We focus on the fabrication and study of controllable holographic gratings based on azo-dye-doped and undoped polymer-ball-type polymer-dispersed liquid-crystal films. Experimental results indicate that the next step of photopolymerization of the sample with the illumination of Ar+ laser beams after UV curing causes a latent density grating to be recorded. This grating is formed by a selective secondary photopolymerization. Heating and applying a voltage change the structure of the liquid crystal and induce the appearance of the latent grating. Diffraction efficiencies versus temperature, voltage, and state of polarization are studied for both dye-doped and undoped cells and are found to be quite different. This discrepancy is attributable to the reorientation effect of liquid crystals through their interaction with the photo-induced adsorption of the doped dyes on the surface of polymer balls in the dye-doped cell.

This study investigates the characteristics of the holographic grating formed in polymer-ball-type polymer-dispersed-liquid crystal (PBT-PDLC) films, doped with a diazo dye (G206). A dye-doped PBT-PDLC sample was fabricated, and used to write a holographic grating. Experimental results indicated that the grating had memory of the polarization of the writing beams. This polarization memory effect was inerasable if the sample was heated to the isotropic phase, and then cooled down to room temperature. Based on these observations, we believe that the memory of the grating effect does not relate to the intrinsic memory in the transmission versus applied voltage curve of PBT-PDLC films, which is thermally erasable. Rather, the effect is due to a feature of the grating, resulting from the reorientation of the liquid crystals through their interaction with the photo-induced adsorption of the doped dyes on the surface of the polymer balls.

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A discharge adaptor, composed of a metal casing and platinum (Pt) wire needle, was directly attached to an electrospray ionization (ESI) probe tip, to transform the ionization into atmospheric pressure chemical ionization (APCI). Six generic drugs were analyzed with the developed discharge adaptor (DA) and two commercial interfaces. The DA interface produced more intense radical anions, [M]˙⁻, and less sodium adduct ions, [M + Na]⁺, than the ESI interface, whereas almost the same molecular ions were detected as the APCI interface. The effects of solvent and desolvation gas flow in the DA interface were similar to those in the ESI interface, but differed from those in the APCI interface. Better sensitivity of the tested drugs was obtained relative to the commercial APCI interface. For human plasma samples, the DA interface also demonstrated good tolerance to plasma matrices, linearity from 5 or 20 to 500 ng/mL (r² > 0.99) and ruggedness.