Thermal behavior, structure, dynamic properties of aqueous glycine solutions confined in mesoporous silica MCM-41 investigated by x-ray diffraction and quasi-elastic neutron scattering

2018 ◽  
Vol 149 (12) ◽  
pp. 124502 ◽  
Author(s):  
K. Yoshida ◽  
T. Inoue ◽  
M. Torigoe ◽  
T. Yamada ◽  
K. Shibata ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Thermal Behavior ◽  
Neutron Scattering ◽  
Dynamic Properties ◽  
X Ray Diffraction ◽  
Elastic Neutron ◽  
X Ray ◽  
Structure Dynamic ◽  
Elastic Neutron Scattering ◽  
Mcm 41

Thermal behavior, structure, and dynamics of low-temperature water confined in mesoporous organosilica by differential scanning calorimetry, X-ray diffraction, and quasi-elastic neutron scattering

2012 ◽  
Vol 85 (1) ◽  
pp. 289-305 ◽  
Author(s):  
Mai Aso ◽  
Kanae Ito ◽  
Hiroaki Sugino ◽  
Koji Yoshida ◽  
Takeshi Yamada ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Water Molecule ◽  
Neutron Scattering ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Elastic Neutron ◽  
X Ray ◽  
Mesoporous Organosilica ◽  
Condensed Water ◽  
Elastic Neutron Scattering

Differential scanning calorimetry (DSC), X-ray diffraction (XRD), and quasi-elastic neutron scattering (QENS) measurements have been made at 200~330 K for capillary-condensed water confined in periodic mesoporous organosilica (PMO) materials with the phenyl groups embedded in silica matrix (Ph-PMO; pore diameter 30 Å). The DSC data showed that the capillary-condensed water in Ph-PMO freezes at 228 K. X-ray radial distribution functions (RDFs) showed that the tetrahedral-like hydrogen-bonded structure of water is distorted in Ph-PMO pores, compared with bulk water; however, with lowering temperature the tetrahedral moiety of water is gradually recovered in the pores. Below the freezing point, cubic ice Ic was formed in the Ph-PMO pores. The QENS data showed that the translational diffusion constant and the residence time and the rotational relaxation time of water molecule in Ph-PMO are comparable with those in bulk. The corresponding activation energies suggested that the more hydrophobic the nature of the wall is, the smaller the activation energy of diffusion and rotation of a water molecule; this implies that water molecules confined in the hydrophobic pores are present in the core of the pores, whereas those in the hydrophilic pores strongly interact with the silanol groups.

Multidisciplinary study on the hydrogelation of digold(I) complex [{Au(9N-adeninate)}2(μ-dmpe)]: optical, rheological, and quasi-elastic neutron scattering perspectives

2021 ◽  
Author(s):  
José Maria López-de-Luzuriaga ◽  
Daniel Blasco ◽  
Miguel Monge ◽  
Maria Elena Olmos ◽  
María Rodríguez-Castillo ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
X Ray Diffraction ◽  
Elastic Neutron ◽  
X Ray ◽  
Multidisciplinary Study ◽  
Elastic Neutron Scattering ◽  
Aurophilic Interaction

Herein, the syntheses of [{Au(9N-adeninate)}2(μ-dmpe)] (2, dmpe = 1,2-bis(dimethylphosphino)ethane) and its chloride precursor [(AuCl)2(μ-dmpe)] (1) are described. X-ray diffraction of 2 reveals a short intramolecular aurophilic interaction (2.9919(8) Å), which...

Synthesis of SBA-15/MCM-41 bimodal mesoporous silica

2016 ◽  
Vol 1817 ◽  
Author(s):  
Leyla Y. Jaramillo ◽  
Wilson A. Henao ◽  
Elizabeth Pabón-Gelves
Keyword(s):  
Mesoporous Silica ◽  
Textural Properties ◽  
New Materials ◽  
X Ray Diffraction ◽  
Main Interest ◽  
Structure Directing Agent ◽  
X Ray ◽  
Synthesis Parameters ◽  
Nanostructured Silica ◽  
Mcm 41

ABSTRACTNanostructured silica materials with different morphologies and adjustable pore size have been studied by researches worldwide for several applications such as catalysis, separation, adsorption, and templates for new materials. The main interest in the development of these materials is to obtain a structure with a specific combination of pore sizes for a particular application. The morphology and textural properties of pores can be easily changed with the modification of the synthesis parameters, among these, the choice of surfactant or structure directing agent (SDA).Accordingly, in this work, three types of nanostructured silica with different mesoporosity were synthesized by using of CTAB and Pluronic 123 as structure directing agents: SBA-15 and MCM-41 unimodal mesoporous silica and SBA-15/MCM-41 bimodal mesoporous silica.To evaluate the effect of surfactant on the morphology and textural properties of pores, the materials were characterized by scanning electron microscopy (SEM), X-ray Diffraction (XRD) and nitrogen sorption (BET).

scholarly journals Simple Synthesis and Characterization of Hexagonal and Ordered Al–MCM–41 from Natural Perlite

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 264 ◽  
Author(s):  
Hongyun Chen ◽  
Siyao Fu ◽  
Liangjie Fu ◽  
Huaming Yang ◽  
Deliang Chen
Keyword(s):  
Mesoporous Silica ◽  
Bet Surface Area ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Structures ◽  
Ordered Mesoporous ◽  
Silica Materials ◽  
Mesoporous Silica Materials ◽  
Mcm 41

Silica reagents are expensive and toxic for use in the synthesis of mesoporous silica materials. It is imperative to take an interest in green silicon sources. In this paper, we report the synthesis of hexagonal and ordered aluminum-containing mesoporous silica materials (Al–MCM–41) from natural perlite mineral without addition of silica or aluminum reagents. A pretreatment process involving acid leaching, alkali leaching, and strongly acidic cation exchange resins treatment was critical to obtain silicon and aluminum sources from natural perlite mineral. The Al–MCM–41 material was synthesized via a hydrothermal reaction with hexadecyl trimethyl ammonium bromide (CTAB) as the template and subsequent calcination. The resulting mesophase had a hexagonal and ordered mesoporous structure, confirmed by small-angle X-ray diffraction (SAXRD) and transmission electron microscopy (TEM). Al–MCM–41 material had a high Brunauer–Emmet–Teller (BET) surface area of 1024 m2/g, pore volume of 0.72 cm3/g and an average pore diameter of 2.8 nm with a pore size distribution centered at 2.5 nm. The thermal behavior of the as-synthesized samples during calcination was investigated by thermogravimetry (TG) and differential thermogravimetry (DTG) analysis. The Al–MCM–41 material showed a negative surface charge in aqueous solution with the pH value ranging from 2 to 13. The variations of chemical structures from natural perlite to Al–MCM–41 were traced by wide-angle X-ray diffraction (WAXRD) and Fourier-transform infrared spectroscopy (FTIR). A proposed mechanism for the synthesis of hexagonal and ordered mesoporous silica materials from natural perlite is discussed.

Interlayer Water Molecules in Vanadium Pentoxide Hydrate. 8. Dynamic Properties by Quasi-Elastic Neutron Scattering

Langmuir ◽  
2005 ◽  
Vol 21 (4) ◽  
pp. 1389-1397 ◽  
Author(s):  
Shigeharu Kittaka ◽  
Shuichi Takahara ◽  
Toshio Yamaguchi ◽  
Marie-Claire Bellissent Funel
Keyword(s):  
Neutron Scattering ◽  
Vanadium Pentoxide ◽  
Dynamic Properties ◽  
Water Molecules ◽  
Interlayer Water ◽  
Elastic Neutron ◽  
Elastic Neutron Scattering
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