Characterisation and photo-fatigue behaviour of UV-sensitive photochromic systems produced using electrospinning

This research aimed to create a UV sensor using photochromic pigment in nonwoven form and analyse its fatigue resistance under continuous ultraviolet (UV) light. The photochromic polymeric matrices consist of a photochromic pigment, a polymer, and a photo stabilizer, which enhance the stability of the photochromic systems under light exposure. As a base matrix, we used polyvinyl butyral. Then, we added different amounts of the photochromic pigment 5-chloro-1,3,3-trimethylspiro [indoline-2,3′-(3H) naphtho (2,1-b) (1,4)-oxazine]. We produce photochromic nonwovens by electrospinning a polymeric matrix solution with varying pigment concentrations. The study aimed to create a UV sensor with photochromic nanofibers that are very sensitive to light. It also tested how well it can degrade under continuous UV radiation by looking at its photo fatigue resistance under constant UV irradiation for its final use as a UV sensor material. Using FTIR, CRM, SEM, and XRD techniques, this study investigates the physiochemical properties and photodegradation behaviour of photochromic nonwovens and writes a report on it. The photo-light stability of photochromic materials is a major problem concerning its external stimuli in different substrate forms. It also looks at how well they resist photo-chemically towards the UV light. The fatigue resistance measurements were carried out using a FOTOCHROM3 spectrophotometer under continuous UV irradiance using two different modes. This study evaluated and reported their photodegradation behaviour in cyclic and continuous UV irradiance modes. The tests showed that the prepared photochromic system works well with photostability and can go through more than 20 exposure cycles, each with 100 min of UV light and intensity equal to 1/3 of the sun’s rays on a clear day. Given the PVB applications in our daily lives, it can serve as a UV sensor in numerous industrial applications. Photochromic nanofibers possessing excellent photosensitivity hold immense promise as optical rewritable devices and colourimetric-based UV sensors.