Swelling transition of a clay induced by heating

Adsorption and assembly of colloidal particles at the surface of liquid droplets are at the base of particle-stabilized emulsions and templating. Here we report that electrohydrodynamic and electro-rheological effects in leaky-dielectric liquid drops can be used to structure and dynamically control colloidal particle assemblies at drop surfaces, including electric-field-assisted convective assembly of jammed colloidal ‘ribbons’, electro-rheological colloidal chains confined to a two-dimensional surface and spinning colloidal domains on that surface. In addition, we demonstrate the size control of ‘pupil’-like openings in colloidal shells. We anticipate that electric field manipulation of colloids in leaky dielectrics can lead to new routes of colloidosome assembly and design for ‘smart armoured’ droplets.

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“…The Fh clay minerals used here comes from the same batch of materials as reported and characterized by Hansen et al 41. and references therein.…”

Section: Methodsmentioning

confidence: 99%

Active structuring of colloidal armour on liquid drops

et al. 2013

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“…In addition, these materials have been shown to be non-toxic for trans-dermal application and oral administration [5,9]. Their swelling transition [10], on the other hand, suggests their potential as hosts of large molecules of pharmaceutical interest and their temperature controlled release. However, few reports about the use of fluorohectorite, a commercially available synthetic smectite, as a drug hosting material, can be found in the literature [5,6,11].…”

Section: Introductionmentioning

confidence: 99%

Smectite as ciprofloxacin delivery system: Intercalation and temperature-controlled release properties

Rivera

Valdés

Jiménez

et al. 2016

Applied Clay Science

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Ciprofloxacin (Cipro) incorporation into Li-fluorhectorite (LiFh) clay and its temperaturecontrolled release. with potential pharmaceutical and biomedical applications.Structural characterization of the raw material and the clay-drug composites.Demonstration of the temperature-controlled drug release abilities of a colloidal suspension of the clay-drug composite, following pharmaceutical standards. AbstractClays have shown to be good candidates as drug delivery carriers. In the present paper, we use the temperature-dependent swelling of smectite clays to produce clay-drug composites with sizable drug load capacity. Specifically, we obtain a fluorohectorite-ciprofloxacin (Fh-Cipro) composite, in which a true intercalation of the drug between the clay interlayers has been verified by various experimental techniques. We evaluate the thermally activated drug release from a colloidal suspension of nanosized composite particles in water as well as in synthetic gastric juice from 37 0 C (body temperature) to 85 0 C. The temporal profiles of drug release from the clay fulfil the pharmaceutical standards for these systems. In this work, we have been able to produce a clay-based Temperature Controlled Release System (TCRS) with potential biomedical applications.

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“…In this paper we study a synthetic 2:1 clay mineral, sodium fluorohectorite (Na-FH) with the chemical formula Na 1 [15], and references therein. The samples were prepared as rectangular shaped plates made out of many individual clay mineral particles.…”

Section: Methodsmentioning

confidence: 99%

Electric Alignment of Plate Shaped Clay Aggregates in Oils

et al. 2016

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We experimentally investigate the rotation of plate shaped aggregates of clay mineral particles immersed in silicone oil. The rotation is induced by an external electric field. The rotation time is measured as a function of the following parameters: electric field strength, the plate geometry (length and width) and the dielectric properties of the plates. We find that the plates always align with their longest axis parallel to the direction of the electric field (E), independently of the arrangement of individual clay mineral particles within the plate. The rotation time is found to scale as E −2 and is proportional to the viscosity (η), which coincides well with a model that describes orientation of dipoles in electric fields. As the length of the plate is increased we quantify a difference between the longitudinal and transverse polarizability. Finally, we show that moist plates align faster. We attribute this to the change of the dielectric properties of the plate due to the presence of water.

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Swelling transition of a clay induced by heating

Cited by 64 publications

References 26 publications

Active structuring of colloidal armour on liquid drops

Active structuring of colloidal armour on liquid drops

Smectite as ciprofloxacin delivery system: Intercalation and temperature-controlled release properties

Electric Alignment of Plate Shaped Clay Aggregates in Oils

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