Mechanism of Zeolite A Nanocrystal Growth from Colloids at Room Temperature

Science ◽  
1999 ◽  
Vol 283 (5404) ◽  
pp. 958-960 ◽  
Author(s):  
S. Mintova ◽  
N. H. Olson ◽  
V. Valtchev ◽  
T. Bein
Keyword(s):  
Room Temperature ◽  
Zeolite A ◽  
Nanocrystal Growth

scholarly journals Precise Control of CsPbBr3 Perovskite Nanocrystal Growth at Room Temperature: Size Tunability and Synthetic Insights

2021 ◽  
Vol 33 (7) ◽  
pp. 2387-2397
Author(s):  
Alasdair A. M. Brown ◽  
Parth Vashishtha ◽  
Thomas J. N. Hooper ◽  
Yan Fong Ng ◽  
Gautam V. Nutan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Precise Control ◽  
Nanocrystal Growth

scholarly journals Parameters Expediting the Thermal Conversion of Ba-Exchanged Zeolite A to Monoclinic Celsian

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
A. Marocco ◽  
M. Pansini ◽  
G. Dell'Agli ◽  
S. Esposito
Keyword(s):  
Phase Transition ◽  
Amorphous Phase ◽  
Room Temperature ◽  
Thermal Conversion ◽  
Zeolite A ◽  
Thermal Transformations ◽  
Final Phase ◽  
Temperature Range ◽  
Thermally Treated

Four samples of Ba-exchanged zeolite A, bearing small residual amounts of Na (0.27, 0.43, 0.58, and 0.74 meq/g), were thermally treated in the temperature range 200–1500∘C for times up to 28 hours. The same samples were pressed at 30 and 60 MPa to form cylindrical pellets which were thermally treated at 1300∘C for 5 hours. All materials were characterized by room temperature XRD. The sequence of thermal transformations that Ba-exchanged zeolite A undergoes (zeolite → amorphous phase → hexacelsian → monoclinic celsian) and the strong mineralizing action developed by Na are confirmed. Pressing the Ba-exchanged zeolite A powder-like samples to obtain cylindrical pellets is found to expedite the sluggish final phase transition hexacelsian → monoclinic celsian. The optimum residual Na content of Ba-exchanged zeolite A for transformation into monoclinic celsian is assessed to be between 0.27 and 0.43 meq/g.

Non Conventional Synthesis of Monoclinic Celsian from Ba-Exchanged Zeolite A: Study of the Effect of Residual Na and Forming Pressure

2006 ◽  
Vol 45 ◽  
pp. 963-968 ◽  
Author(s):  
C. Ferone ◽  
M. Pansini ◽  
Fernandanora Andreola ◽  
Luisa Barbieri ◽  
Cristina Siligardi ◽  
...  
Keyword(s):  
Phase Transition ◽  
Amorphous Phase ◽  
Room Temperature ◽  
Zeolite A ◽  
Thermal Transformations ◽  
Final Phase ◽  
Temperature Range ◽  
Thermally Treated

Four samples of Ba-exchanged zeolite A, bearing 0.27, 0.43, 0.58 and 0.74 meq/g Na residual amounts, were thermally treated in the temperature range 200-1500 °C for times up to 28 hours. The same samples were pressed at 30 and 60 MPa to manufacture cylindrical pellets, which were thermally treated at 1300 °C for 5 hours. Thermally treated materials were characterized by room temperature XRD. The sequence of thermal transformations that Ba-exchanged zeolite A undergoes (zeolite ® amorphous phase ® hexacelsian ® monoclinic celsian) and the strong mineralizing action developed by Na are confirmed. Pressing the Ba-exchanged zeolite A powder-like samples to obtain cylindrical pellets is found to expedite the sluggish final phase transition hexacelsian ® monoclinic celsian. The optimum residual Na content of Ba-exchanged zeolite A to be transformed into monoclinic celsian is assessed to range between 0.27 and 0.43 meq/g.

Local structure change of luminescent Ag zeolite-A and -X studied by in situ XAFS and IR spectroscopy

2020 ◽  
Vol 27 (6) ◽  
pp. 1640-1647
Author(s):  
Takafumi Miyanaga ◽  
Yushi Suzuki ◽  
Sho Narita ◽  
Reki Nakamura
Keyword(s):  
Local Structure ◽  
Room Temperature ◽  
Structural Changes ◽  
Zeolite A ◽  
Zeolite X ◽  
Zeolite Cavity ◽  
Ag Clusters ◽  
The Difference ◽  
X Ray Absorption

The in situ X-ray absorption fine structure (XAFS) for the structural changes of Ag clusters produced in the cavity of luminescent zeolites by thermal treatment of Ag zeolite-A and Ag zeolite-X has been studied. The following procedures are compared: (i) samples are heated and cooled to room temperature under atmosphere (under air); (ii) samples are heated and cooled to room temperature in a vacuum and then exposed to air. It was confirmed that the Ag clusters were broken when the Ag zeolite was exposed to air for Ag zeolite-X, which complements our previous results for Ag12-A. It is suggested that the deformation of the Ag clusters plays an important role in the generation of a strong photoluminescence band, and Ag clusters may not be direct species producing the strong photoluminescence. The local structure of the Ag ions was found to be slightly different from that of the unheated species. The difference may originate from the formation and breakdown of Ag clusters in the zeolite cavity.

scholarly journals Room-Temperature Activation of Methane and Direct Formations of Acetic Acid and Methanol on Zn-ZSM-5 Zeolite: A Mechanistic DFT Study

2020 ◽  
Vol 93 (3) ◽  
pp. 345-354 ◽  
Author(s):  
Muhammad Haris Mahyuddin ◽  
Seiya Tanaka ◽  
Yoshihito Shiota ◽  
Kazunari Yoshizawa
Keyword(s):  
Acetic Acid ◽  
Room Temperature ◽  
Dft Study ◽  
Zeolite A ◽  
Temperature Activation

Incorporation of 2-Arylhexa-1,5-diene into Pentasil Zeolite:  A Distorted 1-Arylcyclohexane-1,4-diyl Radical Cation at Room Temperature

2005 ◽  
Vol 109 (7) ◽  
pp. 2504-2511 ◽  
Author(s):  
Hiroshi Ikeda ◽  
Tomonori Minegishi ◽  
Tsutomu Miyashi ◽  
Prasad S. Lakkaraju ◽  
Ronald R. Sauers ◽  
...  
Keyword(s):  
Radical Cation ◽  
Room Temperature ◽  
Zeolite A ◽  
Pentasil Zeolite

The Effect of Aging on Synthesis of Zeolite at High Temperature

2009 ◽  
Vol 620-622 ◽  
pp. 225-228 ◽  
Author(s):  
Yeong Seok Yoo ◽  
Hyo Jin Ban ◽  
Kyeong Ho Cheon ◽  
Jae Ik Lee
Keyword(s):  
High Temperature ◽  
Hydrothermal Method ◽  
Aging Time ◽  
Firing Temperature ◽  
Crystallization Temperature ◽  
Aging Temperature ◽  
Room Temperature ◽  
Zeolite Synthesis ◽  
Zeolite A ◽  
Synthesis Time

Zeolite are used as adsorbent, catalyst and ionexchang material. But it limited to extend the usage of the zeolite since almost zeolite synthesized by hydrothermal method. The purpose of this study was to synthesis zeolite by calcination at high temperature due to extend the application of zeolite, as ceramics process. The effect of aging temperature and time, crystallization temperature on the synthesis of zeolite has been studied. Aging was performed at room temperature~70°C during 0~3days. After aging, zeolite precursor sinter for 1 hours at 300, 400, 500°C in furnace. The resulting materials were characterized by XRD, TG, SEM When the aging time is less than 1 day zeolite was not synthesized. But zeolite A obtained from precursor of aging time is more than 1 day at all firing temperature. As a result the aging time and aging temperature is increased, the zeolite synthesis time is decreased. Therefore aging is benefit process on synthesis of zeolite at high temperature.

Stabilization of Artificial Organic Soil at Room Temperature Using Blended Lime Zeolite

2013 ◽  
Vol 723 ◽  
pp. 985-992 ◽  
Author(s):  
Felix Ngee Leh Ling ◽  
Khairul Anuar Kassim ◽  
Ahmad Tarmizi Abdul Karim ◽  
Tze Wei Chan
Keyword(s):  
Room Temperature ◽  
Organic Soil ◽  
Pozzolanic Reaction ◽  
Organic Content ◽  
Organic Soils ◽  
Zeolite A ◽  
Reaction Products ◽  
Lime Stabilization ◽  
Curing Period ◽  
Strength Increment

Organic content in soil is believed to inhibit formation of reaction products in lime stabilization which resulted in low gain of strength when dealing with organic soils. Zeolite, a kind of pozzolan with high CEC capacity is proposed to be use in this study in order to improve lime stabilization of organic soil. The effectiveness of blended lime zeolite in stabilization of organic soils was investigated by using two types of artificial organic soils with predetermined organic contents. Artificial organic soils were formed by mixing inorganic soil (commercial kaolin) with organic matter (commercial humic acid) at specific ratio. Initial consumption of lime for organic soils was determined in order to determine the minimum percentage of stabilizer required for each soil. Potential influencing factors that might affect the strength such as organic contents, contents of stabilizer, and curing periods were studied. The findings of the study showed that high organic contents and low lime contents resulted in lower gain of strength. However, it is found that slight replacement of lime with zeolite works well with low organic soil at long curing period which resulted in highest strength among all the mixes. Overall, longer curing periods will increase the strength of the soil in the order of 56 days > 28 days > 7 days. Nevertheless, the percentage of strength increment over curing periods is linear with the lime contents, which proved that lime is required for pozzolanic reaction.

A facile method to synthesize highly uniform zeolite A at near room temperature for copper (II) removal

2021 ◽  
pp. 103046
Author(s):  
Yuhan Huang ◽  
Min Li ◽  
Yuexin Guo ◽  
Bo Ren ◽  
Xiaojia Liu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Zeolite A ◽  
Highly Uniform
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