RESUMO
We wish to present a simple, rapid, cost-effective and environmentally safe method for staining proteins in polyacrylamide gels, using aqueous-based natural extracts from fresh green walnut (Juglans regia) hulls/husks. The technique takes not more than 10 min for staining and is comparable in sensitivity to the most commonly used Coomassie R-250 staining method when applied to different concentrations of Bovine Serum Albumin (BSA) and various amounts of E. coli extracts. The protein (BSA) band (~0.5 µg) and E. coli extract comprising ~25 µg total protein can be visualized on polyacrylamide gels. Compared to both Coomassie and Ponceau S staining, the current method displayed more intense bands when proteins are transferred to polyvinylidene fluoride (PVDF) membrane. Although the walnut-dye (WD) method does not require a time-consuming destaining step, excess background stain can simply be removed by washing in water. Extract from old dried black husks and extract from fresh green husks kept for a year was also effective. Using LC-MS, Myricetin and/or Kaempferol were found to be active compounds responsible for staining proteins. Compared to traditional Coomassie method, the inclusion of expensive and toxic solvents (methanol and acetic acid) is completely avoided resulting in positive health, environmental and economic benefits. In view of all these advantages, the WD method has immense potential to replace currently used protein staining techniques.
Assuntos
Química Verde/economia , Química Verde/métodos , Juglans/química , Extratos Vegetais/química , Proteínas/química , Coloração e Rotulagem/economia , Coloração e Rotulagem/métodos , Resinas Acrílicas/química , GéisRESUMO
There is an increasing trend of developing various low-cost biogenic sorbents for the efficient and economical removal of noxious metals . Curry leaf powder (CLP), a promising non-toxic biosorbent containing several bioactive compounds was prepared by the pulverization of the dried leaves for the effective removal of Lead (Pb) and Cadmium (Cd). Various batch sorption experiments were carried out under constant temperature (25 °C), different pH (4.5-10.5), initial concentrations (50-200 mg L-1), adsorbent dosages (0.10-0.40 g) and contact times (0-60 min) to understand the optimum experimental conditions and simultaneously evaluate the adsorption isotherms and removal kinetics of CLP. Adsorption equilibrium was established in less than an hour interval (50 min). The pseudo-equilibrium process was best described by the pseudo-second-order kinetic (R2 ≥ 0.99), Freundlich and Langmuir isotherm model (R2 ≥ 0.94). The removal rate of Pb and Cd gradually increased (15.7 and 12.7 mg g-1 for Pb and Cd) at 100 mg L-1 of initial concentration till 60 min of contact period in a single contaminant system, the effect was non-significant for multiple adsorbent dosage systems (p > 0.05; t-test) though. The regeneration potential of the exhausted biosorbent was excellent upto 5 cycles with the better efficiency observed for Pb. The obtained results explicitly validated the probable utilization of CLP as a promising green adsorbent for metal removal . Future study may highlight the decontamination aspects of emerging contaminants with such green bio sorbents in large scale as well as mimicing the stomach conditions.
Assuntos
Cádmio/química , Chumbo/química , Murraya , Preparações de Plantas/química , Polifenóis/química , Pós/química , Poluentes Químicos da Água/química , Adsorção , Análise Custo-Benefício , Química Verde/economia , Cinética , Folhas de Planta , Reciclagem , Purificação da Água/economia , Purificação da Água/métodosRESUMO
Aim: The primary goal of this work was to synthesize low-cost superparamagnetic iron oxide nanoparticles (SPIONs) with the aid of coconut water and evaluate the ability of macrophages to internalize them. Our motivation was to determine potential therapeutic applications in drug-delivery systems associated with magnetic hyperthermia. Materials & methods: We used the following characterization techniques: x-ray and electron diffractions, electron microscopy, spectrometry and magnetometry. Results: The synthesized SPIONs, roughly 4 nm in diameter, were internalized by macrophages, likely via endocytic/phagocytic pathways. They were randomly distributed throughout the cytoplasm and mainly located in membrane-bound compartments. Conclusion: Nanoparticles presented an elevated intrinsic loss power value and were not cytotoxic to mammalian cells. Thus, we suggest that low-cost SPIONs have great therapeutic potential.
Assuntos
Compostos Férricos/uso terapêutico , Química Verde/métodos , Macrófagos/metabolismo , Nanopartículas de Magnetita/uso terapêutico , Animais , Sistemas de Liberação de Medicamentos , Compostos Férricos/farmacocinética , Química Verde/economia , Hipertermia Induzida/métodos , Nanopartículas de Magnetita/análise , Nanopartículas de Magnetita/ultraestrutura , Camundongos , Células RAW 264.7RESUMO
The present study underlines a statistically optimized, low cost, effective approach for efficient co-valorization of two non-efficiently utilized, highly accumulated, raw agro-industrial wastes: corn cob and glycerol for co-production of natural biopigments: monascus orange and red pigments by the aid of Monascus purpureus strain ATCC 16436. A three step sequential, statistical modeling approach: one variable at a time (OVAT), Plackett-Burman design (PBD), and central composite design (CCD) was employed to optimize the production of monascus pigments using co-solid state fermentation of the two raw agro-industrial wastes. Corn cob among other carbon sources (e.g., rice grains, sugarcane bagasse, and potato peel) was the most appropriate substrate triggering co-production of orange and red monascus pigments; deduced from OVAT. Glycerol and inoculum size proved to impose significant consequences (P<0.05) on the production of monascus pigments as inferred from PBD. The optimal levels of inoculum size (12 x 1011 spores/mL) and glycerol (2.17 M) did achieve a maximal color value of 133.77 and 108.02 color value units/mL of orange and red pigments, respectively at 30 oC after 10 days; concluded from CCD with an agitation speed of 150 rpm. Present data would underpin the large scale production of monascus pigments using the present approach for efficient exploitation of such biopigments in food, pharmaceutical and textile industries.
Assuntos
Glicerol/metabolismo , Química Verde/métodos , Monascus/metabolismo , Pigmentos Biológicos/biossíntese , Zea mays/metabolismo , Celulose/metabolismo , Cor , Análise Custo-Benefício , Fermentação , Química Verde/economia , Humanos , Resíduos Industriais/análise , Modelos Biológicos , Oryza/metabolismo , Pigmentos Biológicos/química , Saccharum/metabolismo , Solanum tuberosum/metabolismoRESUMO
The nutraceutical potential of microalgae boomed with the exploitation of new species and sustainable extraction systems of bioactive compounds. Thus, a laboratory-made continuous pressurized solvent extraction system (CPSE) was built to optimize the extraction of antioxidant compounds, such as carotenoids and PUFA, from a scarcely studied prokaryotic microalga, Gloeothece sp. Following "green chemical principles" and using a GRAS solvent (ethanol), biomass amount, solvent flow-rate/pressure, temperature and solvent volume-including solvent recirculation-were sequentially optimized, with the carotenoids and PUFA content and antioxidant capacity being the objective functions. Gloeothece sp. bioactive compounds were best extracted at 60 °C and 180 bar. Recirculation of solvent in several cycles (C) led to an 11-fold extraction increase of ß-carotene (3C) and 7.4-fold extraction of C18:2 n6 t (5C) when compared to operation in open systems. To fully validate results CPSE, this system was compared to a conventional extraction method, ultrasound assisted extraction (UAE). CPSE proved superior in extraction yield, increasing total carotenoids extraction up 3-fold and total PUFA extraction by ca. 1.5-fold, with particular extraction increase of 18:3 n3 by 9.6-fold. Thus, CPSE proved to be an efficient and greener extraction method to obtain bioactive extract from Gloeothece sp. for nutraceutical purposes-with low levels of resources spent, while lowering costs of production and environmental impacts.
Assuntos
Carotenoides/isolamento & purificação , Cianobactérias/química , Suplementos Nutricionais , Ácidos Graxos/isolamento & purificação , Química Verde/métodos , Microalgas/química , Antioxidantes/isolamento & purificação , Produtos Biológicos/isolamento & purificação , Biomassa , Etanol/química , Química Verde/economia , Extração Líquido-Líquido/economia , Extração Líquido-Líquido/métodos , Temperatura , Ondas UltrassônicasRESUMO
Sideritis montana L. endemic of Turkey was screened for its polyphenols content and antioxidant activity. Factor analysis and experimental design have been applied to understand the structure of the separation process, to determine the effective parameters, and to accomplish the performance improvement. Face-centred composite design (FCD) of response surface methodology (RSM) was applied to evaluate the influences of solvent concentration, solvent amount, extraction time, and stirring speed of homogenizer-assisted extraction (HAE) as well as to model and to optimize the HAE. Quadratic models were highly significant (pâ¯<â¯0.0001) for the responses studied with high coefficients of determination (R2) of 0.9440, 0.9415 and 0.9521. The result of the study suggests that 15.02â¯mL of 22.69% EtOH solution (v/v), 70.16â¯s, and 9524.52â¯rpm of mixing speed are the optimal conditions to obtain the highest yield of total polyphenols (TPC) and flavonoids (TFC), and the best antioxidant activity (AA). Rosmarinic acid was identified as the most abundant component.
Assuntos
Antioxidantes/isolamento & purificação , Fracionamento Químico/métodos , Extratos Vegetais/isolamento & purificação , Polifenóis/isolamento & purificação , Sideritis/química , Antioxidantes/farmacologia , Fracionamento Químico/instrumentação , Cinamatos/isolamento & purificação , Cinamatos/farmacologia , Depsídeos/isolamento & purificação , Depsídeos/farmacologia , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Química Verde/economia , Química Verde/instrumentação , Química Verde/métodos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Solventes/química , Ácido RosmarínicoRESUMO
AIM AND OBJECTIVE: The present method is simple, green and highly efficient for the synthesis of 2-amino-4H-pyran derivatives which are achieved by a one pot three component cyclocondensation of aldehyde, malanonitrile and ethyl acetoacetate or methyl acetoacetate using DABCO under solvent free with grinding conditions at room temperature. MATERIAL AND METHODS: Some of the synthesized compounds were screened for their antimicrobial and antifungal activity. The study shows that these compounds show good antimicrobial activity. Furthermore, eight of the synthesized compounds were selected for screening of their anticancer activity against human astrocytoma-glioblastoma cell line (U373MG). Some of the compounds show good anticancer activity. RESULT: Grinding synthesis of 2-amino-4H-pyran derivatives catalyzed by DABCO with various aromatic aldehydes under solvent-free conditions at room temperature was examined. The obtained compounds (22 entries) were well synthesized in good to excellent yields. CONCLUSION: The present method is simple, rapid, and most efficient green protocol for the synthesis of 2-amino-4H-pyran derivatives using highly inexpensive and easily available DABCO as an efficient catalyst under grinding and solvent free condition at room temperature.
Assuntos
Antibacterianos/síntese química , Antineoplásicos/síntese química , Piranos/síntese química , Animais , Antifúngicos/síntese química , Catálise , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos , Química Verde/economia , Química Verde/métodos , Humanos , Piranos/farmacologiaRESUMO
Many technologically relevant semiconductors contain toxic, heavily regulated (Cd, Pb, As), or relatively scarce (Li, In) elements and often require high manufacturing costs. We report a facile, general, low-temperature, and size tunable (4-28 nm) solution phase synthesis of ternary APnE2 semiconductors based on Earth-abundant and biocompatible elements (A = Na, Pn = Bi, E = S or Se). The observed experimental band gaps (1.20-1.45 eV) fall within the ideal range for solar cells. Computational investigation of the lowest energy superstructures that result from "coloring", caused by mixed cation sites present in their rock salt lattice, agrees with other better-known members of this family of materials. Our synthesis unlocks a new class of low cost and environmentally friendly ternary semiconductors that show properties of interest for applications in energy conversion.
Assuntos
Bismuto/química , Selênio/química , Semicondutores , Sódio/química , Enxofre/química , Química Verde/economia , Química Verde/métodos , Modelos Moleculares , Energia Solar , Propriedades de SuperfícieRESUMO
A novel method for indirect determination of MCPD esters levels in lipid samples has been developed. The method is based on combination of extraction and derivatization in the same sample preparation step. It is achieved by the application of diethyl ether as extraction solvent for isolation of analytes released from esterified forms from the water phase and as dilution solvent for solid PBA - the derivatization agent. It is a noteworthy improvement of recommended indirect approaches available in the literature because such steps as sample clean-up, multiple liquid-liquid extractions, and preconcentration are excluded in the proposed solution. In this way, the developed procedure is shortened and simplified. Such an approach also minimizes the utilization of organic solvents; therefore, it is in accordance with the principles of "green analytical chemistry." In spite of the fact that the step of sample clean-up is omitted, no deterioration in GC-MS system performance was observed. Equivalence testing of the developed procedure and AOCS cd 29b-13 official method (SGS) has been conducted. It was concluded that results obtained by both methods do not significantly differ statistically. The procedure has been applied to determination of MCPD esters concentrations in lipid fractions isolated by accelerated solvent extraction technique from such foodstuffs as bakery products, salty deep-fried snacks, and instant products. In all investigated samples, the level of bound MCPD was elevated. Additionally, for both procedures, the environmental impact (with the use of analytical Eco-scale) and uncertainty budget have been assessed and compared.
Assuntos
Gorduras Insaturadas na Dieta/análise , Ácidos Graxos/análise , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Química Verde/métodos , alfa-Cloridrina/análise , Esterificação , Análise de Alimentos/economia , Cromatografia Gasosa-Espectrometria de Massas/economia , Química Verde/economia , Limite de Detecção , Fatores de TempoRESUMO
As part of a long-term strategy toward renewable feedstock, a feasibility study into options for the production of bioethylene by integrating the sugar beet-to-ethanol-to-ethylene value chain. Seven business cases were studied and tested for actual economic feasibility of alternative sugar-to-ethanol-to-ethylene routes in comparison to fossil-fuel alternatives. An elaborate model was developed to assess the relevant operational and financial aspects of each business case. The calculations indicate that bioethylene from sugar beet is not commercially viable under current market conditions. In light of expected global energy and feedstock prices it is also reasonable to expect that this will not change in the near future. To consider biorenewable sources as starting material, they need to be low in cost (compared to sugar beets) and also require less capital and energy-intensive methods for the conversion to chemicals. In general, European sugar prices will be too high for many chemical applications. Future efforts for in sugar-to-chemicals routes should, therefore, focus on integrated process routes and process intensification and/or on products that contain a significant part of the original carbohydrate backbone.
Assuntos
Beta vulgaris/química , Etilenos/química , Química Verde/economia , Estudos de ViabilidadeRESUMO
A facile rapid green eco-friendly method to synthesize gold nanoparticles (Au NPs) of tunable size using aqueous Terminalia arjuna fruit extracts has been demonstrated herein. Formation of Au NPs was confirmed by Surface Plasmon Resonance (SPR) study at 528 nm using UV-visible spectrophotometer. The time of reduction, size and morphological variations of Au NPs were studied with varying quantities of T. arjuna fruit aqueous extracts. Synthesized Au NPs were characterized using UV-visible spectroscopy, Fourier transformed infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and Energy dispersive X-ray spectroscopy (EDAX). Polyphenols responsible for reduction of Au(3+) to Au(0) were identified using High Performance Liquid Chromatography (HPLC) as ascorbic acid, gallic acid and pyrogallol. The oxidized forms of polyphenols formed coordination with surface of Au NPs which protected their further growth and aggregation. We also propose a plausible mechanism how to tune size and shape of Au NPs by varying the quantity of extracts. Thus obtained Au NPs were stable for more than four months.
Assuntos
Ouro/química , Química Verde/métodos , Nanopartículas/química , Extratos Vegetais/química , Polifenóis/química , Terminalia/química , Química Verde/economia , Nanopartículas/ultraestrutura , Oxirredução , Tamanho da PartículaRESUMO
The use of natural reagents from plant extracts for chemical analysis is one of the approaches in the development of low cost and environmentally friendly green analytical chemistry methodology. Here, crude extract from Indian Almond (Terminalia Catappa L.) leaves was used for colorimetric determination of aluminum by monitoring the absorbance of the Al(3+)-extract complex at 435 nm. Dry leaves and freeze-dried fresh leaf extract can be kept for extended use. A simple flow injection analysis (FIA) system was also employed for rapid analysis (approximately 180 injections/h). The linear working range up to 100 mg L(-1) was established with a detection limit (blank + 3SD) of 0.8 mg L(-1), a limit of quantitation (blank + 10SD) of 2.4 mg L(-1), and a relative standard deviation of 3-5%. This simple green analytical chemistry methodology was applied for the determination of Al(3+) in waste water samples from ceramic factories. The results agreed well with the results obtained from the ICP-OES technique.
Assuntos
Alumínio/análise , Cerâmica , Química Verde , Folhas de Planta , Prunus , Terminalia , Águas Residuárias/química , Técnicas de Química Analítica , Colorimetria , Análise de Injeção de Fluxo/métodos , Química Verde/economia , Íons , Estrutura Molecular , Fatores de TempoRESUMO
The present study was to investigate the feasibility of carrying out effective microalgae cultivation and high-rate tertiary wastewater treatment simultaneously in a vertical sequencing batch photobioreactor with small areal footprint, suitable for sustainable urban microalgae production. For 15 consecutive days, Chlorella sorokiniana was cultivated in synthetic wastewater under various trophic conditions. A cycle of 12-h heterotrophic: 12-h mixotrophic condition produced 0.98 g l(-1) d(-1) of algal biomass in tandem with a 94.7% removal of 254.4 mg l(-1) C-acetate, a 100% removal of 84.7 mg l(-1) N-NH4 and a removal of 15.0 mg l(-1) P-PO4. The cells were harvested via cost-effective chitosan flocculation with multiple dosing (3 times) applying established chitosan:cell ratio (1:300 w/w) and pH control (6.3-6.8). Reproducible flocculation efficiencies of greater than 99% and high-concentration algal broths (>20% solids) were achieved.
Assuntos
Biomassa , Biotecnologia/métodos , Cidades , Química Verde/métodos , Microalgas/crescimento & desenvolvimento , Acetatos/isolamento & purificação , Processos Autotróficos , Biodegradação Ambiental , Biotecnologia/economia , Quitosana/química , Análise Custo-Benefício , Floculação , Química Verde/economia , Processos Heterotróficos , Concentração de Íons de Hidrogênio , Nitrogênio/isolamento & purificação , Fosfatos/isolamento & purificação , Fósforo/isolamento & purificação , Compostos de Amônio Quaternário/isolamento & purificaçãoRESUMO
A simple method for the green synthesis of silver nanoparticles (AgNPs) using aqueous extract of Lakshmi tulasi (Ocimum sanctum) leaf as a reducing and stabilizing agent. AgNPs were rapidly synthesized using aqueous extract of tulasi leaf with AgNO(3) solution within 15 min. The green synthesized AgNPs were characterized using physic-chemical techniques viz., UV-Vis, X-ray diffraction (XRD), scanning electron microscope (SEM) coupled with X-ray energy dispersive spectroscopy (EDX) and Fourier transform-infrared spectroscopy (FT-IR). Characterization data reveals that the particles were crystalline in nature and triangle shaped with an average size of 42 nm. The zeta potential of AgNPs were found to be -55.0 mV. This large negative zeta potential value indicates repulsion among AgNPs and their dispersion stability.
Assuntos
Química Verde/métodos , Nanopartículas Metálicas/química , Ocimum/química , Extratos Vegetais/química , Folhas de Planta/química , Prata/química , Química Verde/economia , Nanopartículas Metálicas/ultraestrutura , Oxirredução , Espectrometria por Raios X , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios XRESUMO
The biological approach to synthesis of AuNPs is eco-friendly and an ideal method to develop environmentally sustainable nanoparticles alternative to existing methods. We have developed a simple, fast, clean, efficient, low-cost and eco-friendly single-step green chemistry approach for the synthesis of biocompatible gold nanoparticles (AuNPs) from chloroauric acid (HAuCl(4)) using a water extract of Eclipta Alba leaves at room temperature. The AuNPs using Eclipta extract have been formed in very short time, even in less than 10 min. The as-synthesized AuNPs were thoroughly characterized by several physico-chemical techniques. The in vitro stability of as-synthesized AuNPs was studied in different buffer solutions. A plausible mechanism for the synthesis of AuNPs by Eclipta extract has been discussed. The biocompatibility of AuNPs was observed by in vitro cell culture assays. Finally, we have designed and developed a AuNPs-based drug delivery system (DDS) (Au-DOX) containing doxorubicin (DOX), a FDA approved anticancer drug. Administration of this DDS to breast cancer cells (MCF-7 and MDA-MB-231) shows significant inhibition of breast cancer cell proliferation compared to pristine doxorubicin. Therefore we strongly believe that the use of Eclipta Alba offers large-scale production of biocompatible AuNPs that can be used as a delivery vehicle for the treatment of cancer diseases.
Assuntos
Portadores de Fármacos/química , Eclipta/química , Ouro/química , Química Verde/métodos , Nanopartículas Metálicas/química , Extratos Vegetais/química , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cloretos/química , Doxorrubicina/administração & dosagem , Doxorrubicina/farmacologia , Portadores de Fármacos/síntese química , Feminino , Compostos de Ouro/química , Química Verde/economia , Humanos , Extratos Vegetais/isolamento & purificação , Folhas de Planta/químicaRESUMO
In the present study, the biosynthesis of rutile TiO(2) nanoparticles (TiO(2) NPs) was achieved by a novel, biodegradable and convenient procedure using fruit peel Annona squamosa aqueous extract. This is the first report on the new, simple, rapid, eco-friendly and cheaper methods for the synthesis of rutile TiO(2) NPs at lower temperature using agricultural waste. Rutile TiO(2) NPs were characterized by UV, XRD, SEM, TEM and EDS studies. The UV-Vis spectrophotometer results were promising and showed a rapid production of TiO(2) NPs with a surface plasmon resonance occurring at 284 nm. The formation of the TiO(2) NPs as observed from the XRD spectrum is confirmed to be TiO(2) particles in the rutile form as evidenced by the peaks at 2θ=27.42°, 36.10°, 41.30° and 54.33° when compared with the literature. The TEM images showed polydisperse nanoparticles with spherical shapes and size 23±2 nm ranges.
Assuntos
Annona/química , Corantes/química , Química Verde/métodos , Nanopartículas/química , Extratos Vegetais/química , Titânio/química , Química Verde/economia , Nanopartículas/ultraestrutura , Extratos Vegetais/síntese química , Espectrofotometria Ultravioleta , Ressonância de Plasmônio de Superfície , Difração de Raios XRESUMO
A simple, efficient and economical method for the recovery of P(3HB-co-3HHx) was developed using various chemicals and parameters. The initial content of P(3HB-co-3HHx) in bacterial cells was 50-60 wt%, whereas the monomer composition of 3HHx used in this experiments was 3-5 mol%. It was found that sodium hydroxide (NaOH) was the most effective chemical for the recovery of biodegradable polymer. High polyhydroxyalkanoate purity and recovery yield both in the range of 80-90 wt% were obtained when 10-30 mg/ml of cells were incubated in NaOH at the concentration of 0.1 M for 60-180 min at 30 °C and polished using 20 % (v/v) of ethanol.
Assuntos
Ácido 3-Hidroxibutírico/química , Ácido 3-Hidroxibutírico/isolamento & purificação , Caproatos/química , Caproatos/isolamento & purificação , Fracionamento Químico/métodos , Cupriavidus necator/genética , DNA Recombinante/genética , Química Verde/métodos , Ácido 3-Hidroxibutírico/biossíntese , Aciltransferases/genética , Cupriavidus necator/citologia , Cupriavidus necator/metabolismo , Química Verde/economia , Óleo de Palmeira , Óleos de Plantas/metabolismo , Plasmídeos/genética , Hidróxido de Sódio/química , Solventes/química , Água/químicaRESUMO
The simple transfer of established chemical production processes from batch to flow chemistry does not automatically result in more sustainable ones. Detailed process understanding and the motivation to scrutinize known process conditions are necessary factors for success. Although the focus is usually "only" on intensifying transport phenomena to operate under intrinsic kinetics, there is also a large intensification potential in chemistry under harsh conditions and in the specific design of flow processes. Such an understanding and proposed processes are required at an early stage of process design because decisions on the best-suited tools and parameters required to convert green engineering concepts into practice-typically with little chance of substantial changes later-are made during this period. Herein, we present a holistic and interdisciplinary process design approach that combines the concept of novel process windows with process modeling, simulation, and simplified cost and lifecycle assessment for the deliberate development of a cost-competitive and environmentally sustainable alternative to an existing production process for epoxidized soybean oil.
Assuntos
Meio Ambiente , Compostos de Epóxi/química , Química Verde/economia , Química Verde/métodos , Óleo de Soja/químicaRESUMO
The synthesis of metal nanoparticles of different sizes, shapes, chemical composition and controlled monodispersity is an important area of research in nanotechnology because of their interesting physical properties and technological applications. Present work describes an eco-friendly method for the synthesis of spherical gold nanoparticles using aqueous extract of Macrotyloma uniflorum. The effects of quantity of extract, temperature and pH on the formation of nanoparticles are studied. The nanoparticles are characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and FTIR analysis. The high crystallinity of nanoparticles with fcc phase is evident from HRTEM images, SAED and XRD patterns. Synthesized nanoparticles have size in the range 14-17nm. FTIR spectrum indicates the presence of different functional groups present in the bio-molecule capping the nanoparticles. The possible mechanism leading to the formation of gold nanoparticles is suggested.
Assuntos
Fabaceae/química , Ouro/química , Química Verde/métodos , Nanopartículas Metálicas/química , Nanotecnologia/métodos , Extratos Vegetais/química , Química Verde/economia , Nanopartículas Metálicas/ultraestrutura , Nanotecnologia/economia , Tamanho da PartículaRESUMO
Here we report a new "green" method to synthesize Zn(1-x)Cd(x)Se (x = 0-1) and stable red-green-blue tricolor Zn(1-x)Cd(x)Se core/shell nanocrystals using only low cost, phosphine-free and environmentally friendly reagents. The first excitonic absorption peak and photoluminescence (PL) position of the Zn(1-x)Cd(x)Se nanocrystals (the value of x is in the range 0.005-0.2) can be fixed to any position in the range 456-540 nm. There is no red or blue shift in the entire reaction process. Three similar sizes of alloyed Zn(1-x)Cd(x)Se nanocrystals with blue, green, and yellow emissions were successfully selected as cores to synthesize high quality blue, green, and red core/shell nanocrystal emitters. For the synthesis of core/shell nanocrystals with a high quantum yield (QY) and stability, the selection of shell materials has been proven to be very important. Therefore, alternative protocols have been used to optimize thick shell growth. ZnSe/ZnSe(x)S(1-x) and CdS/Zn(1-x)Cd(x)S have been found as an excellent middle multishell to overcoat between the alloyed Zn(1-x)Cd(x)Se core and ZnS outshell. The QYs of the as-synthesized core/shell alloyed Zn(1-x)Cd(x)Se nanocrystals can reach 40-75%. The Cd content is reduced to less than 0.1% for Zn(1 -x)Cd(x)Se core/shell nanocrystals with emissions in the range 456-540 nm. More than 15 g of high quality Zn(1-x)Cd(x)Se core/shell nanocrystals were prepared successfully in a large scale, one-pot reaction. Importantly, the emissions of such thick multishell nanocrystals are not susceptible to ligand loss and stability in various physiological conditions.