Crystallization Kinetics Modulation and Defects Suppression of All-Inorganic CsPbX3 Perovskite Film

Recently, all-inorganic CsPbX3 perovskite solar cells have stimulated enormous research interests due to their numerous merits including superior thermal and light stability and become one of the most prominent research...

Multi-Chromophore Dyes for Improving Light Stability of Electro-Fluidic Displays

Electro-fluidic display (EFD) is a new reflective display based on electrowetting phenomenon which is applied to the outdoor billboard. Organic dyes are the most important materials for the color gamut and reliability of the EFD devices, which are always synthesized based on mono-chromophore dye in previous work. In this paper, we report our research on azopyrazolone as the chromophore to construct a polychromic macromolecular dye system. The light stability and photo-electric properties of these new dyes are researched detailed. It is found that the light stability of multi-chromophore dyes and backflow properties are much better than corresponding mono-chromophore dye.

A new lighting method for cultural materials using selective chromatic light

Lighting is a critical component in a museum environment because, together with temperature, relative humidity and pollutants, it is one of the damaging factors able to produce long‐term, cumulative and irreversible photodegradation processes. To correctly preserve artworks, limiting illuminance and exposure is recommended, allowing on one side the preservation of the object, but on the other limiting the display of the object, especially for sensitive materials. The aim of this research was to develop, evaluate and compare a new lighting method for paintings and other cultural materials to improve the experience of the objects whilst reducing the risks from exposure. The idea is based on the use of selective chromatic light where the component of the spectrum absorbed by the materials is removed. This absorption is the principal cause of photodegradation. The proposed lighting system can be obtained by combining different types of projection systems together with filtering using an appropriate light source. Six methods of light projection have been compared for two mock-ups simulating real artworks with high and medium light sensitivity. The efficiency of illumination increased from 30% to 111% compared to standard lighting systems. Light stability tests were additionally performed, finding reduced colour changes compared to traditional lighting systems.

Photochemical stability of warfarin potassium in powdered pharmaceutical tablets

BACKGROUND: Warfarin potassium (Wf) commercial tablets originally formulated for adults are ground before administration to pediatric patients and elderly patients with dysphagia. OBJECTIVE: The present study investigated the effect of tablet grinding on the photostability of four types of commercial Wf tablets and predicted the photostability of the tablet powders by chemometric analysis. METHODS: The photodegradation of Wf content was evaluated by reversed-phase column high-performance liquid chromatography with ultraviolet (HPLC-UV). RESULTS: The bulk Wf powder was relatively photostable, whereas ground Wf tablets underwent substantial photodegradation. The photostability of the ground powders of a brand-name Wf commercial tablet and three generic Wf commercial tablets was quantitatively assessed and compared. In certain cases, the Wf in all the three ground generic tablets was less photostable than in the ground brand-name tablets. After 28 days of light irradiation, the Wf content decreased to 69.79% in the brand-name tablets, while it was 31.90% in some generic tablets. To clarify the factors influencing the relative photostability in various Wf formulations, we analyzed the intermolecular interactions between the active ingredient and the excipients by partial least-squares regression analysis based on photostability screening for each additive. CONCLUSION: The results suggested that the additives light anhydrous silicic acid and povidone adversely affect the stability of Wf tablets. In addition, the light stability of ground tablets was affected considerably by their formulation.