Dissolving and aligning carbon nanotubes in thermotropic liquid crystals.

It has been widely recognized that the combination of carbon nanotubes (CNTs) and low molar mass thermotropic liquid crystals (tLCs) not only provides a useful way to align CNTs, but also dramatically enhances the tLC performance especially in the liquid crystal display technology. Such CNT-tLC nanocomposites have ignited hopes to address many stubborn problems within the field, such as low contrast, slow response, and narrow view angle. However, this material development has been limited by the poor solubility of CNTs in tLCs. Here, we describe an effective strategy to solve the problem. Prior to integrating with tLCs, pristine CNTs are physically "coated" by a liquid crystalline polymer (LCP) which is compatible with tLCs. The homogeneous CNT-tLC composite obtained in this way is stable for over 6 months, and the concentration of CNTs in tLCs can reach 1 wt %. We further demonstrate the alignment of CNTs at high CNT concentrations by an electric field with a theory to model the impedance response of the CNT-tLC mixture.

Thermally-induced change in the relaxation behavior of skin tissue.

Skin biothermomechanics is highly interdisciplinary, involving bioheat transfer, burn damage, biomechanics, and physiology. Characterization of the thermomechanical behavior of skin tissue is of great importance and can contribute to a variety of medical applications. However, few quantitative studies have been conducted on the thermally-dependent mechanical properties of skin tissue. The aim of the present study is to experimentally examine the thermally-induced change in the relaxation behavior of skin tissue in both hyperthermal and hypothermic ranges. The results show that temperature has great influence on the stress-relaxation behavior of skin tissue under both hyperthermal and hypothermic temperatures; the quantitative relationship that has been found between temperature and the viscoelastic parameter (the elastic fraction or fractional energy dissipation) was temperature dependent, with greatest dissipation at high temperature levels.