Paul C. Trulove

Direct X-Ray Diffraction Evidence for Imidazolium Intercalation into Graphite from an Ionic Liquid

1,2-dimethyl-3--butylimidazolium (DMBI) tetrafluoroborate was electrochemically characterized at a graphitic paper working electrode. Cyclic voltammetry indicated reversible cationic intercalation of the graphitic paper. X-ray powder/thin film diffraction measurements of intercalated graphitic paper gave one primary diffraction peak at 3.44671 A. In addition, detailed diffraction studies revealed several additional reflections at 0 0 l positions. The X-ray diffraction results are consistent with a intercalate that has a axis of and a resulting axis expansion of 6.98 A. This result suggests that the plane of the five membered imidazolium ring is lying nearly parallel to the graphite sheets.

Characterization of Polymer Movement in Fiber Welded Cellulose Composites

Ionic liquids are effective solvents for the dissolution of biopolymers such as cellulose and silk. New materials can be created from these natural feedstocks by processes that involve the full dissolution of biomaterials. Many reports show that the dissolution and reconstitution processes eliminate the native polymer structure, often with deleterious consequences to the physical properties of the material. Recently, it has been shown that robust biopolymer based structures may be created without full dissolution of the material by a method we call “Natural Fiber Welding”. The welding process generates modified natural fiber structures while leaving much of the material in its native state. As a result, natural fiber welding enables tunable preservation of native microstructure while also affording manipulation of important material properties.

Phase Behavior and Solvation of Lithium Triflate γ-Butyrlactone

Data describing the concentration and temperature dependent solvation and phase behavior of lithium trifluoromethanesulfonate (LiTf) in γ-butyrolactone (GBL) is presented. Differential scanning calorimetry (DSC), Raman spectroscopy and X-ray diffraction measurements are employed to elucidate the electrolyte interactions. DSC analysis show the presence of a crystallinity gap at concentrations between 2.56:1 and 5.00:1 GBL:LiTf (mole:mole) and a high melting solvate in more concentrated samples. Raman spectroscopic analysis indicates that the coordination of ions in the high melting solvate undergoes temperature dependent transitions. X-ray diffraction analysis showed that lithium triflate forms a 1:1 aggregated solvate having 6 ion pair coordinated by 6 solvent molecules. Taken together, data suggest ion transport in electrolytes is influenced by solvation.