Oficina de cianotipia como recurso de aprendizado de conceitos da química.

Abstract

Cyanotype is a photographic technique that uses chemical reagents in the image creation process. When mixing two reagents containing iron (potassium ferricyanide and ferric ammonium citrate) and subjecting the mixture, previously applied to a suitable substrate and containing the objects chosen for creating the image, to UV radiation, a photochemical reaction occurs that results in the formation of Prussian blue (iron (III) hexacyanoferrate (II)), which is a substance insoluble in water. The technique includes concepts of chemical reactions, solutions, acidity and basicity, photochemical reactions and chemical kinetics. Therefore, the use of the technique in the form of a pedagogical workshop is interesting, since cyanotype allows the construction of learning in an active and dynamic way, considering its experimental nature and the amount of chemical concepts present in it. According to Gérard Vergnaud's theory of conceptual fields, in order to learn, the individual needs to form conceptual fields, which are acquired through the individual's exposure/confrontation of concepts involved in a situation and over a period of time. In this sense, the main objective of the research was to analyze the learning of high school students from a cyanotype workshop, using the practice as a tool for teaching fundamental concepts of chemistry, such as chemical reactions, solutions, acidity and basicity, and chemical kinetics. sense, the cyanotype workshop was able to expose the students to different situations and concepts, allowing the conceptual fields to be established and the knowledge to be fixed in a theoretical-practical way. Thus, the workshop was divided into five moments: on the first day, the first cyanotype practice was carried out; on the second and third days, practices and theoretical insertions were carried out on the chemical concepts present in cyanotype; on the fourth day, the cyanotype workshop was held again considering the conceptual fields acquired by the students; and on the last day, the workshop was concluded, with the artwork produced and the students' evaluation of the workshop. The evaluation of the acquired concepts was done through the creation of mental models after the two cyanotype practices were carried out. The analysis of the mental models produced in both moments showed the enrichment of textual and visual elements comparing the models obtained in the second moment in relation to the first. In addition, two word clouds were created referring to the mental models, whose elements reported in the form of words brought an increase in chemical concepts involved in cyanotype in the second model. However, the models and, consequently, the word clouds still brought elements characteristic of experimental procedures and not conceptual fields, evidencing that there is a need to work with the students on reporting situations in the form of conceptual models in more moments. Finally, the students reported that the workshop contributed positively and significantly to the acquisition of conceptual fields through the proposed practices and didactics used, since they actively participated in the experiments, were able to be heard and expressed their conclusions, doubts and opinions.