Orbital: The Electronic Journal of Chemistry

Conversion of Waste Cooking Oil with Transesterification Process in Ultrasonicator using SrO-KF Catalyst

2024-10-18T14:27:44+00:00

Waste cooking oil has the potential to be a raw material for biodiesel. The use of heterogeneous catalysts and ultrasonicator will optimize the transesterification and environmentally friendly. Transesterification study of waste cooking oil with SrO-KF nano catalyst has been carried out. This researchs were: refinement of waste cooking oil, synthesis of SrO-KF nano-catalyst, and the transesterification. The catalyst applied ratio of 1:1, 1:2, and 1:3 of SrO:KF with concentrations of 2%, 3% and 4% by weight of oil respectively. The results of heterogeneous catalyst using XRD and SEM showed that SrF2, SrO and KF compounds had been formed. The optimum transesterification conditions were obtained on SrO-KF catalyst (1:2), concentration of 4% (w/w) with a yield of 84.4% (w/w). The methyl ester of waste cooking oil has density of 884 kg/m3, acid number of 0.48 mg/g, and viscosity of 4.2 cSt. Methyl esters of waste cooking oil were composed of 25.14% methyl palmitate and 33.65% methyl elaidate, 11.27% methyl linoleate, 10.14% methyl lauric and a mixture of methyl esters from waste cooking oil has the potential to be used as biodiesel.

Preparation and Characterization of Blends with Small Amounts of Polyaniline and Polypyrrole Mixed with ABS Copolymer Matrix

2024-10-18T14:27:44+00:00

In this study, ABS copolymers were blended with doped polyaniline (PAni) and undoped polypyrrole (PPy) at concentrations of up to 2.5 % by weight. This allowed to understand how the mechanical and electrical resistivity properties of the ABS copolymer were affected by small quantities of these polymers. Scanning electron microscopy revealed that even with the smallest amounts of PAni or PPy added, significant morphological changes occur. The contact angle values revealed that there is a different limit in the addition of PAni or PPy to maximize the dispersive component effect. Mechanical analysis of the composites indicated that the addition of 0.625 % and 1.25 % PPy produced the highest values of Toughness, 3.87 MJ m^-3 and 3.89 MJ m^-3, respectively. The stress at rupture varied from 57 to 61 MPa for ABS-PAni composites and from 25 to 61 MPa for ABS-PPy composites. In addition, the strain at break of ABS-PAni composites ranged from 4 to 7 %, while that of ABS-PPy composites varied from 5 to 12 %. Both ABS-PAni and ABS-PPy composites did not reveal significant changes by Thermogravimetric analysis (TGA). Finally, the electrical conductivity (σ) of the composites increased six and eleven-fold, respectively, upon the addition of 2.5 % of doped PAni or undoped PPy, which were considered significant changes.

Novel Piperidone Hydrazine Carbodithioate Derivative: Synthesis, In Silico Drug-Likeness Analysis and Anticancer Properties

2024-10-18T14:27:43+00:00

An efficient synthesis of a novel compound of hydrazine carbodithioate derivative of piperidone, (E)-methyl-2-(3-methyl-2,6-diphenylpiperidin-4-ylidene)hydrazinecarbodithioate (1), was performed using methyl dithiocarbazinate and 3-methyl-2,6-diphenylpiperidin-4-one as the starting materials. The reaction was carried out in an acidic medium using methanol as a solvent. The novel compound was characterized by FTIR, Mass, and NMR spectral techniques. The hydrazine carbodithioate derivative (1) was then tested for its anticancer activity against the liver cancer cell line, Hep G2, using the MTT assay. The IC₅₀ values of the newly synthesized compound were found to be 34.33 ± 0.79 µM (24 hours) and 27.64 ± 1.42 µM (48 hours). The in vitro antitumor studies demonstrated that the novel compound (1) exhibited good inhibitory activity against the Hep G2 cancer cells. Furthermore, in silico properties such as lipophilicity, water solubility, pharmacokinetic properties, drug likeness, and medicinal chemistry were analyzed using the SwissADME tool.

Using Tillandsia usneoides as Biomonitor for Toxic Metals in the Air of Guanajuato's Tunnel Network

2024-10-27T02:20:04+00:00

Guanajuato town is an important touristic center of Mexico, and one of its main attractions is its tunnel network (subterranean streets). In this work the air quality inside this tunnel network was evaluated using samples of Tillandsia usneoides as a biomonitor. Twenty-one plastic passive samplers, containing 50 g of plants each, were installed at different points of this tunnel network. In addition, surface layer of the tunnel walls, close to the plant sampling sites, were collected. Estimates for the enrichment factor, using Fe as reference and standard metal crustal data, suggest that the origin of the suspended metals is probably geogenic for Cr, a mix for Cu, and anthropogenic for Zn and Hg. It is important to emphasize that the Guanajuato’s tunnel network is used both by pedestrians and vehicular traffic and, probably, the last one is acting as the main source for toxic elements for the tunnel’s air.

Alternatives for the Processing of Natural Gas in Espírito Santo

2024-10-18T14:27:42+00:00

Natural gas has shown an increase in demand in recent years, largely due to its competitive advantages over other fossil fuels. However, in Brazil, its production and supply chain remain under the monopoly of Petrobras, which makes it difficult for new agents to enter the market and often causes other producers to dispose of their production without any financial return. Therefore, the objective of this work is to identify alternative technologies for natural gas processing, to allow other natural gas producing companies to commercialize their natural gas production without depending on Petrobras' infrastructure. As a result, three technologies were identified that are already being applied in other countries, which are: compressed natural gas, liquefied natural gas and gas-to-liquids.

Simultaneous Synthesis and Characterization of Quinolinates to Obtain Cobalt Ferrite

2024-10-18T14:27:41+00:00

8-Hydroxyquinoline and its derivatives are compounds with a variety of applications in various fields of knowledge such as medicine, biological sciences, and chemistry. Many of these applications are possible because 8-hydroxyquinoline forms stable and insoluble metal chelates with a range of metals such as copper, cobalt, calcium, iron, and nickel. One of the possible applications of 8-HQ chelates is the production of metal oxides by thermal decomposition, however, there are few studies in the literature using quinolinates for this purpose. If the chelates are synthesized simultaneously, it is possible to obtain double oxides such as cobalt ferrite, which has numerous applications due to its magnetic properties. In this way, the present work aims to the simultaneous synthesis of cobalt II and iron III quinolinates at different pH values, as well as their characterization by XDR, SEM, TEM, FTIR and Raman analysis. Finally, the quinollinate synthetized were applied as precursors to obtain cobalt ferrite by thermal decomposition.

Green Synthesis of Polyesters Using Surfactant Catalysts in Microemulsions: The Role of Micelle Shape and Aggregation on Polymer Formation

2024-10-18T14:27:41+00:00

In this study, we explored traditional methods commonly found in the literature to analyze how surfactants and polymers interact during the synthesis of polyesters in emulsion systems. The study justifies its focus on micellar catalysis by exploring its effectiveness and suggesting methods for enhancing the synergy among surfactants, reactants, and catalys. We looked at factors like surface tension, critical micelle concentration, micelle shapes, aggregation numbers, and interfacial phenomena in the process of macromolecular packing in emulsion polycondensation. A surfactant-water system consisting of dodecylbenzenesulfonic acid and sodium dodecyl sulfate was employed. Polyesters were prepared from glycerol, ethylene glycol, diethylene glycol, and dicarboxylic acids in a surfactant-water system under mild conditions ranging from 70-150 °C. FTIR and 1H NMR confirmed the esterification. Differential scanning calorimetry indicated no crystallinity and a glass transition temperature range of –53 to –46 °C, typical of soft matter. The resulting polymers had molecular weights ranging from 1180 – 6800 g/mol. We found that these polymer aggregate shapes are able to respond by changing their sizes, both in bulk and at the air-solution interface, when the concentration of surfactant is increased above the critical micelle concentration. The results showed narrow spherical and ellipsoidal polymer aggregates, and the system was found to be suitable for green chemistry applications.

Cerium-Iron Oxide: An Efficient Photocatalyst for the Degradation of Methylene Blue Dye

2024-10-18T14:27:39+00:00

This study investigates the photocatalytic degradation of methylene blue using cerium-iron oxide (Ce-FeO) nanoparticles as efficient photocatalysts. The Ce-FeO nanoparticles were synthesized and characterized using X-ray diffraction (XRD) technique and their photocatalytic activity was evaluated for the degradation of methylene blue dye by monitoring the degradation of Methylene Blue under visible light irradiation. Furthermore, the effects of various parameters such as the pH of the dye solution, dye concentration, amount of photocatalyst and light intensity on the dye degradation efficiency were investigated. The progress of dye degradation was monitored spectrophotometrically by observing the optical density of the dye solution at regular intervals. Maximum dye degradation was observed with a dye solution of 2.25 x 10^-5 M concentration at 11.5 pH and 700 Wm^-2 light intensity using 0.04g cerium-iron oxide nanoparticles per 50 ml of dye solution. It was observed that Ce-FeO nanoparticles serve as an effective and environmentally friendly photocatalyst for dye degradation under visible light.

E5-((3-phenoxyphenyl)diazenyl)quinolin-8-ol (PPDQ) : A Novel Promising Anticorrosive for Mild Steel in Acid Media, and a Pharmacologically Potent Antidiabetic, Antioxidant Azo Dye

2024-10-18T14:27:38+00:00

A novel quinoline based azo dye 5-((3-phenoxyphenyl)diazenyl)quinolin-8-ol (PPDQ) was synthesized using conventional one pot MCR pathway and its structure has been confirmed by multinuclear (¹H & ¹³C) and mass spectral techniques. PPDQ subjected for remarkable analytical applications like anticorrosion potential for mild steel in acidic media. Further, the experimental results were compared with that of the theoretical DFT based calculations and found to be in good agreement with each other. To evaluate the pharmacological activity of the compound invitro antidiabetic and antioxidant activity were carried out. The corrosion inhibition potential of the PPDQ was explored using electrochemical method which exhibited maximum corrosion inhibition efficiency up to 77% on mild steel in 1 M HCl media, further the anticorrosion potential was confirmed by quantum chemical calculations (DFT, ESP diagrams). Antidiabetic activity and antioxidant potency was evaluated using DPPH, and ABTS radical scavenging assay. Further, the in-vitro values were compared with insilico molecular docking studies.

Gold Nanoparticles in Cancer Treatment and Diagnostics: A Review of Emerging Trends and Therapeutic Potential

2024-10-18T14:27:38+00:00

This comprehensive review delves into the burgeoning role of gold nanoparticles in both cancer treatment and diagnostics. The advent of gold nanoparticle (AuNP) vaccines has opened avenues for therapeutic and prophylactic applications, suggesting the potential to prevent or treat infections and various pathologies. The exceptional efficacy of AuNPs in cancer treatment is a focal point of exploration, with ongoing investigations into their utility for targeted delivery and therapy across diverse cancer types. A distinctive attribute of AuNPs lies in their ability to selectively target cancerous cells while safeguarding healthy cells, attributed to their unique size and shape that facilitate selective accumulation in cancer cells. Upon cellular entry and aggregation, they exhibit prompt activation to eradicate cancer cells. Furthermore, AuNPs possess inherent capabilities to enhance and modulate immune responses, functioning as both an adjuvant and a delivery system. Another advantageous feature is their amenability to functionalization with diverse molecules, including antibodies and drugs, augmenting specificity and effectiveness. This customization enables precise targeting of cancer cells and direct delivery of therapeutic agents to tumor sites, mitigating the adverse effects associated with conventional chemotherapy. Despite ongoing research, the promise of AuNPs as a potent tool in the battle against cancer is evident, underscoring their potential significance in future therapeutic strategies.

Environmental Education and Sustainability in the Brazilian High School: To Raise Awareness is to Commit to Life

2024-10-27T02:15:21+00:00

Environmental Education (EE) is an essential theme that must be addressed broadly and effectively in High School. Brazilian High School students are aware of environmental issues that devastate the country they live in. Thus, the Base Nacional Comum Curricular (BNCC) is a mandatory document whose norms guide and define common learning results of curricula in all public and private schools in Brazil. Therefore, this study aimed at analyzing how EE was inserted into the latest version of the High School BNCC. It is an exploratory study which analyzed documents and bibliographic sources. Regarding its methodology, key words connected to EE and to promotion of sustainability in High School were used for the search in the document. After data issued by the BNCC were analyzed, we perceived that EE is briefly inserted in the document; as a result, it is neither taught nor practiced as it should be. Since EE is generically treated and poorly addressed, it does not contribute to a broad, transversal and integrative approach. Teaching EE and sustainability in High School is an important step to achieve legally established goals, go beyond theories and, mainly, put into practice speeches given by the Brazilian public management.

Your Favorite Beverage is an Opportunity to Talk About Chemistry: Didactic Application to the Brazilian High School

2024-10-18T14:27:39+00:00

“Let he who has had neither doubts nor difficulties in Chemistry in his school life cast the first pipette.” This science is full of information but it is often limited to formulas, memorization of concepts, experiments in laboratories and activities that only focus on its contents. The world must be seen through the eyes of science which must be used as a tool that helps to explain phenomena of nature so that all knowledge learned in school may be used for benefiting human beings. Therefore, this study aimed at making Chemistry accessible and attractive by using contextualized dialogues about “favorite beverages and their Chemistry”. This study was developed by a High School senior who goes to the Instituto Federal do Triângulo Mineiro - Campus Uberlândia Centro, Uberlândia, Minas Gerais (MG), Brazil. Contextualizing Chemistry was a tool that made teaching easier since students participated and mentioned their favorite beverages, such as soft drinks, coffee, alcoholic drinks and energy drinks. Teachers had the opportunity to teach several chemical concepts, such as methods of separating mixtures, fermentation and molecules, besides chemical structures of sugar, caffeine, ethanol and taurine. Teachers and students also talked about solubility of gas in liquid and dissolution of carbon dioxide in manufacturing of carbonated drinks. This project showed that contextualized Chemistry teaching makes students construct their own learning process.