Pallbo, Jon; Sparr, Emma; Olsson, Ulf
Aggregation behavior of the amyloid model peptide NACore
The aggregation of the 11 residue long NACore peptide segment of ?-synuclein (68-GAVVTGVTAVA-78) has been investigated using a combination of cryogenic transmission electron microscopy (cryo-TEM), small- and wide-angle X-ray scattering, and spectroscopy techniques. The aqueous peptide solubility is pH dependent, and aggregation was triggered by a pH quench from pH…
Mechanism of stress induced crystallization of polyethylene
Yakovlev, Sergey; Fiscus, David; Brant, Pat; Butler, Jeff; Bucknall, David G.; Downing, Kenneth H.
When polymer melt is subjected to stress, molecular chains become aligned along the elongation direction. However, when polyethylene film crystallizes under stress, molecular chains frequently align perpendicular to the elongation direction. In this paper we investigate why this happens. Evaluating metallocene LLDPE film we show that under the stress lamellae…
Understanding the Static Interfacial Polymer Layer by Exploring the Dispersion States of Nanocomposites
Genix, Anne-Caroline; Bocharova, Vera; Carroll, Bobby; Lehmann, Michelle; Saito, Tomonori; Krueger, Susan; He, Lilin; Dieudonné-George, Philippe; Sokolov, Alexei P.; Oberdisse, Julian
The dynamic and static properties of the interfacial region between polymer and nanoparticles have wide-ranging consequences on performances of nanomaterials. The thickness and density of the static layer are particularly difficult to assess experimentally due to superimposing nanoparticle interactions. Here, we tune the dispersion of silica nanoparticles in nanocomposites by…
Pressure-Driven Solvent Transport and Complex Ion Permeation through Graphene Oxide Membranes
Wang, Kai; Ausri, Irfani R.; Chu, Kyle A.; Seddon, Annela; Tang, Xiaowu (Shirley)
In this paper, an in-depth investigation of three graphene oxide (GO) based membranespure GO, Al3+ intercalated GO (Al-GO), and poly(ethylene glycol) (PEG) modified GO (PEG-GO)is presented. Both Al-GO and PEG-GO membranes have wider interlayer d-spacing compared to pure GO, and the d-spacing size correlates well to the cross-membrane water flux…
Nafion/Protic Ionic Liquid Blends: Nanoscale Organization and Transport Properties
Danyliv, Olesia; Martinelli, Anna
In this work, the possibility of using the protic ionic liquids N-ethylimidazolium trifluoromethylsulfonate, , and N-ethylimidazolium bis(trifluoromethylsulfonyl)imide, , as charge carriers in appropriately modified Nafion membranes has been investigated. The superior thermal stability of ionic liquids, as compared to that of water-based electrolytes, hypothetically offers a
Adjustable self-assembly in polystyrene-block-poly(4-vinylpyridine) dip-coated thin films
Konefa?, Magdalena; Zhigunov, Alexander; Pavlova, Ewa; ?ernoch, Peter; Pop-Georgievski, Ognen; pírková, Milena
This work studies the influence of dip-coating parameters on self-assembly in ultra-thin films of asymmetric polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) copolymers from a 1-chloropentane solution using a combination of several experimental techniques. Small-Angle X-ray Scattering, Atomic Force Microscopy, Grazing Incidence Small Angle X-ray Scattering and Transmission Electron Microscopy
Widely tunable persistent micelle templates via homopolymer swelling
Sarkar, Amrita; Thyagarajan, Akshay; Cole, August; Stefik, Morgan
The combination of precision control with wide tunability remains a challenge for the fabrication of porous nanomaterials suitable for studies of nanostructurebehavior relationships. Polymer micelle templates broadly enable porous materials, however micelle equilibration hampers independent pore and wall size control. Persistent micelle templates (PMT) have emerged as a kinetic controlled
Self-assembly of oppositely charged polyelectrolyte block copolymers containing short thermoresponsive blocks
Hees, I. A. van; Swinkels, P. J. M.; Fokkink, R. G.; Velders, A. H.; Voets, I. K.; Gucht, J. van der; Kamperman, M.
The assembly of oppositely charged block copolymers, containing small thermoresponsive moieties, was investigated as a function of salt concentration and temperature. Aqueous solutions of poly--b-poly (NIPAM44-b-DMAEMA216) and PNIPAM-b-poly-b-PNIPAM (NIPAM35-b-AA200-b-NIPAM35) were mixed in equal charge stoichiometry, and
Investigation of Micromechanical Behavior and Voiding of Polyethylene Terephthalate/Polyethylene-stat-methyl Acrylate Blends during Tensile Deformation
Lee, Bongjoon; Onbulak, Sebla; Xu, Yuewen; Topolkaraev, Vasily; McEneany, Ryan; Bates, Frank; Hillmyer, Marc
Micromechanical deformation of polyethylene terephthalate (PET)/ethylene-stat-methyl acrylate copolymer blends was investigated for various MA contents and molar masses of p(E-s-MA). The copolymers were synthesized by ring-opening metathesis polymerization and subsequent hydrogenation. Varying the MA content and molar mass of the copolymer alters the interfacial adhesion between the
Transparent, Lightweight, and High Strength Polyethylene Films by a Scalable Continuous Extrusion and Solid-State Drawing Process
Lin, Yunyin; Tu, Wei; Verpaalen, Rob C. P.; Zhang, Han; Bastiaansen, Cees W. M.; Peijs, Ton
The continuous production of transparent high strength ultra-drawn high-density polyethylene films or tapes is explored using a cast film extrusion and solid-state drawing line. Two methodologies are explored to achieve such high strength transparent polyethylene films; i) the use of suitable additives like 2-(2H-benzotriazol-2-yl)-4,6-ditertpentylphenol (BZT) and ii) solid-state drawing at…