Viviane G. P. Ribeiro

Thermo-oxidative evaluation of new cardol derivatives as antioxidants for mineral oils

In this study, the thermo-oxidative stability of two new phosphorylated derivatives of cardol, a compound from the cashew (Anacardium occidentale L.) industry waste CNSL (cashew nutshell liquid), were evaluated. The antioxidant capacity of these new molecules upon two mineral oils, NH10 and NH20 were also studied by thermogravimetric analysis (TG/DTG), observing the onset and offset temperatures variation. The results showed that both MP and DP Cardol increased considerably the onset and offset temperatures of NH10 and NH20 oils.

Magnetic nanoparticles coated with anacardic acid derived from cashew nut shell liquid

Magnetic nanoparticles functionalized with biomolecules have received special attention due to their various biomedical applications, such as drug delivery and magnetic hyperthermia treatment for cancer. In this study, we present the synthesis and characterization of new nanoparticles coated with anacardic acid derived from cashew nut shell liquid. The results showed that Fe3O4 nanoparticles coated with anacardic acid (AA-MAG) have superparamagnetic behavior and the magnetization is almost equal when compared with the pure Fe3O4. This coating provides stability by preventing the aggregation nanoparticles without losing its magnetization potential. The AA-MAG demonstrates excellent and fast magneto-temperature response which can be used as high-performance hyperthermia agents.

New ZnO@Cardanol Porphyrin Composite Nanomaterials with Enhanced Photocatalytic Capability under Solar Light Irradiation

This work describes the synthesis, characterization, and photocatalytic activity of new composite nanomaterials based on ZnO nanostructures impregnated by lipophlilic porphyrins derived from cashew nut shell liquid (CNSL). The obtained nanomaterials were characterized by X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and steady-state photoluminescence spectra (PL). The results confirm nanostructures showing average diameter of 55 nm and an improved absorption in the visible region. Further, the FTIR analysis proved the existence of non-covalent interactions between the porphyrin molecules and ZnO. The photocatalytic activity of prepared photocatalysts was investigated by degradation of rhodamine B (RhB) in aqueous solution under visible light irradiation and natural sunlight. It was demonstrated that the photocatalytic activity increases in the presence of the porphyrins and, also, depends on the irradiation source. The development of composite photocatalysts based on porphyrins derived from CNSL provides an alternative approach to eliminate efficiently toxic wastes from water under ambient conditions.

Developing eco-friendly methods for purification of compounds derived from hydrogenated cardanol

ABSTRACT The present work made a comparative study between two purification methods, column chromatography and recrystallization, for compounds derived from cardanol, a by-product of the cashew industry (Anacardium occidentale L.). The compounds were successfully synthesized and characterized, focusing our attention to results obtained in terms of yield, purity, generation of solid waste and amount of solvent used in each purification process. For all the synthesized compounds, the amount of solvent used was greatly reduced in the recrystallization process, with purities above 80%, when compared to chromatographic column, which still demands high amounts of eluent.

Theater in Chemistry Teaching: Experience Report

O Ensino de Quimica no contexto atual exige que educadores busquem cada vez mais novas ferramentas de ensino. A forma tradicional defronta-se com a resistencia e apatia dos alunos. A fim de modificar essa tendencia, muitas metodologias interessantes vem sendo propostas. Dentre elas, uma que vem ganhando bastante destaque, e o teatro cientifico, que une arte e ciencia no palco. Nesta perspectiva, o presente trabalho tem como objetivo relatar experiencias envolvendo teatro cientifico no Ensino de Quimica, atraves de 6 montagens cenicas, decorrentes de tres anos de pesquisas e divulgacao cientifica teatral em parceria com a Seara da Ciencia da Universidade Federal do Ceara (UFC) e outras Instituicoes de Ensino Superior do pais. As pecas produzidas foram: “ A Liga da Ciencia”, “O Alquimista”, “Somos o que Comemos?”, “Lampiao e Maria Bonita em Busca da Quimica do Amor”, “Os Vingadores Quimicos” e “Doutorado em Quimica do Amor”. Para analisar as contribuicoes pedagogicas advindas dessa experiencia utilizou-se questionarios, debates e comentarios com a plateia. Os resultados apontam que atraves deste meio de divulgacao cientifica foi possivel estimular o aprendizado da Quimica e a motivacao dos alunos.

Synthesis, Characterization and Dielectric Properties of New 5-(4-Hydroxyphenyl)- 10,15,20-tri-4-(2-(3-pentadecylphenoxy)ethoxy)phenyl porphyrin and Their Ni, Co and Cu Complexes

New asymmetric cardanol-based porphyrins, free-base and coordinated with Ni, Co and Cu, were synthesized and completely characterized as A3B type. Such porphyrins were obtained aiming improved solubility in polar solvents due insertion of an −OH phenolic group. Their thermal and dielectric properties were also evaluated. Changes in the synthetic route reduced the reaction time and improved the yields of the aldehyde precursor obtainment. Electronic absorption spectra of the new porphyrins in CH2Cl2, EtOH and acetone, indicated a decrease in the e (molar absorptivity) values with increasing solvent polarity, except for the nickel complex which, in acetone, showed a slight increase of 2% in the e value. The dielectric measurements showed that the conductivity (σ) and the loss tangent (tan δ) increased with frequency, but the permittivity (e’) decreased. The results showed that the coordination of the porphyrin promoted a significant change in thermal and dielectric properties, specially for to the Ni-complex compound, which presented the best dielectric properties with interesting values of permittivity and loss tangent at 100 MHz (19.46 and 0.011 a.u., respectively).

The Training of Licensed in Chemistry in the UFC Discussed in the Distance Education and Presential Modalities

Currently, distance learning is being adopted strategically to expand higher education in the country, that in addition to reduce geographical boundaries, eases studies. This paper describes the first overview of the Chemistry course offered by the Federal University of Ceará (UFC) in the distance education model, after four years of existence, seeking to assess its evolution, the profile and the degree of student satisfaction. A comparison with its analogue in presential modality also part of the scope of work within feasible criteria of comparison. Initially, a questionnaire was applied with students who were enrolled in the virtual learning system. The data obtained in this study were compared with data obtained from the coordination of the degree course of Chemistry presential. The results showed that in the profile of the distance course prevails older students, from public school and workers. In both of modalities, students have declared to be satisfied with the progress of course, despite challenges

A Formação do Licenciado em Química na UFC Discutida nas Modalidades Ensino à Distância e Presencial

Atualmente, o Ensino a Distância vem sendo adotado estrategicamente para expandir o ensino superior no pais, que alem de reduzir limites geograficos, flexibiliza os estudos. O presente trabalho descreve o primeiro panorama do curso de Licenciatura em Quimica Semipresencial da UFC, apos quatro anos de existencia, buscando avaliar sua evolucao, o perfil e o grau de satisfacao dos alunos. Uma comparacao com seu analogo na modalidade presencial tambem fez parte do escopo do trabalho, dentro de criterios factiveis de comparacao. Inicialmente, foi aplicado um questionario com os estudantes matriculados no sistema virtual de aprendizagem. Os dados obtidos neste estudo foram comparados com os dados obtidos junto a coordenacao do Curso de Licenciatura em Quimica presencial. Os resultados mostraram que no perfil do curso a distância prevalecem alunos mais velhos, da escola publica e profissionalmente ativos. Em ambas as modalidades, os estudantes declararam-se satisfeitos com o andamento do curso, apesar dos desafios encontrados. DOI: 10.5935/1984-6835.20130068