Organic Phase Concentration Research Articles

Sustainable and efficient recovery of lithium from rubidium raffinate via solvent extraction

In recent years, with the increasing prevalence of rechargeable lithium-ion batteries in the burgeoning markets of electric vehicles and portable electronic devices, the consumption of lithium batteries has significantly surged. Hence, the efficient development and utilization of associated lithium resources bear paramount significance. This study aims to recover lithium from rubidium raffinate via solvent extraction. A systematic investigation was conducted to examine the effects of various parameters such as organic phase concentration, contact time, and phase ratio (O/A) during the separation process. The results indicated that the organic phase composed of 0.1 mol/L 4,4,4-Trifluoro-1-phenyl-1,3-butanedione (HBTA) and 0.1 mol/L Trioctylphosphine oxide (TOPO) could efficiently extract lithium from the rubidium raffinate. The optimal conditions were observed at a temperature of 20℃, O/A=1, and a contact time of 5 min. After three-stage countercurrent extraction, a lithium extraction rate of 99.24 % could be achieved, with over 95 % of the sodium easily scrubbed by 0.1 mol/L HCl at an O/A=10. With the use of 3 mol/L HCl, stripping efficiency exceeding 99 % could be attained at an O/A=10, consequently a successful preparation of battery-grade lithium carbonate product was achieved. Regeneration experiments confirmed the organic phase's excellent reproducibility efficiency. Slope analysis and density function theory (DFT) simulations indicated that optimal lithium extraction is achieved when HBTA and TOPO are at equal molar concentrations. The proposed process is expected to provide a green and sustainable route for the recovery of associated lithium resources.

High-efficiency triplet-triplet annihilation upconversion microemulsion with facile preparation and decent air tolerance.

Current research of triplet-triplet annihilation upconversion (TTA-UC) faces difficulty such as overuse of organic solvents and quenching of excited triplet sensitizers by molecular oxygen. Herein, we propose an efficient and facile preparation strategy of TTA-UC microemulsion to overcome these issues. With simple device and short preparation process, air-stable TTA-UC with a high upconversion efficiency of 16.52% was achieved in microemulsion coassembled from TritonX114, tetrahydrofuran and upconverting chromophores (platinum octaethyl-porphyrin and 9,10-diphenylanthracene). This is comparable to the highest UC efficiency ever reported for TTA-UC microemulsion systems. The excellent UC performance of TX114-THF could be attributed to two perspectives. Firstly, small-size micelle accommodated chromophores up to high concentrations in organic phase, which promoted efficient molecular collision. Additionally, high absorbance at 532nm ensured full use of excitation light, getting more long wavelength photons involved in the TTA-UC process. Moreover, air-stable TTA-UC also performed well in microemulsion with various surfactants, including nonionic surfactants (Tween 20, Tween 80, Triton X-110, Triton X-114), ionic surfactants (sodium dodecyl sulfate, cetyltrimethyl ammonium bromide) and block copolymers (pluronic F127, pluronic P123), through three conjectural assembly models according to the structural characteristics of surfactant molecules (concentrated, uncompacted and scattered). These discoveries could provide estimable reference for selection of surfactants in relevant fields of TTA-UC.

From waste to added-value product: A case of efficient separation and recovery of zinc and iron from spent galvanizing acid

Spent galvanizing acid solution contains high concentrations of zinc salts, ferrous salts, and residual acids, exhibiting extremely high value-added recovery potential. However, achieving the efficient extraction and separation of Zn over Fe becomes particularly challenging under elevated Zn ion concentration. Here, the key extraction parameters, such as modifier ratio, Cyanex 923 concentration and ratio of organic phase to aqueous phase (O/A), are investigated. The stripping and regeneration of extractant, extraction mechanism, as well as high-value recovery of Zn and Fe resources are also comprehensively expounded. After the two-stage extraction, the extraction efficiency of Zn and Fe is 98.92 ​% and 2.09 ​%, respectively. Moreover, the stripping efficiency of Zn reaches 92.3 ​% with O/A ratio of 1 : 2, using oxalic acid as stripping agent. The predominant extracted species is confirmed to be ZnCl3−, resulting in the formation of HZnCl3∙R3PO complex. More importantly, the regenerated extractant can be recycled back into the extraction process, and the reproduced HCl, high-value recovered ZnO and Fe2O3 can be used for different industrial fields. These findings lay a solid foundation for the efficient separation and comprehensive recovery of high-concentration spent galvanizing acid solution.

Design of experiment-oriented development and validation of novel bioanalytical reverse phase high performance liquid chromatography method of palbociclib in rat plasma and tissues, and its application in pharmacokinetic studies.

The current research involved the development and validation of an easy, cost-effective, and sensitive bioanalytical reverse-phase high-performance liquid chromatography method for the assessment of palbociclib (PAL) in rat plasma and kidney, liver, spleen and heart. A response surface methodology-based Box-Behnken design was used to optimize critical chromatographic conditions such as buffer pH, organic phase concentration and flow rate to attain good sensitivity, tailing factor and retention time. The conditions were: pH of buffer, 4.5; organic phase concentration, 40%; Shimpac column with 1.0ml/min flow rate. The responses were: tailing factor, 1.29 ± 0.03, sensitivity, 366,593 ± 8,592; and retention time, 4.5 ± 0.05 min. The samples were extracted by a protein precipitation method, and absolute recoveries were in the range of 88.99-95.08%. The linearity of the developed method was validated over the range 100-2,000 ng/ml (r2 ≥ 0.994) in all tested matrices. The developed bioanalytical method showed greater accuracy (0.98 and 4.01%) and precision (<4.88%). The method was optimized for the sensitive analysis of the PAL in rat plasma, and the kidney, liver, spleen and heart were effectively applied to pharmacokinetic studies.

Investigation of the Extraction of Natural Alkaloids in Karr Reciprocating Plate Columns: Mass Transfer Study

ABSTRACT Solvent extraction plays a vital role in manufacturing high purity alkaloids from natural poppies. Cyanex® 923, which has been widely used in hydrometallurgical processes, is shown to be an effective extractant for natural alkaloid extraction. In this work, 0.2 M Cyanex® 923 in xylene (dispersed phase) was used to investigate the equilibrium isotherm of morphine at pH 9 and morphine extraction in two different reciprocating Karr columns. Two sources of morphine solution (continuous phase), including technical morphine with few impurities and industrial upstream morphine rich extract containing more impurities and other alkaloids, were studied to investigate morphine mass transfer efficiencies in the Karr columns based on different dispersed phase velocities and reciprocating frequencies. The mass transfer coefficients of technical morphine solution were calculated using a backflow model associated with axial dispersion, and the mass transfer coefficients were further used to regress a mass transfer correlation. The regressed correlation was further validated, and the process model was shown to be reliable to predict the extraction efficiency, and outlet morphine concentration of both aqueous phase and organic phase. This work provides insights to scale-up the process design in a short time, bridging the gap between bench scale research and pilot industry scale testing using a simple correlation method.

Simple and low–cost transition metal-free borophosphate glass catalyst for aromatic alcohol oxidation by sodium hypochlorite

The oxidation of primary and secondary alcohols to their respective aldehydes/ketones is one of the most important reactions in fine chemistry due to the industrial application of these products. Based on this, a large number of new catalysts and oxidants have been tested using this reaction as a catalytic model, mainly looking for a process that ensures high aldehyde selectivity. In this paper, we have used moisture stable borophosphate glass doped with 10 mol% Al2O3 as a heterogeneous catalyst in the oxidation of sodium hypochlorite, an effective, greener, and low-cost oxidant, using acetonitrile as solvent under mild conditions. The glass catalyst mass and the particle size were evaluated, as were the reaction temperature and oxidant amount, to determine the ideal reaction conditions where the conversions achieved 87.0 mol% for 1-phenylethanol to acetophenone and 79.4 mol% for benzyl alcohol to benzaldehyde, with benzaldehyde selectivity above 95%. Although sodium hypochlorite is a strong oxidant, benzaldehyde was the main product of the oxidation of benzyl alcohol due to the formation of a biphasic organic-aqueous system that protects the aldehyde from oxidation and allows the reaction to occur without the use of a phase transfer catalyst (PTC). HPLC analysis of both phases showed that alcohols, aldehyde, and ketone were mostly present in the organic phase (concentrations above 98.7%). During the reaction, a small amount of alcohol is transferred to the aqueous phase, where the oxidation took place. Once formed, the products are transferred back to the organic phase. ICP-OES analysis indicates that borophosphate glass acts in the reaction by partially releasing phosphate-based groups, reducing the pH of hypochlorite to 9. In this sense, borophosphate glasses prove to be a simple and inexpensive alternative for the development of new catalysts.

Inhibitory Effect of Solvent Extractants on Growth and Metabolism of Acidophiles

ABSTRACT Due to entrainment or dissolution, organic extractants can contaminate aqueous raffinate during the solvent extraction (SX) process. This study aims to evaluate the effect of conventional SX reagents on the bio-oxidation and metabolism of industrial bacteria. Evaluating the effect of LIX 984N, Chemorex CP 150, D2EHPA, and Acorga M5640 at three concentrations on mesophiles and moderate thermophiles revealed that all extractants reduced the bacterial efficiency at different extents. It was observed that organic phases at 0.02% v/v resulted in a decrement of ferrous iron bio-oxidation rate and a negligible decrease in the bacterial population. At high dosages like 2% v/v, bio-oxidation and bacterial reproduction were utterly disrupted. The oxime-based extractants had a more significant effect on bacteria due to their lower stability and production of toxic substances by hydrolysis. Organic phases more impacted moderate thermophiles at a higher temperature compared to mesophiles. The analysis of Kendall tau-b revealed a strong inter-correlation between the concentration of organic phase and bio-oxidation parameters such as pH, ORP, bacterial population, bio-oxidation rate, and iron precipitation.

A systematic approach for achieving the maximum loading of Eu(III) in TODGA/n-dodecane phase with the aid of TBP phase modifier

Determining the stoichiometry of Eu(III) to N,N,N′,N′-tetraoctyldiglycolamide (TODGA) in the organic phase containing TODGA in n-dodecane (n-DD) is a challenging job due to the formation of third phase prior to the maximum loading of Eu(III) in the organic phase. The phase modifier tri-n-butyl phosphate (TBP) has been added to the organic phase to minimize and prevent the undesirable third phase formation. Even though the added TBP prevented the third phase, the loading behavior of Eu(III) in TODGA + TBP/n-DD and the role of TBP in altering the stoichiometry of Eu(III) to TODGA is unknown so far. To unravel the role of TBP at higher loadings of Eu(III) in the organic phase, the extraction behaviorof Eu(III) from nitric acid solution was studied in a solution of 0.1 M TODGA + TBP/n-DD. The concentration of nitric acid and Eu(III) in aqueous phase, and TBP concentration in organic phase were varied in those investigations to determine the maximum loading of Eu(III) and stoichiometry of Eu(III) to TODGA in organic phase. The results revealed that the Eu(III) to TODGA stoichiometry of 1:1 could be achievable at higher concentrations of TBP in the organic phase (> 1 M), which served as a sacrificial proton acceptor during extraction. The results were supported by FTIR investigations in the loaded organic phase.

Separation of lithium and cobalt with N-salicylideneaniline from sulfate solution by hollow fiber membrane contactors

The study of the equilibrium concentrations for the extraction separation of cobalt from mixed sulfate solution with N-salicylideneaniline in membrane contactors is investigated. The reaction equilibrium constant (Kex) of 4.7 L2mol−2 was obtained from the modeling of the equilibrium distribution curves, which is carried out from the mass action law. A separation factor of 30,74 of cobalt was obtained. The calculation of the distribution coefficient (D) in the membrane contactors is carried out from global mass balances (operating line) and linear extraction isotherms in membrane contactors. The extraction kinetics of cobalt in the aqueous and organic phases in hollow fiber membrane contactors became slow and steady state is quickly reached. The steady state experimental concentration in aqueous and organic phase does not correspond to the concentration predicted by the calculation this deviation between the steady state concentration and calculated data could be explained that the diffusion of metal complex in the microporous is the main limiting step of mass transfer..

Extraction of Zinc in Presence of Cobalt through Hollow Fibre Supported Liquid Membrane from Simulated Industrial Wastewater

Many industrial wastewaters contain toxic metals such as zinc, chromium, cobalt in the form of fluorides and nitrates as anions. Transport of Zn 2+ from simulated industrial wastewater was studied using di-2-ethylhexyl phosphoric acid (D2EHPA) diluted in kerosene as the organic phase. The hollow fibre supported liquid membrane was operated in continuous recycle mode. Effect of feed phase pH, carrier concentration, sulphuric acid concentration in the strip phase, and flow rate on Zn 2+ transport was examined. The feed phase pH was varied in the range of 1.5–2.5. The organic phase concentration was varied in the range of 10-30 %. At the feed phase pH of 2, the extraction rates were found to be high. About 12% rise in mass transfer flux of Zn 2+ ions was observed with an increase in D2EHPA concentration from 10% to 20%. The mass transfer flux of Zn 2+ ions was found to be increased by 28% with an increase in sulphuric acid concentration from 0.5 M to 1 M. The flow rate variation study suggests that mass transfer resistance is mainly contributed by diffusion mechanism through the membrane.

The influence of PBAT content in the nanocapsules preparation and its effect in essential oils release

Nanoencapsulation provides new alternatives for the food industry, enabling a controlled and slow release of active antimicrobial agents, such as essential oils (EO). Poly (butylene adipate-co-terephthalate) (PBAT) nanocapsules loaded with linalool EO were prepared using an extrusion method with 1, 3, and 5% w/v (PBAT to chloroform). Nanocapsules' sizes ranged from 100 to 250 nm and were spherical. The release profile was studied using an ethanoic medium over 24 h, and according to the Korsmeyer-Peppas model, a Fick diffusion mechanism was involved. FT-IR and thermogravimetric analyses confirmed EO encapsulation with an encapsulation efficiency of 55%, 71%, and 74% for 1, 3, and 5%, respectively. The results indicated that encapsulation depended on organic phase concentration, with higher PBAT contents achieving better results. The resulting nanocapsules had antimicrobial activity against E. coli, which could be extended to develop active packaging systems.

Reactive separation of malic acid from aqueous solutions and modeling by artificial neural network (ANN) and response surface methodology (RSM)

Malic acid is a commercially valuable chemical which used in food, pharmaceutical and personal care products, and its biotechnological production is of great attention. The biotechnological manufacture of carboxylic acids by fermentation processes produces multi-constituent aqueous solutions with the acid concentration less than 10% (w/w). Therefore, carboxylic acid separation from the fermentation environment or waste stream is economically important. In this study, the reactive separation of malic acid with tributylamine (TBA) in octyl acetate was carried out. The effects of initial malic acid concentration, initial amine concentration in organic phase, and phase ratio (organic phase volume/aqueous phase volume) on the separation were determined experimentally. Experimental results were analyzed, optimized and modeled by both artificial neural network (ANN) and response surface methodology (RSM). It was obtained that ANN had a slightly better coefficient of determination. The modeling results showed that TBA concentration in the organic phase among the parameters examined was the most effective parameter for the reactive separation of malic acid from aqueous solutions.

Selective Recovery of Molybdenum over Rhenium from Molybdenite Flue Dust Leaching Solution Using PC88A Extractant

Selective solvent extraction of molybdenum over rhenium from molybdenite (MoS2) flue dust leaching solution was studied. In the present work, thermodynamic calculations of the chemical equilibria in aqueous solution were first performed, and the potential–pH diagram for the Mo–Re–SO42−–H2O system was constructed. With the gained insight on the system, 2-ethylhexyl phosphonic acid mono-(2-ethylhexyl)-ester (PC88A) diluted in kerosene was used as the extractant agent. Keeping constant the reaction temperature and aqueous-to-organic phase ratio (1:1), organic phase concentration and pH were the studied experimental variables. It was observed that by increasing the acidity of the solution and extractant concentration, selectivity towards Mo extraction increased, while the opposite was true for Re extraction. Selective Mo removal (+95%) from leach solution containing ca. 9 g/L Mo and 0.5 g/L Re was achieved when using an organic phase of 5% PC88A at pH = 0. No rhenium was coextracted during 10 min of extraction time at room temperature. Density functional theory (DFT) calculations were performed in order to study the interactions of organic extractants with Mo and Re ions, permitting a direct comparison of calculation results with the experimental data to estimate selectivity factors in Mo–Re separation. For this aim, PC88A and D2EHPA (di-(2-ethylhexyl) phosphoric acid) were simulated. The interaction energies of D2EHPA were shown to be higher than those of PC88A, which could be due to its stronger capability for complex formation. Besides, it was found that the interaction energies of both extractants follow this trend considering Mo species: MoO22+ &gt; MoO42−. It was also demonstrated through DFT calculations that the interaction energies of D2EHPA and PC88A with species are based on these trends, respectively: MoO22+ &gt; MoO42− &gt; ReO4− and MoO22+ &gt; ReO4− &gt; MoO42−, in qualitative agreement with the experimental findings.

Removal of benzo [a]pyrene vapours from the air stream using the two-phase partitioning bioscrubber: an intervention study

ABSTRACT In this study, the absorption of BaP in gas phase and biodegradation in liquid phase were examined in a bioscrubber. Important operational parameters including, input concentration (mg/m3), output concentration (mg/m3), pollutant load (g/m3.h), removal efficiency (%), removal capacity (g/m3.h) and biomass value (g/l) were examined. The results of the study showed that the BaP degrading strain performed better degradation by increasing the organic phase concentration and detention time. The results showed that the highest efficiency and removal capacity of bioscrubber occurred at 30% organic phase concentration. Furthermore, by increasing the organic phase concentration, the removal efficiency and capacity of the bioscrubber increased. The results of the study also showed that the removal efficiency of bioscrubber increased by increasing the organic phase concentration from 0%–10%, by increasing the concentration of 10%–20% is gradually increased, and by increasing the organic phase percentage to 30%, the efficiency increased sharply. The results indicated that TPPB can have an acceptable efficacy in removing BaP, which increases by increasing the organic phase concentration leading to more BaP removal.

Thermodynamic modeling of Pu(IV) and nitric acid extraction by 1.1 M tri-iso-amyl phosphate in n-dodecane

A thermodynamic model for the liquid–liquid extraction of tetravalent plutonium (Pu(IV)) by 1.1 M Tri iso Amyl Phosphate (TiAP) in n-dodecane was developed. The activity coefficients of species in the aqueous phase were estimated using eUNIQUAC activity coefficient model. The plutonium speciation in the aqueous nitric acid solution of 1–6 M concentration region was modelled by taking account of mono nitrate (Pu(NO3)3+), di nitrate $$({\text{Pu}}({\text{NO}}_{3} )_{2}^{2 + } )$$ , tetra nitrate (Pu(NO3)4) and hexa nitrate $$({\text{Pu}}({\text{NO}}_{3} )_{6}^{2 - } )$$ complexes. The eUNIQUAC activity coefficient model parameter and stability constant of tetra and hexa nitrate complexes were determined using the experimental water activity as well as extraction data. The distribution coefficient of nitric acid and Pu(IV) in the 1.1 M TiAP was estimated by accounting HNO3·TiAP, HNO3·2TiAP and Pu(NO3)4·2TiAP complexes in the organic phase. A good correlation between the estimated and experimental organic phase concentration of nitric acid and plutonium nitrate was obtained.

Experimental study on the reduction of loratadine particle size through confined liquid impinging jets.

The confined liquid impinging jets (CLIJ) technique was applied as a simple and effective approach to reducing the particle size of loratadine to enhance its solubility. The effect of anti-solvent (AS) to solution (S) flow rate ratio, organic phase concentration, Reynolds number (Re), and stabilizer concentration was investigated in this reduction process. After the synthesis, the chemical and physical properties of loratadine nanoparticles were determined through different characterization and analytical techniques. The results indicated that the particle size of loratadine decreases from 320nm to 80nm by increasing the AS/S ratio from 1 to 25. It was found that the particle size of loratadine was unchanged at the higher AS/S ratios. The loratadine nanoparticle size was optimized by changing the solution concentration, Re, and Tween 80 as a stabilizer. The finest loratadine nanoparticle size of about 53nm was obtained with a narrow size distribution, which corresponds to solution concentration of 35mg/mL, Re of 5687, and 0.1% (w/v) stabilizer concentration. It was revealed that the optimized loratadine nanoparticles completely dissolved after 11min, indicating the loratadine nanoparticle dissolution rate 50 times faster than raw loratadine.

Polyarylate membrane with special circular microporous structure by interfacial polymerization for gas separation

Microporous polymer membranes have received extensive attention in the membrane separation field based on the advantage of high gas permeance and low cost. However, there are a few reports of microporous polyacrylate membranes fabricated by interfacial polymerization (IP), and the formation mechanism and influence factor of the microporous structure is rarely illuminated. In this work, thin-film polyacrylate membrane with circular microporous morphology were prepared by IP method with cyclodextrin and acyl chloride as the aqueous and oil phase monomer respectively for effective gas separation. The effects of the aqueous and organic phase monomer structure and concentration, the concentration and type of alkali in the aqueous solution on the membrane morphology and gas separation performance were investigated in detail. As a result, the polyacrylate membrane fabricated by β-cyclodextrin (β-CD) and trimesoyl chloride (TMC) with optimal content of NaOH in the aqueous phase formed the special circular microporous structure by the scanning electronic microscope (SEM) characterization. The resulting membrane showed CO2 permeance of 200 GPU with CO2/N2 ideal separation selectivity of 10.53. This work provides an effective strategy to fabricate high performance polyacrylate membrane by regulating the monomer structure and the alkali concentration in the aqueous phenol solution with IP method, which would inspire the exploration of other phenolic monomer for the assembly of microporous polymer membranes for gas separation or seawater desalination.

One step prepared Janus acid-resistant nanofiltration membranes with opposite surface charges for acidic wastewater treatment

In order to enhance the membrane separation efficiency of multivalent metal ions and acid, high performance Janus acid-resistant nanofiltration membranes (NFMs) with opposite charge properties (selective layer) were fabricated by polyethyleneimine (PEI) and cyanuric chloride (CC) via interfacial polymerization. A novel and facile method (named LC-CT) was developed to obtain the Janus acid-resistant NFMs in one step, by controlling the organic phase (CC) concentration to be low followed by the curing treatment. It was found that CC concentration had a significant effect on the charge property of the membrane surface. Low CC concentration endowed a loose selective layer with many unreacted –NH2 on the flip side while curing treatment attributed to the less defective layer. Thus, LC-CT method endowed the membrane Janus property with high salt rejection and flux. The new generated Janus NFMs exhibited better acid stability than NFM-1 (commercial, polyamide), and higher MgCl2 rejection than NFM-1 and NFM-2 (commercial, acid-resistant) after soaking in 3 wt% HCl at 25 °C for 1800 h or 50 °C for 72 h. Also, the flux of this polyamine Janus NFM was 4.2 ~ 19 times higher than that of previous reported polyamine acid-resistant NFMs, which indicated a good application potential of this membrane in acidic wastewater treatment.

Effect of positive electrode modification on the performance of zinc-bromine redox flow batteries

Abstract Performance of the zinc-bromine redox flow battery is correlated to the surface properties of the positive electrode. Herein, we have modified the graphite felt electrode by thermal treatment and plasma treatment under oxygen and nitrogen atmospheres. These treatments induced specific changes to the electrode surface. Under the experimental conditions, thermal treatment increased overall surface area whereas, the O2 and N2 plasma increased the defects in the felt, by generating oxygen functional groups as well as N doping respectively. By combining both thermal and O2 plasma treatment, an increase in both surface area, as well as oxygen functional groups, were achieved. The performance of the cell was influenced by the surface area and surface functional groups. Most importantly surface oxygen functionalization proved to be a decisive factor for the enhanced performance especially when the concentration of organic polybromide phase is higher. A better charge transfer/adhesion between the electrode and polybromide phase is expected through halogen/hydrogen bonding between the complexed Br and oxygen/proton of the phenolic or carboxyl functional groups.

Non-isocyanate polyurethane nanoprecipitation: Toward an optimized preparation of poly(hydroxy)urethane nanoparticles

This study describes the influence of different parameters on the production of original monodisperse and stable poly(hydroxy)urethane (PHU) nanoparticles with a size inferior to 100 nm by nanoprecipitation. DMSO and SDS were used as polymer solvent and surfactant respectively. Nanosuspensions were characterized by dynamic light scattering (DLS) and cryo-transmission electronic microscopy (cryo-TEM). A 23 full-factorial design was employed to study the main effects and interaction effects of three independent variables − polymer concentration in the organic phase (X1), water volume (X2) and surfactant concentration in the aqueous phase (X3) − on two responses – particle size (Y1) and size distribution (Y2). The results allowed to determine the experimental conditions favouring the smallest diameter or the narrowest size distribution. The critical micellar concentration value of SDS in various water-solvent mixtures helped to highlight the role of the surfactant in the PHU nanosuspension characteristics and stability. The results showed that the use of surfactant was mandatory for nanosuspension stabilization, but the presence of numerous surfactant micelles induced nanoparticle aggregation. Finally, the ageing study evidenced that nanosuspensions with the lowest size distribution were the most stable over time.