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10 results on '"Sorenson, Gregory P."'

1. High-resolution structures of a heterochiral coiled coil

Author

Mortenson, David E., Steinkruger, Jay D., Kreitler, Dale F., Perroni, Dominic V., Sorenson, Gregory P., Huang, Lijun, Mittal, Ritesh, Yun, Hyun Gi, Travis, Benjamin R., Mahanthappa, Mahesh K., Forest, Katrina T., and Gellman, Samuel H.

Published
2015

4. Unusually Stable Aqueous Lyotropic Gyroid Phases from Gemini Dicarboxylate Surfactants.

Author

Sorenson, Gregory P., Coppage, Keiva L., and Mahanthappa, Mahesh K.

Subjects
*LIQUID crystals, *SURFACE active agents, *ADDITION polymerization, *ALIPHATIC compounds, *ALKYLATING agents
Abstract

Aqueous lyotropic liquid crystal (LLC) assemblies with bicontinuous cubic morphologies (Q-phases) have shown promise in applications ranging from selective chemical separations to ion transporting media, yet universal design criteria for amphiphiles that adopt these unique structures remain elusive. Recent reports have demonstrated that cationic gemini surfactants exhibit a tendency to form bicontinuous cubic LLCs as compared to single-tail amphiphiles; however, the universality of this surfactant design motif in stabilizing Q-phases remains untested. Herein, we report the modular synthesis of a new class of anionic gemini surfactants derived from aliphatic carboxylic acids and demonstrate their unexpectedly strong propensity to form gyroid LLC phases with unprecedented stability between 25 and 100 °C over amphiphile concentration windows up to 20 wt % wide. By systematically varying the alkyl spacer length and surfactant counterions (Na+, K+, and (CH3)4N+), we identify molecular motifs that favor formation of technologically useful bicontinuous cubic LLC morphologies. [ABSTRACT FROM AUTHOR]

Published
2011
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5. Cobalt-mediated radical polymerization routes to poly(vinyl ester) block copolymers.

Author

Bunck, David N., Sorenson, Gregory P., and Mahanthappa, Mahesh K.

Abstract

Cobalt-mediated radical polymerizations (CMRPs) utilizing redox initiation are demonstrated to produce poly(vinyl ester) homopolymers derived from vinyl pivalate (VPv) and vinyl benzoate (VBz), and their block copolymers with vinyl acetate (VAc). Combining anhydrous Co(acac)2, lauroyl peroxide, citric acid trisodium salt, and VPv at 30 °C results in controlled polymerizations that yield homopolymers with Mn = 2.5-27 kg/mol with Mw/ Mn = 1.20-1.30. Homopolymerizations of scrupulously purified VBz proceed with lower levels of control as evidenced by broader polydispersities over a range of molecular weights ( Mn = 4-16 kg/mol; Mw/ Mn = 1.34-1.65), which may be interpreted in terms of the decreased nucleophilicity of these less electron donating propagating polymer chain ends. Based on these results, we demonstrate that sequential CMRP reactions present a viable route to microphase separated poly(vinyl ester) block copolymers as shown by small-angle X-ray scattering analyses. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 [ABSTRACT FROM AUTHOR]

Published
2011
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7. Revisioning Philosophy: An Inquiry into Better Ways of Knowing—in the Humanities, in the Arts, in the Sciences, and in the World

Author

Knightly, Nickolas

Subjects
Philosophy, Ethics, Ecology, Ecology, Epistemology, Ethics, Philosophy, Philosophy as a Way of Life, Spirituality
Abstract

An inquiry into the cultivation of an ethically-, aesthetically-, ecologically-rooted way of knowing and a meditation on philosophy as a way of life. This text considers how the climate crisis and general ecological degradation (along with other phenomena) indicate the need for a better way of knowing. The text begins with the multidisciplinary scientist Gregory Bateson’s suggestion that “the most important task today is . . . to learn to think in [a] new way.” This may sound like a platitude, but Bateson was a careful scientist who was sensitive to the unprecedented social and ecological challenges humanity now faces. His suggestion was meant as a sober, perhaps even a sobering imperative. He was not alone in making this suggestion. Perhaps philosophy always demands this of us, and it seems to have become incredibly important, given the state of the world. But how can we actually think differently, and what is wrong with our current ways of thinking and known? To find out, the dissertation engages in a “philosophical meta-analysis,” a kind of archaeology of the soul, considering various spiritual artefacts from western and non-western, Indigenous and non-Indigenous cultures, including insights from Eihei Dogen, Plato, Buddha, Blackfoot epistemology, C.G. Jung, John Dewey, Friedrich Nietzsche, E. Richard Sorenson, Gregory Bateson, and others. The inquiry offers steps toward an ethically and aesthetically embodied, ecologically and spiritually embedded epistemology of practice and realization that amounts to a paradigm shift out of the forms of life and forms of discourse not only of the western academy, but of the dominant culture as a whole.

Published
2019

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