The photothermal therapy (PTT) technique is regarded as a promising method for cancer treatment. However, one of the obstacles preventing its clinical application is the non-degradability and biotoxicity of the existing heavy-metal and carbon-based therapeutic agents. Therefore, a PTT material with a high photothermal efficiency, low toxicity, and good biocompatibility is urgently wanted. Herein, we report a titanium oxide-based therapeutic agent with a high efficacy and low toxicity for the PTT process. We demonstrated that Magnéli-phase Ti8O15 nanoparticles fabricated by the arc-melting method exhibit >98% absorption of near infrared light and a superior photothermal therapy effect in the in vivo mouse model. The Ti8O15 nanoparticle PTT material also shows a good biocompatibility and biosafety. Our study reveals Magnéli-phase titanium oxide as a new family of PTT agents and introduces new applications of titanium oxides for photothermal conversion.
Perspectives and limits of the application of the photothermal technique are given for the measurement of absorption, thermal, and thermoelastic properties in thin films. The peculiarities of this technique in the frequency and time domains are discussed in some detail, and selected important results with respect to laser damage studies in optical coatings are pointed out. Emphasis is placed on the absolute measurement of both optical and thermophysical properties in dielectric materials in thin-film form and, also, on the influence of both absorption and changed thermal properties in thin films on their thermally induced laser damage resistance. 相似文献
Controlling the orientation of highly periodic supramolecular structures of small feature size (<5 nm) is the first step for potential applications in optoelectronics, membranes, and template synthesis. A new method, namely, laser photothermal writing, is introduced to direct the orientation of supramolecular columns over a large area. Supramolecular columns consisting of taper-shaped molecules with long aliphatic tail groups are aligned by a thermal gradient, which is induced by exposing a near-infrared laser beam to a graphene photothermal conversion layer. Intriguingly, the orientation of the supramolecular columns can be controlled in a facile manner by varying the laser scanning velocity and power. In contrast to previous methodologies for aligning supramolecular structures, this laser photothermal mechanism allows the directional and continuous alignment of supramolecular structures over an arbitrary large area with the easy control of laser irradiation. Besides, the laser process also enables area-selective orientation of the supramolecular structures for device-oriented nanopatterning. 相似文献
A novel comparative method has been developed at the National Physical Laboratory (NPL) to measure the thermal diffusivity of semi-infinite samples without a priori knowledge of the boundary conditions. It is based on photothermal radiometry, and involves the detection of modulated thermal radiance from a target irradiated by a modulated, focused diode laser beam with a power of 1W. The technique exploits the fact that the frequency response of the surface temperature modulation scales with thermal diffusivity for a given target geometry (this is a fundamental property of the heat diffusion equation). In the process two samples are measured, one of which is known, and the diffusivity of the second material is derived from scaling the results over frequency. Measurements on samples of platinum and Inconel have shown the validity of the methodology but also raised issues concerning the difficulty of accurate measurements due to surface coatings or roughness.Paper presented at the Fifteenth Symposium on Thermophysical
Properties, June 22--27, 2003, Boulder, Colorado, U.S.A. 相似文献
Photothermal deflection is among the most sensitive techniques available for the measurement of small, localized heating, such as that from the absorption of a focused laser beam in the bulk or surface of a material. A thin optical probe beam is deflected by the refractive-index gradients arising from the heating, and the size of the deflection provides the measure of the heating. We describe the use of a critical fluid to enhance the sensitivity of the technique by at least 103. The diverging coefficient of thermal expansion of a pure fluid near the gas-liquid critical point gives this dramatic enhancement when used as a sensing fluid. With sensitivity calculations and measurements in supercritical xenon,Tc16.7C, we show that the noise floor of our apparatus when used for surface absorption measurements corresponds to a fractional power absorbed ofPabsorbed/Pincident=10–10, while the noise floor for bulk measurements corresponds to an absorption coefficient=10–13 cm–1. We report the first measurements of the surface absorption of superpolished surfaces of sapphire and fused quartz,Pa/Pi2×10–5, and the first measurements of the bulk absorption in xenon,2×10–6 cm–1. We also show how the present work fits into the current status of absorption measurement techniques and describe the effects of the peculiar properties of critical fluids on the execution of photothermal deflection measurements. 相似文献