Top Phase Research Articles

Influence of Top Layer Composition on the Photovoltaic Parameters of P3HT:PCBM Organic Solar Cells

Spin and spray deposition techniques have been used sequentially to examine the effect of the composition of top blend layer on the photovoltaic properties of organic solar cells using well-known poly(3-hexylthiophene):[6,6]-Phenyl C61 butyric acid methyl ester (P3HT:PCBM) blend. Devices were prepared by spraying an extra layer of P3HT or PCBM (~15 nm) onto spin coated (1:1) blend film. P3HT-rich top phase slightly perturbs photovoltaic activity whereas PCBM-rich top phase drastically changes the power conversion efficiencies with a marked decrease in fill factors. Carrier mobilities were only marginally affected by the presence of spray coated top layers. However, series resistance of top phase P3HT-rich blends remained the same with respect to spin coated sample whereas top phase PCBM-rich blends exhibit relatively higher series resistances for both annealed and non-annealed samples. Based on the presented results, one might speculate that electron injection to cathode with P3HT is almost as efficient as with PCBM for active layers utilizing P3HT:PCBM blend.

Application of aqueous two-phase systems for the extraction of pharmaceutical compounds from water samples

In this study, the proposal was to use aqueous two-phase systems (ATPS) as a sample preparation technique for the determination of five pharmaceuticals, classified as emerging contaminants (EC): ibuprofen, paracetamol, ciprofloxacin, norfloxacin and amoxicillin. The evaluation of this study was performed through the partition coefficient (K) of each pharmaceutical by varying some parameters of the system, such as the pH value of the medium, the nature of the ATPS-forming electrolyte and polymer, the tie-line length (TLL), the system temperature and the mass ratio between the top and bottom phases of the ATPS. Values of K between 9.30 and 1150 were obtained for the five pharmaceuticals during the system optimization. The ATPS also proved to be efficient as a sample preparation technique in the partition of the studied pharmaceuticals when applied to water samples, including drinking water, surface water and filtered water from a water treatment plant. The values of the partition coefficients found in these complex samples ranged from 2.49 to 74.2.

Efficiency of Ionic Liquids-Based Aqueous Two-phase Electrophoresis for Partition of Cytochrome c.

Cytochrome c is a small water-soluble protein that is abundantly found in the mitochondrial intermembrane space of microorganism, plants and mammalians. Ionic liquids (ILs)-based aqueous two-phase electrophoresis system (ATPES) was introduced in this study to investigate the partition efficiency of cytochrome c to facilitate subsequent development of two-phase electrophoresis for the separation of cytochrome c from microbial fermentation. The 1-Hexyl-3-methylimidazolium bromide, (C6mim)Br and potassium citrate salt were selected as the phase-forming components. Effects of phase composition; position of electrodes; pH and addition of neutral salt on the partition efficiency of cytochrome c in the ATPES were evaluated. Highest partition coefficient (K = 179.12 ± 0.82) and yield of cytochrome c in top phase (YT = 99.63% ± 0.00) were recorded with IL/salt ATPES composed of 30% (w/w) (C6mim)Br and 20% (w/w) potassium citrate salt of pH7 and 3.0% (w/w) NaCl addition with anode at the bottom phase and cathode at the top phase. The SDS-PAGE profile revealed that cytochrome c with a molecular weight of 12kDa was preferably partitioned to the IL-rich top phase. Present findings suggested that the single-step ATPES is a potential separation approach for the recovery of cytochrome c from microbial fermentation. Graphical Abstract.

Characterising the conversion of transesterification reaction by modelling of glycerol-rich phase

The preparation of fatty acid methyl esters (FAME) involves different phase changes which are not yet characterised. The reaction media in its initial and final stages form two phases; top phase being FAME/unreacted oil and bottom phase being glycerol/methanol. The exact point when the bottom phase starts forming is not well defined. Experimental data of the reaction media composition gives an understanding of the formation of the glycerol phase. A model built for its theoretical concurrence showed good agreement with experimental data. From experimentation, the density of the bottom glycerol/methanol phase showed to be a good and simple indicator of the reaction conversion.

Characterising the conversion of transesterification reaction by modelling of glycerol-rich phase

The preparation of fatty acid methyl esters (FAME) involves different phase changes which are not yet characterised. The reaction media in its initial and final stages form two phases; top phase being FAME/unreacted oil and bottom phase being glycerol/methanol. The exact point when the bottom phase starts forming is not well defined. Experimental data of the reaction media composition gives an understanding of the formation of the glycerol phase. A model built for its theoretical concurrence showed good agreement with experimental data. From experimentation, the density of the bottom glycerol/methanol phase showed to be a good and simple indicator of the reaction conversion.

In vitro bioaccessibility of fish oil-loaded hollow solid lipid micro- and nanoparticles.

Fish oil-loaded hollow solid lipid micro- and nanoparticles were prepared by atomization of the CO2-expanded lipid mixture. The obtained particles were spherical and free-flowing with an average particle size of 6.9 μm. Fish oil loading efficiency was achieved at 92.3% (w/w). The in vitro digestive stability, lipid digestibility and EPA and DHA bioaccessibility of the fish oil-loaded particles were examined using an in vitro sequential digestion model. The mean particle diameter increased markedly after oral (15.2 μm) and gastric (32.4 μm) digestion and then decreased after the small intestinal stage (24.0 μm). Fish oil-loaded particles remained spherical and intact but mainly agglomerated on the top phase throughout the oral and gastric digestion. However, a mixed digesta was formed after the small intestinal digestion, which contained digested broken particle pieces, undigested fish oil-loaded particles, free fatty acids, monoacylglycerols and micelles. The extent of lipolysis was significantly increased for the 30% fish oil-loaded particles as compared to physical mixtures of empty hollow solid lipid particles or bulk FHSO and fish oil (p < 0.05). Moreover, EPA and DHA bioaccessibility was significantly improved from 9.7 to 18.2% with the 30% fish oil-loaded particles (p < 0.05).

Investigation on the control of multiphase flow behavior in a continuous casting tundish during ladle change

The transient multiphase flow behavior in a single-strand tundish during ladle change was studied using physical modeling. The water and silicon oil were employed to simulate the liquid steel and slag. The effect of the turbulence inhibitor on the slag entrainment and the steel exposure during ladle change were evaluated and discussed. The effect of the slag carry-over on the water-oil-air flow was also analyzed. For the original tundish, the top oil phase in the impact zone was continuously dragged into the tundish bath and opened during ladle change, forming an emulsification phenomenon. By decreasing the liquid velocities in the upper part of the impact zone, the turbulence inhibitor decreased considerably the amount of entrained slag and the steel exposure during ladle change, thereby eliminating the emulsification phenomenon. Furthermore, the use of the TI-2 effectively lowered the effect of the slag carry-over on the steel cleanliness by controlling the movement of slag droplets. The results from industrial trials indicated that the application of the TI-2 reduced considerably the number of linear inclusions caused by ladle change in hot-rolled strip coils.

ОПРЕДЕЛЕНИЕ ПАРАМЕТРОВ ОБЛАЧНОГО ПОКРОВА СИСТЕМАМИ АВТОМАТИЧЕСКОЙ ОБРАБОТКИ СПУТНИКОВЫХ ДАННЫХ

The paper discusses the results of comparing cloud cover properties determined by using polar orbiting satellite data (AVHRR/NOAA and MSU-MR/Meteor-M No. 2) for the European territory of Russia and Western Siberia. The cloud characteristics were computed by two threshold techniques: Complex Threshold Technique (CTT) (developed at the European Centre of the State Research Center ‗Planeta‘) and Cloud Cover Detection Technique (CCDT) (developed at the Siberian Centre of ‗Planeta‘). Pixel-by-pixel comparison was performed for very close in time satellite observations, and it showed that in spite of technical similarity of the two radiometers and little difference between both techniques used for the classifications, the results were not the same. The quality of the MSU-MR classification is significantly worse than that of the two AVHRR classifications. In fact, the MSU-MR derivation of cloud parameters fails in optically thin cirrus and altocumulus clouds, thus underestimating the cloud top height for multilayered clouds. As a result, the cloud top is found to be lower, warmer and less iced in comparison with both AVHRR estimates, regardless of the region and other conditions; on the contrary, the cloud top of low and middle clouds appears to be colder, higher and more iced according to MSU-MR data. The MSU-MR cloud mask is strongly underestimated at night during the cold period of the year. The CTT and CCDT‘s cloud top height, temperature and water phase retrieved by AVHRR data are quite close for both regions.

Study of electromotive force of a new type of membraneless fuel cell operating on renewable fuel

The possibility of using base metals and alloys based on them as electrodes for a new type of membraneless fuel cells operating on renewable fuel has been investigated. The phase boundary of two immiscible liquids in the ethanol-water-potassium hydroxide system plays a role of a membrane in these elements. Top phase of this fuel cell has significant alcohol content and insignificant electrolyte content, bottom phase has significant electrolyte content and insignificant alcohol content. Platinum- and ruthenium-coated titanium electrode, carbon electrode and stainless steel electrode were used as the anode. Stainless steel electrode and carbon steel electrode were used as the cathode. The possibility of using ferrous alloys as anode and cathode catalysts in this type of fuel cells is shown.

Systems of two immiscible liquids for a new type of membraneless fuel cells using renewable fuel

Systems of two immiscible liquids are proposed for a new type of membraneless fuel cells using renewable fuel, in which the stationary phase boundary carries out a role of membrane. These systems consist of water, alcohol (preferable ethanol) and a number of electrolytes (salts and bases) leading to the layering of aqueous alcohol. In such systems top phase has significant alcohol content and insignificant electrolyte content, bottom phase has significant electrolyte content and insignificant alcohol content. To study the layering conditions in these systems, binodal curves were plotted for three two-phase liquid systems (EtOH + K2CO3 + H2O; EtOH + K3PO4 + H2O, EtOH + KOH + H2O), using the cloud point method. Comparison of our experimental data with the results of other authors showed that they are consistent for the first and second systems, and the temperature dependence of the binodal curves is clearly visible for the third system. The specific system EtOH – 30 % m/m; KOH – 40 % m/m; H2O – 30 % m/m was taken as the basis for studies of fuel cells based on two immiscible liquids. A further area of research lies in the field of optimizing the composition of both phases, studying the processes of mass transfer in these systems and their physicochemical characteristics.

First report on Chlorella vulgaris collagenase production and purification by aqueous two-phase system

Collagen is triple helical structured protein, which is undegradable by most proteases and reacts only with collagenases. These enzymes are applied and important in several commercial segments and the interest for new collagenases has only been increasing. Microalgae are not a very prominent source of enzymes but are extremely commercially attractive forms of life due to photosynthetic growth. Yet, the literature is absent on reports about algae collagenases and this work is the first report on Chlorella vulgaris collagenolytic enzyme production, purification and characterization. C. vulgaris was cultivated in autotrophic and mixotrophic conditions and the biomass used to obtain the cell extract. The autotrophic extract displayed a higher collagenolytic activity and was used for ATPS experimental design. Through 24-full factorial design, high collagenolytic activity was observed at pH 8.0, PEG molar mass of 1500 g/mol, PEG concentration of 12.5% (w/w) and phosphate buffer concentration of 15% (w/w). In these conditions, a purification factor of 10.79 was obtained for a partition coefficient of 23.74 with the collagenase retained in top PEG rich phase. Purified collagenase optimum activity was observed under pH 9 and 37 °C, displayed less gelatinolytic and caseinolytic activity, with higher collagenolytic activity with azocoll than crude extract, attesting this enzyme is a true collagenase. The collagenolytic activity was inhibited by EDTA, an indicative of a metallocollagenase.

Potensi Produk Cair (Oil Phase dan Water Phase) Pirolisis Mikroalga Sebagai Pengawet Makanan

Microalgae is one of the oldest living organisms namely Thallophyta (plant lacking roots, stems, and leaves) that have chlorophyll as a pigment to mainly photosynthesis process. Microalgae as the water plant had some characteristics such as high carbohydrate, protein, and lipid content in which can be produced energy (liquid, solid, and gas) by using the pyrolysis process. The raw material in this experiment was used Spirulina platensis as the type of microalgae. The residue of Spirulina platensis was content acid, phenol, dan carbonyl in which this product liquid is potential as a food preservative. The experiment was performed by using the pyrolysis process which is equipped with a cooler (condenser) to condense the combustion vapor. Thermal decomposition was conducted in the pyrolysis reactor with a temperature of 300 ℃, 400 ℃, 500 ℃, and 600 ℃ under atmospheric condition. The result indicated that the pyrolysis proses had oil phase as the top result and water phase as the bottom result. The result from GC/MS analysis reported that the pyrolysis process on temperature of 300 ℃ can produce the oil phase with the phenol content of 6.7 wt.%, acid of 33.03 wt.%, carbonyl of 4.95 wt.%, and Poly Aromatic Hydrocarbon (PAH) of 6.23 wt.%, respectively. Otherwise, the pyrolysis process can produce the water phase (liquid smoke) on temperature 400 °C, 500 °C, dan 600 °C with the phenol content of 0.22 wt.%, acid content of 0.69-9.12 wt.%, carbonyl content of 10.46-13.02 wt.% and PAH of 26.93-45.18 wt.%. The superiority of preservatives from residual Spirulina platensis has a high nitrogenate content from protein decomposition (10.13-31.22 wt.%). High protein content in food preservatives can be used as an additive compound to increase protein intake.

Enzymatic hydrolysis of cellulose recovered from ionic liquid-salt aqueous two-phase system

Regenerated cellulose can be prepared by treatment with an ionic liquid (IL) and an anti-solvent such as water, which significantly enhances the enzymatic hydrolysis in comparison to crystalline cellulose. The IL-aqueous two-phase system (IL-ATPS) is consisted of IL-condensed top phase and salt-condensed bottom phase, which could be suitable to produce regenerated cellulose with smaller amount of IL. Using IL-ATPS with different pH, the enzymatic saccharification efficiency of crystalline cellulose was determined. The use of 1-allyl-3-methylimidazolium chloride resulted in relatively higher yield of glucose production as compared to 1-butyl-3-methylimidazolium chloride. The IL-ATPS showing optimal pH for cellulase was prepared with mixed salt (NaH2PO4/Na2HPO4=5/1 (wt/wt)), which provide a regenerated cellulose with the pH range of 4.8-4.9 in enzymatic reaction mixture. Using such regenerated cellulose as feed of saccharification, the final yield of glucose was about 70%.

Sequential degradation of raw vinasse by a laccase enzyme producing fungus Pleurotus sajor-caju and its ATPS purification

This study evaluated simultaneously the raw vinasse degradation, an effluent from the sugar-alcohol industry, the laccase production by Pleurotus sajor-caju and its purification using aqueous two-phase systems (ATPS). To improve laccase production, different concentrations of inducers (ethanol and CuSO4) were added. The higher laccase production promoted an increase of 4-fold using 0.4 mM of CuSO4 as inducer, with maximum enzymatic activity of 539.3 U/L on the 3rd day of fermentation. The final treated vinasse had a decolorization of 92% and turbidity removal of 99% using CuSO4. Moreover, the produced laccase was then purified by ATPS in a single purification step, reaching 2.9-fold and recovered ≈ 99,9 %, in the top phase (PEG-rich phase) using 12 wt% of PEG 1500 + 20 wt% of citrate buffer + enzyme broth + water, at 25 °C. Thus, an integrated process of vinasse degradation, laccase production and purification with potential industrial application was proposed.

Protic ionic liquids as constituent of aqueous two-phase system based on acetonitrile: Synthesis, phase diagrams and genipin pre-purification

The aim of this study was to evaluate the formation of aqueous two-phase systems (ATPS) based on different protic ionic liquids (PIL), synthesized using amines, and organic or inorganic acid, and acetonitrile (ACN). The ATPSs are used to pre-purify genipin from genipap (Genipa americana L.). All PILs (purity above 98%) were able to form ATPSs with ACN, the size of the biphasic region being directly dependent on salting-out aptitude of PIL anions and relative hydrophilicity of the corresponding cations. The highest solid–liquid extraction of genipin from genipap was achieved by using aqueous ACN solution at 75% (16.79 ± 0.06 mg g−1 dry raw material) as extractant. After the extraction stage, the ATPS was used as an integrated platform to pre-purify the genipin present in the extract. Three different overall mixture point compositions were tested, and those formed by [MEA][H2Cit] (25 wt%) + ACN (45 wt%) + water (30 wt%) at 298.15 ± 1.00 K and 0.10 ± 0.01 MPa showed the highest selectivity (S = 4.202 ± 0.009) and recovery of genipin in top phase (RTG = 56.74 ± 0.04%), and the purification factor in top phase was 5.9 fold.

Selective and continuous recovery of ascorbic acid and vanillin from commercial diet pudding waste using an aqueous two-phase system

In this study, ascorbic acid and vanillin were recovered using semi-continuous and continuous operation of an aqueous two-phase system (ATPS) formed by ethanol (C2H5OH) and dipotassium hydrogen phosphate (K2HPO4). For operation, a column reactor was designed, allowing temperature control by a coating system and the circulation of up to two phases simultaneously. The reactor was equipped with a stirring system composed of a shaft and impellers known as vanes. In the experiments, the influence of volumetric flow rate and agitation speed were analysed to enhance recovery of the biomolecules of interest. The best recovery values were obtained in semi-continuous operation at low rotations (60rpm) and high volumetric flow rate (6.0mLmin−1). These parameters were used to verify partitioning using a real food matrix (Dr. Oetker Diet Pudding), achieving recovery of up to 94% for vanillin in the top phase and ascorbic acid in the bottom phase.

Thermodynamics for curcumin (Curcuma longa L.) partitioning in the alcohol–salt aqueous two‐phase system

AbstractBACKGROUNDCurcumin is a polyphenol used as a natural colorant or spice with pharmacological properties including analgesic, anti‐inflammatory, anticarcinogenic and antioxidant. In this work the partition of curcumin was carried out in an aqueous two‐phase system (ATPS) under different conditions.RESULTSLiquid–liquid equilibrium data for the ATPS composed of 2‐propanol + sodium phosphate + water were determined experimentally by the turbidimetric method at temperatures T = 288.15, 293.15, 298.15 and 303.15 K and pH values 4.0 and 5.0. The phase‐forming and salting‐out capability of the mentioned salt were discussed by determination of the exclusion volume effect (EEV) and salting‐out coefficient. The partition of curcumin was carried out. In order to investigate the driving forces that govern the curcumin partition we conducted a thermodynamic study by isothermal titration calorimetry (ITC). The Gibbs free energy transfer (ΔtrG), transfer enthalpy variation (ΔtrH) and transfer entropy variation (TΔtrS) were measured during the dye partition for the systems at 298.15 K.CONCLUSIONThe increase in the pH value promoted an increase in the salting‐out effect as well as in the exclusion volume value. It was observed that the dye had a strong tendency to transfer to the alcohol‐rich top phase, showing Kp high values (13.725–112.764). Thermodynamic analysis indicated that curcumin partition in the ATPS at 298.15 K was entropically driven to the top phase. The high values of theoretical recovery, selectivity and partition coefficient obtained in this study show that the investigated systems may be a promising alternative for curcumin pre‐concentration and purification. © 2019 Society of Chemical Industry

Recovery of Protein from Dairy Milk Waste Product Using Alcohol-Salt Liquid Biphasic Flotation

Expired dairy products are often disposed of due to the potential health hazard they pose to living organisms. Lack of methods to recover valuable components from them are also a reason for manufactures to dispose of the expired dairy products. Milk encompasses several different components with their own functional properties that can be applied in production of food and non-food technical products. This study aims to investigate the novel approach of using liquid biphasic flotation (LBF) method for protein extraction from expired milk products and obtaining the optimal operating conditions for protein extraction. The optimized conditions were found at 80% concentration ethanol as top phase, 150 g/L dipotassium hydrogen phosphate along with 10% (w/v) milk as bottom phase, and a flotation time of 7.5 min. The protein recovery yield and separation efficiency after optimization were 94.97% and 86.289%, respectively. The experiment has been scaled up by 40 times to ensure it can be commercialized, and the protein recovery yield and separation efficiency were found to be 78.92% and 85.62%, respectively. This novel approach gives a chance for expired milk products to be changed from waste to raw materials which is beneficial for the environment and the economy.

Functional deep eutectic solvent-based chaotic extraction of phycobiliprotein using microwave-assisted liquid-liquid micro-extraction from Spirulina (Arthrospira platensis) and its biological activity determination

The selective purification of phycocyanin from Spirulina was achieved using a potentail functional deep eutectic solvents (FDES). FDES were synthesized using carbohydrate glycerol as hydrogen bond acceptor and donor respectively. Thermophysical evaluation of FDES revealed a close interaction within the hydrogen bond donor and acceptor resulting in high density, refractive index and viscosity. The increase of temperature promotes relative linear reduction in values of the former two parameters and non-linear association with the viscosity. Microwave-assisted liquid-liquid microextraction favours the enrichment of phycocyanin to the top phase along with FDES. The linearity, limit of detection and level of quantification for phycocyanin was found to be 7–60, 11 and 85 μg/ml, respectively. A maximum yield 86% (w/w) was obtained at 6 min with the solid-substrate ratio of 23% (w/v) at microwave temperature of 348 K and FDES volume of 650 μl at 70% (v/v). The purity of concentrated extract was enhanced by ion exchange chromatography and the purified fractions were evaluated for antibacterial activity against Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Zymomonas mobilis, Pseudomonas aeruginosa, and Bacillus cereus.

Demulsification of crude oil emulsions tracked by pulsed field gradient NMR. Part II: Influence of chemical demulsifiers in external AC electric field

Crude oil emulsions can reach stability levels that pose severe challenges for the processing industry. Certain conventional methods are used to deal with these challenges, such as chemical demulsification. In this article, two chemicals were mixed with crude oil emulsions to study their separation capabilities in the presence and absence of external AC fields. Experiments were conducted at 65 ⁰C to lower crude oil viscosity, which in turn affects separation efficiency. Effects from the chemical and electrical constituents on the crude oil emulsion was tracked by a pulsed field gradient NMR method, developed in a previous study. The NMR measured emulsified water content for 2 h, continuously, as a function of sample height. Given the water content, droplet sedimentation and free water layer kinetics could be quantified. Droplet size distributions from the top half oil phase were obtained at the beginning and end of each experiment, with the intent of mapping coalescence and sedimentation development of droplets. However, tracking droplet size evolution proved challenging due to rapid changes within the emulsion. The main focus with the NMR technique was therefore on sedimentation and free water layer kinetics. A synergy was observed between the two chemicals and low AC fields. The two chemicals showed varied degrees of separation efficiency, where limited amounts of water was resolved by chemical 1 without electric field, though it improved separation past the limit of electrical treatment when used in combination with AC field. Above a given electric field, sedimentation by electrocoalscence dominates, and the effect of chemical demulsifier is marginal. Chemical 2 achieved promising results as a lone separation method, while further enhancing separation in collaboration with AC fields.