ABSTRACT. Partially reduced graphene oxide (prGO) was covalently functionalized with an diazonium containing, imidazolium based, polyzwitterionic polymer to afford a composite material with excellent dispersibility and long-term stability in high salinity brines including standard API and Arab-D found in deep oil reservoirs. When heated at 90 °C, the dispersions remained stable in excess of 140 days. These results suggest the utility of imidazolium-based polymers for brine stabilization as well as the use of diazonium containing polymers for a 'grafting-to' approach to nanocarbon functionalization.
A triptycene based poly(ether ether ketone) (tripPEEK) was synthesized and sulfonated to form proton exchange membranes. The increase in intrinsic free volume resulting from the incorporation of sterically bulky triptycene moiety, imparts high affinity to water at all levels of relative humidity (RH) from 10 %RH to 90 %RH. S-tripPEEK membranes showed proton conductivities of 334 mS/cm at 85 °C at 90 %RH and 0.37 mS/cm at 85 °C at 20 %RH. Membranes of similar ion exchange capacity (IEC) are compared to deconvolute the effect of free volume from IEC in enhancing proton conductivity. Increasing the free volume of the membranes increases the proton conductivity and decreases the activation energy for proton conduction between 10 %RH to 90 %RH.
The synthesis of a covalently modified graphene oxide derivative with exceptional and tunable compressive strength is reported. Treatment of graphene oxide with triethyl phosphite in the presence of LiBr produces monolithic structures comprised of lithium phosphate oligomers tethered to graphene through covalent phosphonate linkages. Variation of the both phosphate content and associated cation produces materials of various compressive strengths and elasticity.
Executive SummaryDate of Study: November 5, 2013 We have performed FT-IR microspectroscopic analysis on both sides of the Gospel of Jesus's Wife (GJW) and the Gospel of John (John) papyrus fragments. Professor Karen L. King of Harvard University provided the papyrus fragments on Tuesday, November 5, 2013.
GJWThe fragment is predominantly composed of oxidized cellulosic material, which is consistent with old papyrus.The fragment is largely homogenous in chemical composition. We found one anomalous feature that we were unable to identify. We did not observe any major spectral differences between "bare" papyrus and papyrus coated with ink. We did not observe any major spectral differences between the recto and verso sides of the papyrus fragment.The degree of oxidation is similar to that of the John fragment; however, the GJW fragment appears to be slightly less oxidized overall than the John fragment. Oxidation of the fragments is dependent on both their storage conditions and their ages, among other factors.
JohnThe fragment is predominantly composed of oxidized cellulosic material, which is consistent with old papyrus. Our analysis indicates that the extent of oxidation is slightly greater than the GJW fragment.Like the GJW fragment, the John fragment is mostly homogeneous in chemical composition with no significant differences either between bare papyrus and papyrus covered in ink) or between the recto and verso sides.The John fragment shares a majority of characteristic spectral features with the GJW fragments.terms of use, available at https://www.cambridge.org/core/terms. https://doi
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