Research On Electromagnetic Heating Effect Of Nanomaterials

With the development of nanoscience and nanotechnolgoy,nanomaterials are being investigated for the use in electromagnetic hyperthermia for cancer therapy in recent years. One of the key issue of this modality is electromagnetic heating effect of nanomaterials and its quantitative description.In the literature, many frequency bands are studied, such as light waveband, 13.56 MHz medical radiofrequency waveband, 2.45 GHz and 5.8 GHz microwave bands. Also, a range of nanomatrials have been investigated, for instance, gold nanoparticles, silver nanoparticles,magnetic nanomaterials, carbon nanotubes. The heating modalities employed include laser heating, electric heating and magnetic heating.The aim of this project is to systematically investigate the heating effect, including the following parts:1. The fundamental properties of nanomaterials are discussed, with the principle of photothermal effect, electric heating effect and magnetic heating effect of nannomaterials being investigated. The principle of the photothermal effect of nanomaterials is explained from the perspective of the Mie's theory. The thermal effect model of several nanomaterials is bult.2. A laser heating system is built. The heating experiments are conducted on deionized water, silver nanoparticles, gold nanoparticles and silver nanowire solution using a 450nm laser and 532nm laser. The thermal effects of the solutions are compared and analyzed, with a model proposed to shed some light on the phenomenon of thermal stratification.3. A 13.56 MHz radio frequency heating system is designed and implemented. The electric field strength in the parallel capacitive plate is measured. Deionized water, silver nanoparticle, gold nanoparticle and silver wire solutions are heated. The properties of concentration and conductivity dependent heating of the solutions are analyzed.It is seen from the experimental results that silver nanowires do not contribute too much to the heating effect neither for laser heating or for RF heating. It is also shown that non-uniform temperature distribution of silver nanoparticle solution and gold nanoparticle solution can be observed, and that the temperature rise of the solutions increases with the concentration of the solutions. Overall, the heating effect of gold nanoparticle solution is better than that of silver nanoparticle solution. At 13.56MHz, the temperature rise of the two solutions also increases with the conductivity of the solutions, but the heating effect of sliver nanoparticle solution is better than that of gold nanoparticle solution.