Category

Characteristic dimension

(Natural) polymersApplicationCharacteristic dimensionCharacterizationCustomer publicationsMaterialPolymer researchSAXSSelf-assembled materialTechniqueTemperature

Power Law Relaxations in Lamellae Forming Brush Block Copolymers with Asymmetric Molecular Shape

Yavitt, Benjamin M.; Fei, Hua-Feng; Kopanati, Gayathri N.; Winter, H. Henning; Watkins, James J.

We report the linear viscoelasticity of densely grafted poly(styrene)-block-poly(ethylene oxide) (PS-b-PEO) diblock bottlebrush block copolymers (dbBB) of equal mass fraction over a wide range of backbone degree of polymerization (Nbb = 21–119). The difference in side chain length (PS Mn = 2.9 kg/mol, PEO Mn = 5 kg/mol) produces an…
sergio.rodrigues@xenocs.com
27 January 2020
(Natural) polymersApplicationCharacteristic dimensionCharacterizationCustomer publicationsMaterialPolymer researchSAXSTechniqueWAXS

Gas separation properties of polybenzimidazole/thermally-rearranged polymer blends

Moon, Joshua D.; Bridge, Alexander T.; D’Ambra, Colton; Freeman, Benny D.; Paul, Donald R.

Polybenzimidazole (PBI) is highly selective for H2 removal from mixtures with CO2, but it exhibits low gas permeabilities. Celazole® PBI was blended with more permeable HAB-6FDA-CI, an ortho-functional thermally rearrangeable polyimide, to improve its gas permeabilities while attempting to maintain high selectivity. A compatibilizer, 1-methylimidazole, enhanced phase dispersion when added…
sergio.rodrigues@xenocs.com
27 January 2020
(Natural) polymersApplicationCharacteristic dimensionCharacterizationCustomer publicationsMaterialPhase analysisPolymer researchSAXSTechnique

Gradient supramolecular interactions and tunable mechanics in polychaete jaw inspired semi-interpenetrating networks

Thompson, Chase B.; Chatterjee, Sourav; Korley, LaShanda T. J.

Polychaete worms display a remarkable jaw structure, where a gradient in metal-ligand coordination down the length of the jaw results in a shift from hard to soft mechanics. To mimic these gradient structures, a Zn-coordinated supramolecular polymer is crosslinked into a covalent matrix to afford supramolecular semi-interpenetrating networks (SIPNs). These…
sergio.rodrigues@xenocs.com
27 January 2020
(Natural) polymersApplicationCharacteristic dimensionCharacterizationCustomer publicationsMaterialOrientation analysisPolymer researchSAXSTechnique

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…
sergio.rodrigues@xenocs.com
27 January 2020
ApplicationCharacteristic dimensionCharacterizationCustomer publicationsMaterialOtherPorous materialSAXSTechnique

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 membranes—pure 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…
sergio.rodrigues@xenocs.com
27 January 2020
(Natural) polymersApplicationCharacteristic dimensionCharacterizationCustomer publicationsMaterialRenewable energySAXSSpecific surfaceTechnique

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…
sergio.rodrigues@xenocs.com
27 January 2020
(Natural) polymersApplicationCharacteristic dimensionCharacterizationCustomer publicationsMaterialPorous materialRenewable energySAXSSelf-assembled materialTechnique

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 nanostructure–behavior 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…
sergio.rodrigues@xenocs.com
27 January 2020
(Natural) polymersApplicationCharacteristic dimensionCharacterizationCustomer publicationsMaterialPolymer researchSAXSSelf-assembled materialTechnique

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…
sergio.rodrigues@xenocs.com
27 January 2020
(Natural) polymersApplicationCharacteristic dimensionCharacterizationCustomer publicationsMaterialRenewable energyTechniqueWAXS

Preparation of cellulose nanofibers from Miscanthus x. Giganteus by ammonium persulfate oxidation

Yang, Han; Zhang, Yefei; Kato, Ryo; Rowan, Stuart J.

Carboxylic acid functionalized cellulose nanofibers (MxG-CNFA-CO2H) were successfully isolated from a sustainable grass hybrid Miscanthus x. Giganteus by a new two-step chemical oxidation, that involves bleach treatment and ammonium persulfate oxidation, followed by ultrasonication. The resulting MxG-CNFA-CO2Hs have ca. 1200?mmol/kg carboxylic acid surface groups, an aspect ratio of 230 (height…
sergio.rodrigues@xenocs.com
27 January 2020
(Natural) polymersApplicationCharacteristic dimensionCharacterizationCustomer publicationsMaterialOrientation analysisPhase analysisPolymer researchSAXSTechniqueTensileWAXS

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…
sergio.rodrigues@xenocs.com
27 January 2020