Versatile acid solvents for pristine carbon nanotube assembly.

Chlorosulfonic acid and oleum are ideal solvents for enabling the transformation of disordered carbon nanotubes (CNTs) into precise and highly functional morphologies. Currently, processing these solvents using extrusion techniques presents complications due to chemical compatibility, which constrain equipment and substrate material options. Here, we present a novel acid solvent system based on methanesulfonic or p-toluenesulfonic acids with low corrosivity, which form true solutions of CNTs at concentrations as high as 10 g/liter (≈0.7 volume %). The versatility of this solvent system is demonstrated by drop-in application to conventional manufacturing processes such as slot die coating, solution spinning continuous fibers, and 3D printing aerogels. Through continuous slot coating, we achieve state-of-the-art optoelectronic performance (83.6 %T and 14 ohm/sq) at industrially relevant production speeds. This work establishes practical and efficient means for scalable processing of CNT into advanced materials with properties suitable for a wide range of applications.

Washable, Sewable, All-Carbon Electrodes and Signal Wires for Electronic Clothing.

Smart wearable electronic accessories (e.g., watches) have found wide adoption; conversely, progress in electronic textiles has been slow due to the difficulty of embedding rigid electronic materials into flexible fabrics. Electronic clothing requires fibers that are conductive, robust, biocompatible, and can be produced on a large scale. Here, we create sewable electrodes and signal transmission wires from neat carbon nanotube threads (CNTT). These threads are soft like standard sewing thread, but they have metal-level conductivity and low interfacial impedance with skin. Electrocardiograms (EKGs) obtained by CNTT electrodes were comparable (P > 0.05) to signals obtained with commercial electrodes. CNTT can also be used as transmission wires to carry signals to other parts of a garment. Finally, the textiles can be machine-washed and stretched repeatedly without signal degradation. These results demonstrate promise for textile sensors and electronic fabric with the feel of standard clothing that can be incorporated with traditional clothing manufacturing techniques.

Temperature and pressure dependence of methane correlations and osmotic second virial coefficients in water.

We report methane's osmotic virial coefficient over the temperatures 275 to 370 K and pressures from 1 bar up to 5000 bar evaluated using molecular simulations of a united-atom description of methane in TIP4P/2005 water. In the first half of this work, we describe an approach for calculating the water-mediated contribution to the methane-methane potential-of-mean force over all separations down to complete overlap. The enthalpic, entropic, heat capacity, volumetric, compressibility, and thermal expansivity contributions to the water-mediated interaction free energy are subsequently extracted from these simulations by fitting to a thermodynamic expansion over all the simulated state points. In the second half of this work, methane's correlation functions are used to evaluate its osmotic second virial coefficient in the temperature-pressure plane. The virial coefficients evaluated from the McMillan-Mayer correlation function integral are shown to be in excellent agreement with those determined from the concentration dependence of methane's excess chemical potential, providing an independent thermodynamic consistency check on the accuracy of the procedures used here. At atmospheric pressure the osmotic virial coefficient decreases with increasing temperature, indicative of increasing hydrophobic interactions. At low temperature, the virial coefficient decreases with increasing pressure while at high temperature the virial coefficient increases with increasing pressure, reflecting the underlying hyperbolic dependence of the virial coefficient on temperature and pressure. The transition between a decreasing to increasing pressure response of the osmotic virial coefficient is shown to follow the response of the methane-methane contact peak to changes in pressure as a function of temperature, though a universal correlation is not observed.

Note: Nonpolar solute partial molar volume response to attractive interactions with water.

The impact of attractive interactions on the partial molar volumes of methane-like solutes in water is characterized using molecular simulations. Attractions account for a significant 20% volume drop between a repulsive Weeks-Chandler-Andersen and full Lennard-Jones description of methane interactions. The response of the volume to interaction perturbations is characterized by linear fits to our simulations and a rigorous statistical thermodynamic expression for the derivative of the volume to increasing attractions. While a weak non-linear response is observed, an average effective slope accurately captures the volume decrease. This response, however, is anticipated to become more non-linear with increasing solute size.

Nd:YAG photodestruction of a presumed corneal Toxocara canis larva.

PURPOSE: To describe the technique of Nd:YAG photodestruction of a presumed Toxocara canis corneal larval migrans and to report the unique clinical combination of a corneal nematode and diffuse unilateral subacute neuroretinitis (DUSN). METHODS: Clinical case report. RESULTS: A 63-year-old white male presented with idiopathic neuroretinitis treated empirically with systemic anti inflammatory therapy. Subsequently, he developed keratouveitis with an obvious corneal larva. Serology was positive for T. canis. Laser destruction of the larva combined with topical steroid and oral albendazole therapy led to initial resolution, followed by 1 episode of recurrent keratouveitis without identified ocular surface or intraocular larvae. This was cleared with topical steroids. A second empiric course of oral albendazole was also administered. The patient has shown no ocular recurrences or evidence of systemic involvement 1 year after the second course of treatment. CONCLUSIONS: Corneal larvae can be safely and successfully destroyed by Nd:YAG photodestruction. T. canis may be one of several nematodes responsible for DUSN. A careful examination of the anterior segment is essential in the management of patients with DUSN.