RESUMO
New sets of functionalized thiazolidinone and thiadiazole derivatives were synthesized, and their cytotoxicity was evaluated on HepG2, MCF-7, HTC-116, and WI38 cells. The synthetic approach is based on the preparation of 4-(4-acetamidophenyl)thiosemicarbazide (4) and their thiosemicarbazones 5 a-e, which are converted to the corresponding thiazoldin-4-one compounds 6 a-e upon cyclization with ethyl bromoacetate. The thiadiazole compounds 9 and 12 were obtained by reacting 4-(4-acetamidophenyl)thiosemicarbazide with isothiocyanates and/or ethyl 2-cyano-3,3-bis(methylthio)acrylate, respectively. The thiazolidinone compounds 6 c and 6 e exhibited strong cytotoxicity against breast cancer cells, with an IC50 (6.70±0.5â µM) and IC50 (7.51±0.8â µM), respectively, very close to that of doxorubicin (IC50: 4.17±0.2â µM). In addition, the anti-cancer properties of the tested thiazolidinone and thiadiazole scaffolds were further explored by the molecular docking program (MOE)-(PDB Code-1DLS). Compounds 5 d, 5 e, 6 d, 6 e, and 7 have the best binding affinity, ranging from -8.5386â kcal.mol-1 to -8.2830â kcal.mol-1.
Assuntos
Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Simulação de Acoplamento Molecular , Tiadiazóis , Tiazolidinas , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Tiadiazóis/química , Tiadiazóis/farmacologia , Tiadiazóis/síntese química , Tiazolidinas/química , Tiazolidinas/farmacologia , Tiazolidinas/síntese química , Relação Estrutura-Atividade , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Estrutura Molecular , Relação Dose-Resposta a DrogaRESUMO
The aim of this study involves the synthesis novel thiophene analogues that can be used as anticancer medications through a strategic multicomponent reaction connecting ethyl 4-chloroacetoacetate (1), phenyl isothiocyanate, and a series of active methylene reagents, including ethyl acetoacetate (2), malononitrile, ethyl cyanoacetate, cyanoacetamide 6a-c, N-phenyl cyanoacetamide derivatives 13a-c, and acetoacetanilide derivatives 18. This reaction was facilitated by dry dimethylformamide with a catalytic quantity of K2CO3. The resultant thiophene derivatives were identified as 4, 8a-b, 9, 12a-d, 15a-c, and 20a-b. Further reaction of compound 4 with hydrazine hydrate yielded derivative 5, respectively. When compound 1 was refluxed with ethyl 3-mercapto-3-(phenylamino)-2-(p-substituted phenyldiazenyl)acrylate 10a-e in the presence of sodium ethoxide, it produced thiophene derivatives 12a-d. Comprehensive structural elucidation of these newly synthesized thiophene-analogues was accomplished via elemental and spectral analysis data. Furthermore, the study delves into the cytotoxicity of the newly synthesized thiophenes was evaluated using the HepG2, A2780, and A2780CP cell lines. The amino-thiophene derivative 15b exhibited an increased growth inhibition of A2780, and A2780CP with IC50 values 12±0.17, and 10±0.15â µM, respectively compared to Sorafenib with IC50 values 7.5±0.54 and 9.4±0.14. This research opens new avenues for developing thiophene-based anticancer agents.
Assuntos
Antineoplásicos , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Tiofenos , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Estrutura Molecular , Relação Estrutura-Atividade , Tiofenos/química , Tiofenos/farmacologia , Tiofenos/síntese químicaRESUMO
The dam failure of the Córrego do Feijão Mine (CFM) located in Minas Gerais State, Brazil, killed at least 278 people. In addition, large extensions of aquatic and terrestrial ecosystems were destroyed, directly compromising the environmental and socioeconomic quality of the region. This study assessed the pollution and human health risks of soils impacted by the tailing spill of the CFM dam, along a sample perimeter of approximately 200 km. Based on potential ecological risk and pollution load indices, the enrichments of Cd, As, Hg, Cu, Pb and Ni in soils indicated that the Brumadinho, Mário Campos, Betim and São Joaquim de Bicas municipalities were the most affected areas by the broken dam. Restorative and reparative actions must be urgently carried out in these areas. For all contaminated areas, the children's group indicated an exacerbated propensity to the development of carcinogenic and non-carcinogenic diseases, mainly through the ingestion pathway. Toxicological risk assessments, including acute, chronic and genotoxic effects, on people living and working in mining areas should be a priority for public management and mining companies to ensure effective environmental measures that do not harm human health and well-being over time.
Assuntos
Metais Pesados , Poluentes do Solo , Criança , Humanos , Solo , Metais Pesados/toxicidade , Metais Pesados/análise , Ecossistema , Brasil , Monitoramento Ambiental , Poluição Ambiental/análise , Poluentes do Solo/toxicidade , Poluentes do Solo/análise , Medição de RiscoRESUMO
The aim of the work was to establish the effect of anthropogenic activities and seasonality on physico-chemical parameters and heavy metal levels of River Yala (RY) within RY Basin of Lake Victoria (LV), as well as the associated ecological risks. Analyses were done on the collected samples in order to establish the levels of EC, pH, DO, temperature, conductivity, turbidity, acidity, alkalinity, BOD, COD, DOC, TOC and heavy metals (Cu, Fe, Pb, Mn, Zn, Cr and Cd) in RY water and sediments adjacent to Agricultural Farms during dry and wet seasons. The levels in terms of µg/mL, µS/cm (EC), NTU (turbidity) of analyzed parameters in the Agricultural Farms in water ranged from 0.01±0.00 to 121.75±15.23 (Upstream pristine sources of RY - S), 0.02±0.01 to 184.83±23.43 (Nandi Tea Estate and Kaimosi Agricultural Farms - N), 0.02±0.01 to 149.67±22.77 (Subsistence Farms - Sub), 0.02±0.01 to 209.33±18.09 (Lake Agro Limited Agricutural Farms and Yala Swamp - D) and 0.01±0.00 to 164.25±30.33 (Terminal of RY - T). The levels in µg/g of analyzed parameters in sediments ranged from 7.2±1.46 to 3342.8±538.7 (S), 9.12±0.2 to 4063.2±90.4 (N), 3.15±1.14 to 5998.5±588.4 (Sub), 2.03±0.76 to 4519.8±194.9 (D) and 2.13±0.75 to 5514.4±201.4 (T). The significant differences in the levels of analyzed parameters in water between dry and wet seasons were computed as; EC (+20.54 µS/cm), alkalinity (-2.85 µg/mL), DOC (+0.24 µg/mL), Fe (+0.58 µg/mL), Pb (+0.11 µg/mL), Zn (+0.07 µg/mL) and Cd (+0.01 µg/mL) while that for Mn in sediment samples was +163.8937 µg/g. The significantly (p ≤ 0.05) positive values indicated that wet season had more impact on the levels than dry season. There was positive correlation of zinc in water and sediments during dry and wet season. Chromium correlated positively in water and sediments during wet season. Copper and cadmium correlated negatively during dry and wet season while Mn only wet season. Results of geostatistical indices (CF, Cd, mCd, PLI, Er and RI) indicated that sediments located at regions N, D and T were highly contaminated with the heavy metals. However, a wetland at the mouth of Lake Victoria cleaned the water before it drained into the lake. Therefore, despite contamination of RY through anthropogenic activities, wetland mitigation protects LV from pollution by the river, indicating the important ecological and restorative functions played by wetlands.
Assuntos
Cádmio , Metais Pesados , Lagos , Rios , Chumbo , Monitoramento Ambiental , ÁguaRESUMO
The oil spill represents one of the most important pollution sources for marine environments, that occurs due to tanker collisions, ship accidents, and platforms. Several techniques are used for treating oil spill disasters including chemical, physical, and biochemical. The use of chemicals, magnetite nanomaterials (MNMs) in particular, is one of the most applied techniques used for oil spill remediation due to their low cost, fast remediation, and reusability. This work aims to synthesize and use new ionic liquids (ILs) for the modification of MNMs surfaces to enhance their performance for crude oil uptake. For that, octadecylamine (OA) was reacted with epichlorohydrin (EH), followed by reaction with either diethylenetriamine (DT), or tetraethylenepentamine (TP) to obtain corresponding amines, OADT, and OATP, respectively. The produced amines were quaternized using acetic acid (AA) forming corresponding ILs, OADT-IL, and OATP-IL. The obtained ILs, OADT-IL, and OATP-IL were applied for modification of magnetite nanomaterials (MNMs) surface to obtain the surface-modified MNMs, DT-MNMs, and TP-MNMs, respectively. The surface-modified MNMs were characterized using different techniques including Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and contact angle. The efficacy of DT-MNMs, and TP-MNMs for heavy crude oil uptake (EMU) was evaluated. Further, the factors affecting on the crude oil uptake including MNMs: heavy crude oil ratio, and contact time were also evaluated. The data exhibited that, the EMU relatively declined as the ratio of DT-MNMs, and TP-MNMs decreased. Even at low MNMs:crude oil ratio (1:50), DT-MNMs, and TP-MNMs displayed EMU 87%, and 90%, respectively, which means 1 g of either DT-MNMs, or TP-MNMs can uptake 45 g, or 43.5 g, respectively. These values are high as compared with other studies that reported the use of MNMs for oil spill cleanup. Furthermore, the data indicated that the EMU increased as the contact time increased, and reached maximum EMU of 98% for both MNMs samples after 10 min.
Assuntos
Líquidos Iônicos , Nanoestruturas , Transportadores de Ânions Orgânicos , Poluição por Petróleo , Petróleo , Aminas , Óxido Ferroso-Férrico , Poluição por Petróleo/análiseRESUMO
This work aimed to use abietic acid (AA), as a widely available natural product, as a precursor for the synthesis of two new amphiphilic ionic liquids (AILs) and apply them as effective demulsifiers for water-in-crude oil (W/O) emulsions. AA was esterified using tetraethylene glycol (TEG) in the presence of p-toluene sulfonic acid (PTSA) as a catalyst obtaining the corresponding ester (AATG). AATG was reacted with 1-vinylimidazole (VIM) throughout the Diels-Alder reaction, forming the corresponding adduct (ATI). Following this, ATI was quaternized using alkyl iodides, ethyl iodide (EI), and hexyl iodide (HI) to obtain the corresponding AILs, ATEI-IL, and ATHI-IL, respectively. The chemical structure, surface activity, thermal stability, and relative solubility number (RSN) were investigated using different techniques. The efficiency of ATEI-IL and ATHI-IL to demulsify W/O emulsions in different crude oil: brine volumetric ratios were evaluated. ATEI-IL and ATHI-IL achieved promising results as demulsifiers. Their demulsification efficiency increased as the brine ratios decreased where their efficiency reached 100% at the crude oil: brine ratio (90:10), even at low concentrations.
Assuntos
Líquidos Iônicos , Petróleo , Emulsões/química , Iodetos , Líquidos Iônicos/química , Petróleo/análise , Água/químicaRESUMO
BACKGROUND: The British Thoracic Society (BTS) recommends that all patients admitted with COVID-19 pneumonia should have a chest X-ray (CXR) and clinical follow-up at 6 or 12 weeks, depending on the disease severity. Little data is available on long-term CXR follow-up for moderate and severe COVID-19 pneumonia. This study aims to evaluate compliance with clinico-radiological follow-up of patients recovering from COVID-19 pneumonia at a local hospital in the UK, as per the BTS guidance, and to analyse radiological changes at clinical follow-up at 12 weeks, in order to risk-stratify and improve patient outcomes. METHODS: This is a single-centre retrospective audit of 255 consecutive COVID-19 positive patients admitted to a local hospital in the UK over 5 months between May and October 2020. All CXRs and clinic follow-up at 12 ± 8 weeks were checked on an electronic database. RESULTS: Over one in two (131/255) patients had CXR evidence of COVID-19 pneumonia during the initial hospital admission. Half of the patients (60/131) died before CXR or clinic follow-up. Fifty-eight percent (41/71) of the surviving patients had a follow-up CXR, and only two developed respiratory complications- one had residual lung fibrosis, another a pulmonary embolism. Eighty-eight percent (36/41) of the patients had either resolution or improved radiological changes at follow-up. Most patients who had abnormal follow-up CXR were symptomatic (6/8), and many asymptomatic patients at follow-up had a normal CXR (10/12). CONCLUSIONS: Although there were concerns about interstitial lung disease (ILD) incidence in patients with COVID-19 pneumonia, most of our patients with COVID-19 pneumonia had no pulmonary complications at follow-up with CXR. This emphasises that CXR, a cost-effective investigation, can be used to risk-stratify patients for long term pulmonary complications following their COVID-19 pneumonia. However, we acknowledge the limitations of a low CXR and clinic follow-up rate in our cohort.
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COVID-19 , Seguimentos , Hospitais Gerais , Humanos , Radiografia Torácica , Estudos Retrospectivos , SARS-CoV-2 , Reino Unido/epidemiologiaRESUMO
In the last few decades, there has been an increasing trend for the usage of natural products and their derivatives as green and renewable oil-filed chemicals. Use of these compounds or their derivatives contributes to reducing the use of traditional chemicals, and enhances green chemistry principles. Curcumin (CRC) is one of the most popular natural products and is widely available. The green character, antioxidant action, and low cost of CRC prompt its use in several applications. In the present study, Curcumin was used to synthesize two new amphiphilic ionic liquids (AILs) by reacting with 1,3-propanesultone or bromoacetic acid to produce corresponding sulfonic and carboxylic acids, CRC-PS and CRC-BA, respectively. Following this, the formed CRC-PS and CRC-BA were allowed to react with 12-(2-hydroxyethyl)-15-(4-nonylphenoxy)-3,6,9-trioxa-12-azapentadecane-1,14-diol (HNTA) to form corresponding AILs, GCP-IL and GRB-IL, respectively. The chemical structures, surface tension, interfacial tension, and relative solubility number (RSN) of the synthesized AILs were investigated. The efficiency of GCP-IL and GRB-IL to demulsify water in heavy crude oil (W/O) emulsions was also investigated, where we observed that both GCP-IL and GRB-IL served as high-efficiency demulsifiers and the efficiency increased with a decreased ratio of water in W/O emulsion. Moreover, the data showed an increased efficiency of these AILs with an increased concentration. Among the two AILs, under testing conditions, GCP-IL exhibited a higher efficiency, shorter demulsification time, and cleaner demulsified water.
Assuntos
Curcumina/análogos & derivados , Emulsificantes/síntese química , Emulsões/química , Líquidos Iônicos/química , Óleos/química , Purificação da Água/métodos , Curcumina/síntese química , Interações Hidrofóbicas e Hidrofílicas , TensoativosRESUMO
Two novel amphiphilic polyethylene amine terephthalate have been prepared via the glycolsis of polyethylene terephthalate (PET). The product, bis (2-hydroxyethyl terephthalate) (BHET), was converted to the corresponding dialkyl halide, bis(2-chloroethyl) terephthalate (BCET), using thionyl chloride (TC). This dialkyl compound was used for alkylation of dodecyl amine (DOA) and tetraethylenepentamine (TEPA) or pentaethylenehexamine (PEHA) to form the corresponding polyethylene amine terephthalate, i.e., DOAT and DOAP, respectively. Their chemical structure, surface tension, interfacial tension (IFT), and dynamic light scattering (DLS) were determined using different techniques. The efficiency of the prepared polyethylene amine terephthalate to demulsify water in heavy crude (W/O) emulsions was also determined and found to increase as their concentrations increased. Moreover, DOAT showed faster and higher efficiency, and cleaner separation than DOAP.
Assuntos
Petróleo/análise , Polietilenotereftalatos/química , Aminas/síntese química , Aminas/química , Difusão Dinâmica da Luz , Emulsões/química , Espectroscopia de Ressonância Magnética , Micelas , Estrutura Molecular , Polietilenotereftalatos/síntese química , Eliminação de Resíduos/métodos , Espectroscopia de Infravermelho com Transformada de Fourier , Tensão Superficial , Tensoativos/síntese química , Tensoativos/química , Águas Residuárias/químicaRESUMO
INTRODUCTION: Methanol is a widely available chemical with a range of uses including as solvent, as a fuel, in chemical synthesis and anti-freeze preparations. Most of the cases are accidental exposures to drinking beverages contaminated with methanol. MATERIALS AND METHODS: In mid-September 2018, there was a single outbreak of methanol poisoning in Malaysia especially involving the state of Federal Territory Kuala Lumpur and Selangor. There were 33 reported deaths suspected due to methanol poisoning in this current outbreak where 11 of them were brought in to the Institute of Forensic Medicine (NIFM), Kuala Lumpur. The last outbreak was in the year 2013 with 29 deaths reported out of 44 cases. RESULTS: There were 3 cases (27.2%) died in hospital and the remaining 8 cases (72.8%) were found dead at home and were later brought in dead to the hospital. A full autopsy was carried out for each case. Autopsy findings, as well as lab results pertaining to cases that survived and directly brought in dead, were of a different spectrum. CONCLUSION: Methanol related deaths are almost always as a result of greed. The running truism is 'methanol poisoning is a result of deliberate addition/adulteration with industrial methanol'. Prevention of the illegal production of methanol and methylated spirits should be established to curb this matter in the future.
Assuntos
Metanol/intoxicação , Síndromes Neurotóxicas/epidemiologia , Síndromes Neurotóxicas/etiologia , Adulto , Feminino , Humanos , Malásia/epidemiologia , Masculino , Pessoa de Meia-IdadeRESUMO
The ionic crosslinked 2-acrylamido-2-methylpropane sulfonic acid-co-acrylic acid hydrogel, AMPS/AA and its Ag and Fe3O4 composites were synthesized using an in situ technique. The surface charge, particle sizes, morphology, and thermal stability of the prepared AMPS/AA-Ag and AMPS/AA-Fe3O4 composites were evaluated using different analytical techniques and their adsorption characteristics were evaluated to remove the methylene blue cationic dye, MB, from their aqueous solutions at optimum conditions. Also, the same monomers were used to synthesize AMPS/AA microgel and its Ag and Fe3O4 nanocomposites, which were synthesized using the same technique. The AMPS/AA-Fe3O4 nanocomposite was selected as conventional iron-supported catalyst due to the presence of both Fe(II) and Fe(III) species besides its magnetic properties that allow their easy, fast, and inexpensive separation from the aqueous solution. It was then evaluated as a heterogeneous catalyst for complete MB degradation from aqueous solution by heterogeneous Fenton oxidation. It achieved a high rate of degradation, degrading 100 mg L-1 of MB during a short time of 35 min as compared with the reported literature.
Assuntos
Azul de Metileno/química , Nanocompostos/química , Prata/química , Catálise , Óxido Ferroso-Férrico/química , Microgéis/química , Purificação da Água/métodosRESUMO
Spontaneous coronary artery dissection is a rare event and commonly associated with pregnancy and female gender. This condition can reduce or completely obstruct the blood flow to the heart, causing a myocardial ischaemia, abnormalities in heart rhythm or sudden death. We present a case of a 28-year-old Indian male with no previous medical illness who complained sudden onset of chest pain prior to his death. Autopsy revealed a left anterior descending coronary artery dissection associated with plaque rupture. The anterior wall of left ventricle showed contraction band necrosis. There was also atheroma present in the right coronary artery which was insignificant. Histologically, dissection was associated with atherosclerosis. There was no evidence of vasculitis. The cause of death was given as coronary artery dissection due to coronary artery atherosclerosis.
Assuntos
Doença da Artéria Coronariana/complicações , Anomalias dos Vasos Coronários/etiologia , Morte Súbita Cardíaca/etiologia , Doenças Vasculares/congênito , Adulto , Doença da Artéria Coronariana/mortalidade , Doença da Artéria Coronariana/patologia , Anomalias dos Vasos Coronários/mortalidade , Anomalias dos Vasos Coronários/patologia , Morte Súbita Cardíaca/patologia , Humanos , Masculino , Doenças Vasculares/etiologia , Doenças Vasculares/mortalidade , Doenças Vasculares/patologiaRESUMO
INTRODUCTION: Coronary artery disease (CAD) is a known cause of major cardiovascular events and calcium score (CS) has been developed as a marker of coronary atherosclerosis. Yet, the relationship between post mortem computed tomography (PMCT) CS with histologically observed calcification and the severity of coronary artery stenosis has not been widely explored and is still unclear. This study aims to determine the association between coronary artery PMCT CS with histologically observed calcification and degree of stenosis of coronary arteries in post-mortem cases. MATERIALS & METHODS: This was a cross-sectional study involving 101 subjects recruited from the National Institute of Forensic Medicine (IPFN) Hospital Kuala Lumpur (HKL) over a period of 15 months, from December 2012 until April 2014. PMCT CS of the coronary arteries was calculated using Agatston-Janowitz score. Histological presence of calcification was observed and the degree of stenosis was calculated using an image analysis technique. RESULTS: PMCT CS increased with increasing severity of stenosis (p<0.001). PMCT CS showed a positive correlation with the presence of calcification (r=-0.82, p<0.001). CONCLUSION: Calcium score is strongly associated with coronary artery calcification and the degree of luminal stenosis in post mortem subjects. Thus, PMCT may be useful as a non-invasive tool in diagnosing CAD in the event that an autopsy is not possible.
Assuntos
Calcinose/diagnóstico , Estenose Coronária/diagnóstico , Vasos Coronários/patologia , Adulto , Autopsia , Calcinose/patologia , Cálcio , Estenose Coronária/patologia , Vasos Coronários/diagnóstico por imagem , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios XRESUMO
A disaster is a natural or man-made (or technological) hazard resulting in an event of substantial extent causing significant physical damage or destruction, loss of life, or drastic change to the environment. It is a phenomenon that can cause damage to life and property and destroy the economic, social and cultural life of the people; and overwhelms the capacity of the community to cope with the event. The recent tragic aviation accidents in 2014 involving Malaysia Airlines flights MH370 and MH17 shocked the world in an unprecedented manner. This paper focuses on the Malaysian experience in the MH17 mission in Ukraine as well as the first ever international Disaster Victim Identification (DVI) operation for the Malaysian DVI team. The DVI operations in Hilversum, the Netherlands were well described in stages. The Netherlands' Landelijk Team Forensische Opsporing as the lead DVI team in Hilversum operated systematically, ensuring the success of the whole mission. This paper discusses the lessons learned by the Malaysian team on proper DVI structure, inter- and intra-agency cooperation, facilities planning and set up, logistics and health and safety aspects, as well as effective communication and collaboration with other international delegates. Several issues and challenges faced by the Malaysian team were also documented. In addition, the authors shared views, opinions and recommendations for a more comprehensive DVI operation in the future.
Assuntos
Acidentes Aeronáuticos , Antropologia Forense/métodos , Medicina Legal/métodos , Agências Internacionais , Incidentes com Feridos em Massa , Autopsia , Comunicação , Comportamento Cooperativo , Impressões Digitais de DNA , Antropologia Forense/organização & administração , Medicina Legal/organização & administração , Humanos , Comunicação Interdisciplinar , Agências Internacionais/organização & administração , Cooperação Internacional , Malásia , Países Baixos , Objetivos Organizacionais , UcrâniaRESUMO
Ruptured dissecting aortic aneurysm more commonly occur in men in the 40 to 70 age group, and most commonly is associated with atherosclerosis. Uncommon causes are previous heart surgery, connective tissue disorders and aortitis. Despite its rarity, Clostridium spp aortitis progresses very rapidly with a mortality rate of approximately 79% in adults, typically occurring within 48 hours of infection. We present a case of sudden death due to clostridial aortitis causing ruptured aortic dissection in an apparently healthy adult female, 7 weeks post-spontaneous vaginal delivery. This case highlights the pathology of aortic dissection and cystic media necrosis as presentations of clostridium spp infection in young female adult.
Assuntos
Dissecção Aórtica/microbiologia , Ruptura Aórtica/microbiologia , Aortite/microbiologia , Infecções por Clostridium/complicações , Adolescente , Morte Súbita , Evolução Fatal , Feminino , Humanos , Período Pós-PartoRESUMO
In this study, inexpensive magnetite nanoparticles (Fe3O4) were prepared and applied to oil spill remediation. To do so, two novel hydrophobic amides, HADN and HATN, were prepared and applied to Fe3O4 surface modification, producing HAN-Fe3O4 and HAT-Fe3O4, respectively. The efficiency of HAN-Fe3O4 and HAT-Fe3O4 for oil spill remediation (EOSR) was investigated using different HAN-Fe3O4 and HAT-Fe3O4 weights and at various contact times. The data indicated that the EOSR increased with increased HAN-Fe3O4 and HAT-Fe3O4 weights, as their EOSR reached 100% and 89%, respectively, using 100 mg. The results also revealed that the optimum time for HAN-Fe3O4 and HAT-Fe3O4 (50 mg) to achieve the highest EOSR is 8 min, as their EOSR reached 98% and 84%, respectively, at this time. In addition, HAN-Fe3O4 exhibited higher EOSR than HAT-Fe3O4, which could be linked to the presence of an aromatic ring in HADN that is used for surface modification of Fe3O4, making them more compatible with crude oil components.
Assuntos
Amidas , Recuperação e Remediação Ambiental , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas de Magnetita , Poluição por Petróleo , Nanopartículas de Magnetita/química , Amidas/química , Recuperação e Remediação Ambiental/métodos , PetróleoRESUMO
The current work aims to synthesize new amphipathic compounds, TGHA and PGHA, and investigate their demulsification performance (DP) in water-in-crude oil emulsions. Their chemical structures, thermal stability, interfacial activity, and micelle formation were investigated by different techniques. The bottle test method was used to investigate the effect of demulsifier concentration, water content, temperature, and demulsification time (DT) on the DP of TGHA and PGHA compared to a commercial demulsifier (CD). The results indicated that these parameters have a noticeable impact on the DP of TGHA and PGHA. The results also showed that TGHA exhibited higher DP than PGHA at all investigated parameters, which could be explained by increasing its hydrophobicity due to lower oxyethylene units in its structure than PGHA. An increase in these units means increased hydrophilicity, which led to obstruction of PGHA molecule diffusion in crude oil as a continuous phase. Moreover, TGHA gave a comparable DP with CD, as it gave a higher DP and shorter DT than CD at a higher water content (50%), while the latter achieved the highest DP and the shortest DT at a low water content (10%).
RESUMO
This study aimed to synthesize ecofriendly and low-cost surfactant-based sugar, HA-ST, under mild conditions and a short route via an opening ring of hexadecylsuccinic anhydride (HA) using starch (ST). HA-ST's chemical structure, thermal behavior, and surface activity were evaluated using Fourier Transform Infrared (FTIR) spectroscopy, thermogravimetric analysis, and a pendant drop technique. The results indicated HA-ST formation, thermal stability, and surface activity. HA-ST's green character, low cost, and surface activity recommended its use as a demulsifier for crude oil emulsions at different affecting parameters such as temperature, seawater ratio (SR), demulsifier concentration, demulsification time (DT), and pH. HA-ST demulsification efficiency (DE) was evaluated and compared with a commercial demulsifier (CD). The results showed improved HA-ST's DE with rising temperature, SR, demulsifier concentration, DT, and pH. The DE of HAST reached 100% at 50% of SR and 250 ppm of demulsifier concentration; the same results were obtained using CD. In contrast, HA-ST gave relatively lower DE at low SR (10%) with a value of 70% than the obtained using CD with a value of 75%. The green character, low cost, and DE of HA-ST make it suitable for demulsifying crude oil emulsions, especially those containing more than 30% seawater, compared with CD, which commonly contains two or more traditional surfactants.
RESUMO
New cellulose (CL) fibers are derived from Chamaerops humilis (Ch) rachis. They play an essential role in various industries to produce environmentally friendly products as an alternative to enhancing and strengthening lightweight composites, such as dashboards automotive. Distinctive properties of Ch fibers (ChFs) were determined by extracting fibers from dwarf palm plant branches using anaerobic analysis. This search comprehensively studies morphological, physical, mechanical, and thermal characteristics and water absorption testing. The fiber diameter was 241.23 ± 34.77 µm, while the obtained linear density and density were 13.71 ± 0.57 Tex and 0.801 ± 0.05 g/cm3, respectively. The moisture content was 8.5 %, and the moisture regain was 9.29 %. Scanning electron microscopy images showed the fibers and smooth and rough surfaces. The thermogravimetric analysis demonstrated the maximum degradation of 352 °C, thermal stability of 243 °C, and the kinetic activation energy reached (79.78 kJ/mol). X-ray diffraction proves the availability of CL, with a crystallinity index = 68.38 % and crystal size = 2.92 nm. Fourier transform infrared succeeded in detecting functional groups and chemical compounds of fibers. The fibers exhibited a tensile stress of 110.85 ± 77.08 MPa, an elongation at a break rate of 2.29 ± 1.27 %, and Young's modulus of 6.05 ± 3.9 GPa. The maximum likelihood method (2P-Weibull distribution) was employed to examine the distribution of mechanical properties of fibers. According to the results above, new ChFs are an excellent reinforcement for elaborating fiber-reinforced biocomposites.
RESUMO
This study addresses the critical need for efficient and recyclable photocatalysts for water treatment applications by presenting a novel approach for the synthesis and characterization of copper (I) oxide (Cu2O) nanoparticles modified with ascorbic acid (Cu2O/AA). The motivation for this research stems from the increasing concern about environmental pollution caused by organic pollutants, such as Brilliant Cresyl Blue (BCB), and the necessity for sustainable solutions to mitigate this issue. Through comprehensive characterization techniques including Ultraviolet-Visible spectroscopy (UV-Vis), Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), zeta potential measurements, and Brunauer-Emmett-Teller (BET) analysis, we demonstrate a significant modification to the electronic structure, enhancing the photocatalytic activity of Cu2O/AA. BET analysis revealed a mesoporous structure with a specific surface area of 2.7247 m2/g for Cu2O/AA, further emphasizing its potential for enhanced catalytic performance. The photocatalytic degradation studies showcased remarkable efficiency improvements, with degradation coefficients of 30.8% and 73.12% for Cu2O NPs and Cu2O/AA NC, respectively, within a 120 min timeframe. Additionally, recyclability experiments indicated sustained efficiency over five consecutive cycles, with both catalysts retaining crystalline integrity. These findings underscore the promising potential of Cu2O/AA nanoparticles as highly efficient and recyclable photocatalysts for the degradation of organic pollutants, offering superior performance compared to pure Cu2O NPs and addressing the pressing need for sustainable water treatment solutions.