Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil.
Departamento de Física, Universidade do Estado do Rio Grande do Norte, 59610-090, Mossoró, RN, Brazil.
Sci Rep. 2021 Jun 4;11(1):11867. doi: 10.1038/s41598-021-91334-9.
We investigate the magnetic nanoparticles hyperthermia in a non-adiabatic and radiating process through the calorimetric method. Specifically, we propose a theoretical approach to magnetic hyperthermia from a thermodynamic point of view. To test the robustness of the approach, we perform hyperthermia experiments and analyse the thermal behavior of magnetite and magnesium ferrite magnetic nanoparticles dispersed in water submitted to an alternating magnetic field. From our findings, besides estimating the specific loss power value from a non-adiabatic and radiating process, thus enhancing the accuracy in the determination of this quantity, we provide physical meaning to a parameter found in literature that still remained not fully understood, the effective thermal conductance, and bring to light how it can be obtained from experiment. In addition, we show our approach brings a correction to the estimated experimental results for specific loss power and effective thermal conductance, thus demonstrating the importance of the heat loss rate due to the thermal radiation in magnetic hyperthermia.
我们通过量热法研究了非绝热和辐射过程中的磁性纳米粒子热疗。具体来说,我们从热力学角度提出了一种磁热疗的理论方法。为了测试该方法的稳健性,我们进行了热疗实验,并分析了分散在水中的磁铁矿和镁铁氧体磁性纳米粒子在交变磁场下的热行为。根据我们的发现,除了从非绝热和辐射过程中估计比吸收率值,从而提高对该量的确定的准确性之外,我们还为文献中发现的一个仍未完全理解的参数——有效热导率赋予了物理意义,并揭示了如何从实验中获得该参数。此外,我们还表明,我们的方法对比吸收率和有效热导率的实验结果进行了修正,从而证明了在磁热疗中由于热辐射导致的热损失率的重要性。