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We report the interfacial structures and chemical environments of ionic liquid films as a function of dilution with molecular solvents and over a range of film thicknesses (a few micrometers). Data from spectroscopic ellipsometry and infrared spectroscopy measurements show differences between films comprised of neat ionic liquids, as well as films comprised of ionic liquids diluted with two molecular solvents (water and acetonitrile). While the water-diluted IL films follow thickness trends predicted by the Landau-Levich model, neat IL and IL/MeCN films deviate significantly from predicted behaviors. Specifically, these film thicknesses are far greater than the predicted values, suggesting enhanced intermolecular interactions or other non-Newtonian behaviors not captured by the theory. We correlate film thicknesses with trends in the infrared intensity profiles across film thicknesses and IL-solvent dilution conditions and interpret the changes from expected behaviors as varying amounts of the film volume existing in isotropic (bulk) vs anisotropic (interfacial) states. The hydrogen bonding network of water-diluted ionic liquids is implicated in the agreement of this system with the Landau-Levich model's thickness predictions.

Ionic liquids (ILs) are becoming important solvents in commerce, but monitoring their purity and performance in industrial applications presents new challenges. Fiber welding technology utilizes ILs to mold and shape natural fibers (cotton, hemp, flax, silk, and wool) into morphologies that are typically attained only using synthetic, petroleum-based non-biodegradable plastics. The result is an atom-efficient process that up-converts fibrous substrates to value-added products and materials. A key aspect of bringing this and other IL-enabled technologies to market relies on efficient monitoring and recycling of IL-based solvents. Implementing online IL quality monitoring enhances the unit economics of these processes. Here, we characterize and report conductivity measurements, refractometry, and ATR-FTIR spectroscopy techniques for online IL monitoring during an industrial fiber welding process. The online analysis enables more efficient recycling of the IL solvent, increasing the process efficiency and product quality.

The process of ozone treatment of high kappa kraft pulp is studied using polarization modulated Fourier transform infrared spectroscopy and atomic force microscopy. The complementary information from the two methods enables a detailed analysis of reaction sites on the fibers, and gives a detailed view of the reaction mechanisms of delignification by ozone treatment. Furthermore we describe a simple method to measure the kappa number of paper sheets that can be used on-line.

Ionic liquids exhibit heterogeneous structures in both the normal and parallel planes with respect to an interface. The formation of these structures can be almost instantaneous or require hours to develop. The impact of these structures on molecular diffusion and local chemical environment can be significant, impacting tribology, solvation, and catalysis. Our work uses DC and AC electrochemistry, linear and non-linear spectroscopies, probe and optical microscopies, and thermochemistry to examine the IL structures that form near surfaces and within the electrochemical double layer. We probe the dynamics of the order/disorder transitions and attempt to reconcile experimental deviations from predicted, theoretical behaviors (i.e. capacitance or redox). In this talk, we will present series of DC and AC electrochemical data paired with spectroscopic analysis of ionic-liquid interfaces with electrodes to describe the interfacial, or sometimes micron scale ordered structures we observe in IL solvents. We incorporate redox probe molecules to observe the effects of IL ordering on electron transfer. We also probe how the electrochemical system changes in response to diluting the IL with molecular liquid cosolvents (water or acetonitrile). Finally we extend our studies to the electroreduction of carbon dioxide in IL systems, and present preliminary data on the optimization of a mixed IL+cosolvent system on Ag electrodes. Figure 1

Infrared spectroscopy has been used to measure the amount of carboxymethyl cellulose (CMC) attached to cellulosic fibers. CMC was attached to an unbleached kraft pulp in aqueous conditions. Isotropic handsheets were then prepared and ATR spectroscopy was used to measure the intensity of the carboxyl vibration, which correlates to the amount of attached CMC that was determined using a wet chemical approach. The ATR method is rather time consuming as several measurement points on the sample have to be averaged, although it is still much faster than the wet chemical approach. Infrared reflection absorption spectroscopy (IRRAS) using polarized light was further used to measure the amount of attached CMC. In this method the intensity of an electromagnetic wave confined to the thin layer is used to correlate the spectroscopy to the amount of CMC on the fiber surface in the paper sample. The measurement time is shorter than with the ATR method. The proposed IRRAS method could be employed as a fast and reliable way to quantify adsorption of chemicals on pulp fibers.

We report the clinical and pathological features of a cardiac fatality caused by granulocytic sarcoma in a young adult man with no evidence of leukemia involving bone marrow or peripheral blood. At autopsy, walls of the four cardiac chambers were massively infiltrated by tumor, resulting in a cardiac weight of almost three times normal. Routine cytochemical stains plus immunoperoxidase staining for OKM1 confirmed the diagnosis. Although subclinical cardiac infiltrates are commonly detected at autopsy in patients with acute nonlymphoblastic leukemia (ANLL), massive cardiac granulocytic sarcoma in the absence of bone marrow disease has not been previously described. Cytochemical and immunological methods of diagnosing granulocytic sarcoma in fixed tissues are reviewed.