Obtenção E Caracterização De Complexo De Inclusão De ?-Ciclodextrina E Eugenol / Preparation And Characterization Of ?-Cyclodextrin Inclusion Complex Of Eugenol

O eugenol é um fenilpropanóide presente em óleos essenciais de diversas plantas, cabendo destaque ao Cravo-da-Índia. Esta substância possui considerável importância farmacológica devido às suas atividades antioxidantes, porém, sua alta volatilização e instabilidade físico-química a fatores ambientais (luz, oxigênio e calor) têm dificultado seu uso tal qual nas formulações farmacêuticas. Neste contexto, buscou-se no presente trabalho produzir complexos de inclusão de eugenol em ?-ciclodextrina a fim de amenizar tais limitações. A complexação foi realizada por meio de coprecipitação e evaporação do solvente, em proporção molar de eugenol:?-ciclodextrina (1:1). Os complexos foram caracterizados por Difratometria de Raios-X (DRX); Espectroscopia de Infravermelho por Transformada de Fourier (FTIR). Os resultados revelaram que é possível caracterizar a interação hóspede/hospedeiro e, portanto, o êxito no processo de complexação, a partir de dados difratométricos (DRX) e espectrais (FTIR), o que torna o uso destas duas técnicas adequado para pesquisas no desenvolvimento de compostos com interesse biológico

Mg-bentonite in the Parnaíba paleozoic Basin, northern Brazil

Bentonite deposits are rare in Brazil and most of their production comes from a single region. A new bentonite occurrence, the Formosa bentonite from northern Brazil, is described here. The occurrence is associated with altered Mesozoic volcanic rocks of the Parnaíba Sedimentary Basin, one of the largest continental flood basalt (CFB) provinces on Earth. The purpose of the present study was to evaluate the physical and chemical properties of a new smectite-bearing deposit in Brazil. Analysis has shown that the major mineral present in the Formosa bentonite is a dioctahedral smectite along with minor amounts of hematite, K-feldspar, and kaolinite. Quartz is absent. A Li-saturation test (Hofmann-Klemen treatment) revealed a montmorillonite smectite; large interlayer-Mg contents revealed by N adsorption/desorption and cation exchange capacity results suggested a Mg-bentonite. This characterization helped to explore the structure-functionality (reactivity) relationship and to develop index tests for industrial applications and the research of new materials. Use of this material as a desiccant-grade bentonite is envisaged (desiccant-grade bentonites contain Mg and/or Ca as the dominant exchangeable cations), or it could be activated with Na for use in many industrial applications (e.g. as a drilling fluid or for pelletizing iron ore). The large areal occurrence of the flood basalts suggests the possibility of very large deposits of these bentonites, a promising new exploration target for this class of industrial minerals in northern Brazil

Hydrothermal synthesis of basic sodalite from a thermically activated kaolin waste

Basic sodalite was successfully synthesized by hydrothermal method using kaolin waste as source of Aluminum and Silicon. This waste is mainly composed by kaolinite and is produced in large amount by kaolin processing industries for paper coating from the Amazon region. Initially, the waste has been calcined at 700 ºC for 2 h and then reacted with the following solutions: Na2CO3 and mixture of Na2CO3 + NaOH to 150 ºC with autogenous pressure for 24 h. The raw materials and transformed materials were characterized by XRD, FTIR and SEM. In both studied media, well-crystallized, basic sodalite was the only phase synthesized, while in the literature usually a mixture of zeolites is obtained

Color and shade parameters of ultramarine zeolitic pigments synthesized from kaolin waste

Ultramarine pigments were successful synthesized from zeolite A obtained from kaolin waste. This waste has been used as an excellent source of silicon and aluminum for zeolite synthesis because of its high kaolinite concentrations and low contents of other accessory minerals. The cost is naturally less than the industrialized product. Color additives (Sulfur and Sodium Carbonate) were mixed with different proportions of zeolite A and further calcined for 5 h at 500 °C. They were characterized by XRD and XRF in addition to visual classification by color and shade. These products show colors from blue to green at different shades, both influenced by the amount of additives and cooling rate after calcination. Thus, a different quantity of the same additives in the same zeolitic matrix provides an increase in the color intensity. Cooling rate after calcination induces the color change which is substantially important in the pigments production

Phosphorus Recovery from Wastewater Aiming Fertilizer Production: Struvite Precipitation Optimization Using a Sequential Plackett–Burman and Doehlert Design

The precipitation of struvite from wastewater is a potential alternative for the recovery of nutrients, especially phosphorus, which is an essential macronutrient for agriculture but can be harmful to the environment when improperly disposed of in water bodies. In addition, struvite has elements of great added value for agricultural activity (P, N, and Mg) and is, therefore, considered a sustainable alternative fertilizer. In its formation process, several intervening physicochemical factors may be responsible for the production yield levels. Optimization processes can help to define and direct the factors that truly matter for precipitation. In this context, a sequential design of experiments (DOE) methodology was applied to select and optimize the main struvite precipitation factors in wastewater. Initially, a screening was performed with eight factors with the aid of Plackett–Burman design, and the factors with a real influence on the process were identified. Then, a Doehlert design was used for optimization by applying the response surface methodology and the desirability function. The results were used to identify the optimal points of the pH (10.2), N/P ratio (≥4), and initial phosphorus concentration (183.5 mg/L); these values had a greater effect on phosphorus recovery and the production of struvite, which was confirmed through thermochemical analysis of the decomposition of its structure by differential scanning calorimeter—glass transition temperature (DSC-TG) and phase identification by X-ray diffraction (XRD). The determination of the best synthesis conditions is an enormous contribution to the control of the process because these conditions lead to better yields and higher levels of phosphorus recovery

Chitosan Membrane Containing Copaiba Oil (<i>Copaifera</i> spp.) for Skin Wound Treatment

The interaction of copaiba oil in the polymer matrix of chitosan can produce a favorable synergistic effect and potentiate properties. Indeed, the bioactive principles present in copaiba oil have anti-inflammatory and healing action. In the present work, chitosan membranes containing different contents of copaiba oil copaíba (0.1, 0.5, 1.0 and 5.0% (v/v)) were for the first time investigated. The membranes were developed by the casting method and analyzed for their morphology, degree of intumescence, moisture content, contact angle, Scanning Electron Microscope, and X-ray diffractometry. These chitosan/copaiba oil porous membranes disclosed fluid absorption capacity, hydrophilic surface, and moisture. In addition, the results showed that chitosan membranes with the addition of 1.0% (v/v) of copaiba oil presented oil drops with larger diameters, around 123.78 μm. The highest fluid absorption indexes were observed in chitosan membranes containing 0.1 and 0.5% (v/v) of copaiba oil. In addition, the copaiba oil modified the crystalline structure of chitosan. Such characteristics are expected to favor wound treatment. However, biological studies are necessary for the safe use of chitosan/copaiba oil membrane as a biomaterial

Nanostructured 3D bioprinting of PLA with bioglass-CNT scaffolds for osseus tissue graft manufacturing

Bone involvement promoted by aging and accidents has raised interest in biomaterials and biofabrication technologies for bone regeneration purposes. Thus, 3D printing technology has gained prominence in the production of scaffolds due to its versatility in producing complex geometries with interconnected pores. In this work, composite scaffolds of poly (lactic acid) (PLA), bioglass (BG) and carbon nanotubes (CNT) were produced by 3D printing, using hexagonal, honeycomb-like geometry interspersed. The samples were analyzed in terms of chemical structure, crystallinity and morphology using Fourier transform infrared spectroscopy and Raman spectroscopy, X-ray diffraction and scanning electron microscopy, respectively. The thermal stability of the composite was evaluated by thermogravimetry and the mechanical properties by compression tests. The cell viability was determined by Alamar Blue. The results that raman spectroscopy confirmed the interaction of BG in the polymer matrix by new peaks in the spectrum between 1400 and 2600 cm−1 and the presence of the D, G and 2D bands of the CNTs. In terms of compressive strength, PLA scaffolds with 2 mm inner spacing demonstrated higher compressive strength of 14.88 ± 2.35 MPa, while PLA/CNT higher apparent compressive modulus of 0.58 ± 0.36 GPa. In cell viability, statistical tests showed that there was no significant difference between scaffolds with 2 and 4 mm inner spacing

Synthesis and Characterization of Natural Polymeric Membranes Composed of Chitosan, Green Banana Peel Extract and Andiroba Oil

Chitosan comprises polymeric macromolecules with technical and biological properties that have been used in biomedical healing applications requiring anti-microbial and anti-inflammatory capacities worldwide. In the tropical regions, green banana peel extract and andiroba oil are considered natural products with wound healing properties. The present study, for the first time, synthesized chitosan/green banana peel extract/andiroba oil (CGA) membranes and analyzed them using scanning electron microscopy (SEM) and the swelling and moisture tests. The CGA membranes together with control membranes of plain chitosan and chitosan plus green banana peel extract, were characterized by contact angle measurement, X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Macroscopic analysis showed significant differences in color and transparency caused by the number of decoction days used for extract preparation and the oil content. SEM observations disclosed the formation of two phases, lipid and polymer, in the CGA. The number of decoction days and the andiroba oil content were inversely related to the swelling moisture uptake. All membranes were found to be hydrophilic with contact angles less than 90°. The incorporation of plant extract and oil promoted the appearance of related XRD peaks. DSC curves revealed a reduction in the enthalpy of the CGA membranes compared with plain chitosan, which might be attributed to the evaporation of the natural extract and oil. Based on these findings, the studied newly synthesized membranes demonstrated a potential for healing epithelial lesions