Colloidal properties of synthetic hectorite clay dispersions

Avery, R. G.; Ramsay, J.D.F.

doi:10.1016/0021-9797(86)90322-x

Cited by 191 publications

(127 citation statements)

References 13 publications

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“…Exfoliated Laponite forms single smectite layers 0.96 nm thick and 25-35 nm in diameter. 31 The average value of the clay sublayer thickness might indicate that each clay sublayer was built up by 2-3 clay mineral layers. The measured * value means that the Laponite clay particles 25-35 nm in diameter are more tilted as it is possible within a flat sublayer 2.1 nm thick.…”

Section: A Geometrical Characteristicsmentioning

confidence: 99%

Fast assembly of bio-inspired nanocomposite films

et al. 2008

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This paper presents a spin-coating layer-by-layer assembly process to prepare multilayered polyelectrolyte-clay nanocomposites. This method allows for the fast production of films with controlled layered structure. The preparation of a 100-bilayer film with a thickness of about 330 nm needs less than 1 h, which is 20 times faster than conventional dip-coating processes maintaining the same hardness and modulus values. For validation of this technique, nanocomposite films with thicknesses up to 0.5 m have been created with the common dip self-assembly and with the spin coating layer-by-layer assembly technique from a poly(diallyldimethylammonium)chloride (PDDA) solution and a suspension of a smectite clay mineral (Laponite). Geometrical characteristics (thickness, roughness, and texture) as well as mechanical characteristics (hardness and modulus) of the clay-polyelectrolyte films have been studied. The spin-coated nanocomposite films exhibit clearly improved mechanical properties (hardness 0.4 GPa, elastic modulus 7 GPa) compared to the "pure" polymer film, namely a sixfold increase in hardness and a 17-fold increase in Young's modulus.

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Section: A Geometrical Characteristicsmentioning

confidence: 99%

Fast assembly of bio-inspired nanocomposite films

et al. 2008

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“…The RD clay has the molecular formula 21 Si 8 (Mg 5.45 Li 0.4 )O 20 (OH) 4 Na 0.7 which is the unitary cell of the disk-like shape clay platelet having a diameter of about 25 nm and a thickness of 1 nm. 22 Each RD dispersion was prepared by gradually adding the necessary amount of powder to a known mass of water under continuous and vigorous stirring. Once that resulted clear, it was left for ca.…”

mentioning

confidence: 99%

Adsorption of triblock copolymers and their homopolymers at laponite clay/solution interface. Role played by the copolymer nature

Lisi

Lazzara

Lombardo

et al. 2005

Phys. Chem. Chem. Phys.

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The adsorption thermodynamics of copolymers, based on ethylene oxide (EO) and propylene oxide (PO) units, at the laponite (RD) clay/liquid interface was determined at 298 K. The copolymer nature was tuned at molecular level by changing the hydrophilicity, the architecture and the molecular weight (Mw) keeping constant the EO/ PO ratio. Polyethylene (PEGs) and polypropylene (PPGs) glycols with varying Mw and their mixture were also investigated to discriminate the role of the EO and the PO segments in the adsorption process. Enthalpies of transfer of RD, at fixed concentration, from water to the aqueous macromolecule solutions as functions of the macromolecule molality were determined. They were treated quantitatively by means of a model based on two equilibria: (1) one-to-one binding between the macromolecule and the site on the solid and (2) two-to-one binding following which one macromolecule interacts with another one adsorbed onto the solid. The good agreement between the equilibrium constants obtained from calorimetry and those determined from kinetic experiments confirmed the reliability of the experimental and theoretical approaches. Almost all of the systems investigated are highlighted by the one-to-one binding; the L35 and 10R5 systems present both equilibria. The insights provided by the thermodynamics of adsorption of their homopolymers onto RD were fruitful in obtaining detailed information on the nature of the forces involved between RD and the copolymers. The data obtained in the present work clearly evidenced that for comparable polymer Mw, PPG is more suitable in building up a steric barrier around the RD particles and, indeed, exhibits several advantages and no drawbacks. Moreover, the parent copolymers may properly functionalize the RD surface by exploiting both their high affinity to the solid surface and the ability to self-assemble onto it as L35 and 10R5 clearly showed.

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“…It means that the delamination was restrained by pre-adsorption of SDS and 1831. The delamination of Na-MMT in water is often caused by the interlayer hydration [6,[11][12][13][14][15][16][17][18][19][20]. However, after 1 h mixing in planetary mill, the agent and MMT particles mixed with each other sufficiently.…”

Section: Restraining Montmorillonite Delaminationmentioning

confidence: 99%

Restraining Na-Montmorillonite Delamination in Water by Adsorption of Sodium Dodecyl Sulfate or Octadecyl Trimethyl Ammonium Chloride on the Edges

Zhao

Chen

et al. 2016

Minerals

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Abstract:The delamination of montmorillonite in water leads to sliming in ore slurry, which is detrimental to mineral flotation and solid/water separation. In this work, the delamination of Na-montmorillonite (Na-MMT) has been restrained by sodium dodecyl sulfate (SDS) or octadecyl trimethyl ammonium chloride (1831) through the adsorption on the edge of the mineral. The experimental results have shown that the pretreatment by adding SDS and 1831 could greatly reduce the Stokes size percentage of −1.1 µm particles in the aqueous Na-MMT suspension. From the X-ray diffractometer (XRD) results, the interlayer spacing of the MMT pre-treated by SDS and 1831 is smaller than that of original MMT particles. Adsorption position of SDS and 1831 on MMT surfaces was analyzed by the measurements of adsorption capacity of SDS and 1831, inductively-coupled plasma spectra, and zeta potential before and after the plane surface of MMT was covered with tetraethylenepentaminecopper ([Cu(tetren)] 2+ ). The results indicated that SDS and 1831 are adsorbed on the edge and the whole surface of Na-MMT, respectively. Delamination of MMT could be well restrained by the adsorption of SDS and 1831 on the edges of MMT.

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Colloidal properties of synthetic hectorite clay dispersions

Cited by 191 publications

References 13 publications

Fast assembly of bio-inspired nanocomposite films

Fast assembly of bio-inspired nanocomposite films

Adsorption of triblock copolymers and their homopolymers at laponite clay/solution interface. Role played by the copolymer nature

Restraining Na-Montmorillonite Delamination in Water by Adsorption of Sodium Dodecyl Sulfate or Octadecyl Trimethyl Ammonium Chloride on the Edges

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