Preparation and characterization of DNA/allophane composite hydrogels

Kawachi, Takuya; Matsuura, Yoko; Iyoda, Fumitoshi; Arakawa, Shuichi; Okamoto, Masami

doi:10.1016/j.colsurfb.2013.08.011

Cited by 14 publications

(10 citation statements)

References 27 publications

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“…The zeta potential of the reference halloysite increased from − 45 mV at pH =1 0 to + 10 mV at pH =~2, with a PZC at pH =~3. These results are largely consistent with the literature (Vergaro et al 2010;Kawachi et al 2013). The zeta potential of the slip surface material largely behaved in a similar manner to the reference halloysite but differed at lower pH.…”

Section: Resultssupporting

confidence: 93%

Mineralogical and physico-chemical properties of halloysite-bearing slip surface material from a landslide during the 2018 Eastern Iburi earthquake, Hokkaido

Kameda

2021

Prog Earth Planet Sci

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Destructive landslides were triggered by the 6.7 Mw Eastern Iburi earthquake that struck southern Hokkaido, Japan, on 6 September 2018. Heavy rainfall on 4 September in addition to intermittent rainfall around the Iburi Tobu area saturated and weakened the slope-forming materials (mostly altered volcanoclastic soils), making them susceptible to failure because of the earthquake’s strong ground motion. Most of the shallow landslides exhibited long runouts along gentle hill slopes, with characteristic halloysite-bearing slip surface at the base of the volcanic soils. This study investigated the mineralogical and physico-chemical properties of the slip surface material with the aim of understanding weakening and post-failure behaviors during the landslides. Halloysite in the slip surface had irregular-to-hollow-spherical morphology with higher mesopore volumes than tubular halloysite, which is related to a high capacity for water retention after rainfall. To reproduce possible chemical changes in the slip surface during rainfall, the sample was immersed in varying amounts of rainwater; solution pH increased and ionic strength decreased with increasing water content. These findings, alongside electrophoretic analysis, suggest that rainwater infiltration could have increased the absolute zeta potential value of the slip surface material. It is suggested that rainfall before the earthquake enhanced the colloidal stability of halloysite particles within the slip surface, owing to an increase in electrostatic repulsion. This decreased the material’s cohesive strength, which might have led to destabilization of the slope during ground shaking generated by the earthquake, and subsequent high-mobility flow after failure.

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Section: Resultssupporting

confidence: 93%

Mineralogical and physico-chemical properties of halloysite-bearing slip surface material from a landslide during the 2018 Eastern Iburi earthquake, Hokkaido

Kameda

2021

Prog Earth Planet Sci

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show abstract

“…The zeta potential of the standard halloysite increased from −45 mV at pH = ~10 to +10 mV at pH = ~2, with a PZC at pH = ~3. These results are largely consistent with the literature (Vergaro et al 2010;Kawachi et al 2013). The zeta potential of the slip surface material largely behaved in a similar manner to the standard halloysite, but differed at lower pH.…”

Section: Resultssupporting

confidence: 91%

Mineralogical and Physico-chemical Properties of Halloysite-bearing Slip Surface Material From a Landslide During the 2018 Eastern Iburi Earthquake, Hokkaido

Kameda

2020

Preprint

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Destructive landslides were triggered by the 6.7 Mw Eastern Iburi earthquake that struck southern Hokkaido, Japan on 6 September 2018. Heavy rainfall on 4 September in addition to intermittent rainfall around the Iburi Tobu area saturated and weakened altered volcanoclastic soils containing halloysite minerals, making them susceptible to failure because of the earthquake’s strong ground motion. The landslides exhibited laminar flow behavior, with long runouts along gentle hill slopes. This study investigated the mineralogical and physicochemical properties of the halloysite-bearing slip surface material with the aim of understanding weakening and post-failure behaviors during the landslides. Halloysite in the slip surface had irregular-to-hollow-spherical morphology with higher mesopore volumes than tubular halloysite, which is related to a high capacity for water retention after rainfall. To reproduce possible chemical changes in the slip surface during rainfall, the sample was immersed in varying amounts of rainwater; solution pH increased and ionic strength decreased with increasing water content. These findings, alongside electrophoretic analysis, suggest that rainwater infiltration could have increased the absolute zeta potential value of the slip surface material. It is suggested that rainfall before the earthquake enhanced the colloidal stability of halloysite particles within the slip surface, owing to an increase in electrostatic repulsion. This decreased the material’s cohesive strength, which might have led to destabilization of the slope during ground shaking generated by the earthquake, and subsequent high-mobility flow after failure.

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“…16−19 The walls of the allophane spherules are perforated, with pore diameters around 0.3 nm, and on these wall perforations there are rich aluminol groups (i.e., Al−OH, Al−OH 2 ) leading to their pH-dependent charge characteristics. 20,21 Owing to their large specific surface areas, excellent stability, and active surface properties, allophanes have long been used as adsorbents for adsorption of various cations, anions, and organics. 20−23 There are also numerous studies where allophanes are used for heterogeneous catalysis 22,24−28 as well as for other technological applications.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Self-Assembly, Transformation, and Functionalization of Nanoscale Artificial Allophane Spherules for Catalytic Applications

Zhou

Zeng

2017

Chem. Mater.

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Mesoporous materials with large surface area and chemical inertness are of great importance, and currently prevailing synthetic approaches involve usages of micelles as pore-directing agents to create such mesopores. In this work, allophanes, which are hollow aluminosilicate spherules of 3.5–5.5 nm in size, have been synthesized and assembled simultaneously for the first time in a controlled manner to generate mesoporous spherical allophane assemblages (MSAAs) with diameters of 445 ± 40 nm, specific surface area as high as 1032 m2/g, pore volume 1.104 mL/g at P/P 0 = 0.975, and average mesopore size at 3.4 nm. Furthermore, the thus-prepared MSAA could be doped with transition metal ions to create a series of isomorphous derivatives; they could also be converted to aluminum-based hierarchical assemblages of layered double hydroxide easily. Different from the conventional channel-like mesopores, the new mesoporosity attained in MSAA is easily accessible because their mesopores are generated from the interparticle spaces of spherical building units of hollow spherules. Therefore, the mesoporous MSAA provides an excellent platform for construction of integrated nanocatalysts. Highly dispersed noble metal nanoclusters such as Pt, Au, and Pd could be deposited on the surface or in the interior mesopores of the MSAA. Excellent activity and stability of MSAA-based catalysts for Suzuki couplings and electrochemical sensing of H2O2 have been demonstrated using Pd/MSAA and Au/MSAA nanocomposites, respectively.

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Preparation and characterization of DNA/allophane composite hydrogels

Cited by 14 publications

References 27 publications

Mineralogical and physico-chemical properties of halloysite-bearing slip surface material from a landslide during the 2018 Eastern Iburi earthquake, Hokkaido

Mineralogical and physico-chemical properties of halloysite-bearing slip surface material from a landslide during the 2018 Eastern Iburi earthquake, Hokkaido

Mineralogical and Physico-chemical Properties of Halloysite-bearing Slip Surface Material From a Landslide During the 2018 Eastern Iburi Earthquake, Hokkaido

Synthesis, Self-Assembly, Transformation, and Functionalization of Nanoscale Artificial Allophane Spherules for Catalytic Applications

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