Preparation Of Gold Nanorods-Silicone Hybrid Film Materials And Optical Limiting Property

With the improvement of laser weapon automation and development of the short pluse of tunable laser, it is necessary to prepare new type laser protection device with wide wavelength, high speed and transparency. Optical limiting materials used in laser protection have been becoming more and more popular in the field of laser research recently. Optical limiting materials toward laser protection showed significant importance and became an interesting topic in recent laser research field. Particularly, nanomaterials have attracted much attention as a new kind of optical limiting materials, in which the optical limiting behavior of Au and Ag nanoparticles is demonstrated to be closely related with the surface plasmon resonance of metal nanoparticles. Because Au nanorods have the special surface Plasmon resonance(SPR) chracter, the transversal SPR resonance of Au nanorods absorbance is at about 520 nm and the longitudinal SPR resonance is tunable in a wide range. Therefore, when they are used as optical limiting materials, the protection against tunable laser weapon can be realized.In this paper, gold nanorods with different aspect ratios were prepared by controlling the amount of the silver nitrate and its surface resonance absonbance and optical limiting property were studied. In order to have a good stability,the surface modification of gold nanorods with mPEG-SH or SiO2 was carried out,which provided a good nanorod dispersion in polydimethylsiloxane prepolymers. Then the gold nanorods doped organosilicone films were prepared after vulcanization, whose optical nonlinearity and optical limiting properties were studied and optical limiting mechanism was analysized. The results showed that gold nanorods with different aspect ratios were successful prepared, whose aspect ratios ware from 2.0 to 4.5. The surface-modified gold nanorods had good dispersion and stability in orgnic solution and prepolymer. To the 532 nm laser, silicone films doped with gold nanorods have the optical limiting characteristics. and the optical limiting properties were related with the concentration and the aspect ratios of the gold nanorods. The optical limiting property is attributed to the excited state of carrier absorption(reverse saturable absorption). To the lase having the tunabe wavelength from 690 nm to 1024 nm, the results also indicated that if the the composite materials have a strong absorbance at some waveband other than the maximum abosrbance peak, the gold nanorods / silicon rubber sheets also showed good optical limiting property in that waveband. This work will not only provide basic data for new(especial wide range) solid optical limiting device, but also have an important the theory and application value.