Research On Assembly Morphological Regulate And Soft Actuator Application Based On Spiropyran Derivatives

Spiropyran,as a commonly used photo-responsive molecule,can not only achieve reversible structural changes under light,but also be accompanied by changes in molecular polarity,hydrophilicity,appearance color and fluorescence.Based on this,spiropyran is applied in the study of controlled assembly and software actuators,and the following two works are carried out.1.Three spiropyran derivatives with different light response ability are designed and synthesized.Scanning electron microscope and transmission electron microscope show that the three structures have different degree of assembly morphological transformation after UV light irradiation,from solid nanospheres to hollow tadpole-likes,hollow tubes,and micron sheets.The differences in morphology transformation of the three structures are closely related to the degree of photoisomerization by UV-vis absorption spectrum,fluorescence spectrum,open/closed-ring ratio calculation.In addition,theoretical simulation results show that the interaction force between the open-ring form and methanol molecules is stronger than that between the closed-ring form,which is the key factor for the transformation of solid nanospheres into hollow tubular structures.Finally,the surface water contact angle test shows that the interface hydrophilicity is improved after UV light irradiation,which provides a basis for its development in the field of new interface materials.2.A water-soluble spiropyran with excellent photochromic properties is designed and synthesized.A soft actuator is prepared by mixing with agarose solution and spiropyran,which can oscillate spontaneously under the stimulation of water vapor.The excellent photo-response property of spiropyran is confirmed by UV-vis absorption and fluorescence spectra.The ability of the composite membrane to quickly adsorb and desorb water molecules is characterized by attenuated total reflection infrared spectroscopy,which is the key factor to realize self-oscillation driven by humidity.The humidity driven self-oscillation performance of the composite film with different thickness,different sizes and different loads are studied.It is found that the self-oscillation effect of the composite film is better when the size is40 mm × 8 mm × 60 μm and the load is 116 mg.Finally,the composite membrane is used for intelligent window,energy collection,and bionic flowers.This provides new ideas for the development of soft actuator in the future.