Preparation of rectangular and 2D-hexagonal mesostructured silica at neutral conditions using poly(oxyethylene) cholesteryl ethers and a water-soluble silica precursor

Takahashi, Shun; Ikkai, Yasunari; Sakamoto, Kazutami; Rodríguez‐Abreu, Carlos; Aramaki, Kenji

doi:10.1016/j.jcis.2009.02.066

Cited by 14 publications

(8 citation statements)

References 52 publications

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“…Therefore, the silica structures resemble the hexagonal liquid crystal found in PDI aqueous solutions, as it occurs in some surfactant systems. 38 Note, however, that the starting composition for the synthesis fall into the isotropic (nonliquid crystalline) region, which suggests that the formation of ordered silica does not take place by direct templating but by precipitation (phase separation) into a more concentrated phase induced by cooperative self-assembly between aggregates and silica species.…”

Section: Resultsmentioning

confidence: 99%

Characterization of Perylene Diimide Dye Self-Assemblies and Their Use As Templates for the Synthesis of Hybrid and Supermicroporous Nanotubules

Rodríguez‐Abreu

Aubery-Torres

Solans

et al. 2011

ACS Appl. Mater. Interfaces

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The self-organizing structures formed by a water-soluble perylene diimide dye (PDI) have been studied by several experimental techniques as potential templates for the preparation of hybrid nanomaterials. The dye forms chromonic-nematic and hexagonal liquid crystals in water. The aggregates in liquid crystals consist of one-molecule-wide stacks. From the changes in the solution proton NMR chemical shifts with concentration, it appears that adjacent molecules are twisted. There is significant broadening of the aromatic resonances at higher concentrations, arising from nonmotionally averaged dipole-dipole coupling between adjacent aromatic hydrogens. This is attributed to slow overall rotation of the aggregates in solution, suggesting that they grow up to several tens of nanometers. Dye aggregates serve as templates for the formation of silica tubules (1-5 μm length, average diameter ≈300 nm), with aligned and very thin (1-2 nm) dye nanostripes embedded in the walls. The silica tubes precipitated from solution are formed by the cooperative interaction between PDI and silica species during the sol-gel reaction. Upon calcination, silica nanotubules with supermicroporous walls are obtained. In comparison with conventional surfactant systems, the use of π-π stacked chromonic aggregates brings new possibilities for the templated fabrication of pores with sizes below the mesoporous range. Materials could find applications in photovoltaics as well as in shape selective catalysis and adsorption.

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Section: Resultsmentioning

confidence: 99%

Characterization of Perylene Diimide Dye Self-Assemblies and Their Use As Templates for the Synthesis of Hybrid and Supermicroporous Nanotubules

Rodríguez‐Abreu

Aubery-Torres

Solans

et al. 2011

ACS Appl. Mater. Interfaces

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“…MCM-41, as one of the most famous ordered mesoporous silica materials since the discovery of M41S silica in 1992 [ 27 ], has been commonly applied for the adsorption of heavy-metal ions [ 28 , 29 ], owing to large surface areas, regular pore structure and adjustable pore sizes [ 30 , 31 ]. Up to now, noticeably, tetraethyl orthosilicate (TEOS), as a silica source for preparation of most mesoporous materials is usually expensive and toxic to the environment, which is inconsistent with the requirements of green chemistry [ 32 ].…”

Section: Introductionmentioning

confidence: 99%

Preparation of chitosan/MCM-41-PAA nanocomposites and the adsorption behaviour of Hg(II) ions

Fu¹,

Ying²,

Hu³

2018

R. Soc. open sci.

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A novel functional hybrid mesoporous composite material (CMP) based on chitosan and MCM-41-PAA was reported and its application as an excellent adsorbent for Hg(II) ions was also investigated. Innovatively, MCM-41-PAA was prepared by using diatomite and polyacrylic acid (PAA) with integrated polymer–silica hybrid frameworks, and then CMP was fabricated by introducing MCM-41-PAA to chitosan using glutaraldehyde as a cross-linking agent. The structure and morphology of CMP were characterized by X-ray diffraction, Fourier transform infrared spectra, thermogravimetric analysis, scanning electron microscopy and Brunauer–Emmett–Teller measurements. The results showed that the CMP possessed multifunctional groups such as –OH, –COOH and –NH2 with large specific surface area. Adsorption behaviour of Hg(II) ions onto CMP was fitted better by the pseudo-second-order kinetic model and the Langmuir model when the initial Hg(II) concentration, pH, adsorption temperature and time were 200 mg l−1, 4, 298 K and 120 min, respectively, as the optimum conditions. The corresponding maximum adsorption capacity could reach 164 mg g−1. According to the thermodynamic parameters determined such as free energy, enthalpy and entropy, the adsorption process of Hg(II) ions was spontaneous endothermic adsorption.

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“…18 Recently, mesoporous silica has attracted considerable attention because of its wide range of applications as an adsorbent. Mesoporous silica possesses the following characteristics: well-dened channels, hydrothermal stability, 19 controllable pore sizes, 20 enormous surface area and pore volume, 21 hydrothermal stability and narrow size distribution. 22 These materials are known for promising applications in sorbents, catalysis and sensors.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of surface nano-molecularly imprinted polymers for sensitive baicalin detection in biological samples

Wang

et al. 2015

RSC Adv.

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Surface molecularly imprinted polymers (MIP@SBA-15) imprinted on the surface of hybrid nanostructured organic/inorganic materials (SBA-15) were prepared for the selective extraction and detection of baicalin (BA) from biological samples. The surface morphologies and characteristics of the imprinted and non-imprinted polymers were characterized by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo–gravimetric analysis (TGA) and nitrogen adsorption–desorption isotherms. The results indicated that the polymers were successfully grafted on the surface of SBA-15 and possessed a highly ordered mesoporous structure. In binding tests, MIP@SBA-15 reached saturated adsorption within 80 min and exhibited significant specific recognition toward BA with large adsorption capacity. Meanwhile, the prepared MIP@SBA-15 was used as a selective sorbent for solid-phase extraction of BA from biological samples. Recoveries of BA from the liver and spleen ranged from 90.6% to 90.9% with RSD < 3.7%. All these results reveal that this method is simple, rapid and sensitive for effectively extracting and detecting trace BA in biological samples.

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Preparation of rectangular and 2D-hexagonal mesostructured silica at neutral conditions using poly(oxyethylene) cholesteryl ethers and a water-soluble silica precursor

Cited by 14 publications

References 52 publications

Characterization of Perylene Diimide Dye Self-Assemblies and Their Use As Templates for the Synthesis of Hybrid and Supermicroporous Nanotubules

Characterization of Perylene Diimide Dye Self-Assemblies and Their Use As Templates for the Synthesis of Hybrid and Supermicroporous Nanotubules

Preparation of chitosan/MCM-41-PAA nanocomposites and the adsorption behaviour of Hg(II) ions

Synthesis of surface nano-molecularly imprinted polymers for sensitive baicalin detection in biological samples

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