Preparation of Mesoporous Carbon Membranes for Ultrafiltration with Properties of Environmental Materials

2012 ◽  
Vol 600 ◽  
pp. 104-107 ◽  
Author(s):  
Wei Wei ◽  
Na Li ◽  
Guo Tong Qin
Keyword(s):  
Mesoporous Carbon ◽  
Pure Water ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Supercritical Drying ◽  
Carbon Membrane ◽  
Carbon Membranes ◽  
Environmental Materials ◽  
Sol Gel Synthesis ◽  
Important Kind

Ultrafiltration carbon membrane is an important kind of environmental materials for removal of particular and macromolecular pollutants. The mesoporous carbon membranes were synthesized via sol-gel synthesis followed by supercritical drying and carbonization. The formaldehyde and resorcinol were used as original precursor. The membrane was analyzed using nitrogen adsorption. It was found that the carbon membrane was mesoporous material. The pure gases of H2, N2 and CO2 were used to characterize the selective and integrity of the carbon membrane. The gas permeance through the mesoporous carbon membrane is predominantly governed by the Knudsen mechanism. The pure water is 13.4 L•m-2•h-1 and the molecular weight cut-off is about 2000.

Preparation of highly mesoporous carbon membranes via a sol–gel process using resorcinol and formaldehyde

Carbon ◽  
2008 ◽  
Vol 46 (7) ◽  
pp. 1031-1036 ◽  
Author(s):  
Miki Yoshimune ◽  
Takuji Yamamoto ◽  
Masaru Nakaiwa ◽  
Kenji Haraya
Keyword(s):  
Mesoporous Carbon ◽  
Sol Gel ◽  
Carbon Membranes ◽  
Sol Gel Process

Effect of the Sol-Gel Synthesis Parameters on the Incorporation of an Anti-inflammatory Drug in a Ceramic Material

2007 ◽  
Vol 1007 ◽  
Author(s):  
Aracely Hernandez ◽  
Patricia Esquivel-Ferriño ◽  
Idalia Gomez ◽  
Lucia Cantu
Keyword(s):  
Ceramic Material ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Molar Ratio ◽  
Inflammatory Drug ◽  
Synthesis Conditions ◽  
Synthesis Parameters ◽  
Anti Inflammatory ◽  
Drug Incorporation ◽  
Sol Gel Synthesis

ABSTRACTIn the present work, sol-gel method was used to incorporate in a ceramic material a non steroidal anti-inflammatory drug (piroxicam) as model drug. The incorporation of the drug in the SiO2 network was carried out at different sol-gel synthesis parameters, such as pH (3 and 5) and the alkoxide/water ratio (1:6 and 1:8). The biomaterial obtained was analyzed by thermal analysis TGA-DTA, infrared spectroscopy (FTIR), Scanning Electronic Microscopy (SEM) and X-ray diffraction (XRD); specific surface area and porosity were analyzed from nitrogen adsorption isotherm. Better drug incorporation into the material was achieved at the synthesis conditions of pH 5 and 1:6 alkoxide/water molar ratio.

scholarly journals Preparation and Properties of SiBCO Aerogel and Its Composites

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 40 ◽  
Author(s):  
Xiafei Li ◽  
Junzong Feng ◽  
Jie Yin ◽  
Yonggang Jiang ◽  
Jian Feng
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Thermal Insulation ◽  
Phenylboronic Acid ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Supercritical Drying ◽  
Temperature Resistance ◽  
Mullite Fiber ◽  
Boron Source

To obtain new high-temperature resistant composites that can meet the requirements of aircraft development for thermal insulation and mechanical properties, SiBCO aerogel composites were prepared by sol-gel, supercritical drying and high-temperature pyrolysis with trimethyl borate (TMB) or phenylboronic acid (PBA) as the boron source and mullite fiber as reinforcement. The structure and composition of the SiBCO aerogel and its composites were characterized with SEM, FT-IR, ICP and nitrogen adsorption tests. The specific surface area of the SiBCO aerogel is 293.22 m2/g, and the pore size is concentrated in the range of 10–150 nm. The mechanical properties, the thermal insulation properties and the temperature resistance were also studied. Due to the introduction of boron, the temperature resistance of SiBCO aerogel composites is improved greatly, and the service temperature of composites reached 1773 K. When n (TMB)/n (TEOS) = 1/1, the temperature resistance of the composites is the best. After heating in air at 1773 K for 30 min, the shrinkage of SiBCO aerogel composites is only 2.45%, and the thermal conductivity of the composites is 0.138 W/(m·K) at 1773 K. In addition, the type and amount of catalyst also have certain effects on the mechanical properties and temperature resistance of the composites.

Synthesis and Structural Characterization of SiO2-Al2O3 Xerogels

2007 ◽  
Vol 336-338 ◽  
pp. 2286-2289
Author(s):  
Fei He ◽  
Xiao Dong He ◽  
Yao Li
Keyword(s):  
Structural Change ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Mesoporous Structure ◽  
Supercritical Drying ◽  
High Specific Surface Area ◽  
Molar Ratio

Low-density xSiO2-(1-x)Al2O3 xerogels with x=0.9, 0.8, 0.7, 0.6 (mole fractions) were prepared by sol-gel and non-supercritical drying. Silica alkogels, which were the framework of binary composite materials, formed from tetraethyl orthosilicate (TEOS) by hydrolytic condensation with a molar ratio of TEOS: H2O: alcohol: hydrochloric acid: ammonia =1: 4: 10: 7.5×10-4: 0.0375. Aluminum hydroxide derived from Al(NO3)3·9H2O and NH4OH acting in the alcohol solution under the condition of catalyst. After filtrating and washing, the precipitation was mixed into silica sols to form SiO2-Al2O3 mixed oxide gels with different silicon and aluminum molar ratio. The structural change and crystallization of the binary xerogels were investigated after heat treatment at 600 for 2 h by the means of X-ray diffraction. Nitrogen adsorption experiment was performed to estimate specific surface area, porous volume and pore size distribution. The structural change of xerogels was observed by FT-IR spectroscopy. The resulting mixed xerogels possess of mesoporous structure which is characteristic of cylindrical pores, high specific surface area of 596-863 m2/g and a relatively narrow pore distribution of 2.8-30 nm. Al2O3 is introduced into the SiO2 phase and some of Al-O-Si bonds form.

Preparation and Characterization of CNT/C Composite Membranes from 6FAPB-PMDA Type Polyimide

2013 ◽  
Vol 726-731 ◽  
pp. 691-694
Author(s):  
Bing Zhang ◽  
Yi Shi ◽  
Yong Hong Wu ◽  
Yun Hua Lu ◽  
Tong Hua Wang
Keyword(s):  
Thermal Stability ◽  
Carbon Nanotube ◽  
Porous Structure ◽  
Nitrogen Adsorption ◽  
Composite Membranes ◽  
Carbon Membrane ◽  
Carbon Membranes ◽  
Composite Carbon ◽  
Thermal Stability Of

A novel precursor, 6FAPB-PMDA type polyimide, was developed to prepare carbon membranes and carbon nanotube (CNT) composite carbon membranes. The thermal stability of precursors was characterized by TGA. The morphology of carbon membrane was observed by SEM. The microstructure was measured by XRD and nitrogen adsorption technique. Results have shown that 6FAPB-PMDA type polyimide is a promising precursor, and the introduction of CNT can obviously modify the thermal stability, as well as the carbon and porous structure of resultant carbon membranes.

scholarly journals Preparation and Characterization of a Calcium Carbonate Aerogel

2009 ◽  
Vol 2009 ◽  
pp. 1-3 ◽  
Author(s):  
Johann Plank ◽  
Heinz Hoffmann ◽  
Joachim Schölkopf ◽  
Wolfgang Seidl ◽  
Ingo Zeitler ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Average Diameter ◽  
Supercritical Drying ◽  
Adsorption Method ◽  
X Ray ◽  
Sol Gel Process

We report on a facile method for the preparation of a calcium carbonate aerogel consisting of aggregated secondary vaterite particles with an approximate average diameter of 50 nm. It was synthesized via a sol-gel process by reacting calcium oxide with carbon dioxide in methanol and subsequent supercritical drying of the alcogel with carbon dioxide. The resulting monolith was opaque, brittle and had overall dimensions of  cm. It was characterized by X-ray powder diffraction, nitrogen adsorption method (BET), and scanning electron microscopy.

Metallic Calcium as a Precursor for Sol-Gel Synthesis of CaCO3-SiO2 and CaO-SiO2 Systems

Ceramics ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 278-290
Author(s):  
Piotr Marciniak ◽  
Bogna Sztorch ◽  
Agnieszka Martyła ◽  
Agnieszka Czapik ◽  
Mikołaj Stodolny ◽  
...  
Keyword(s):  
Sol Gel ◽  
Phase Segregation ◽  
Calcium Content ◽  
Nitrogen Adsorption ◽  
Point Of View ◽  
Oxide Systems ◽  
Molar Ratios ◽  
High Calcium ◽  
Sol Gel Synthesis ◽  
Metallic Calcium

A series of binary oxide systems with Ca/Si molar ratios of 0.05, 0.1, 0.25, 0.5 and 1.0 have been synthesized by the sol-gel technique from tetraethyl orthosilicate (TEOS) and metallic calcium powder. Upon calcination, a side effect of wollastonite formation as a result of the reaction between the components of the material has been observed in the two calcium-richest systems. The increase in calcium content produces an effect of porosity promotion. At high calcium contents, the homogeneity of the systems is limited by the ability of silica to disperse the calcium component. The properties of these systems are determined by the silica surface coverage with a large amount of the scattered CaCO3 fine microcrystallites (calcite), resulting from the phase segregation. The gels were characterized by X-ray powder diffraction, low temperature nitrogen adsorption, transmission and scanning electron microscopy (TEM, SEM and SEM/EDS), thermogravimetric analysis (TGA), and FT-IR spectra, to describe the parameters important from the point of view of their application as a support for metal-based catalysts.

Synthesis and characterization of a low-cost aerogel structure using classical drying methods for thermal insulation

2017 ◽  
Vol 8 (2) ◽  
pp. 256-263
Author(s):  
Abir Nachawaty ◽  
Maria Bassil ◽  
Antoine Choueiry ◽  
Mario Tahchi ◽  
Roland Habchi
Keyword(s):  
Thermal Insulation ◽  
Low Cost ◽  
Sol Gel ◽  
Synthesis Method ◽  
Infrared Camera ◽  
Supercritical Drying ◽  
Drying Methods ◽  
Content Type ◽  
Surface Cracking ◽  
Sol Gel Synthesis

Purpose Lightweight insulators are of major importance for the industry, in particular for thermal insulation in buildings. The purpose of this paper is to present a low-cost method to obtain aerogels with high insulating properties. Design/methodology/approach Silica aerogel structures have been obtained by a low-cost sol-gel synthesis method. Surface modification, using dimethyldichlorosilane and trimethylchlorosilane, has been applied in order to get different thermal and optical properties. Findings The samples show very promising thermal properties as tested through an infrared camera observation. A 5-mm-thick piece of aerogel is able to withstand the temperature of a brazing flame and reduce the heat by at least 150 degrees on its opposite side. The samples have a vitreous like structure as observed by SEM, some surface cracking is observed but they stay within acceptable limits. Originality/value A very good thermal insulator is obtained with a very simple and low-cost method. The bulkiness of the supercritical drying is eliminated and the obtained structure has good properties.

Mechanical and Adiabatic Properties of Silica Aerogel Doped with TiO2 Nanowire

2014 ◽  
Vol 633 ◽  
pp. 336-339
Author(s):  
Zhao Kui Jin ◽  
Xiong Peng ◽  
Hong Yi Gao ◽  
Chao Hao Peng ◽  
Yi Luan
Keyword(s):  
Silica Aerogel ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Nitrogen Adsorption ◽  
Supercritical Drying ◽  
Drying Methods ◽  
X Ray Diffraction ◽  
Static Compression ◽  
Gel Processing

A novel silica aerogel insulation composite was prepared by using TiO2 nanowires as modifier via sol-gel processing and supercritical drying methods in order to address issues of the poor mechanical and the infrared shading performance of silica aerogel. The effects of TiO2 nanowire content on the mechanical and adiabatic performance were investigated by X-Ray diffraction (XRD), nitrogen adsorption (BET), field emission scanning electron microscopy (FESEM), static compression test and thermal analysis. The results show that TiO2 nanowire reinforced aerogels had great thermal insulation properties, while high surface area, low density and mechanical strength were retained.

scholarly journals Aerogels: II. Applications in catalysis

2002 ◽  
Vol 56 (12) ◽  
pp. 514-520
Author(s):  
Aleksandar Orlovic ◽  
Djordje Janackovic ◽  
Ljiljana Kostic-Gvozdenovic ◽  
Dejan Skala
Keyword(s):  
Molecular Level ◽  
Sol Gel ◽  
Supercritical Drying ◽  
Structural Features ◽  
Metastable Phases ◽  
Drying Process ◽  
Sol Gel Process ◽  
One Step ◽  
Sol Gel Synthesis

Sol-gel synthesis, and the resulting materials (xerogels and aerogels) are finding increasing application in the synthesis of catalysts, due to their unique characteristics. The most important features of the sol-gel process are: the ability to achieve homogeneity at the molecular level, the introduction of several species in only one step and the ability to stabilize metastable phases. The supercritical drying process produces aerogels with structural features quite different to conventional materials. Some of these characteristics of aerogels can make them very effective catalysts.

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