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Versatile devices with tunable capabilities for controlling lasing wavelength and intensity are in high demand. Liquid crystals (LCs) exhibit immense potential for such applications, offering fine-tuning possibilities through external factors. On the other hand, laser technology is currently a research hotspot in optoelectronics, and also in practical applications. The recent market introduction of laser television marks a significant stride toward making such advanced technology accessible in every household. In synergy with laser pumping, the LCs unquestionably can be rediscovered. This study presents a comprehensive investigation into the crystallization phenomenon within a host-guest device, compact in size, free from moving parts, and integrating the liquid crystalline (LC) matrix doped with 3,4,9,10-tetra-(3-alcoxy-carbonyl)-perylene (THCP) dye. The focus lies in examining the influence of varying dye concentrations on multicolor fluorescence, lasing behavior, and device morphology. The systematic analysis of Random Lasing (RL) energy thresholds and the impact of DC voltage on light intensity modulation is demonstrated. Morphological changes were monitored in real-time using optical microscopy techniques, including crossed polarizer, and fluorescence imaging under 450 nm excitation. Utilizing advanced Transmission Electron Microscopy (TEM) techniques, we explore exceptional insights into our set of devices, providing novel information about the THCP crystallization process for the first time in the literature. To gain a comprehensive understanding of the crystal forming and molecular geometry we examined additionally the THCP dye, using X-ray diffraction and Raman spectroscopy. Furthermore, we showcase that varying the pumping energy enables multicolor tuning in the fabricated systems, presenting an attractive feature in the context of laser display technologies.

Composite materials containing zero valent copper (ZVC) dispersed in the matrix of two commercially available strongly basic anion exchangers with a macroreticular (Amberlite IRA 900Cl) and gel-like (Amberlite IRA 402OH) structure were obtained. Cu0 particles appeared in the resin phase as the product of the reduction of the precursor, i.e., copper oxide(I) particles previously deposited in the two supporting materials. As a result of a one-step transformation of preformed Cu2O particles as templates conducted using green reductant ascorbic acid and under mild conditions, macroporous and gel-type hybrid products containing ZVC were obtained with a total copper content of 7.7 and 5.3 wt%, respectively. X-ray diffraction and FTIR spectroscopy confirmed the successful transformation of the starting oxide particles into a metallic deposit. A scanning electron microscopy study showed that the morphology of the deposit is mainly influenced by the type of matrix exchanger. In turn, the drying steps were crucial to its porosity and mechanical resistance. Because both the shape and size of copper particles and the internal structure of the supporting solid materials can have a decisive impact on the potential applications of the obtained materials, the results presented here reveal a great possibility for the design and synthesis of functional nanocrystalline solids.

This work shows that the titanium dioxide coatings obtained by low-pressure cold gas spraying with the use of the sol–gel amorphous TiO2 powder are characterized by photocatalytic activity despite their partial amorphous content. Moreover, the research outcome suggests that the decomposition rate of organic pollutants is enhanced after long-term exposure to moisture. The condensation humidity test is not detrimental to the continuity and integrity of the coating, but the phase composition of coatings changes—with the exposure to water vapor, the portion of the amorphous phase crystallizes into brookite. The mechanism responsible for the conversion of amorphous TiO2 into brookite is attributed to the water-driven dissolution and reprecipitation of TiO6 octahedra. It has been shown that an additional parameter necessary for the stabilization of the brookite is the oxygen depletion of the amorphous structure of titanium dioxide. Considering the results presented in this paper and the advantages of a portable, low-pressure cold spray system for industrial applications, it is expected that TiO2 coatings produced from a sol–gel feedstock powder can be further developed and tested as efficient photocatalysts. [ABSTRACT FROM AUTHOR]