The Study Of Photothermal Dynamics Of Nanocomposites Through Optical Microfiber Interferometer

People's demand for physical health promotes the progress of biomedical drug development and diagnostic methods.Under the promotion of information technology,microfiber sensor combined with nano-composite materials has become a focus of research.Among them,optical microfiber sensor is a special device developed in recent years,many traditional fiber structures are processed to the subwavelength scale for some special phenomenon.The optical microfiber sensor has made a lot of new achievements in many fields,and can be used in the study of nanocomposite materials.In recent years,the design and development of near-infrared(NIR)photothermal nanomaterials have attracted great attention.Their thermal dynamic process and mechanism play important role in the design and preparation of materials,while there is still no perfect instrument to realize in-situ monitoring of photothermal process of these materials.Although some instruments,such as dynamic light scattering,absorption spectroscopy,and infrared thermal images have been used to observe the changes of photothermal process,they require large instruments and are often difficult to monitor in situ in real matrix.Based on this,this thesis introduces a method for in-situ monitoring the photothermal process of photothermal composites based on the silica-based microfiber interferometer,which relies on detecting the local refractive index(RI)changes or temperature changes of the nanocomposite matrix to monitor the photothermal dynamic process.The main research contents are as follows:1.Microfiber M-Z interferometer was used to monitor the photothermal dynamic process of Graphene oxide(GO)-based temperature-sensitive composites.Graphene oxide-poly(N-isopropyl acrylamide)(GO-p NIPAM)and silver@graphene oxide-poly(N-isopropyl acrylamide)(Ag@G-p NIPAM)were taken as typical photothermal composites,basing on the temperature response of poly(N-isopropylacrylamide)(PNIPAM)with lower critical solution temperature(LCST).The optical microfiber interferometer was employed to capture the morphological changes of the molecules inside the composite material caused by the photothermal effect,so as to obtain thephotothermal dynamics process of the composites.2.In-situ monitoring of photothermal dynamics of gold nanostructure-molybdenum disulfide composites based on optical microfiber M-Z interferometer.The photothermal-induced reconstruction process of the composite was tracked by in-situ sensing the local temperature change and the temperature change rate of the composite with the optical microfiber interferometer,accompanied by the transmission electron microscope images.The above work can realize in-situ monitoring of the photothermal dynamics process of nanocomposites through the optical microfiber interferometer.This method is simple and low-cost,and it is expected to be an alternative means to study the internal structure change process of nanocomposites.The above work also provides new ideas and theoretical basis for the design and development of NIR photothermal nanomaterials.