一种基于罗丹明衍生物的力致变色力敏团

A Novel Mechanochromic Mechanophore Based on a Rhodamine Derivative

为了探测聚合物材料受力时的损伤和断裂机理,延长材料的使用寿命和耐久度,将一种基于罗丹明衍生物的力致变色力敏团共价连接到聚甲基丙烯酸甲酯(PMA)中,并通过溶液超声、固体压缩、紫外-可见吸收光谱和荧光光谱对其力致变色性能进行了表征.结果显示,含罗丹明力敏团的PMA受力后从无色转变为红色,其550nm处的紫外-可见吸收峰和567nm处的荧光发射峰强度均明显提升,这种转变可通过加热(70℃)恢复到初始状态,且能够多次重复.以上实验结果可通过外力诱导的罗丹明力敏团开环反应和加热导致的逆反应加以解释.结果表明合成的罗丹明力敏团是一类较为理想的损伤探测力敏团,可用于力响应材料的开发.

Stress-sensing in polymeric materials is important to prevent destructive failure,interpret failure mechanism,and improve the lifetime and durability of the product.Inthisstudy,a mechanochromic mechanophore based on a rhodamine derivative was synthesized,and the mechanophore was covalently linked to poly（methyl acrylate）（PMA）.Then its mechanochromic properties were investigated by ultrasound sonication,compression,UV-vis and fluorescence spectroscopies.Under mechanical force,the rhodamine-containing PMA changed from colorless to pink（activation）,accompanying the increase of absorption at 550 nm and fluorescence intensity at 567 nm,while the pink color faded upon heating at 70 ℃,and such an activation-fading of color were repeatable.These results could be interpreted as a consequence of force-induced ring-opening and heat-induced ring-closure reactions of rhodamine mechanophore.The results showed that the rhodamine mechanophore could be an ideal force-probe for stress-sensing applications and stress-responsive polymers.