Aohan Wang

Synthesis of Isothianaphthene (ITN) and 3,4-Ethylenedioxy-Thiophene (EDOT)-Based Low-Bandgap Liquid Crystalline Conjugated Polymers

Copolymers, consisting of isothianaphthene and phenylene derivatives with liquid crystal groups, were synthesized via Migita-Kosugi-Stille polycondensation reaction. IR absorption, UV-vis optical absorption, and PL spectroscopy measurements were carried out. Thermotropic liquid crystallinity of the polymers with bandgap of ~2.5 eV was confirmed.

Mechanical orientation in thermotropic liquid crystal state and magnetic orientation in solvent evaporation process via lyotropic liquid crystal state of an amphotropic low-bandgap liquid-crystalline π-conjugated polymer

Molecular orientations by shear stress and magnetic field were carried out to obtain a uniaxial, low-bandgap, amphotropic liquid-crystalline (LC) π–conjugated polymer. Orientation of a thick polymer film shows orientation along the shear stress, but a thin sample produced by a spatula drawing on a glass substrate produces LC band structure with a chevron pattern. Furthermore, we report the orientation of a lyotropic LC polymer under magnetic field.

Synthesis and optical properties of poly(phenylenethiophene)s bearing conjugated side chains

A series of π-conjugated polymers bearing conjugated side chain were prepared by Migita–Kosugi–Stille coupling polycondensation reaction. The polymers consisting of phenylene–thiophene (CCPTO), phenylene–isothianaphthene (CCPIO), and phenylene-3,4-ethylenedioxythiophene (CCPEO) conjugated backbones in the main chains showed optical absorption peaks in the same region, while fluorescence peak of CCPTO was at larger wavelengths compared with those of CCPIO and CCPEO. The polymers showed optical rotary dispersion, indicating the optically active substituents induced one-handed helicity to the polymers.

Thiophene-based chiral small bandgap π-conjugated polymers: synthesis and optical properties

A series of thiophene-based chiral small bandgap π-conjugated polymers was successfully synthesized. Optical properties of the polymers were investigated by using UV–vis, photoluminescence (PL), circular dichroism (CD) spectroscopies, and specific rotation measurements. Especially, the isothianaphthene–thiophene based copolymers display 10–20 nm longer absorption maximum than those of thiophene–thiophene copolymers in the UV–vis. PL measurements demonstrate that the polymer exhibit light emission. CD spectroscopy measurements reveal helical π-stacking structure of the polymers.

Light Transmission by Lotus Plant Stem and Leaf Tissue: Natural Textiles for Optical Fibers

ABSTRACT Application of plant stem for optical transmitting devices is considered. This research indicates a possibility of application of vascular bundles as natural textiles for optical fibers. Observations of lotus stem tissue were carried out. Laser beam transmission of lotus stem was confirmed. New functions of photoconduction through lotus stem and confinement of incident light on the leaf surface are discussed.