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In this work, we performed a comparison study between the kinetic parameters associated to the KCl:Eu2+ crystal, which is excited separately with ultraviolet light and a source of beta particles. To obtain the kinetic parameters easily (peak and trap parameters), the glow curve deconvolution technique was implemented in a novel and friendly spreadsheet, the KCl:Eu2+ crystal was used as an example. Also, was employed a new mathematical equation to realize the glow curve deconvolution (based on Kiti’s original expressions) and was designed a low cost electronic configuration was implemented. In literature it is reported that, regardless of the excitation source, the glow curves of KCl:Eu2+ crystal have a similar shape. However, when the overlapped peaks are analyzed in detail (using their kinetic parameters), only some peaks of both glow curves have the same kinetic parameters. Some peaks appear only when beta particles are used, while other peaks appear only when UV light is used. The similarity between the glow curves, produced with ionizing and non-ionizing radiation, could indicate a common damage mechanism behind both irradiation processes.

Silver nanoparticles were synthesized in aqueous solution using an ecofriendly, fast, and easy photochemical technique through the use of Albizia lebbeck (L.) Benth seed (ALS) extract and sunlight. The phytochemical screening of ALS extract revealed the presence of reducing carbohydrates, and saponins. Also, infrared spectroscopy analysis of the ALS extract confirms the presence of functional groups, characteristics of these compounds. The experiments were conducted near noon during winter by exposing aqueous mixtures of silver nitrate and ALS extract to sunlight at 25 °C. The nanoparticles were characterized by optical absorption spectroscopy, Fourier-transform infrared spectroscopy, and scanning transmission electron microscopy. The nanoparticle formation was evaluated by following the temporal evolution of the absorbance. This data was analyzed using first-order kinetics, finding good correlation to the experimental data. The nanoparticle micrograph analysis shows narrow size distribution and acceptable polydispersity indices. The sunlight driven synthesis of silver nanoparticles using ALS extract is more effective to produce small spheroidal AgNPs than sodium citrate. In addition, ALS extract inhibits the growth of nanoparticles with different morphologies, even when both reducing agents are incorporated at the same time. The proposed methodology presents a reliable and sustainable way to obtain small-sized silver nanoparticles according to the principles of green chemistry.

Silver nanoparticles were synthesized by direct exposure of mixtures of silver nitrate and sodium citrate to sunlight. The reactions were performed near noon, at ~32 °C during winter, varying the precursors ratio. Nanoparticles were characterized by optical absorption spectroscopy, scanning transmission electron microscopy, as well as proton nuclear magnetic resonance spectroscopy. The kinetic of nanoparticles formation was followed by the temporal evolution of absorbance, and analyzed by using Finke-Watzky two-step model, showing good fit to experimental data. A possible reaction mechanism for the formation of silver nanoparticles is proposed based in the experimental results and the kinetic analysis. This mechanism consists of multiple stages, where the formation of complexes between citrate and cationic silver dimers limits the nucleation process and determines the final size and morphology of the nanoparticles. The proposed approach offers a simple, economic and ecological route for the synthesis of silver nanoparticles.