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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 34 for “"laponite"”.
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Rheological characterization and modeling of Laponite gels with application to snug-like locomotion
Using various concentrations of Laponite, results were obtained on an AR1000 rheometer through various testing methods: stress sweep, creep tests, and large amplitude oscillatory shear tests, defined as LAOS. Concentrations of 1%, 2%, 2.5%, 3%, and 4% wt. of Laponite and distilled water solutions …
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The modification of Laponite® with silver or copper and investigation of their antibacterial activity
Silver and copper modified Laponite® RD were synthesised either by ion exchange or isomorphous substitution into Laponite® RD sheet. Six different concentrations of silver-exchanged Laponite® RD (AGLAP1-6) or copper exchanged Laponite® RD (CULAP1-6) were produced in this work via ion exchange and …
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Nonlinear Optically Active Ionically Self-Assembled Monolayer Thin Films of Organic Polymers Intercalated with an Inorganic Hectorite, Laponite RD
… further away from the hard substrate interface. Laponite RD, a synthetic hectorite was introduced in the films in an effort to minimize interpenetration of adjacent bilayers and hence maintain chromophore orientation in every bilayer of the ISAM film. The film was deposited in quadlayers that …
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Self-Assembly of Surface-modified Clays for Functional Biomimetic Materials
Synthetic Laponite-clay particles with a platelet-like shape display strong gelation when dispersed in aqueous solutions because of their positively charged rims and negatively charged flat surfaces. In this thesis, my aim was to modify the surfaces of these clay particles such that we can both …
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Interlamellar modification of smectite clays
… In particular, the synthetic hectorite clay, laponite, is employed to produce paper which is used in automated drawing offices where electro graphic printing is common. The primary objective of this thesis was to modify smectite clays, particularly laponite, to achieve enhanced conductivity. …
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PMMA Clay Nanocomposites
… (Cloisite 15a), a synthetic clay (Laponite RD) and a PEO modified Laponite RD. To produce the modified Laponite RD, mono amino PEO was synthesised via anionic polymerisation using dimethyl ethanol amine as an initiator. The modification of the Laponite RD clay took place in the …
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Organometallic precursors for pillared clay synthesis
The synthetic hectorite, laponite has been used within the paper industry to produce mildly conducting paper for use in electrographic printing. The aim of this research was to modify laponite in order to improve the electrical conductivity. In a continuation of a previous investigation involving …
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Degradable nanocomposite preformed particle gel for chemical enhanced oil recovery applications
… three nanocomposite hydrogels were made using Laponite XLG, Calcium Montmorillonite, and Sodium Montmorillonite nanomaterials. It was observed that after degradation, Laponite XLG nanocomposite hydrogels had the highest post-degradation viscosity (4437 cp), followed by sodium nanocomposite …
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Preferential nanoreinforcement of thermoplastic polyurethane elastomers with dispersed nano-clay
… exfoliate and disperse discotic smectic clay, Laponite (diameter = 25 nm, thickness = 1 nm), in three thermoplastic polyurethane elastomers (TPUs) -- Elasthane 80A, HDI-PTMO PU, and PU-1-33 -- has been developed. This clay was selected because the diameter of one platelet is similar to the …
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Bulk and micro-scale rheology of an aging, yield stress fluid, with application to magneto-responsive systems
… soft matter researchers is the synthetic clay Laponite® . This material is attractive as a rheological modifier in industrial applications and consumer products because a rich array of rheological properties, including a yield stress, viscoelasticity, and a shear-thinning viscosity, can be …
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Studies in clay chemistry
… and to interlayer Cu2+ in Cu2+ exchanged laponite. No charge transfer was observed for laponite (Na+ form) itself. Ion exchange of TTF3(BF4)2 with laponite was found to proceed quantitatively. The intercalated species were believed to be (TTF)2+ dimers. Conductivity data showed an order of …
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Structural Analysis of Cylindrical Particles by Small Angle X-ray Scattering
… systems with cylinder-shaped particles: (1) Laponite particles in aqueous solutions, (2) Poly(carbon suboxide) particles in binary water/DMF solutions, and (3) Suprastructural aggregates of coil-ring-coil block copolymers in cyclohexane, have been studied by SAXS performing either a …
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Characterize the molecular dynamics of materials for 4D printing
… Using a model system, N-isopropylacrylamide/Laponite, the electrostatic interactions between Laponite platelets is modified to tune critical rheological properties in order to improve printability. Rheological measurements and X-ray scattering experiments are carried out to monitor the …
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Synthesis and characterisation of pillared clay catalysts for hydro-cracking of heavy liquid fuels
… pillared montmorillonite and tin oxide pillared laponite clay catalysts, as well as new pillared clay materials such as cerium and europium oxide pillared montmorillonites were synthesised. Methods included both conventional ion exchange techniques and microwave enhanced methods to improve …
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The development and evaluation of antibacterial polymer-phyllosilicate composite systems for the treatment of infected wounds
… (rMMT), montmorilonite K10 (MMTK10), Laponite® RD (LRD), and Laponite® XL21 (LXL21) were investigated for their differing structure and physicochemical properties. Their ability to adsorb and desorb the antibacterial agents tetracycline (TC), doxycycline (DC) and ciprofloxacin (CIP) …
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An experimental method for visualizing undrained shearing failure in a transparent soft clay surrogate
… techniques in a soft clay surrogate, Laponite RD, at shallow depths with minimal boundary effects. The thesis developed a procedure for tracking deformation in Laponite RD as a soft clay surrogate for the miniature shear vane and the T-bar, ball, and cone penetrometers and provided the …
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Development of Novel Thermosensitive Polymers for Bioresponsive Drug Delivery
… nanocomposite thermogel was based on a nanoclay, laponite, and pH-sensitive thermogelling polymer. Finally, the nanocomposite thermogel incorporated with laponite sustained the release properties of small proteins comparing to regular thermogels. Taken all together, the novel thermosensitive …
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Novel catalytic methods for the upgrading of coal liquids
… montmorillonite and a tin intercalated laponite, Layered Double Hydroxides (LDH's) have exhibited encouraging thermal stability. Development of novel methods for hydrocracking coal derived liquids, using a commercial microwave oven, modified reaction vessels and coal model compounds has …
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Bio-inspired fluid locomotion
… of a flat foot on a mucus substitute such as Laponite or Carbopol. Robosnail 2 exploits the non-Newtonian qualities (yield-stress, shear thinning) of the fluid solution to locomote. The glue-like behavior of the unyielded fluid allows Robosnail 2 to climb up a 90 degree incline or inverted 180 …
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Propulsion devices for locomotion at low-Reynolds number
… feet segments to move on a layer of 8 percent Laponite, a shear thinning clay suspension which gives it the ability to adhere to and scale inclines and inverted surfaces. The three link swimmer was found to travel up to 0.034 body lengths per four-stroke cycle, Robosnail 1 was found to move at …
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