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Papers by Anne Juggernauth

Research paper thumbnail of Electro-Optical Materials: Electrically Addressable Hybrid Architectures of Zinc Oxide Nanowires Grown on Aligned Carbon Nanotubes (Adv. Funct. Mater. 15/2010)

Advanced Functional Materials, Aug 9, 2010

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Research paper thumbnail of Correlating bulk properties and nanoscale rearrangement during UV-initiated gelation of hybrid nanoparticle/ block copolymer systems

We use rheology and Small Angle X-Ray Scattering (SAXS) to investigate UV initiated gel formation... more We use rheology and Small Angle X-Ray Scattering (SAXS) to investigate UV initiated gel formation in aqueous dispersions of clay nanoparticles in the presence of poly(ethyleneoxide-b-propyleneoxide-b-ethyleneoxide) block copolymer surfactants (Pluronics) and small amounts of a photoacid generator (PAG). This material system demonstrates stable liquid-like behavior in the absence of UV but undergoes bulk gelation upon UV exposure. Rheology was used to monitor the bulk properties of a series of samples undergoing UV exposure and confirm bulk gel formation. We further probe nanoparticle rearrangement using time resolved synchrotron SAXS with simultaneous UV exposure. Time dependent SAXS indicate an absence of long range order and crystallinity while changes in the scattering profile are related to short range interparticle interactions leading to a stable or arrested structure. Finally, we compare the time scales for structural rearrangement of nanoparticles with the bulk gelation beha...

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Research paper thumbnail of In situ photogelation kinetics of Laponite nanoparticle-based photorheological dispersions

Soft Matter, 2011

ABSTRACT In situ photorheology experiments were conducted to investigate the kinetics of UV-trigg... more ABSTRACT In situ photorheology experiments were conducted to investigate the kinetics of UV-triggered photogelation of aqueous Laponitenanoparticle dispersions formulated with less than 10 wt% of a triblock copolymer (PluronicF127) and diphenyliodonium-2-carboxylate monohydrate, a photoacid generator (PAG). We show that gelation kinetics depend strongly on solution composition and intensity of UV light used during in situ photorheology experiments. A decrease in gelation rate was observed with increasing Pluronic F127 concentrations while higher PAG and Laponite concentrations result in higher gelation rates. Changing the intensity of UV light from 100 mW cm−2 to 150 mW cm−2 at a constant composition reduced the exposure time required prior to onset of gelation by half. Finally, the effect of Laponite and PAG on the micellization of F127 was probed using differential scanning calorimetry (DSC). The results show that the presence of Laponite particles and PAG suppresses the enthalpic endotherm associated with micelle formation in solutions containing up to 7.2 wt% PluronicF127. Using these results, we present a detailed mechanism for the photogelation phenomenon as well as the parameters surrounding intelligent design and formulation of these systems.

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Research paper thumbnail of Measuring the lengthening kinetics of aligned nanostructures by spatiotemporal correlation of height and orientation

Nanoscale, 2010

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Research paper thumbnail of Structural Changes in PEO–PPO–PEO Gels Induced by Methylparaben and Dexamethasone Observed Using Time-Resolved SAXS

Macromolecules, 2011

Aqueous solutions of polyoxyethylene-polyoxypropylene-polyoxyethylene (PEO-PPO-PEO) triblock copo... more Aqueous solutions of polyoxyethylene-polyoxypropylene-polyoxyethylene (PEO-PPO-PEO) triblock copolymers (commercially available as Pluronic surfactants) micellize and structurally arrange into cubic quasicrystalline lattices as their temperature is raised. This structural evolution is seen macroscopically as a gelation, and the presence of these ordered phases can be controlled through both polymer concentration and temperature. The presence of added solutes within the dispersions can also

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Research paper thumbnail of Electro-Optical Materials: Electrically Addressable Hybrid Architectures of Zinc Oxide Nanowires Grown on Aligned Carbon Nanotubes (Adv. Funct. Mater. 15/2010)

Advanced Functional Materials, 2010

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Research paper thumbnail of Electrically Addressable Hybrid Architectures of Zinc Oxide Nanowires Grown on Aligned Carbon Nanotubes

Advanced Functional Materials, 2010

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Research paper thumbnail of Stress-induced martensitic phase transformation in thin sheets of Nitinol

Acta Materialia, 2007

Using the in situ optical technique known as digital image correlation (DIC), full-field quantita... more Using the in situ optical technique known as digital image correlation (DIC), full-field quantitative strain maps of localization have been experimentally obtained for the first time in thin sheets of Nitinol. The use of DIC provides new information connecting previous observations on the micro- and macro-scales. It shows that the transformation initiates before the formation of localized bands, and the

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Research paper thumbnail of Photoconductive Hybrid Films via Directional Self-Assembly of C60 on Aligned Carbon Nanotubes

Advanced Functional Materials, 2012

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Research paper thumbnail of Watching Carbon Nanotube Forest Growth using X-rays

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Research paper thumbnail of Electro-Optical Materials: Electrically Addressable Hybrid Architectures of Zinc Oxide Nanowires Grown on Aligned Carbon Nanotubes (Adv. Funct. Mater. 15/2010)

Advanced Functional Materials, Aug 9, 2010

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Correlating bulk properties and nanoscale rearrangement during UV-initiated gelation of hybrid nanoparticle/ block copolymer systems

We use rheology and Small Angle X-Ray Scattering (SAXS) to investigate UV initiated gel formation... more We use rheology and Small Angle X-Ray Scattering (SAXS) to investigate UV initiated gel formation in aqueous dispersions of clay nanoparticles in the presence of poly(ethyleneoxide-b-propyleneoxide-b-ethyleneoxide) block copolymer surfactants (Pluronics) and small amounts of a photoacid generator (PAG). This material system demonstrates stable liquid-like behavior in the absence of UV but undergoes bulk gelation upon UV exposure. Rheology was used to monitor the bulk properties of a series of samples undergoing UV exposure and confirm bulk gel formation. We further probe nanoparticle rearrangement using time resolved synchrotron SAXS with simultaneous UV exposure. Time dependent SAXS indicate an absence of long range order and crystallinity while changes in the scattering profile are related to short range interparticle interactions leading to a stable or arrested structure. Finally, we compare the time scales for structural rearrangement of nanoparticles with the bulk gelation beha...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of In situ photogelation kinetics of Laponite nanoparticle-based photorheological dispersions

Soft Matter, 2011

ABSTRACT In situ photorheology experiments were conducted to investigate the kinetics of UV-trigg... more ABSTRACT In situ photorheology experiments were conducted to investigate the kinetics of UV-triggered photogelation of aqueous Laponitenanoparticle dispersions formulated with less than 10 wt% of a triblock copolymer (PluronicF127) and diphenyliodonium-2-carboxylate monohydrate, a photoacid generator (PAG). We show that gelation kinetics depend strongly on solution composition and intensity of UV light used during in situ photorheology experiments. A decrease in gelation rate was observed with increasing Pluronic F127 concentrations while higher PAG and Laponite concentrations result in higher gelation rates. Changing the intensity of UV light from 100 mW cm−2 to 150 mW cm−2 at a constant composition reduced the exposure time required prior to onset of gelation by half. Finally, the effect of Laponite and PAG on the micellization of F127 was probed using differential scanning calorimetry (DSC). The results show that the presence of Laponite particles and PAG suppresses the enthalpic endotherm associated with micelle formation in solutions containing up to 7.2 wt% PluronicF127. Using these results, we present a detailed mechanism for the photogelation phenomenon as well as the parameters surrounding intelligent design and formulation of these systems.

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Research paper thumbnail of Measuring the lengthening kinetics of aligned nanostructures by spatiotemporal correlation of height and orientation

Nanoscale, 2010

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Research paper thumbnail of Structural Changes in PEO–PPO–PEO Gels Induced by Methylparaben and Dexamethasone Observed Using Time-Resolved SAXS

Macromolecules, 2011

Aqueous solutions of polyoxyethylene-polyoxypropylene-polyoxyethylene (PEO-PPO-PEO) triblock copo... more Aqueous solutions of polyoxyethylene-polyoxypropylene-polyoxyethylene (PEO-PPO-PEO) triblock copolymers (commercially available as Pluronic surfactants) micellize and structurally arrange into cubic quasicrystalline lattices as their temperature is raised. This structural evolution is seen macroscopically as a gelation, and the presence of these ordered phases can be controlled through both polymer concentration and temperature. The presence of added solutes within the dispersions can also

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Electro-Optical Materials: Electrically Addressable Hybrid Architectures of Zinc Oxide Nanowires Grown on Aligned Carbon Nanotubes (Adv. Funct. Mater. 15/2010)

Advanced Functional Materials, 2010

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Electrically Addressable Hybrid Architectures of Zinc Oxide Nanowires Grown on Aligned Carbon Nanotubes

Advanced Functional Materials, 2010

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Stress-induced martensitic phase transformation in thin sheets of Nitinol

Acta Materialia, 2007

Using the in situ optical technique known as digital image correlation (DIC), full-field quantita... more Using the in situ optical technique known as digital image correlation (DIC), full-field quantitative strain maps of localization have been experimentally obtained for the first time in thin sheets of Nitinol. The use of DIC provides new information connecting previous observations on the micro- and macro-scales. It shows that the transformation initiates before the formation of localized bands, and the

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Photoconductive Hybrid Films via Directional Self-Assembly of C60 on Aligned Carbon Nanotubes

Advanced Functional Materials, 2012

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Watching Carbon Nanotube Forest Growth using X-rays

Bookmarks Related papers MentionsView impact

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