Presence Of Inorganic Material Research Articles

Unsuspected Organometallic Fibers Used As Potential Separators for Supercapacitors Device

Since the last decade, the interest of organic frameworks for electrochemical application the been more studied.1 In general, very few works have been found in the literature. We can mainly mention the use of these derivatives in the presence of inorganic materials both to form solid electrolytes or to protect electrodes. For example, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (H4DOTA) has been used to functionalize PVA to coat the surface of the negative electrode in order to suppress its degradation.2 This resulted in the improvement of the electrochemical properties of the LMNO/graphite cell. Recently, Kim et al. reported the addition of 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane to a carbonate-based electrolyte intended to stabilize the Li metal-electrolyte interface by improving the solid electrolyte interphase.3 More recently, Liu et al. reported a novel carbonyl network polymer NP4 used as a cathode material for organic lithium batteries.4 Very few examples of fully organic frameworks used as separators have been reported.Therefore, our investigation to develop new supramolecular metal-based objects via a self-assembly process of molecular bricks will be presented. The work on cyclen derivatives allows to obtain metal complexes very stable able to pack in a well oriented dimension. Cyclen derivatives, in the presence of metal salts such as copper or zinc chlorides and polar solvents such as aliphatic alcohols, have a strong affinity for metals and spontaneously assemble in some conditions.5 In terms of applications, these self-assembled "organometallic" fibers represent an original and relatively easy to access substrate for fabricating 1D organic objects. Moreover, taking advantage of the properties and potentialities of these materials, we format an adequate shape to handle it as a potential separator for application in Energy Storage Systems (ESS).After a presentation of their synthesis and their formatting as potential separators for supercapacitors, preliminary electrochemical studies will be discussed. 1. J. Mater.Chem. A 2016, 4, 16812; ACS Energy let., 2022, 7, 885.2. ACS Appl. Energy Mater., 2021, 4, 128.3. ACS Appl. Matter. Interface, 2022, 14, 35645.4. J. Electoanalytical. Chem. 2023, 117251.5. Chem. Commun. 2010, 46, 1464. Figure 1

Physicochemical characterization of the vegetal drug and nebulized extract of the roots from Apodanthera congestiflora Cogn. (Cucurbitaceae)

Apodanthera congestiflora Cogn. is a Brazilian Cucurbitaceae, known for its anti-inflammatory and antiparasitic activities. The objective of this work was to determine the physicochemical characteristics of the vegetal drug (VD) and the nebulized aqueous extract (NAE) from A. congestiflora using official methods and other analytical techniques: scanning electron microscopy, energy-dispersive spectrometry (EDS), thermal analysis (TG/DTA), X-ray diffraction and infrared, applied in the characterization of plant extracts. The VD and NAE presented varied granulometry and acceptable moisture, ash, pH and density. X-ray diffraction and scanning electron microscopy have suggested that the particles of the compounds analyzed are amorphous, with different sizes. The thermal decomposition of the vegetal raw material occurred in four stages, with characteristic events of the loss of free water, volatile substances, bound water to herbal products and organic compounds, besides the presence of inorganic material, verified in elemental analysis in EDS. The curves observed in the DTA showed three peaks, the first being endothermic and others exothermic. Such characteristics have confirmed the preliminary analysis of sieving, ash content and moisture. Phytochemical screening showed positive results for saponins, alkaloids and polysaccharides, and in the semiquantitative assays, the values were 59.84 ± 1.24 mg g−1 for total polyphenols, 55.28 ± 7.14 mg g−1 for tannins and 34.78 ± 2.79 mg g−1 for flavonoids. Infrared spectra showed characteristic peaks of O–H, C–H, C=O, C=C and C–O groups, which together with the results of the phytochemical analysis reinforce the presence of these phytochemicals. The results revealed that the analytical techniques allowed the joint characterization of the VD and the NAE, providing subsidies for the obtaining of a phytotherapic.

Structural analysis and defect evaluation of ion exchange composite membranes used in electrolysis of sodium chloride in chlor-alkali process

Various tests were conducted to characterize a used ion exchange membrane. The DSC tests provided information on the water absorption capacity and phase transition of the used and fresh membranes. Also, information on the temperature of chemical degradation was obtained by the DSC tests. The DSC test was performed to analyze thermo-physical processes during the increase in temperature. The SEM images were used for the structural analysis of a Nafion composite membrane. The SEM images were taken from the used and fresh membranes. The layers are nearly similar in both the membranes (fresh and used), but the mineral-coated layer is deteriorated and engraved in the used membrane, particularly on the PTFE network fiber. EDX tests were conducted for the elemental analysis of the fresh and used membranes. The EDX analysis indicated the presence of Zr, Ti and O, which could be attributed to ZrO2 and TiO2 on a top layer. At the cathode side of the membranes, one cannot see the mineral layer. The population of S atoms was less in bulk polymer. The fresh membrane consists of F and C, while the used membrane shows new peaks of Ba, Ca, Mg and Si atoms, indicating the presence of inorganic materials in the bulk of the used membrane. This can be ascribed to the impurities present in brine, which is introduced to the membrane during cell operation. FTIR analysis showed that there were no chemical changes in the used membranes, due to its perfect chemical stability in a harsh environment. The results showed significant changes in the mineral composition of the used membrane after operation in a chlor-alkali cell.

Caracterização química e tecnológica das folhas, caules e planta inteira da Ipomoea pes-caprae (L.) R. Br., Convolvulaceae, como matéria-prima farmacêutica

Ipomoea pes-caprae (L.) R. Br., (Convolvulaceae), planta que ocorre abundantemente nas dunas do litoral é popularmente conhecida como "salsa-da-praia", e usada na medicina popular devido às suas propriedades analgésica, antiinflamatória e cicatrizante. A partir das partes aéreas frescas foram desenvolvidos protocolos para o seu tratamento prévio e controle de qualidade, com o propósito de caracterizar a planta como matéria-prima farmacêutica. A perda por secagem mostrou que as folhas apresentam menor rendimento de matéria seca em relação aos caules, devido ao seu maior teor de água. A secagem e moagem teve por objetivo a manutenção da perda por dessecação abaixo do valor máximo permitido para drogas vegetais. As folhas e caules secos e moídos foram classificados como pós grossos através da análise granulométrica por tamisação, e caracterizados segundo testes farmacopeicos para drogas vegetais. A determinação de cinzas indicou a presença de material inorgânico, possivelmente areia, associado ao habitat da espécie. O teor de extrativos solúveis em água foi maior nas folhas, seguido dos caules e proporcional na planta inteira, correlacionando-se ao teor de flavonoides totais. A cromatografia em camada delgada das soluções extrativas hidroetanólicas mostrou diferenças apenas com relação à intensidade das manchas, e indicação da presença de isoquercitrina, sendo mais evidente nas folhas.

Radiation Crosslinking of Poly(Butylene Succinate) in the Presence of Inorganic Material and Its Biodegradability

Three kinds of poly(butylene succinate)s (PBS) with different molecular weight were irradiated with electron beams in the presence of inorganic material. Fourteen kinds of inorganic materials were used in this work. The presence of inorganic material inside cross-linked PBS samples enhances the yield of gel formation. The heat stabilities of PBS samples were checked; it was found that silicon dioxide and carbon black significantly improve these properties. Enzymatic and soil burial tests were performed; the presence of these inorganic materials in cross-linked PBS accelerates the rate of biodegradation.