halloysite, kaolinite and montmorillonite. In the earlier stages of grinding, the parallel array of imogolite tubular structure units is markedly disturbed. On further grinding, disruption of Si-O-Al linkages, polymerization of the silica component released and loss of structural OH groups proceed simultaneously, these changes eventually resulting in complete breakdown of the structure. Ground imogolite is reaggregated finally into granular particles of irregular shape. All these changes are associated with a decrease in water holding capacity, CEC and specific surface area.

Removal of Acid Textile Dye from the Aqueous Solution by a New Adsorbent Obtained from Waste Cotton from the Garment Plant

2020 ◽  
Vol 42 (5) ◽  
pp. 728-728
Author(s):  
Aleksandra Micic Aleksandra Micic ◽  
Dragan Djordjevic Dragan Djordjevic ◽  
Ivona Jankovic Castvan Ivona Jankovic Castvan ◽  
Nenad Cirkovic Nenad Cirkovic ◽  
Bratislav Todorovic Bratislav Todorovic
Keyword(s):  
Aqueous Solution ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Adsorption Process ◽  
Bulk Material ◽  
Textural Properties ◽  
Textile Dye ◽  
Acid Dye ◽  
Microporous Material

The paper investigates the possibility of removing acid dye from the aqueous solution by an adsorption process on new adsorbent prepared from waste cotton textile from the ready-made garment industry. It is a waste generated during the cutting of the layers of cotton knitwear, which is practically the product from the textile cutting process. The obtained adsorbent is a bulk material with heterogeneous porous particles, of ragged shapes. In particle interiors, there are pronounced cracks, cavities and channels that form the basis of microporous material. The qualitative and quantitative characterization of the obtained adsorbent shows that this is a relatively porous material where the carbon is dominant in the chemical composition. The results of textural properties of new adsorbent from cotton knitwear waste show different parameters which with their numerous values characterize the specific surface area, pore volume or pore diameter. It can be said that the obtained new adsorbent has micropores and small mesopores, which produce a high specific surface area. During adsorption, the longer contact time causes a greater amount of dye on the adsorbent, i.e. with the duration of the adsorption process the dye concentration in the solution decreases. A number of isotherms of two- (Langmuir, Freundlich and Jovanovic), three- (Toth, Sips and Radke-Prausnitz), and four-parameter models (Fritz-Schlunder and Marczewski-Jaroniec) were used to describe the adsorption process. The four-parameter isotherms are best covered by experimental points and most accurately describe the events of adsorption of acid dye on the surface and in the interior of the new adsorbent particles obtained from ready–made garment cotton waste. The results of this research suggest the possibility of practical application in the decolorization of the colored waste waters of the textile industry providing a contribution to protecting the environment from both an economic and a practical point of view.

scholarly journals C2H5OH and NO2 sensing properties of ZnO nanostructures: correlation between crystal size, defect level and sensing performance

RSC Advances ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 5629-5639 ◽  
Author(s):  
Chu Thi Quy ◽  
Nguyen Xuan Thai ◽  
Nguyen Duc Hoa ◽  
Dang Thi Thanh Le ◽  
Chu Manh Hung ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Crystal Size ◽  
Gas Sensing ◽  
Zno Nanostructures ◽  
Defect Level ◽  
Sensing Applications ◽  
Sensing Performance

ZnO nanostructures were synthesized for ethanol and nitrogen dioxide gas-sensing applications. Results pointed out that the defect levels dominating the gas-sensing performance but not the morphology, specific surface area or crystal size.

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