The Fabrication Of Polymer/Gold Nanoparticles Hybrid Rainbow Films And Their Intelligently Controllable Chromic Properties

Two-dimensional(2D)luminescent films are a kind of smart materials that can exhibit certain colour under external stimuli(such as light and electricity).The fabrication and applicatons of 2D luminescent films are one of the most important research topics in the field of films.Recently,a variety of luminescent materials including organic small molecule luminophores,fluorescent conjugated polymers,quantum dots(QDs),and semiconductor nanoparticles(NPs)were used to fabricate 2D luminescent films.Due to the limitation in the structures and the physicochemical properties,the obtained 2D luminescent films have several shortages:(1)the films are fragile and difficult to be transferred;(2)the variation of the color is limited;(3)it is difficult to precisely change the color because of the discontinuous variation of the color.Nobel metal NPs have excellent optical properties.Many previous works have pointed out that the unique optical properties of nobel metal NPs strongly depended on their physical parameters,such as size,shape,and composition.Precisely controlling these parameters can give rise to the special optical properties.Due to this,nobel metal NPs are promising candidates for the fabrication of the 2D rainbow films.It is well-known that the color of the nobel metal NPs can be varied by changing the ambient enviroment.In this thesis,by changing the direction of the polarized light,the variation of the color from NPs was achieved,which was attributed to the selective excitation of NPs.Due to the continuous variation of the plasmonic intensity,more different color could be acquired.Besides,in order to obtain a freestanding rainbow film,the polymers were used as the base materials.The obtained organic/inorganic rainbow composite films can be exploited for optical devices.Combining polymers with nobel metal NPs,three works were carried out as follows:1.The polyving akohol(PVA)/Au nanorods(NRs)composite film was fabricated by using the solvent evaporation method.The Au NRs were assembled into ordered 3D arrays via streching the composite film,and then it showed different color by rotating the polarizer.The composite film was used to construct the homemade traffic light due to its unique optical properties.2.The Au-Ag core-shell NRs that had broad plasmon resonamce absorption band were synthesized.Combining PVA with Au-Ag core-shell NRs,we successfully fabricated the PVA/Au-Ag NRs composite rainbow films.The Au-Ag NRs were assembled into ordered arrays by streching the composite films.The intensity of the plasmon resonance absorption peaks could be varied in the range of the visible region.The composite films could show abundant color by changing the trichromatic ratio.3.The reducing agents,dopamine dithiocarbamate(DDTC),were anchored on the surface of the Au seeds via the strong "Au-S" bonds.Because of this,the Ag ions were inhomogeneously reduced.The Au-Ag core-shell superstructure NPs with discontinuous shell were synthesized by controlling the growth modes of the Ag atoms.Then,the effects of the amounts of the AgNO3 on the shape of NPs were discussed.In order to study the Surface Enhanced Raman Scattering(SERS)properties of the Au-Ag superstructure NPs,the rhodamine 6G(R6G)was used as the analytical molecular.The experimental results indicated that the Au-Ag.superstructure NPs had high performance SERS due to the sharp superstructure.