Professor

Physical Chemistry

Research Interests

LIQUID CRYSTALS

Liquid Crystal research has been going on at Temple University since1970. The atmosphere in the group is essentially that of "materials scientists",i.e. fear not to either make molecules or to measure their properties.The laboratories are particularly wellequipped for uv-vis , fluorescenceand infrared spectroscopy, optical microscopy, differential scanning calorimetry,and thermogravimetric analysis. Fully computerized data collection andanalyses capabilities are associated with each of these instrument facilities.Specialized equipment includes a versatile shear apparatus with a programmablestep motor, a small scale wet and dry spinning unit to allow for convenientprocessing of samples as small as a few grams and mechanical testing equipment.

Two examples of current research problems are: (a) to understand howthe macroscopic periodic structures which develop during reorientationof liquid crystal polymers affect their properties, and (b) to utilizelow molecular weight nematic or cholesteric liquid crystals as reactionmedia.

NOVEL CARBONS INCLUDING THE FULLERENES

Particularly with the discovery of the newest form of carbon--the fullerenes--research on the fascinating properties of graphites, fullerenes and diamondare being conducted at many laboratories around the world. At Temple, thereis activity in two of these areas. Research on the fullerenes concentrateson the observation of superconductivity in the alkali metal derivativesof these materials. Attempts to synthesize structural variations are underwayto enhance and stabilize their behavior. Facilities include synthetic apparatusfor preparation of the fullerenes in an arc discharge, glove boxes formanipulation in controlled atmospheres, and conductivity and superconductivitymeasurements down to sub-helium temperatures. Research on novel graphitesinvolves preparation of heteroatom doped flakes of graphite and evaluationof their electronic , mechanical, and optical properties.

Selected Publications

N. X. Yan, M. M. Labes, S. G. Baek and J. J. Magda; Shear-Induced Texturesin the Lyotropic Liquid Crystal Poly(g-benzyl L-glutamate) (PBLG); Macromolecules27, 2784 (1994).

C. L. Lin, T. Mihalisin, M. M. Labes, N. Bykovetz and J. E. Fischer;Nonlinear Logarithmic Time Decay of Magnetization in Superconducting Rb3C60;Solid State Communication 90, 629 (1994).

J. O. Iroh, Y. Suhng and M. M. Labes; Characterization of ElectropolymerizedGraphite Fiber-Polyacrylamide Composites; J. Appl. Polym. Sci. 52,1203 (1994).

M. M. Labes, V. Ramesh, A. Nunez, W. Shang and X. Luo; Reactivity andConformational Control Utilizing Liquid Crystalline Solvent Media; Mol.Cryst. Liq. Cryst. 240, 25 (1994).

W. Shang and M. M. Labes; Effect of Boundary Conditions on the Pitchand Helical Twisting Power of Chiral Solutes in Nematic Liquid Crystals;Mol. Cryst. Liq. Cryst. 239, 55 (1994).