Synthesis and Characterization of the Y/MCM-41 Composite Molecular Sieves

2011 ◽  
Vol 480-481 ◽  
pp. 159-164 ◽  
Author(s):  
Li Qin Wang ◽  
Xiang Ni Yang ◽  
Yang Han ◽  
Ning Yu ◽  
Xiu Li Zhao
Keyword(s):  
Pore Size ◽  
Molecular Sieves ◽  
Average Pore Size ◽  
Nitrogen Adsorption ◽  
Mesoporous Structure ◽  
Decomposition Temperature ◽  
Average Pore ◽  
Y Zeolites ◽  
Ft Ir ◽  
Mcm 41

The Y/MCM-41 composite molecular sieves were synthesized in the method of hydrothermal crystallization with cetyltrimethylammonium bromide (CTMABr) as the template agent. The as-prepared composite molecular sieves were characterized by the means of X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), the thermogravimetric and differential thermal analysis (TG-DTA) and the nitrogen adsorption test. The experimental results were shown as follows: the Y/MCM-41 composite molecular sieves kept properties of Y-zeolites and MCM-41 molecular sieves. In the XRD and FT-IR spectra, it can be found both characteristic peaks of Y-zeolites and MCM-41 molecular sieves. The pore size distribution plot indicated that the Y/MCM-41composite molecular sieves had micro-mesoporous structure, and the average pore size were about 1.5 nm and 15 nm. The decomposition temperature of the template agent was at 320 °C, and the calcined temperature of Y-zeolites was at about 560 °C. There showed an endothermic process constantly in the DTA curve, and there was little mass loss in the TG curve, indicating the obtained Y/MCM-41 composite molecular sieves had higher thermal stability.

Synthesis and Characterization of MCM-41 Molecular Sieves Nanoparticals

2013 ◽  
Vol 662 ◽  
pp. 214-217 ◽  
Author(s):  
Li Qin Wang ◽  
Yang Han ◽  
Xiu Jun Fu ◽  
Hai Tao Wu ◽  
E Chang ◽  
...  
Keyword(s):  
Molecular Sieves ◽  
Room Temperature ◽  
Mesoporous Structure ◽  
Decomposition Temperature ◽  
Surface Areas ◽  
Type Iv ◽  
Typical Type ◽  
Ft Ir ◽  
Adsorption Desorption ◽  
Mcm 41

Nanoparticals of MCM-41 molecular sieves were synthesized at near room temperature with cetyltrimethylammonium bromide (CTAB) as template agent. The prepared samples were characterized by the means of scanning electron microscopy (SEM), X-ray powder diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), N2 adsorption tests, thermogravimetric and differential thermal analysis (TG-DTA). The results suggested that morphology of MCM-41 molecular sieves samples with high crystallinity was almost uniform spherical, and the particles size was almost less than 100 nm. The adsorption-desorption isotherms were corresponded to typical type IV isotherms with the hysteresis loop of type H2, which showed the samples had mesoporous structure. The pore size distribution of samples were 1.69 nm and 3.58 nm, and the specific surface areas was up to 752.23 m2/g. The decomposition temperature of template agent CTAB was around 327 °C, while the framework for MCM-41molecular sieves was stable. So MCM-41 molecular sieve samples synthesized at near room temperature had excellent physical properties.

Experimental Study on Using Fuxin Natural Zeolite to Prepare Molecular Sieves

2012 ◽  
Vol 454 ◽  
pp. 30-34
Author(s):  
Zhi Jun Ma ◽  
Kuan Zhang ◽  
Yi Min Zhu ◽  
Yue Xin Han
Keyword(s):  
Aging Time ◽  
Crystallization Temperature ◽  
Molecular Sieves ◽  
Natural Zeolite ◽  
Average Pore Size ◽  
Nitrogen Adsorption ◽  
Raw Material ◽  
Crystallization Time ◽  
Average Pore ◽  
Relative Crystallinity

In this paper, the natural zeolite as raw material, zeolites was prepared by organic amines hydrothermal synthesis. The results are characterized by SEM and nitrogen adsorption / de-commanded test,and study the influence of the aging time, crystallization temperature and crystallization time on zeolite crystallization. The results showed that using natural zeolite as raw material and butylamine as templating agent, average pore size of 0.77nm, the relative crystallinity of 96.34% of the zeolite was prepared in the hydrothermal system. Optimal aging time is 12h, crystallization time is 48h, crystallization temperature is 170 °C.

Rice Straw and Rice Straw Ash as Precursor for Synthesis of Mesoporous Molecular Sieves MCM-41

2012 ◽  
Vol 550-553 ◽  
pp. 1391-1394
Author(s):  
Xiao Hong Tang ◽  
Bao Jun Li ◽  
Cheng Wei Li
Keyword(s):  
Rice Straw ◽  
Molecular Sieves ◽  
Mesoporous Structure ◽  
Mesoporous Molecular Sieves ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Adsorption Desorption ◽  
Straw Ash ◽  
Mcm 41

In this paper, rice straw (RS) and rice straw ash (RSA) were employed to synthesize mesoporous molecular sieves MCM-41 in an open-vessel. The structure of as-synthesized MCM-41 was characterized by X-ray diffraction (XRD) pattern, Fourier transform infrared (FT–IR) spectrum, NH3-Temperature Programmed Desorption (TPD), and N2 adsorption-desorption isotherms. RS-MCM-41 and RSA-MCM-41 possess the same typical hexagonal mesoporous structure with high long-range order and crystalline degree as those of MCM-41 from water glass (SDS-MCM-41).

Synthesis and Characterization of the ZSM-5/MCM-41 Composite Molecular Sieves

2011 ◽  
Vol 480-481 ◽  
pp. 165-169 ◽  
Author(s):  
Li Qin Wang ◽  
Ning Yu ◽  
Yang Han ◽  
Xiang Ni Yang ◽  
Xiu Li Zhao
Keyword(s):  
Molecular Sieves ◽  
Cetyltrimethylammonium Bromide ◽  
Decomposition Temperature ◽  
High Thermal Stability ◽  
Hydrothermal Crystallization ◽  
X Ray ◽  
Ft Ir ◽  
Prepared Composite ◽  
Mcm 41

The ZSM-5/MCM-41 composite molecular sieves were synthesized in the method of hydrothermal crystallization in the presence of cetyltrimethylammonium bromide (CTMABr) as template agent. The prepared composite molecular sieves were characterized by the means of X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and the thermogravimetric and differential thermal analysis (TG-DTA). The experimental results showed that as-prepared ZSM-5/MCM-41 composite molecular sieves kept both crystal structure and compositions of ZSM-5 zeolites and MCM-41 molecular sieves. The decomposition temperature of the template agent was 293°C, and the decomposition temperature of the molecular sieve framework was higher than 800 °C. We supposed that the obtained ZSM-5/MCM-41 composite molecular sieves had high thermal stability, framework rigidity and structural stability, and could combine the properties of ZSM-5 zeolites and MCM-41 molecular sieves successfully.

Porous Silica Nanomaterial Derived from Organic Waste Rice Husk as Highly Potential Drug Delivery Material

2019 ◽  
Vol 964 ◽  
pp. 88-96
Author(s):  
Hariyati Purwaningsih ◽  
Slamet Raharjo ◽  
Vania Mitha Pratiwi ◽  
Diah Susanti ◽  
Agung Purniawan
Keyword(s):  
Mesoporous Silica ◽  
Pore Size ◽  
Surface Area ◽  
Hydrothermal Treatment ◽  
Rice Husk ◽  
Average Pore Size ◽  
Sol Gel ◽  
Average Pore ◽  
Hydrothermal Temperature ◽  
Mcm 41

Rice became the main product of agriculture in agrarian countries including Indonesia. Rice husk is a waste of rice as one of the largest silica producers. Silica from rice husks can be used as a source of silica in the manufacture of sodium silicate as an alternative to the formation of mesoporous silica at a low price. In this research, the characterization of mesoporous silica nanoparticle (MSN) MCM-41 from rice husk (rice husk) with sol-gel method followed by hydrothermal treatment. Silica extraction was performed by titrating sodium silica using HCl method until the gel was formed. The mesoporous synthesis was performed with the addition of CTAB. The titration is then carried out using a solution of acetic acid. XRD shows silica with an amorphous structure. The FTIR results show that extraction silica and MSN MCM-41 contain pure silica displayed with Si-O-Si functional groups in the sample. The SEM results show MSN MCM-41 images such as a coral-like structure of agglomerated silica and the higher temperature hydrothermal treatment then it would be the more large size of particles. The material has a hexagonal pore structure such as a honeycomb as characteristic of MCM-41 with a pore size of 2.535 nm which includes mesoporous material. The result of nitrogen adsorption-desorption isotherms shows lower hydrothermal temperature will increase the specific surface area and decrease average pore size, where the best result with surface area value is 825.365 m2/gr and average pore size is 6.10426 nm obtained from process hydrothermal at 85°C.

scholarly journals PEMANFAATAN LIMBAH SEKAM PADI MENJADI SILIKA GEL

2014 ◽  
Vol 3 (2) ◽  
Author(s):  
Prima Astuti Handayani ◽  
Eko Nurjanah ◽  
Wara Dyah Pita Rengga
Keyword(s):  
Pore Size ◽  
Surface Area ◽  
Silica Gel ◽  
Pore Volume ◽  
Average Pore Size ◽  
Total Pore Volume ◽  
Rice Hull ◽  
Rice Hull Ash ◽  
Average Pore ◽  
Ft Ir

<p>Sekam padi merupakan salah satu sumber penghasil silika terbesar, berpotensi sebagai bahan pembuatan silika gel. Abu sekam padi mengandung silika sebanyak 87%-97% berat kering. Sintesis silika gel dari abu sekam padi dilakukan dengan mereaksikan abu sekam padi menggunakan larutan NaOH 1N pada suhu 800C selama 1 jam dan dilanjutkan dengan penambahan larutan asam hingga pH=7. Gel yang dihasilkan selanjutnya didiamkan selama 18 jam kemudian dikeringkan pada suhu dikeringkan menggunakan oven pada suhu 800C hingga beratnya konstan. Hasil percobaan diperoleh bahwa silika gel dengan penambahan CH3COOH menghasilkan yield yang lebih besar dibandingkan penambahan HCl. Berdasarkan analisis FT-IR silika gel yang diperoleh memiliki gugus Si-O-Si dan gugus Si-OH. Silika gel dengan penambahan HCl memiliki surface area sebesar 65,558 m2/g, total pore volume 0,1935 cc/g, dan average pore size sebesar 59,0196 Å. Sedangkan silika gel dengan penambahan CH3COOH memiliki surface area sebesar 9,685 m2/g, total pore volume 0,02118 cc/g, dan average pore size sebesar 43,7357Å. Silika gel dengan penambahan<br />CH3COOH memiliki kemampuan menyerap kelembaban udara yang lebih baik dibanding silika gel dengan penambahan HCl.</p><p> </p><p>Rice hull ash (RHA) is one of the biggest source of silica, potential for sintesis silica gel. RHA contains silica as many as 87 % -97 %. Synthesis of silica gel from rice hull ash was done by reaction using NaOH solution at temperature 800C for 1 hour and followed by the addition of an acid solution until pH=7. The gel were rested with time aging 18 hour, and then dried using oven at temperature 800C until constant weigh. The results obtained that the silica gel with the addition of CH3COOH produce higher yields than the addition of HCl. Based on FT-IR analysis, silica gel has a group of silanol (Si-`OH) and siloxan (Si-O-Si) group. Silica gel with the addition of HCl has a surface area 65,558 m2/g, a total pore volume 0,1935 cc/g, and average pore size 59,0196 Å. While the silica gel with the addition of CH3COOH has a surface area 9.685 m2/g, a total pore volume 0,02118 cc/g, and average pore size 43,7357 Å. Silica gel with the addition of CH3COOH<br />has the ability to absorb humidity better than silica gel with the addition of HCl.</p>

scholarly journals Bioactive ceramic powder prepared using a new sol-gel process

2017 ◽  
Vol 11 (2) ◽  
pp. 87-92 ◽  
Author(s):  
Vương Bùi
Keyword(s):  
Average Pore Size ◽  
Sol Gel ◽  
Ceramic Powder ◽  
Nitrogen Adsorption ◽  
Mesoporous Structure ◽  
Average Pore ◽  
Vitro Assay ◽  
Sol Gel Process ◽  
Bioactive Ceramic

Bioactive ceramic powder containing 45% SiO2, 24.5% CaO, 24.5% Na2O and 6% P2O5 (wt.%) was synthesized using a new sol-gel process. The preparedmaterial was investigated by several physico-chemical methods. The X-ray diffraction showed the presence of two crystalline phases, Na6Ca3Si6O18 and NaCaPO4. The high specific surface area (47m2/g) and a mesoporous structure with the average pore size of 2.6 nm were confirmed using low-temperature nitrogen adsorption technique. In vitro experiments were carried out by soaking the powder sample in simulated body fluid (SBF) at different times. XRD, FTIR and SEM coupled with EDS were used for in vitro evaluation of bioactivity. The obtained results confirmed that the ceramic powder can be used as biomaterial for bone tissue engineering due to its high bioactivity expressed by the rapid formation of a biological carbonated hydroxyapatite layer on its surface after in vitro assay.

Alternative Chemical Route to Mesoporous Titania From a Titanatrane Complex

2005 ◽  
Vol 20 (1) ◽  
pp. 128-134 ◽  
Author(s):  
Chavalit Trakanprapai ◽  
Vincenzo Esposito ◽  
Silvia Licoccia ◽  
Enrico Traversa
Keyword(s):  
Average Pore Size ◽  
Morphological Characteristics ◽  
Nitrogen Adsorption ◽  
Mesoporous Structure ◽  
Mesoporous Titania ◽  
Average Pore ◽  
Chemical Route ◽  
Oxide Powders ◽  
Micellar Aggregates ◽  
Direct Methanol

High-purity, mesoporous titania was prepared by reaction of dimethylaminotitanatrane, [NMe2–Ti(OCH2CH2)3N] in the presence of micellar aggregates as templating agents followed by thermal treatments in the temperature range 350–450 °C. The powders were characterized by nitrogen adsorption–desorption isotherms, thermogravimetry–differential thermal analysis, Fourier transform infrared, field-emission scanning electron microscopy, and x-ray diffraction. Analysis of the morphological characteristics of titanium oxide powders calcined at 350 °C for 120 h and at 450 °C for 6 h showed the presence of a mesoporous structure, with an average pore size of about 3.5 nm. Firing temperatures above 450 °C caused the collapse of the mesoporous structure. Composite Nafion-based membranes, containing 5 wt% mesoporous titania fired at 450 °C as a filler were successfully prepared. Preliminary tests in a prototype direct methanol fuel cell demonstrated that the composite membrane allowed cell operation up to 145 °C, thus showing a significant performance improvement over pure Nafion.

Preparation of Mesoporous MCM-41 in Open-Vessel for Catalytic Synthesis of Geranyl Propionate

2012 ◽  
Vol 550-553 ◽  
pp. 358-361
Author(s):  
Xiao Hong Tang ◽  
Bao Jun Li ◽  
Chun Liang Han ◽  
Jin Wang ◽  
Cheng Wei Li
Keyword(s):  
Molecular Sieves ◽  
Mesoporous Structure ◽  
Mesoporous Molecular Sieves ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Geranyl Propionate ◽  
Adsorption Desorption ◽  
Mcm 41

In this paper, the synthesis of mesoporous molecular sieves MCM-41 was carried out in an open-vessel. The mesoporous structure of as-synthesized MCM-41 was characterized by X-ray diffraction (XRD) pattern, Fourier transform infrared (FT–IR) spectrum, NH3-Temperature Programmed Desorption (TPD), and N2 adsorption-desorption isotherms. The catalytic performances of MCM-41 for the synthesis of geranyl propionate (GP) with geraniol and propionic acid as reagents also were investigated. The characterization results show that the as-synthesized MCM-41 possesses typical hexagonal mesoporous structure with high long-range order and crystalline degree. The high GP selectivity of 64.25% with geraniol conversion of 17.21% was achieved under optimum conditions.

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