Preparation And Study Of Spirooxazine Photochromic Materials

Photochromic materials,a class of photoresponsive materials,have been successfully used in sensors,optical recording,switches and memory storage systems.Because of relatively high fatigue resistance and light stability,spirooxazine is promising commercially.The special threedimensional structure grant hydrogels with absorption and retention of water and excellent biocompatibility.The photochromic properties of spiroxazine on hydrogel materials were studied,which not only enriched the types of functional hydrogels,but also extended the application range of spiroxazine.In this paper,SPO-OH and DSPO were synthesized and introduced to gel of HEMA by means of physical doping and covalent polymerization respectively,making P(SPO-OHHEMA)and P(DSPO-HEMA)hydrogel materials,whose photochromic properties were explored,including ultraviolet-visible absorbance,light transmittance and optical fatigue performance.Also the effect on equilibrium moisture content,together with temperature factor,have been investigated.The P(DSPO-HEMA)hydrogel was tested on extraction.At the same time,the hindered amine light stabilizer was introduced into the DSPO-HEMA gel to obtain the P(DSPO-HALS-HEMA)hydrogel material,enhancing the stability of the photochromic hydrogel material.The results are as follows: the introduction of physical doping and covalent polymerization is feasible and simple,giving SPO-OH and DSPO into the HEMA gel system with excellent and stable photochromic performance successfully.Both of two performed sensitive light response,and the total fading rate was less than 10 s,which meets the requirement that be fast replacement of photochromic gels.It can withstand continuous ultraviolet irradiation for 10 h and keep the color state.The light transmittance in the visible light region was above 95 %,indicating that the gel have good fatigue resistance and high light transmittance.The histogram of equilibrium moisture content showed that the addition of two photochromic molecules does not affect the ability of the gel system to retain water.The extraction test showed that DSPO was successfully introduced into the gel system,and the introduction of the hindered amine light stabilizer significantly improved the stability of the photochromic gel.