Inertial Suppression Of Protein Dynamics In A Binary Glycerol-Trehalose Glass,
2014
The University of Akron
Inertial Suppression Of Protein Dynamics In A Binary Glycerol-Trehalose Glass, Gustavo Carri
Gustavo A. Carri
The traditional approach used to predict the ability of a glassy matrix to maximally preserve the activity of a protein solute is the glass transition temperature (T(g)) of the glass. Recently it has been shown that the addition of a low T(g) diluent (glycerol) can rigidify the structure of a high T(g) glassy matrix in binary glycerol-trehalose glasses. The optimal density of glycerol in trehalose minimizes the average mean square displacements of non-exchangeable protons in the glass samples. The amount of glycerol added to a trehalose glass coincides with the maximal recovery of biological activity in a separate study using …
Polymer Chemistry Of Synthetic Elastomers,
2014
The University of Akron
Polymer Chemistry Of Synthetic Elastomers, Joseph Kennedy
Joseph P. Kennedy
No abstract provided.
Structural Properties Of Polystyrene Adsorbed Onto A Solid Surface,
2014
The University of Akron
Structural Properties Of Polystyrene Adsorbed Onto A Solid Surface, Mesfin Tsige
Mesfin Tsige
In the present work, we are studying the local conformation of chains in a thin film of polystyrene adsorbed on a solid substrate by using atomistically detailed simulations. The simulations are carried out by using the readily available and massively parallel molecular dynamics code known as LAMMPS. In particular, a special emphasis is given to the density and orientation of side chains (which consist of phenyl groups and methylene units) at solid/polymer and polymer/vacuum interfaces. Three types of substrates were used in our study: α-quartz, graphite, and amorphous silica. Our investigation was restricted to atactic polystyrene. Our results show that …
Chain Packing And Trajectory Of Isotactic Polypropylene $$Backslash$ Alpha $ Crystals Studied By Solid-State Nmr,
2014
The University of Akron
Chain Packing And Trajectory Of Isotactic Polypropylene $$Backslash$ Alpha $ Crystals Studied By Solid-State Nmr, Toshikazu Miyoshi
Toshikazu Miyoshi
No abstract provided.
Chairman,
2014
The University of Akron
Local Packing Disorders In A Polymer Crystal By Two Dimensional Solid-State Nmr,
2014
The University of Akron
Local Packing Disorders In A Polymer Crystal By Two Dimensional Solid-State Nmr, Toshikazu Miyoshi
Toshikazu Miyoshi
No abstract provided.
Microstructure And Thermal Property Of Isotactic Poly (3-Methyl-1-Butene) Obtained Using Thec2-Symmetrical Zirconocene/Mao Catalyst System,
2014
The University of Akron
Microstructure And Thermal Property Of Isotactic Poly (3-Methyl-1-Butene) Obtained Using Thec2-Symmetrical Zirconocene/Mao Catalyst System, Toshikazu Miyoshi
Toshikazu Miyoshi
No abstract provided.
Molecular Motions Of Crystalline Polymers By Solid-State Mas Nmr,
2014
The University of Akron
Molecular Motions Of Crystalline Polymers By Solid-State Mas Nmr, Toshikazu Miyoshi
Toshikazu Miyoshi
Chain dynamics in the crystalline region of semicrystalline polymers play an important role for bulk material properties such as mechanical strength, creep, drawability, crystallization process, and crystal transformation. Therefore, it is important to characterize chain dynamics in detail. 2D exchange NMR is a reliable tool for polymer dynamics analysis, because this method provides motional geometry and time-kinetic parameters quantitively. However, it is difficult to apply this sophisticated method for polymers with chemically complicated polymers in natural abundance. ID-MAS exchange NMR method is possible to give the same information, and has a great advantage of characterizing molecular dynamics for multi-functional groups …
Liquid- Liquid Interfaces Of Semifluorinated Alkane Diblock Copolymers With Water, Alkanes, And Perfluorinated Alkanes,
2014
The University of Akron
Liquid- Liquid Interfaces Of Semifluorinated Alkane Diblock Copolymers With Water, Alkanes, And Perfluorinated Alkanes, Mesfin Tsige
Mesfin Tsige
The liquid−liquid interface between semifluorinated alkane diblock copolymers of the form F3C(CF2)n−1(CH2)m−1CH3 and water, protonated alkanes, and perfluorinated alkanes are studied by fully atomistic molecular dynamics simulations. A modified version of the OPLS-AA (Optimized Parameter for Liquid Simulation All-Atom) force field of Jorgensen et al. has been used to study the interfacial behavior of semifluorinated diblocks. Aqueous interfaces are found to be sharp, with correspondingly large values of the interfacial tension. Due to the reduced hydrophobicity of the protonated block compared to the fluorinated block, hydrogen enhancement is observed at the interface. Water dipoles in the interfacial region are found …
Carbocationic Polymerization,
2014
The University of Akron
Carbocationic Polymerization, Joseph Kennedy
Joseph P. Kennedy
This article summarizes fundamental and general aspects of carbocationic polymerizations, with a historical overview and up-to-date references. Following general considerations, the basic elements of carbocationic polymerization, such as monomers, initiating systems, solvents, and temperature, are discussed. Special attention is given to carbocation stability and monomer nucleophilicity, and dynamic interactions. The section on the kinetics of carbocationic polymerization presents current understanding of the elementary reactions—initiation, propagation, termination, and transfer reactions, and copolymerization. Controlled (living) carbocationic polymerization is discussed in a separate section. Finally, industrial carbocationic polymerizations are reviewed.
Quantitative And Qualitative Aspects Of Dissolved Organic Carbon Leached From Senescent Plants In An Oligotrophic Wetland,
2014
The University of Akron
Quantitative And Qualitative Aspects Of Dissolved Organic Carbon Leached From Senescent Plants In An Oligotrophic Wetland, Toshikazu Miyoshi
Toshikazu Miyoshi
We conducted a series of experiments whereby dissolved organic matter (DOM) was leached from various wetland and estuarine plants, namely sawgrass (Cladium jamaicense), spikerush (Eleocharis cellulosa), red mangrove (Rhizophora mangle), cattail (Typha domingensis), periphyton (dry and wet mat), and a seagrass (turtle grass; Thalassia testudinum). All are abundant in the Florida Coastal Everglades (FCE) except for cattail, but this species has a potential to proliferate in this environment. Senescent plant samples were immersed into ultrapure water with and without addition of 0.1% NaN3 (w/ and w/o NaN3, respectively) for 36 days. We replaced the water every 3 days. The amount …
Structural Color Change Following Hydration And Dehydration Of Iridescent Mourning Dove,
2014
The University of Akron
Structural Color Change Following Hydration And Dehydration Of Iridescent Mourning Dove, Matthew Shawkey, Liliana D'Alba, Chad Eliason, Jennifer Koop, Li Jia
Li Jia
Dynamic changes in integumentary color occur in cases as diverse as the neurologically controlled iridiphores of cephalopod skin and the humidity-responsive cuticles of longhorn beetles. By contrast, feather colors are generally assumed to be relatively static, changing by small amounts only over periods of months. However, this assumption has rarely been tested even though structural colors of feathers are produced by ordered nanostructures that are analogous to those in the aforementioned dynamic systems. Feathers are neither innervated nor vascularized and therefore any color change must be caused by external stimuli. Thus, we here explore how feathers of iridescent mourning doves …
N-Type Polythiophenes,
2014
The University of Akron
Method Of Transferring Patterned Non-Densely Packed Interfacial Particle Films Onto Substrates,
2014
The University of Akron
Method Of Transferring Patterned Non-Densely Packed Interfacial Particle Films Onto Substrates, Li Jia, Matthew Ray
Li Jia
A process for transferring patterned non-densely packed interfacial particle films onto substrates by providing a substrate, modifying the substrate so that it is non-water wetting, providing an interfacial film of charged particles, applying a surface modifying procedure to said particles, and applying the interfacial particle film to the modified substrate to thereby form a patterned non-densely packed film on the substrate.
Submicron Surface Patterning Using Interfacial Colloidal Particle Self-Assembly,
2014
The University of Akron
Submicron Surface Patterning Using Interfacial Colloidal Particle Self-Assembly, Li Jia
Li Jia
No abstract provided.
The Effect Of The Core On The Thermotropic Behavior Of Three-Arm Star Poly [11-(4-Cyanophenyl-4-Phenoxy) Undecyl Acrylate] S Synthesized By Atom Transfer Radical Polymerization,
2014
The University of Akron
The Effect Of The Core On The Thermotropic Behavior Of Three-Arm Star Poly [11-(4-Cyanophenyl-4-Phenoxy) Undecyl Acrylate] S Synthesized By Atom Transfer Radical Polymerization, Coleen Pugh, Andrea Kasko, Steven Grunwald
Coleen Pugh
“Three-arm star” poly[11-(4′-cyanophenyl-4′′-phenoxy)undecyl acrylate]s were synthesized by atom transfer radical polymerization (ATRP) of 11-(4′-cyanophenyl-4′′-phenoxy)undecyl acrylate using two new trifunctional initiators: 1,3,5-tri- (methyl 2-bromopropionate)benzene and 2,4,6-tri[4′-methyl(2′′-bromopropionate)phenoxymethyl]mesitylene. The polymers synthesized with 1,3,5-tri(methyl 2-bromopropionate)benzene (series II) contained 14–127 repeat units according to gel permeation chromatography relative to linear polystyrene (GPCPSt) and 13–271 repeat units according to GPC with a light scattering detector (GPCLS). Those synthesized with 2,4,6-tri[4′-methyl(2′′-bromopropionate)phenoxymethyl]mesitylene (series III) contained 14–87 repeat units according to GPCPSt and 10–120 repeat units according to GPCLS. The absolute molecular weight, size, and shape of both series of polymers were characterized by light scattering in CH2Cl2, and …
Development Of A Colloidal Lithography Method For Patterning Nonplanar Surfaces,
2014
The University Of Akron
Development Of A Colloidal Lithography Method For Patterning Nonplanar Surfaces, Sarang Bhawalkar, Jun Qing, Michael Heiber, Li Jia
Li Jia
A colloidal lithography method has been developed for patterning nonplanar surfaces. Hexagonal noncontiguously packed (HNCP) colloidal particles 127 nm−2.7 μm in diameter were first formed at the air−water interface and then adsorbed onto a substrate coated with a layer of polymer adhesive 17 nm thick. The adhesive layer plays the critical role of securing the order of the particles against the destructive lateral capillary force generated by a thin film of water after the initial transfer of the particles from the air−water interface. The soft lithography method is robust and very simple to carry out. It is applicable to a …
Characterization Of Linear And Branched Polyacrylates By Tandem Mass Spectrometry,
2014
The University Of Akron
Characterization Of Linear And Branched Polyacrylates By Tandem Mass Spectrometry, Kittisak Chaicharoen, Michael Polce, Anirudha Singh, Coleen Pugh, Chrys Wesdemiotis
Coleen Pugh
The unimolecular degradation of alkali-metal cationized polyacrylates with the repeat unit CH(2)CH(COOR) and a variety of ester pendants has been examined by tandem mass spectrometry. The fragmentation patterns resulting from collisionally activated dissociation depend sensitively on the size of the ester alkyl substituent (R). With small alkyl groups, as in poly(methyl acrylate), lithiated or sodiated oligomers (M) decompose via free-radical chemistry, initiated by random homolytic C-C bond cleavages along the polymer chain. The radical ions formed this way dissociate further by backbiting rearrangements and beta scissions to yield a distribution of terminal fragments with one of the original end groups …
N-Type Conjugated Polymers Containing Diborylene Units, Methods Of Making, And A Device Comprising The Compound,
2014
The University of Akron
N-Type Conjugated Polymers Containing Diborylene Units, Methods Of Making, And A Device Comprising The Compound, Li Jia
Li Jia
N-type conjugated compounds are disclosed which include at least one conjugated electron-acceptor unit The conjugated electron-acceptor unit includes a diborylene unit The compounds find application in an electron acceptor layer of an electronic device.
Synthesis, Isolation, And Thermal Behavior Of Polybutadiene Grafted With Poly (2, 3, 4, 5, 6-Pentafluorostyrene),
2014
The University Of Akron
Synthesis, Isolation, And Thermal Behavior Of Polybutadiene Grafted With Poly (2, 3, 4, 5, 6-Pentafluorostyrene), Marta Paz-Pazos, Coleen Pugh
Coleen Pugh
2,3,4,5,6-Pentafluorostyrene (PFS) was copolymerized with polybutadiene (PB) in tetrahydrofuran using benzoyl peroxide as the initiator at 50, 60, and 80 °C. The copolymerizations follow typical radical polymerization kinetics and behavior. The grafting parameters were evaluated as a function of monomer conversion, initiator concentration, and/or temperature by gel permeation chromatography of directly injected copolymerization mixtures. The grafting efficiencies and grafting ratios are most consistent with a system that terminates by combination and whose graft sites are generated by hydrogen abstraction of allylic radicals by primary initiator radicals. Pure graft copolymers were isolated by extracting unreacted PB into hexanes and PPFS homopolymer …
