Micro- and mesoporous silicas synthesized in acidic water–ethanol solution of equimolar catanionic surfactant

Wang, Yi Meng; Zhuang, Ting Ting; Cao, Yi; Jiang, Qi; Zhu, Jian Hua

doi:10.1016/j.jnoncrysol.2004.12.003

Cited by 4 publications

(3 citation statements)

References 30 publications

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“…The decrement in the ratio of solute to solvent represents the amount of nitrosamines adsorbed by the sample. [74] In the TPSR test, a 20 mg sample (20-40 mesh) was activated at 773 K and then cooled to 313 K to contact with NPYR of about 55 lmol followed by a purge of N 2 for 0.4 h. The N-N bond in the nitrosamines is the weakest, so that the decomposition of nitrosamines is usually accompanied by the liberation of NOx. When the sample was heated at a rate of 10 K min -1 in nitrogen, the NO x liberated in the TPSR process was converted into NO 2 by passing through a CrO 3 tube, and then absorbed in a solution of sulfanilamide and N-1-naphthylethylene diamine dihydrochloride.…”

Section: +mentioning

confidence: 99%

Multiple Functionalization of Mesoporous Silica in One‐Pot: Direct Synthesis of Aluminum‐Containing Plugged SBA‐15 from Aqueous Nitrate Solutions

Wang

Zhuang

et al. 2007

Adv Funct Materials

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Aluminum‐containing plugged mesoporous silica has been successfully prepared in an aqueous solution that contains triblock copolymer templates, nitrates, and silica sources but without using mineral acid. The acidity of the solution can be finely tuned from pH 1.4 to 2.8 according to the amount of the introduced aluminum species which ranged from an Al/Si molar ratio of 0.25/1 to 4.0/1. The aluminum nitrate additive in the starting mixture, along with the weak acidity produced by the nitrates, contributes to the formation of plugged hexagonal structures and the introduction of different amounts of aluminum species into the mesostructure. Characterization by X‐ray diffraction, transmission electron microscopy, and N2 sorption measurements show that the Al‐containing plugged silicas possess well‐ordered hexagonal mesostructures with high surface areas (700–860 m2 g–1), large pore volume (0.77–1.05 cm3 g–1) and, more importantly, combined micropores and/or small mesopores in the cylindrical channels. Inductively coupled plasma–atomic emission spectrometry results show that 0.7–3.0 wt % aluminum can be introduced into the final samples. 27Al MAS NMR results display that about 43–60% aluminum species are incorporated into the skeleton of the Al‐containing silicas and the amount of the framework aluminum increases as the initial added nitrates rises. Scanning electron microscopy images reveal that the directly synthesized Al‐containing plugged silica has a similar morphology to that of traditional SBA‐15. Furthermore, the Al‐containing plugged samples have excellent performances in the adsorption and the catalytic decomposition of isopropyl alcohol and nitrosamine. Finally, the direct synthesis method is used to produce plugged mesoporous silicas that contain other metals such as chromium and copper, and the resultant samples also show good catalytic activities.

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Section: +mentioning

confidence: 99%

Multiple Functionalization of Mesoporous Silica in One‐Pot: Direct Synthesis of Aluminum‐Containing Plugged SBA‐15 from Aqueous Nitrate Solutions

Wang

Zhuang

et al. 2007

Adv Funct Materials

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“…A basic understanding of the synthesis conditions is essential, as mesoporous materials with needed characteristics can only be obtained by suitably controlled synthesis procedures and conditions [3]. Many studies have indicated that several factors of pH and acid species could affect the interaction between organic micelles and inorganic species and consequently influence the final structure of the mesoporous materials during the self-assembly process [4][5].The acidic environment (pH value) of the whole synthesis procedure was variable and influenced by some factors such as the protonation of the surfactant and the hydrolysis of the metal salt according to Li and co-worker [6].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characteristics of Mesoporous SBA-15 Influence by HMTA as an Internal pH Modifier

Husin

Nordin

Mohamad

et al. 2015

AMM

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SBA-15 mesoporous silica was directly synthesised under difference acidic conditions by a “pH modification method” using hexamethylenetetramine (HMTA) as an internal pH-modifier. The synthesised material has been characterised by XRD, Nitrogen adsorption–desorption, and TEM. The characterisation results showed that mesoporous silica lead to high-ordered hexagonal mesoporous morphology by TEM at high acidity compared to low acidity condition. In addition, the physical properties of SBA-15 showed a decrease of surface area and pore size due to the increase in the pH. Use of HMTA as pH modifier is suitable, due to pH value increases occurred in the hydrothermal processes only. This is because during the hydrothermal process at a temperature of 100°C, HMTA decomposes to NH3 which in turn increase of the pH value in the silica gel. It can be concluded that the formation of mesoporous silica SBA-15 to some extent been influenced by the pH value. This can be seen from the results of the study show that mesoporous silica type SBA-15 lead to well-ordered hexagonal mesoporous at high acidity and poor order hexagonal pore structure was formed in low acidity condition.

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“…Recently, considerable efforts have been devoted to the synthesis and application of mesoporous hybrids, because they can exhibit a synergistic combined performance of the individual components [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. In particular, mesoporous polymer/silica hybrids are capable of providing combined advantages such as diverse functionality, flexibility, mechanical stability, chemical inertness, and high surface area.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of mesoporous polymer/silica hybrid using surfactant-mediated sol–gel method

Jang¹,

Bae²

2006

Journal of Non-Crystalline Solids

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Micro- and mesoporous silicas synthesized in acidic water–ethanol solution of equimolar catanionic surfactant

Cited by 4 publications

References 30 publications

Multiple Functionalization of Mesoporous Silica in One‐Pot: Direct Synthesis of Aluminum‐Containing Plugged SBA‐15 from Aqueous Nitrate Solutions

Multiple Functionalization of Mesoporous Silica in One‐Pot: Direct Synthesis of Aluminum‐Containing Plugged SBA‐15 from Aqueous Nitrate Solutions

Synthesis and Characteristics of Mesoporous SBA-15 Influence by HMTA as an Internal pH Modifier

Fabrication of mesoporous polymer/silica hybrid using surfactant-mediated sol–gel method

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