Nanotechnologies of the Treatment and Production of Complex Transition Metal Oxides with High Photothermal Effect

Abstract

The ability to create biofunctional nanoparticles of A_хO · BО_y complex oxides (A = K, Н, Na; B = Ti, Mo, W; 0 < x < 2; y = 2, 3) produced via self-propagating high-temperature synthesis is considered in the present study. Nanoparticles (5–10 nm) and stable aqueous colloidal solutions on their basis are obtained via fragmentation, nanoparticle size separation, magnetic separation, and functionalization with biocompatible gels (starch and polyvinyl pyrrolidone). The optical methods for controlling nanoparticle sizes in solution are developed as well. The optical absorption spectra of colloidal solutions of K_xWO₃ nanoparticles are acquired at wavelengths of λ =1.45 and 1.56 μm and the monochromatic absorption coefficients of bronze nanoparticles are measured at colloid concentrations of 10 to 35 mg/mL. Evaluation of photothermal effects reveals that the greatest impact of laser radiation (λ = 1.45 μm) is achieved in K_0.4WO₃ nanoparticles. Powdered K_xTiO₂ complex oxide subjected to mechanical treatment is found to gain magnetic properties. The electrical conductivity of K_xTiO₂ powder is measured versus temperature over a range of 25–270°С and is shown to be an order of magnitude greater with rising temperature to ~200°С. Data gathered in this study can be used for creation of biofunctional nanomaterials with high photothermal effects.