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The electrical properties of alizarin doped anthraquinone were investigated using a complex impedance spectroscopy technique. Dielectric study revealed a phase transition from the semiconducting to the conducting state at 53°C. The dielectric relaxation was found to be of non-Debye type. Evidence of temperature-dependent electrical relaxation phenomena as well as a positive temperature coefficient of conductivity character were observed in the sample. The frequency dependence of AC conductivity data followed a power law. Electric modulus as well as AC conductivity analyses indicated the possibility of a hopping mechanism for electrical conduction in the system. The activation energy and minimum hopping distance were estimated from the AC conductivity data.

The synthesis and the linear and optical limiting properties of a 2-(2-methoxybenzyllideneamino)-5-methylphenylmercuric chloride-doped poly(methylmethacrylate) (PMMA) film are described. The sample exhibits strong optical power limiting under continuous wave (cw) laser at the experimental wavelength. The mechanisms for the optical limiting were discussed on the basis of the two-photon absorption involved in the process. The nonlinear absorption coefficient β of the sample is estimated and its value is found to be 67 × 10^-2 cm/W. Our study indicated that the investigated compound-doped PMMA film is a potential candidate for optical limiting applications in low power cw regime.

Thermoelectric properties of organic materials have attracted much attention for the potential application in clean energy sources. In this work, we use the master equation method to calculate transport properties of the organic material when there is a temperature gradient in the material. The themoelectric property is analyzed with our model under different temperatures and different disorder strengths. It will be helpful to understand the thermoelectric property of organic materials and make good use of the heat energy.

Environmental issues and energy crisis are huge challenges in today’s world. As one of green energy sources, thermoelectric (TE) materials have attracted tremendous attraction for they can convert free heat energy to electricity. In our work, through the master equation (ME) method, we studied the characteristics of charge transport in the organic material under nonlinear temperature distributions. Under each temperature distribution, Seebeck coefficient is analyzed with different factors such as the temperature, the reorganization energy and the energetic disorder strength. Especially, Seebeck coefficient of different temperature distributions showed different performances when the reorganization energy changes. Our studies will be helpful to look further into TE properties of organic materials and improve the application of TE devices.

The commercial purity dibromobenzene (DBB) and succinonitrile (SCN) were purified using a columnar distillation system. Thin walled rectangular specimen cells (60–80 μm thick) were fabricated and filled with the purified materials under the vacuum. The specimen cell was placed in a horizontal temperature gradient stage. A thin liquid layer was melted and the specimen was annealed in a constant temperature gradient for an enough time to observe the equilibrated grain boundary groove shapes. The thermal conductivities of solid and liquid phases for the purified DBB and DBB–5.7 mol% SCN alloy were determined with the radial heat flow and the Bridgman-type growth apparatuses. From the observed grain boundary groove shapes, the Gibbs–Thomson coefficients, solid–liquid interfacial energies, and the grain boundary energies for solid DBB in equilibrium with its melts and solid DBB in equilibrium with DBB–SCN monotectic liquid have been determined. The temperature coefficients of the purified DBB and DBB–5.7 mol% SCN alloy were also determined from thermal conductivity curve vs temperature.

A comparative study of photo-induced optical anisotropy was carried out on Langmuir–Blodgett films prepared from five different amphiphilic azobenzene derivatives. The anisotropy was induced by a linearly polarized pump beam of an Ar-ion laser at λ=514 nm and monitored by a linearly polarized probe beam of a He–Ne laser at λ=633 nm. Large optical anisotropy up to 0.35 has been induced. Holographic gratings were recorded by two left circularly polarized beams of the Ar-ion laser and time evolution of the first-order diffraction efficiency of the probe beam was recorded in an automatic regime. In such a geometry, the spatial modulation of refraction index reaches 0.14. The experimental data is consistent with a model for a photo-induced collective chromophore realignment in the heterogeneous domain structure of the films studied. The influence of an electric field of the corona discharge on the grating recording process was also studied and polar diffraction gratings have been prepared by a spatially periodic photo-poling process.

New organic "donor–donor" bis-stilbenyl conjugated chromophores arranged in increasing dimensionality (1D to 3D) have been synthesized in high yields by multiple Heck coupling. The central core is based on a biphenyl, triphenylenyl or spiro-bifluorenyl group when the donor part at each extremity is based on a 3,4,5-tridodecyloxyphenyl group that ensures a high solubility in organic solvents and favors the catalytic coupling reactions. Femtosecond two-photon absorption measurements in solution have evidenced improved two-photon absorption cross-sections (≅ 10^-19cm⁴/GW) that depend on the arrangement of the chromophores.

Potent ocular materials with noncentrosymmetric frameworks seek the attention of researchers throughout the globe. A polymorph of 2,4-dinitrophenylhydrazine single crystals with such framework was grown by slow cooling mechanism with 1,4-dioxane as the solvent. The noncentrosymmetric characteristics of the grown material were confirmed by using X-ray diffraction analysis. The presence of functional groups of the title meld was identified with the aid of Fourier transform infrared spectroscopy analysis. The ability of the material to withstand temperature with weight loss and decomposition peak was determined by using TG/DTA analysis. The transmission window and optical bandgap of the materials were determined by using UV–Vis analysis. The nonlinear optical behavior of the grown crystals was determined with the aid of SHG and Z-scan analysis. The computational analysis was performed using Gaussian 09 software package to investigate various parameters of title meld. Hirshfeld surface analysis was performed using Crystal explorer 17 to quantify the intermolecular interactions of the grown material.

Thiophene-based small molecules COMP.1 and COMP.2 are explored for optical, electronic and photophysical properties by using theoretical approach. The density functional theory (DFT) at B3LYP/6-31G** level of theory is used to optimize both molecules COMP.1 and COMP.2 at ground state, while for excited state, the time-dependent DFT (TD-DFT) is utilized at the same level of theory. The optoelectronic and photophysical parameters specify that these materials would be good charge transport materials. Computed global reactivity descriptors indicate that COMP.2 T is more stable exhibiting smaller chemical reactivity. High electron mobility of COMP.1 as 0.78cm${}^2\cdot$V${}^{-1}\cdot$s${}^{-1}$ revealing that COMP.1 might be good n-type material. COMP.1 has been anticipated to be a decent n-type material as compared to COMP.2 and might be good material for solar cell applications.

Composite insulation materials has great prospects for development, combining good heat preservation performance of organic materials with good fireproof performance of inorganic materials. Composite materials have mainly produced by means of physical function. The difficult to solve the problem is how to make inorganic material package in the organic material, and the increase of porosity. The solution is to strengthen material production process management, have strong mechanical pressure and excellent foaming technology.