Aceite de almendras dulces: extracción, caracterización y aplicación

The extraction of sweet almond oil at room temperature and reflux is an easy and accessible procedure to obtain natural oil in a laboratory scale for undergraduates' courses in chemistry and related areas. In this paper we show how the utilization of Fourier Transform Infrared (FTIR) spectroscopy can be interesting in the qualitative analysis of these oils. We also propose the preparation of three different skin creams to demonstrate the effective uses of sweet almond oil in cosmetics and pharmaceutical fields.

Extração e purificação de clorofila a, da alga Spirulina maxima: um experimento para os cursos de química

This work describes a simple and economical experiment for the extraction and purification of chlorophyll a from Spirulina maxima. Extraction and purification of natural compounds can be considered one of the most illustrative experiments that can be performed in Organic Chemistry courses. Particularly, the chromatography of dyes and pigments allows students to have a better comprehension of the chromatography separations. These compounds represent an important class of organic pigments applied in pharmaceutical, cosmetic, detergent compositions, and various other fields and can be extracted from plants and algae. To extract, separate and purify chlorophyll a from associated pigments such as xanthophylls, carotenes, and pheophytins, very costly processes are reported. The present approach is perfectly adequate for use in Chemistry experiments for undergraduate students.

Produtividade em pesquisa do CNPq: análise do perfil dos pesquisadores da Química

The profile of the CNPq Research Productivity Program in Chemistry was studied using the Plataforma Lattes curricula of all researchers with grants in effect as of March 2009. Most of them are male (67.2%), working in Federal Universities (59.4%) and located in Southeastern Brazil (63.7%). There is no evident homogeneity among researchers of the same level/category concerning the productivity criterions used (the H index and the scientific productivity of the last five years). CNPq and the Chemistry Assessor Committee have been focusing on making their judgments unbiased, by using quantitative parameters, but such overlap is still noticeable.

Como pesquisar o perfil patentário de um fármaco: o caso Efavirenz

The importance of the patent system for researchers, especially in chemistry and related areas, is undeniable. In this context, this work aims at guiding the search in major search engines of patents, in order to map the patents related to a specific chemical compound and identify the material that each patent document protects. In this case study, it was performed a search for the drug efavirenz to demonstrate how to conduct a literature search in patents databases and to map patent applications at national and international levels.

O uso de aparelhos de micro-ondas domésticos em aulas experimentais de química orgânica: nitração de salicilaldeído

The use of microwave in chemistry has known benefits over conventional heating methods, e.g. reduced reaction times, chemical yield improvement and the possibility if reducing or eliminating the use of organic solvents. We describe herein a procedure for the nitration of salicylaldehyde in water using a domestic microwave oven, which can be used as an experiment in the undergraduate chemistry laboratory. The experiment involves safe and rapid preparation and identification of the position isomers by thin layer chromatography and 1H NMR, or by their melting points.

Síntese de fotoprotetores e sua imobilização em poli(metacrilato de metilo): um projeto integrado de química orgânica, química de polímeros e fotoquímica

Dibenzalacetone and other aldol condensation products are known sunscreens commonly used in cosmetics. This type of compounds can easily be prepared in an Organic Chemistry Lab by reaction of aldehydes with ketones in basic medium. These compounds can be incorporated in poly(methyl methacrylate) and used as UV light absorbers, for example in sunglasses. This project has the advantage of using inexpensive reagents which are readily available in Chemistry Laboratories. This experiment can also be a base starting point for discussions of organic, polymer and photochemistry topics.

Estudo de casos na formação de professores de química

Case studies were used as teaching methodology in Chemistry teacher education. The reffered methodology consists of teaching principles of Physical Chemistry associated to biodiesel theme in an undergraduate chemistry course with pre-service teachers, who are temporary teachers in high schools in Fortaleza, Ceará, Brazil. The results showed that the methodology was well accepted by the pre-service teachers. The concepts related to Chemistry, by means of multidisciplinary science, technological and social approaches make it able to overcome and improve the present situation in public schools and provided the learning of the chemistry concepts by high school students.

Aspectos históricos dos cursos de licenciatura em química no Brasil nas décadas de 1930 a 1980

This article describes some historical moments in the establishment and development of chemistry teacher's training courses since 1930, with the creation of universities in Brazil, until 1980. Correlations between educational and political questions that influenced the directions taken for the formation of chemistry teachers in Brazil are discussed. From a review of the bibliographical sources available, we revisited stances of discussions on public policies related to science teacher's formation in general and in chemistry, particularly, in order to provoke a reflection on what challenges and prospects exist in the current scenario of undergraduate chemistry education in Brazilian universities and colleges.

Artigos da revista Ciência Hoje como recurso didático no ensino de química

This paper presents the results from the selection and analysis of Ciência Hoje articles published from 2004 to 2009 with the aim to discuss some of their features which can assist teachers in chemistry teaching. Therefore, the articles were analyzed according to their content and format based on an analytical tool proposed by Kawamura and colleagues. The results indicate that this magazine offers a reasonable collection of articles related to chemistry with a variety of contents and approaches.

Recuperação de chumbo, mercúrio e elementos dos grupos 4 a 7 da tabela periódica de seus resíduos

This work shows routes to recover some elements from their laboratory wastes and broken apparatus (thermometers and densimeters). Most elements chosen present a chemical behavior in aqueous solution which is not currently studied in the ordinary experimental classes. The routes were based on the previous knowledge of the qualitative composition of the wastes treated. Wastes containing chromium were the most difficult to treat. The elements were recovered in good yields and can be reused in new experiments. This work was a very good experience in chemistry for students and shows the need of managing wastes for a better environment.

Vinte anos de química verde: conquistas e desafios

The year 2011 has been chosen as the International Year of Chemistry and it will focus on the importance of sustainability in the field of chemistry. The program "Alternative Synthetic Routes for the Prevention of Pollution", implemented 20 years ago in the USA marked the official start of Green Chemistry. Currently, many lines of research in chemistry observe and comply with the concepts of green chemistry contributing significantly to the advancement of science. Hence, the objective of this paper is to present an overview of published papers on Green Chemistry in national and international journals from the "CAPES Portal Database", from 1997 to May 2010.

Tratamento de resíduos de corante por eletrofloculação: um experimento para cursos de graduação em química

This paper describes the use of a simple experiment of electroflocculation for classroom in Chemistry. Parameters such as electrode material, current density and temperature direct influence the process efficiency. Due to the process low cost and efficient color removal, the methodology proposed has shown good potential for use in wastewater treatment. In addition, the proposed experiment allows discussion about environmental electrochemistry, introduction to concepts of water contamination by industry and university, and also about different alternatives in wastewater treatment used nowadays. Finally, the very easy operation make possible to easy adapt this experiment for high school and elementary school.

Avaliação do efeito de gases poluentes na corrosão metálica: um experimento para o ensino da corrosão

In this work one proposes a didactic experience to simulate atmospheric corrosion of copper and nickel, due to sulfur dioxide presence. This is an opportunity to understand some basic aspects of atmospheric corrosion, by using fundamental concepts in chemistry, reactions of extraction and characterization of pollutants, as well as their participation in corrosion process. This subject opens a space for discussion about necessity of pollutant gases emissions control for preservation of materials and the environment.

Noções dos futuros profissionais da Química. eixo I: liberdades e demandas da pesquisa

During the schooling process, images are constructed about research and researcher activities. Based on that, a questionnaire has been structured based on three thematic axes that tend to represent some of the discussions about the translations that integrate the scientific activity collectively: freedom and demands from research, academia as a mediator and science disclosure. The objective of the instrument was to map some notions from entrants to the graduation course in Chemistry in the metropolitan region of Porto Alegre about what, based on the contributions by Bruno Latour, was called vascularizations of research.

Investigando a presença da história da ciência em livros didáticos de Química Geral para o ensino superior

This paper aims at analyzing the history of science content of three general chemistry textbooks used in Brazilian universities: the translations of Kotz and Treichel's Chemistry & Chemical Reactivity, Atkins and Jones's Chemical Principles, and Garritz and Chamizo's Química. Results revealed different trends for the inclusion of history of science in chemistry teaching. Kotz & Treichel and Atkins & Jones used history mainly as curiosity and ornament. Garritz & Chamizo adopted the historical approach as one of the organizing axis of their textbook. Nevertheless, the historical content of the three textbooks may be criticized from current historiographical standpoint.