Synthesis of MCM-41 from Rice Husk Ash and its Utilization for Lipase Immobilization

2014 ◽  
Vol 925 ◽  
pp. 23-27
Author(s):  
Nurhadijah Zainalabidin ◽  
Noor Hasyierah Mohd Salleh ◽  
Dachyar Arbain
Keyword(s):  
Surface Area ◽  
Mesoporous Materials ◽  
Rice Husk ◽  
Fine Particles ◽  
Rice Husk Ash ◽  
Enzyme Stability ◽  
Solid Particles ◽  
Bet Surface Area ◽  
Time Range ◽  
Mcm 41

Mesoporous materials are favorable for enzyme immobilization due to their unique properties of large surface area, uniform pore system and functionalizable surfaces. Immobilization on these materials enhances enzyme stability, activity and resistance towards harsh environmental conditions such as temperature and pH. The present study deals with synthesis of mesoporous materials namely MCM-41. For that purpose, the MCM-41 was synthesized using cetyltrimethylammonium bromide (CTAB) as a template and extractable silica from rice husk ash as a silica source. The synthesis was performed under alkaline conditions to produce white fine solid particles, followed by grafting with 3-aminopropyltriethoxysilane and activation with carbodiimide before it was immobilized with lipase. Characterization of those fine particles using Nitrogen physisorption gives BET surface area, as BET, and the pore diameterto be 1184 m²/g and 2.58 nm respectively. Fourier Transform Infrared spectra show peak of SiO2, NH2 and COOH functional group which confirms the existence of those compounds in covalent bonding formation between amine-grafted MCM-41 and lipase enzyme. Immobilized enzyme shows an increase in pH stability when compared to free enzyme at fixed temperature of 20°C in time range from 30 to 180 minutes.

Synthesis and Preparation of Al-MCM-41 Mesoporous Materials Using Oil Shale Residue

2019 ◽  
Vol 944 ◽  
pp. 1192-1198
Author(s):  
Rong Wang ◽  
Zhi Xiang Lin ◽  
Yang Zhao ◽  
Xiao Dong Xu ◽  
Yan Xi Deng
Keyword(s):  
Surface Area ◽  
Mesoporous Materials ◽  
Pore Volume ◽  
Oil Shale ◽  
Bet Surface Area ◽  
Ammonium Bromide ◽  
Scale Production ◽  
Scanning Electron Micrographs ◽  
One Step ◽  
Mcm 41

An Al-supported cage-like mesoporous silica type MCM-41 has been prepared using a simple one-step synthetic procedure using oil shale residue and CTAB(Hexadecyl trimethyl Ammonium Bromide) as the template. The effects of temperature on the porosity, structure and surface area of Al-MCM-41 mesoporous materials were characterized by X-ray powder diffraction, N2adsorption desorption, scanning electron micrographs (SEM), transmission electron microscopy (TEM) techniques and Fourier transform infrared spectroscopy (FT-IR). The results indicated that temperature was a key to the characteristics of Al-MCM-41 materials, and when the temperature up to 333 K, Al-MCM-41 exhibited excellent characteristics with high degree of order, high surface area and pore volume. The one-step hydrothermal synthesized MCM-41 mesoporous material possessed high BET surface area, high pore size and high pore volume. They are respectively 835.1 m2/g, 32.6 Å and 1.22 cm3/g under the condition of the Si : Al =78:1, pH =10, crystallization temperature was 333K, crystallization time was 48h and calcination at 823 K for 5 h in air. All the results indicated the possibility of using oil shale residue as silicon and aluminum source to produce Al-MCM-41, and gave us a new way to recycle a solid waste. As well as this made it impossible to large-scale production of Al-MCM-41. Keywords: Al-MCM-41 mesoporous materials, oil shale residue, one-step synthesis

scholarly journals Use of rice husk ash as only source of silica in the formation of mesoporous materials

Cerâmica ◽  
2013 ◽  
Vol 59 (349) ◽  
pp. 181-185 ◽  
Author(s):  
A. J. Schwanke ◽  
D. M. A. Melo ◽  
A. O. Silva ◽  
S. B. C. Pergher
Keyword(s):  
Mesoporous Materials ◽  
Rice Husk ◽  
Molecular Sieves ◽  
Rice Husk Ash ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
X Ray ◽  
Type Iv ◽  
Heating Treatment ◽  
Mcm 41

This paper reports the synthesis of molecular sieves similar to MCM-41 using rice husk ash as only source of silica. For comparison purposes, a standard synthesis was performed using aerosil 200 commercial silica. The rice husk silica was obtained by heating treatment at 600 ºC and leaching for 2 h in reflux with HCl 1mol.L-1 and used in the synthesis. The samples prepared were characterized by N2 adsorption, X-ray diffraction (XRD), scanning electronic microscopy (SEM) and thermogravimetric analysis (TG). By type-IV adsorption isotherms, the formation of mesoporous materials was observed. XRD showed the formation of hexagonal unidirectional pore materials similar to MCM-41. By SEM, it could be observed that the rice husk has fibrous aspect and that synthesis using calcined and leached rice husk did not react entirely because silica was only partially dissolved.

scholarly journals Hydrophilic and Hydrophobic Mesoporous Silica Derived from Rice Husk Ash as a Potential Drug Carrier

2018 ◽  
Author(s):  
Supakij Suttiruengwong ◽  
Metta Chareonpanich ◽  
Sommai Pivsa-Art
Keyword(s):  
Mesoporous Silica ◽  
Surface Area ◽  
Rice Husk ◽  
Release Rate ◽  
Pore Diameter ◽  
Rice Husk Ash ◽  
Release Kinetics ◽  
Drug Carrier ◽  
Bet Surface Area ◽  
Hydrophobic Nature

This work describes the preparation of mesoporous silica by the green reaction of rice husk ash (RHA) with glycerol, followed by the modification and the potential use as a drug carrier. The reaction was carried out at 215 °C for 2 h. The solution was further hydrolyzed with deionized water and aged for various times (24, 48, 120, 360, 528 and 672 h) before calcinations at 500 oC for 24 h. Further treatment of prepared mesoporous silica was performed using trimethylmethoxysilane (TMMS) to obtain hydrophobic Mesoporous silica. For all synthesized silica, silica contents were as high as 95%wt, whereas organic residues were less than 3%wt. RHA-glycerol showed the highest specific surface area with smallest pore diameter (205.70 m2/g, 7.46 nm) when aged for 48 h. The optimal hydrolysis-ageing period of 120 h resulted in 500.7 m2/g BET surface area, 0.655 cm3/g pore volume and 5.23 nm pore diameter. The surface modification of RHA-glycerol was succeeded through the reaction with TMMS as confirmed by FTIR. Ibuprofen was selected as a model drug for the adsorption experiments. The adsorption under supercritical CO2 was carried out at isothermal temperature of 40 ˚C and 100 bar, % ibuprofen loading of TMMS modified mesoporous silica (TMMS-g-MS) was 6 times less than mesoporous silica aged for 24 h (MS-24h) due to the hydrophobic nature of modified mesoporous silica, not surface and pore characteristics. The release kinetics of ibuprofen-loaded mesoporous silicas were also investigated in vitro. The release rate of ibuprofen-loaded MS-24h was much faster than that of ibuprofen-loaded TMMS-g-MS, but comparable to the crystalline ibuprofen. The slower release rate was attributed to the diffusion control and the stability of hydrophobic nature of modified silica. This would allow the design for the controlled release drug delivery system.

Synthesis of a novel visible light responsive γ-Fe2O3/SiO2/C-TiO2 magnetic nanocomposite for water treatment

2018 ◽  
Vol 78 (12) ◽  
pp. 2500-2510 ◽  
Author(s):  
Henry H. Mungondori ◽  
Spencer Ramujana ◽  
David M. Katwire ◽  
Raymond T. Taziwa
Keyword(s):  
Water Treatment ◽  
Visible Light ◽  
Surface Area ◽  
Fine Particles ◽  
Uv Light ◽  
Sol Gel ◽  
Spherical Shape ◽  
Solar Irradiation ◽  
Bet Surface Area ◽  
Average Pore

AbstractThis work investigates the preparation of a magnetically recoverable photocatalytic nanocomposite of maghemite nanoparticles coated with silica and carbon doped titanium dioxide. The novel nanocomposite boasts the advantages of efficient photocatalytic degradation of organic pollutants in water and ease of recovery of the fine particles after water treatment. The photocatalytic nanocomposite was successfully synthesized through a stepwise approach via co-precipitation and sol-gel methods. Characterisation by Fourier transform infrared (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) substantiated the existence of the intended structure of the nanocomposite and the particles were found to be in the size range of 15–22 nm with a quasi-spherical shape. Brunauer–Emmett–Teller (BET) surface area analysis revealed an average surface area of 55.20 m2/g, which is higher than that of commercial TiO2 (Degussa P25, 50.00 m2/g), and an average pore diameter of 8.36 nm. A 5 ppm methylene blue solution was degraded with an efficiency of 96.8% after 3 h of solar irradiation, which was 19.7% greater than using the same photo-catalyst under strict UV light irradiation. Photo-catalysis using these nanoparticles was observed to be very effective. The prepared novel visible light active nanocomposite has great potential for incorporation into water treatment systems because it exhibits good stability and magnetism, as well as high photocatalytic efficiency.

Thermal Evolution of Single Phase Lanthanum Zirconate

2006 ◽  
Vol 317-318 ◽  
pp. 31-36 ◽  
Author(s):  
Maria Ophelia D. Jarligo ◽  
Y.S. Kang ◽  
Akira Kawasaki
Keyword(s):  
Surface Area ◽  
Single Phase ◽  
Fine Particles ◽  
Thermal Evolution ◽  
Milled Powder ◽  
Pyrochlore Structure ◽  
Phase Evolution ◽  
Bet Surface Area ◽  
Lanthanum Zirconate ◽  
Complete Disintegration

Lanthania (La2O3) and zirconia (ZrO2) powders in ethanol based suspension were mechanochemically treated in a planetary ball mill for 12 hours at 200 rpm, dried and sintered at various temperatures from 400 to 1500. Particles in nanometer sizes are produced after milling. X-ray diffractometry results show the formation of single phase lanthanum zirconate on subsequent heat treatment for 1h at 1500. Phase evolution based on the intensities of the XRD plots and BET surface area analysis indicates three stages of crystallization: below 800, between 800 and ~1100, and above 1100 where reflections of La2Zr2O7 with pyrochlore structure are increased with further heating. Only endothermic energy peaks are observed in the differential thermal analysis (DTA) curve of the milled powders, which could be attributed to the reactions involving dehydroxylation, decarboxylation and complete disintegration of ethanol. This indicates that probably, lanthanum zirconate has grown on sintering at high temperatures from the very fine particles produced by mechanochemical activation during milling. Thermogravimetric analysis has recorded a total weight loss of ~9% from the original weight of the milled powder on sintering at 1500. The values of the surface area of the powders are found to decrease while the crystallite size of La2Zr2O7 are increased with increasing temperature.

scholarly journals Synthesis of Hydrophobic Mesoporous Material MFS and Its Adsorption Properties of Water Vapor

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Guotao Zhao ◽  
Zhenxiao Zhao ◽  
Junliang Wu ◽  
Daiqi Ye
Keyword(s):  
Water Vapor ◽  
Surface Area ◽  
Mesoporous Material ◽  
High Surface ◽  
Synthesis Method ◽  
Gravimetric Method ◽  
Total Pore Volume ◽  
Adsorption Properties ◽  
Bet Surface Area ◽  
Mcm 41

Fluorine-containing hydrophobic mesoporous material (MFS) with high surface area is successfully synthesized with hydrothermal synthesis method by using a perfluorinated surfactant SURFLON S-386 template. The adsorption properties of water vapor on the synthesized MFS are also investigated by using gravimetric method. Results show that SEM image of the MFS depicted roundish morphology with the average crystal size of 1-2 μm. The BET surface area and total pore volume of the MFS are 865.4 m2 g−1and 0.74 cm3 g−1with a narrow pore size distribution at 4.9 nm. The amount of water vapor on the MFS is about 0.41 mmol g−1at 303 K, which is only 52.6% and 55.4% of MCM-41 and SBA-15 under the similar conditions, separately. The isosteric adsorption heat of water on the MFS is gradually about 27.0–19.8 kJ mol−1, which decreases as the absorbed water vapor amount increases. The value is much smaller than that on MCM-41 and SBA-15. Therefore, the MFS shows more hydrophobic surface properties than the MCM-41 and SBA-15. It may be a kind of good candidate for adsorption of large molecule and catalyst carrier with high moisture resistance.

Optimal Decolorization Efficiency of Reactive Red 3 by Fe-RH-MCM-41 Catalytic Wet Oxidation Coupled with Box-Behnken Design

2013 ◽  
Vol 545 ◽  
pp. 109-114 ◽  
Author(s):  
Kitirote Wantala ◽  
Pongsert Sriprom ◽  
Nusavadee Pojananukij ◽  
Arthit Neramittagapong ◽  
Sutasinee Neramittagapong ◽  
...  
Keyword(s):  
Surface Area ◽  
Hexagonal Lattice ◽  
Hexagonal Structure ◽  
Bet Surface Area ◽  
Molar Ratio ◽  
Wet Oxidation ◽  
Catalytic Wet Oxidation ◽  
Box Behnken Design ◽  
Independent Variables ◽  
Mcm 41

The reactive red 3 was degraded by catalytic wet oxidation process over Fe-RH-MCM-41 prepared by Direct Hydrothermal Technique (DHT) at Si/Fe molar ratio of 10 using silica from rice husk. The extended reaction conditions were studied as a function of reaction temperatures, initial H2O2 concentrations and initial pH of solutions designed by Box-Behnken design (BBD) based on Response Surface Methodology (RSM) to achieve the optimal condition and interaction of independent variables. The characterizations of catalyst were studied by XRD, BET surface area and TEM to explain the morphology of surface and to confirm the hexagonal structure. The results showed the 2theta peak can be indexed to hexagonal lattice that also confirmed by TEM result and surface area about 650 m2/g. All of independent variables showed significant on the degradation of reactive red 3 except for initial H2O2 concentration.

scholarly journals PHYSICOCHEMICAL PROPERTIES AND POZZOLANIC PERFORMANCE OF ULTRAFINE TREATED RICE HUSK ASH (UFTRHA) AS ADDITIVE IN CONCRETE

2018 ◽  
Vol 16 ◽  
Author(s):  
Siti Asmahani Saad ◽  
Nasir Shafiq ◽  
Maisarah Ali
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Rice Husk Ash ◽  
High Energy ◽  
Size Analysis ◽  
Pre Treatment

Rice husk ash (RHA) contains high amount of amorphous silica that is ubiquitous in the pozzolanic reaction of SCM in concrete. However, usage of conventional RHA is currently unfavourable in concrete industry due to its properties inconsistency. In this regard, improvement on the RHA properties by introduction of thermochemical pre-treatment prior to burning procedure is seen as an excellent way to reach the goal. In this paper, raw rice husk was pre-treated using 0.1N hydrochloric acid (HCl) and heated at 80oC. It was then mechanically activated by high energy planetary ball mill for 15 minutes at speed of 300rpmand ball-to-powder ratio (BPR) of 15:1. The chemical composition, mineralogical properties, particle size analysis, specific surface area as well as microstructure properties of ultrafine treated rice husk ash (UFTRHA) were determined accordingly. As for amorphous silica content of the optimum sample was recorded as 98.60% incinerated at 600oC with four hours of pre-treatment soaking duration. In terms of particle size and specific surface, it was also observed that, burning temperature of 600oC, pre-treated at four hours were recorded to produce finest size of UFTRHA where d(0.1), d(0.5) and d(0.9) were obtained as 1.416?m, 4.364 ?m and 14.043 ?m respectively. Largest specific surface area value was obtained at 219.58 m2/g with the similar pre-treatment conditions. Meanwhile, the strength activity of UFTRHA from the optimum pre-treatment process was measured by testing the compressive strength of mortars. The highest compression value obtained was 50.17MPa with 3% UFTRHA replacement at 28 days.

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