Pore Size Determination in Ordered Mesoporous Materials Using Powder X-ray Diffraction

2013 ◽  
Vol 117 (35) ◽  
pp. 18120-18130 ◽  
Author(s):  
Yosuke Ishii ◽  
Yoshiki Nishiwaki ◽  
Ayar Al-zubaidi ◽  
Shinji Kawasaki
Keyword(s):  
Pore Size ◽  
Mesoporous Materials ◽  
Size Determination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ordered Mesoporous Materials ◽  
Ordered Mesoporous

Controlling the Wall Thickness and Pore Size of SBA-15 by Using PPG and PEG as Additives

2010 ◽  
Vol 152-153 ◽  
pp. 1514-1518
Author(s):  
Ji Xin Su ◽  
Ming Bo Zhang ◽  
Li Yuan Ma ◽  
Shen Ping Zhang ◽  
Fei Fei Dong
Keyword(s):  
Pore Size ◽  
Wall Thickness ◽  
Hexagonal Structure ◽  
Polypropylene Glycol ◽  
Ordered Mesoporous Silica ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ordered Mesoporous ◽  
Adsorption Desorption

Ordered mesoporous silica SBA-15 with controlled pore size and wall thickness was synthesized using polypropylene glycol (PPG) and polyethylene glycol (PEG) as different additives. The final samples were characterized by low-angle X-ray diffraction, N2 adsorption-desorption and transmission electron microscopy. The SBA-15 used PPG or PEG as additive all could maintain the two-dimensional hexagonal structure. The addition of PPG could expand the pore size and decrease the wall thickness and the addition of PEG could reduce the pore size and increase the wall thickness of SBA-15.

scholarly journals Controlling Particle Morphology and Pore Size in the Synthesis of Ordered Mesoporous Materials

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4909
Author(s):  
Yaregal Awoke ◽  
Yonas Chebude ◽  
Isabel Díaz
Keyword(s):  
Pore Size ◽  
Mesoporous Materials ◽  
Rational Design ◽  
Amorphous Material ◽  
Synthesis Method ◽  
Short Channel ◽  
Periodic Mesoporous Organosilica ◽  
Ordered Mesoporous Materials ◽  
Ordered Mesoporous ◽  
Short Channels

Ordered mesoporous materials have attracted considerable attention due to their potential applications in catalysis, adsorption, and separation technologies, as well as biomedical applications. In the present manuscript, we aim at a rational design to obtain the desired surface functionality (Ti and/or hydrophobic groups) while obtaining short channels (short diffusion paths) and large pore size (>10 nm). Santa Barbara Amorphous material SBA-15 and periodic mesoporous organosilica PMO materials are synthesized using Pluronic PE 10400 (P104) surfactant under mild acidic conditions to obtain hexagonal platelet-like particles with very short mesochannels (300–450 nm). The use of expanders, such as 1, 3, 5-trimethylbenzene (TMB) and 1, 3, 5-triisopropylbenzene (TIPB) were tested in order to increase the pore size. TMB yielded in the formation of vesicles in all the syntheses attempted, whereas P104 combined with TIPB resulted both in expanded (E) E-SBA-15 and E-PMO with 12.3 nm pore size short channel particles in both cases. Furthermore, the synthesis method was expanded to the incorporation of small amount of Ti via co-condensation method using titanocene as titanium source. As a result, Ti-E-SBA-15 was obtained with 15.5 nm pore size and isolated Ti-sites maintaining platelet hexagonal morphology. Ti-PMO was obtained with 7.8 nm and short channels, although the pore size under the tried synthesis conditions could not be expanded further without losing the structural ordering.

ANALYSIS OF CHARACTERISTICS OF ORDERED MESOPOROUS ASSEMBLED WITH Fe, Bi AND B

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2780-2785
Author(s):  
JIANCHENG ZHANG ◽  
QILIANG NI ◽  
YUE SHEN ◽  
XIAO'AN ZHOU ◽  
SHENGYU JIANG ◽  
...  
Keyword(s):  
Mesoporous Materials ◽  
Sol Gel ◽  
Acid Sites ◽  
Coupling Agents ◽  
X Ray Diffraction ◽  
X Ray ◽  
Specific Saturation Magnetization ◽  
Transmission Electron ◽  
Ordered Mesoporous ◽  
The Relationship

Ordered SiO 2 mesoporous materials called SBA were prepared by hydrothermal or sol-gel method through using the surfactants as the template, such as cetytrimethylammonium bromide or triblock copolymer. SBA assembled with some different elements and compounds, including Fe , Bi , and B or Fe 2 O 3, B 2 O 3 and others by dipping or adding of chelating or coupling agents were prepared to form some composites, which characterized by wide or small angle X-ray diffraction, infrared spectra, N 2 static and kinetic adsorption, high resolution transmission electron microscopy and magnetic intensity instrument, respectively. The assembled α- Fe or α- Fe 2 O 3 under different conditions possessed lower magnetic coercive force (Hc), for instance the latter was about 87-117( Hc –103/4πA*m-1– Os ), but specific saturation magnetization (σ s –A*m2*kg-1) increase by 75.4% as compared with the conventional σ- Fe 2 O 3(1765 Os ) particles. However, the properties of the composites assembled with α- Fe was different from α- Fe 2 O 3 as mentioned-above. And the relationship between σ s or Os and structure for the assembled systems was discussed. After introduced B and Bi to the mesoporous materials, the composites showed not only existence of Brφnsted acid sites for B , but also improvement of the hydrothermal stability and enhance of the long–range order magnitude.

Self-Recognizing π-π Stacking Interactions Designed for the Generation of Ultrastable Mesoporous Hydrogen-Bonded Organic Frameworks

2019 ◽  
Author(s):  
KAIKAI MA ◽  
Peng Li ◽  
John Xin ◽  
Yongwei Chen ◽  
Zhijie Chen ◽  
...  
Keyword(s):  
Pore Size ◽  
Fiber Composite ◽  
Aqueous Media ◽  
Stacking Interactions ◽  
Mustard Gas ◽  
X Ray Diffraction ◽  
X Ray ◽  
Expansion Strategy ◽  
Π Stacking ◽  
Hydrogen Bonded

Creating crystalline porous materials with large pores is typically challenging due to undesired interpen-etration, staggered stacking, or weakened framework stability. Here, we report a pore size expansion strategy by self-recognizing π-π stacking interactions in a series of two-dimensional (2D) hydrogen–bonded organic frameworks (HOFs), HOF-10x (x=0,1,2), self-assembled from pyrene-based tectons with systematic elongation of π-conjugated molecular arms. This strategy successfully avoids interpene-tration or staggered stacking and expands the pore size of HOF materials to access mesoporous HOF-102, which features a surface area of ~ 2,500 m2/g and the largest pore volume (1.3 cm3/g) to date among all reported HOFs. More importantly, HOF-102 shows significantly enhanced thermal and chemical stability as evidenced by powder x-ray diffraction and N2 isotherms after treatments in chal-lenging conditions. Such stability enables the adsorption of dyes and cytochrome c from aqueous media by HOF-102 and affords a processible HOF-102/fiber composite for the efficient photochemical detox-ification of a mustard gas simulant.

Selective oxidation of cyclopentene to glutaraldehyde by H2O2 over Nb-SBA-15

2021 ◽  
Author(s):  
yingmeng qi ◽  
Qi Han ◽  
li wu ◽  
Jun Li
Keyword(s):  
Structural Properties ◽  
Selective Oxidation ◽  
Mesoporous Materials ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
X Ray

A series of niobium-containing mesoporous materials Nb-SBA-15 have been prepared by sonication–impregnation and hydrothermal process. The dispersion and structural properties of niobium-containing species were systematically characterized by X-ray diffraction, scanning...

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