Preparation of Delaminated Clay Having a Narrow Micropore Distribution in the Presence of Hydroxyaluminum Cations and Polyvinyl Alcohol

Suzuki, Kenzi; Mori, Toshiaki; Kawase, Kaoru; Sakami, Hiroshi; Iida, Shozo

doi:10.1346/ccmn.1988.0360208

Cited by 36 publications

(13 citation statements)

References 16 publications

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“…5, these pillared clays had BET surface areas from 160 to 270 m 2 g of which were half that of the other pillared montmorillonite. 6,11,13 This result also conformed to that of fluorine mica. 15,16 This contraction might be due to the insufficiency of the clay delamination.…”

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confidence: 87%

“…12 The polysiloxane pillared clay provided micropores below 1 nm. The method that improves the pore properties can employ the cointercalation of nonionic templates, which are water-soluble polymer [13][14][15][16] or are nonionic surfactants, 9,17,18 other than the cationic surfactants. We have prepared silica-pillared clays with larger surface areas and pore volumes using polysiloxane and polyvinyl alcohol PVA 19 as with the alumina-pillared clay or zirconia-pillared clay by the PVA method.…”

Section: Introductionmentioning

confidence: 99%

“…We have prepared silica-pillared clays with larger surface areas and pore volumes using polysiloxane and polyvinyl alcohol PVA 19 as with the alumina-pillared clay or zirconia-pillared clay by the PVA method. [13][14][15][16] The presence of PVA in the interlayer space left the distance between the silicate layers expanded. PVA was incorporated into the interlayer region of expandable clays without interfering with the ion exchange process.…”

Section: Introductionmentioning

confidence: 99%

“…The 001 peaks of the pillared clay with PVA 2ಚc, 4ಚd, 6ಚ e, and 8ಚf were observed at 2uࢼ1.91cdࢼ4.62 nm, 2uࢼ1.71cdࢼ5.16 nm, 2uࢼ1.64cdࢼ5.38 nm, and 2uࢼ 1.53cdࢼ5.77 nm, respectively. We assigned the peaks of d001 of approximately 12 and 13 to the high order reflections 00l as with other pillared clays with PVA method, [13][14][15][16] although the peaks at around 3.5 nm and 5.5 nm were not distinct due to the broad pattern. The peaks at a low diffraction angle correspond to the basal spacings enlarged by the simultaneous intercalation of the polysiloxane and PVA between the clay layers.…”

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confidence: 99%

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Preparation of Silica-Pillared Fluorohectorite by Cointercalation of Polysiloxane and Polyvinyl Alcohol

Nakao

Nogami

2005

J. Ceram. Soc. Japan

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Silica-pillared clays with mesopores were prepared from fluorohectorite, aminopropyltriethoxysilane APS and tetraethoxysilane TEOS affected using polyvinyl alcohol PVA. The presence of PVA was important in this synthesis and was effective on the porosity of the obtained silica-pillared clays. Based on the X-ray diffraction measurements, the basal spacings of the silica-pillared clays increased from 1.7 to 5.6 nm with an increase in the PVA concentration. As with the basal spacings, the peaks of the pore size distribution and the average pore diameter shifted up to approximately 3 nm. The pore volumes corresponded to the basal spacings expanded by cointercalation of PVA and polysiloxane. The pore properties and structures of the pillared clays were investigated and the results indicated the relation between the layer structure and pore structure. Key-words : Fluorohectorite, Intercalation, Mesoporous, Pillared clay, Sol-gel method, Polysiloxane IntroductionThe successful intercalations of pillaring species into the interlayer space of clay minerals have led to many attempts to prepare new classes of porous materials, which exhibit interesting properties for adsorption, separation and catalysis. Pillared clays are attracting interest with regard to their use under severe conditions since inorganic materials have better thermal and chemical stabilities than organic materials. Various sizes of inorganic polyhydroxocations have been intercalated as pillaring precursors to control the pore size.1-3 Silica is one of the oxides of interest for obtaining thermally stable and catalytically active pillared clays. Silica pillared clays have been prepared from a titania-silica or iron oxide-silica complex sol because silica precursors are silicate anions, which cannot enter between the clay sheets. [4][5][6] In spite of the large interlayer distance of the sol pillared clay, the obtained pores were mainly micropores due to the multilayer stacking the nanosize sol particles between the silicate layers. The mesoporous sol pillared clays have been synthesized using quaternary ammonium surfactants as templating agents.5,7-10 On the other hand, a silica pillared montmorillonite has been synthesized using ion exchangeable aminopropyltriethoxysilane APS to intercalate the clay sheets in aqueous solution instead of inorganic polyhydroxocations. The polycondensation by APS hydrolysis between the silicate layers was expected to form larger pores.11 However, there was no significant increase in the basal spacing even though the silica content significantly increased with the APS. The pore properties were not increased by the addition of an excess APS for the ion exchange capacity. The pre-intercalation of the alkylammonium ions between the clay layers and the controlled addition of water to the reaction achieved a significant enhancement in the surface area and pore volume. Polysiloxane, which are polycondensation of APS molecules, has been incorporated into

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confidence: 87%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

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Preparation of Silica-Pillared Fluorohectorite by Cointercalation of Polysiloxane and Polyvinyl Alcohol

Nakao

Nogami

2005

J. Ceram. Soc. Japan

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“…25,26 Additionally, their potential for modication through, for instance, exfoliation has been extensively investigated in the case of clays, layered zeolite precursors or layered double hydroxides. [27][28][29][30][31][32][33][34][35] During our investigation of Zn 3 [Co(CN) 6 ] 2 DMCs, we discovered single crystals of a phase that was not cubic, but instead, consisted of positively charged DMC layers linked by acetate anions. To the best of our knowledge, such a cationic, layered DMC structure has not yet been reported in the literature.…”

Section: Introductionmentioning

confidence: 99%

Layered Zn₂[Co(CN)₆](CH₃COO) double metal cyanide: a two-dimensional DMC phase with excellent catalytic performance

et al. 2019

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Investigation of properties, nanostructure, and distribution in controlled polyester polymerization with layered silicate

Yang

Zhu

2002

J of Applied Polymer Sci

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This article presents a series of nanocomposites of a polyester [poly(ethylene terephathalate), PET] with different contents of layered silicates of montmorillonite (MMt) by a controlled process, that is, controlling the way to pretreat MMt, the content of MMt, the kind of reagents used, and the way for MMt to be added. Also investigated, in detail, were the properties, nanostructure, and distribution of nanocomposites with an MMt content below 5% by weight. Results by TEM and AFM showed that the nanoparticles are in a normal distribution with a most probable size of 30-70 nm; the exfoliated MMt lamellae interacting with the PET molecular chain produced more regular chain patterns than did pure PET itself when the MMt content was low (lower than 3% by weight); and the agglomerated particles seem not to be found in an MMt content less than 3% by weight, but to increase with the MMt content in the nanocomposites. The investigation of these nanocomposite properties showed that the optimized properties require an optimized MMt content within 2-3% by weight. When MMt is increased from 3 to 5% by weight in the nanocomposites, agglomeration is unavoidable. Thus, the critical content for MMt added to PET is about 3% by weight. X-ray results showed the appearance of several small diffraction peaks in the 2 angle from 1°to 7°for the annealing nanocomposite samples; these peaks are thought to be from the residue of unexfoliated MMt lamellae or metastable (unstable) MMt lamellae. DSC results proved that the nanocomposites have a higher crystallization rate than that of pure PET due to an exfoliated MMt lamellae nucleation effect. Thus, to obtain a stable nanostructure (or nanocomposite), the MMt content needs to be controlled. The nanostructure plays such a role in the crystallization nucleation of nanocomposites. The interaction of exfoliated lamellae with the molecular chain causes a more regular chain pattern and affects the PET crystallization rate and morphology.

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Preparation of Delaminated Clay Having a Narrow Micropore Distribution in the Presence of Hydroxyaluminum Cations and Polyvinyl Alcohol

Cited by 36 publications

References 16 publications

Preparation of Silica-Pillared Fluorohectorite by Cointercalation of Polysiloxane and Polyvinyl Alcohol

Preparation of Silica-Pillared Fluorohectorite by Cointercalation of Polysiloxane and Polyvinyl Alcohol

Layered Zn₂[Co(CN)₆](CH₃COO) double metal cyanide: a two-dimensional DMC phase with excellent catalytic performance

Investigation of properties, nanostructure, and distribution in controlled polyester polymerization with layered silicate

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Preparation of Delaminated Clay Having a Narrow Micropore Distribution in the Presence of Hydroxyaluminum Cations and Polyvinyl Alcohol

Cited by 36 publications

References 16 publications

Preparation of Silica-Pillared Fluorohectorite by Cointercalation of Polysiloxane and Polyvinyl Alcohol

Preparation of Silica-Pillared Fluorohectorite by Cointercalation of Polysiloxane and Polyvinyl Alcohol

Layered Zn2[Co(CN)6](CH3COO) double metal cyanide: a two-dimensional DMC phase with excellent catalytic performance

Investigation of properties, nanostructure, and distribution in controlled polyester polymerization with layered silicate

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Layered Zn₂[Co(CN)₆](CH₃COO) double metal cyanide: a two-dimensional DMC phase with excellent catalytic performance