1M NaCl Research Articles

Layer-by-Layer Assembly for Preparation of High-Performance Forward Osmosis Membrane

Forward osmosis (FO) membrane with high separation performance is needed to promote its practical applications. Herein, layer-by-layer (LbL) approach was used to prepare a thin and highly cross-linked polyamide layer on a polyacrylonitrile substrate surface to prepare a thin-film composite forward osmosis (TFC-FO) membrane with enhanced FO performance. The effects of monomer concentrations and assembly cycles on the performance of the TFC-FO membranes were systematically investigated. Under the optimal preparation condition, TFC-FO membrane achieved the best performance, exhibiting the water flux of 14.4/6.9 LMH and reverse salt flux of 7.7/3.8 gMH under the pressure retarded osmosis/forward osmosis (PRO/FO) mode using 1M NaCl as the draw against a DI-water feed, and a rejection of 96.1% for 2000 mg/L NaCl aqueous solution. The result indicated that layer-by-layer method was a potential method to regulate the structure and performance of the TFC-FO membrane.

Omniphobic membranes for direct contact membrane distillation: Effective deposition of zinc oxide nanoparticles

An omniphobic membrane was fabricated for membrane distillation (MD) by effectively depositing ZnO nanoparticles on a hydrophilic glass fiber (GF) membrane using a chemical bath deposition method to create hierarchical re-entrant structures, followed by surface fluorination and the addition of a polymer coating to lower the surface energy of the membrane. The omniphobic membranes possessed a particulate membrane morphology and an extremely high fluorine concentration on the surface. The omniphobicity of the fabricated membrane was indicated by the contact angles for water and ethanol, which were as high as 152.8±1.1° and 110.3±1.9°, respectively. Compared to hydrophobic GF membranes without deposited ZnO nanoparticles, the omniphobic membrane revealed a higher wetting resistance to low surface tension feed solutions in direct membrane distillation (DCMD) experiments. The water flux was stably maintained in a 0.3mM sodium dodecyl sulfate (SDS) solution (60°C 1M NaCl) with salt rejection rate higher than 99.99%. The results suggest that the omniphobic membrane exhibited not only superior wetting resistance to low surface tension liquids but also promise for desalinating low surface tension wastewaters.

Nanoparticulate delivery systems for alkyl gallates: Influence of the elaboration process on particle characteristics, drug encapsulation and in-vitro release

PLA nanoparticles loaded with n-alkyl gallates (AGs) were prepared either by nanoprecipitation (NP) or by O/W emulsion/solvent evaporation (E/SE). A nonionic hydrophobically modified polysaccharide was used for surface coverage and for ensuring colloidal stability. Different parameters were systematically assessed to enhance the drug incorporation, with the aim of obtaining monomodal and narrow particle size distributions. The nanoparticles were characterized by 1H NMR, transmission electron microscopy (TEM) and laser light scattering granulometry. The colloidal stability of suspensions was evaluated after incubation in NaCl solutions and was maintained up to 1M NaCl. The mean particle diameter and the width of size distribution were found very similar for both processes (slightly lower diameters when using E/SE) with various drug loadings. The amount of encapsulated AG by E/SE was about twice that encapsulated by NP. The in-vitro release of AG was evaluated under sink conditions and no burst effect was observed. Release curves were successfully modeled using the Fick diffusion model with a constant diffusion coefficient and assuming non-swellable particles. Diffusion coefficients of AG loaded in nanoparticles prepared by NP were higher than those found in nanoparticles elaborated by E/SE.

Module scale-up and performance evaluation of thin film composite hollow fiber membranes for pressure retarded osmosis

Pressure retarded osmosis (PRO) demonstrates great potential in energy harvesting when combining with seawater reverse osmosis. However, the lack of suitable membrane modules and the issue caused by the membrane fouling greatly impede the practical application of PRO to a larger scale. In this study, two-inch thin film composite hollow fiber modules were fabricated by using in-house developed PRO membranes. The produced PRO modules have a maximum effective area of 0.5m2. By assessing the PRO performances of the modules with different sizes, external concentration polarization (ECP) was found to have significant impact on the flux reduction during module scale-up. Different module designs, including fiber bundles, distribution baffles and distribution tubes, were thus adopted as an attempt to boost the membrane performance. A power density of 8.9W/m2 at 15bar was obtained using tap water as feed and 1M NaCl solution as draw solution. PRO performance tests were also carried out using the developed two-inch modules on a pilot-scale setup with actual wastewater retentate as feed solution. Low pressure nanofiltration was selected as the pretreatment of the wastewater retentate to mitigate fouling. A power density of larger than 8W/m2 was obtained when pretreated wastewater retentate was used as the feed solution, implying high potential of PRO in the pilot scale. Nevertheless, full potential of PRO can only be realized by mitigating ECP, which could be achieved by improving the module design in the further endeavor.

Corrosion Behavior of Aqua-Blasted and Laser-Engraved Type 316L Stainless Steel

The effect of aqua blasting and laser engraving on surface microstructure development, residual stress and corrosion resistance of type 316L stainless steel has been investigated. Aqua blasting resulted in a deformed near-surface microstructure containing compressive residual stresses. Subsequent laser engraving produced a surface layer with tensile residual stresses reaching to a depth of 200 microns. Changes of surface roughness topography were accompanied by the development of a thick oxide/hydroxide film after laser engraving. The atmospheric corrosion behavior of all surfaces with MgCl2-laden droplets was compared to their electrochemical response in 1M NaCl and 0.7 M HCl aqueous solutions. The measured total volume loss after atmospheric corrosion testing was similar for all investigated surface conditions. Laser-engraved surface exhibited the smallest number of corrosion sites, but the largest mean corrosion depth.

Corrosion Behavior of Anodized Al Coated by Physical Vapor Deposition Method on Cu–10Al–13Mn Shape Memory Alloy

Physical vapor deposition method was utilized to apply Al coating onto Cu–10Al–13Mn alloy, then coated layer was anodized in different temperatures: 5 and 10°C as well as several potentials: 20, 30, 40, 50 V in order to achieve best anodizing parameters. The effects of anodizing parameters on alumina nanotube formation and corrosion resistance were investigated. Phase analysis on surface was conducted by X-ray diffraction method and nanotube characteristics was studied by scanning electron microscopy (SEM) and surface topology was investigated by atomic force microscopy (AFM). Additionally, the corrosion resistance of coatings was studied by potentiodynamic test in 1M NaCl solution. The results depicted that whole deposited Al layer was anodized and FCC alumina was formed merely. Polarization test results was illustrated that Al anodized layer significantly improved Cu–10Al–13Mn corrosion resistance. Uncoated specimen had highest corrosion rate and anodized layer in lower temperature and voltage had minimum alumina nanotube dimension; as a result, it had best corrosion behavior in NaCl corrosive solution.

Hydrophilic polyvinyl alcohol coating on hydrophobic electrospun nanofiber membrane for high performance thin film composite forward osmosis membrane

In this study, the hydrophilic property of polyvinyl alcohol (PVA) was utilized to improve the hydrophilicity and mechanical strength of electrospun polyvinylidene fluoride (PVDF)-supported thin film composite (TFC) forward osmosis (FO) membranes. The PVDF nanofiber support was modified with PVA via dip coating and acid-catalyzed crosslinking with glutaraldehyde prior to formation of polyamide active layer on the support via interfacial polymerization. The influence of PVA modification on the morphology and physical properties of PVDF support was evaluated through several characterization techniques while the flux performance was assessed using lab-scale FO membrane unit. The fabricated PVA-modified TFC FO membranes exhibited high hydrophilicity, porosity, and mechanical strength. FO performance tests reveal excellent flux performance (34.2LMH using 1M NaCl and DI water as draw and feed solution, respectively) and low structural parameters (154μm) of the PVA-modified TFC FO membrane. Dip coating of the nanofiber support in PVA is therefore a simple and effective method for the improvement of PVDF support hydrophilicity to fabricate high performance TFC FO membranes.

The induction of salt stress tolerance by propyl gallate treatment in green microalga Dunaliella bardawil, through enhancing ascorbate pool and antioxidant enzymes activity.

The effect of propyl gallate (PG), a synthetic antioxidant, on antioxidant responses and salinity tolerance was investigated in the cells of the green microalga, Dunaliella bardawil. Algal suspensions grown at three salinity levels of 1, 2, and 3M NaCl were incubated with 1mM of PG. The number of cells was significantly lower in all PG-treated cells compared to untreated controls. Despite PG-induced cell death, the fresh weight of all PG-treated cells was considerably higher than controls. PG-treated cells had enhanced antioxidant capacity because of increased levels of Chlorophyll a, β-carotene, reduced ascorbate, protein, and enzymatic activities, but accumulated lower levels of malonyldialdehyde and hydrogen peroxide compared to untreated cells. The results suggest that PG acts as a signal molecule both directly by reducing of free radical oxidants and indirectly by augmenting ascorbate pool levels, β-carotene production, and antioxidant enzymes activity to boost the capacity of antioxidant systems and radical oxygen species scavenging. Therefore, induction of salt stress tolerance by PG in D. bardawil is associated with metabolic adjustments through activation or synthesis of both enzymatic and non-enzymatic molecules involved in antioxidant systems.

Analysis of the influence of module construction upon forward osmosis performance

The potential of a commercial forward osmosis (FO) module to recover water from NEWater brine, an RO retentate, was assessed by taking an innovative approach to obtaining the mass transfer coefficients. The performance comparison of the spiral wound (S-W) FO module with that of the flat sheet laboratory unit suggests that the winding involved in S-W construction can adversely affect performance; the values for the S-W mass transfer coefficients were half of those expected. This first-of-its-kind performance comparison utilised coupons of the membrane and spacers taken from the module. The module was used both in the conventional manner for FO and in the reverse manner with the active layer facing the draw solution. Estimates of membrane parameters and mass transfer coefficients experiments for the two orientations were obtained using pure water, 10mM and 25mM NaCl solution on the feed side and 1M NaCl as draw solution. The fouling potential of NEWater brine per se was found to be low. These are the first results with a S-W module that suggest potential for this niche application; nevertheless the level of the water flux through the S-W module clearly indicates that industrial applications of S-W FO will be constrained to special cases.

358 Treg dysfunction leads to spontaneous production of autoantibodies to bullous pemphigoid antigens in mice

Bullous pemphigoid (BP) is the most common autoimmune blistering disease caused by autoantibodies to hemidesmosomal proteins; type XVII collagen (COL17 or BP180) and BP230. Regulatory T cells (Tregs) are crucial for peripheral immune tolerance and maintaining cutaneous immune homeostasis. However, it remains largely unknown whether failure of peripheral immune tolerance has an influence on the production of autoantibodies to the epidermal components. To address this, we investigated scurfy mice, which lack functional Tregs due to the mutation in Foxp3, a master transcriptional factor of Tregs. Utilizing direct and indirect immunofluorescence (IF) studies, we found that scurfy mice developed autoantibodies to the dermal-epidermal junction of the skin. The production of IgG autoantibodies, which had been class-switched from IgM, started within 12 days after birth. The autoantibodies reacted to the epidermal side of artificial blisters induced by 1M NaCl by indirect IF. From these findings, we focused on BP antigens. Immunoblotting using recombinant proteins of murine BP230 and COL17 demonstrated the presence of autoantibodies to those proteins in most scurfy sera. However, autoantibodies in scurfy sera have no reactivity to NC14A domain of murine COL17, corresponding to NC16A domain of human COL17, a domain responsible for subepidermal blister formation. This result may explain the fact that blister formation is not observed in scurfy mice. Furthermore, by using a CD4+ T cell-transferred model we revealed that CD4+ T cells mediate the production of those autoantibodies in scurfy mice. These results suggested that Tregs contribute to maintain immune tolerance to COL17 and BP230 at a steady state in mice.

Increased paraoxonase and arylesterase activity in thyroiditis patients compared to healthy individuals

Aim: The aim of this study was to assess whether there is a significant difference in paraoxonase and arylesterase activities and distribution of phenotypes in thyroiditis patients compared to healthy volunteers. Introduction: Human serum paraoxonase 1 (PON1; EC3.1.1.2) is an antioxidant enzyme showing both paraoxonase and arylesterase activities. The PON1-192 polymorphism has two isoforms, namely PON1 Q and PON1 R. PON1 Q contains a glutamine at position 192. PON1 R contains an arginine at position 192. It shows a 6 fold higher activity towards paraoxon hydrolysis compared to Q isoform. Arylesterase activity is similar in both isozymes. The R allozyme shows a greater degree of stimulation of its paraoxon-hydrolyzing activity by 1M NaCl than does the Q allozyme. The ratio of Salt stimulated PON 1 activity/Arylesterase activity (P/A ratio) is trimodally distributed. The three modes correspond to paraoxonase phenotypes, QQ, QR and RR. Methods: Fifty thyroiditis patients and one hundred and thirty seven apparently healthy individuals were enrolled in this study. Serum samples of both groups were analysed for basal paraoxonase activity, salt stimulated paraoxonase activity (with 1M NaCl) and arylesterase activity (spectrophotometrically). P/A ratio was used to assess the phenotypes (dual substrate method). Results: Basal PON 1 activity (205.27±115.00 U/l vs. 251.1±129.6 U/l, p=0.002) and arylesterase activity (159.53±37.11 vs. 177.59±46.90, p=0.024) was significantly higher in thyroiditis patients compared to healthy volunteers. Percentage of QQ phenotype was significantly higher in thyroiditis patients compared to healthy individuals. Percentage of QR phenotype was significantly lower in thyroiditis patients compared to healthy individuals. There was no difference in percentage of RR phenotype in thyroiditis patients and healthy individuals. Conclusion: Serum PON 1 activity and arylesterase activity was significantly higher in thyroiditis patients compared to healthy individuals. Percentage distribution of phenotypes in thyroiditis patients was significantly different from healthy individuals.

Effect of pH and Salinity on Polarization Behavior of Cathodically Protected HY80 Steel, Inconel 625 and Nickel-Aluminum Bronze in Mexican Gulf Seawater

Metal structures submerged in seawater are subject to corrosion. Corrosion protection is usually implemented by applying negative potentials between -0.8 and -1.0 V vs Ag/AgCl reference electrode [1]. At these potentials, anodic metal dissolution is expected to be suppressed, and the typical dominant reactions that govern electron transfer on the protected surface in seawater are oxygen reduction reaction (ORR) and hydrogen evolution from water. The ORR in basic environments (pH~ 8.4) result in the generation of hydroxyl ions, eliciting an increase in the carbonate (CO3 2-) ions from the carbonate buffer system. When concentrations of CO3 2- and OH- near the electrode surface become sufficient to exceed solubility constants of CaCO3 and Mg(OH)2 compounds, they precipitate on the surface, decreasing the electroactive surface area, and making cathodic protection more efficient [2]. Formation of calcareous deposits on metal alloys is affected by applied potential, DO level, salinity, pH and temperature. Although the influence of DO, pH and temperature on the formation of calcareous deposits have been previously reported [3-5], the effect of salinity level has been overlooked. The effect of pH has been explored only minimally for a limited range of pH (usually ~ 7). Here, we explore polarization behavior of three cathodically protected alloys (Inconel 625, HY 80 Steel, and C-632 Nickel-Aluminum Bronze used in marine environment as a function of seawater salinity and pH. Electrochemical experiments were conducted in a three-electrode electrochemical cell (BioLogic, Inc). Freshly polished coupons of three different alloys served as working electrodes (WEs), while platinum mesh and Ag/AgCl in 3M NaCl (BioLogic, Inc) were used as a counter and reference electrodes, respectively. WEs held at -1.0 V were immersed into 0.5, 3.5 or 35 ppt seawater for 24 h, and polarization curves were recorded at 0.6 V/h prior and following the potential hold. Acetic acid, MES and MOPS organic buffers (Sigma Andrich) were used for maintaining pH levels of 5, 6, and 7, respectively. Seawater from Mexican Gulf was collected at Key West, FL. The influence of salinity and pH on polarization behavior of HY 80 steel is shown in Figures 1 and 2, respectively. The presentation will discuss the reasoning behind the changes in HY 80 Steel, Inconel 625 and C-632 Nickel-Aluminum Bronze polarization behavior under different environmental conditions.

Exploitation of agro-climatic environment for selection of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase producing salt tolerant indigenous plant growth promoting rhizobacteria

A comprehensive survey for 09 agro-climatic zones of Uttar Pradesh, India was conducted to isolate and characterize salt tolerant 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase possessing plant growth promoting (PGP) rhizobacteria for salt stress amelioration in rice. Here, we have isolated 1125 bacteria having the ability to tolerate 1M NaCl and out of those, 560 were screened for utilizing ACC as sole nitrogen source. 560 isolates were subjected for bacteria coated seed germination assay under 100mM salt (NaCl) stress resulting to 77 isolates which were further evaluated for seed germination assay, PGP and abiotic stress tolerance ability in vitro. This evaluation revealed 15 potent rhizobacteria representing each agro-climatic zone and salt stress mitigation in vitro. In particular, the biomass obtained for bacteria coated rice seedlings were corroborated with the performance of isolates exhibiting maximum average indole acetic acid (IAA) production respective to the agro-climatic zone. Surprisingly based on 16S rRNA, much of the propitious isolates belonged to same specific epithet exhibited variedly in their characteristics. Overall, Bacillus spp. was explored as dominant genera in toto with highest distribution in Western Plain zone followed by Central zone. Therefore, this study provides a counter-intuitive perspective of selection of native microflora for their multifarious PGP and abiotic stress tolerance abilities based on the agro-climatic zones to empower the establishment and development of more suitable inoculants for their application in agriculture under local stress environments.

Pengembangan Metode Identifikasi Kerusakan DNA Spermatozoa Ternak

The success of artificial insemination is very much determined by the quality of spermatozoa. The detection or identification of damaged chromatin of spermatozoa DNA is very important to forsee the adverse clinical outcome. However, the method of identification is still depended on expensive imported kits. Therefore, the objective of this research was to developed an identification kit to determine the quality of livestock spermatozoa DNA chromatin.This study consist of three step. Step 1) Determination of low melting point agarose (LMP-agarose) concentration which is 0,6%, 0,7% and 0,8%. 2) Comparison of three lysis solution (LS) which is LS I (0.4M Tris, 0.8M DTT, 1% SDS, pH 7.5), LS II (0.4M Tris,2 M NaCl, 1% SDS , pH 7.5), and LS III (0.4M Tris-HCl, 2M NaCl, 1% SDS 0,05 M EDTA, pH 7.5). 3) Comparison different staining which is Eosin yellow and Methylene blue. The results showed that 0.6% LMP-agarose demonstrated the best concentration to “trapped the spermatozoa” compared for sheep and goats. whereas the three concentration of spermatozoa cows can not be used to trap spermatozoa cow. The best formulation to lysis the membrane was LS III (0.4M Tris -HCl, 2M NaCl, 1% SDS 0,05 M EDTA). The best staining was eosin yellow and methylene blue with 2:1 ratio.

In situ monitoring of crevice corrosion morphology of Type 316L stainless steel and repassivation behavior induced by sulfate ions

To analyze the repassivation mechanism induced by SO42− ions, in situ monitoring of the crevice corrosion morphology on Type 316L stainless steel was performed. The repassivation of the crevice corrosion was observed when the solution was changed from 1M NaCl to 0.88M Na2SO4 or to 1M NaCl-0.88M Na2SO4. The active dissolution of Type 316L stainless steel was suppressed by SO42− ions at pH 0.4 in anodic polarization measurements. The transition from active to passive states inside the crevice was likely promoted by SO42− ions.

RHEOLOGICAL PROPERTIES OF PALYGORSKITE-SMECTITE SUSPENSIONS FROM THE VENTZIA BASIN, W. MACEDONIA, GREECE

In this contribution we examine the rheological properties of palygorskite rich clays from the Ventzia Basin, W. Macedonia, Greece. The clays consist of palygorskite and/or dioctahedral Fe-rich smectite (nontronite) and quartz as main components, and serpentine, amphibole and sepiolite as minor constituents. The apparent and plastic viscosity and yield point increase with increasing concentration of clay in the suspension. Flow is Newtonian for 1% suspensions, becoming gradually Bingham plastic (3% clay suspensions) and then pseudoplastic with yield point described by the Herschel Bulckley flow model. In the case of suspensions cf smectite-free clays Bingham plastic flow behaviour was not observed. Addition of 1M NaCl electrolyte deteriorates the rheological behaviour of the smectite-bearing palygorskite clays but it does not affect significantly the smectite-free, palygorskite rich clays. The different rheological properties of the palygorskite compared to smectite is due to the different morphological and crystal-chemical properties of these two minerals. It is suggested that the palygorskite-rich clays can be used successfully as drilling muds in seawater based drilling fluids, in which smectite-based drilling muds tend to flocculate.

Comparison of cadmium absorption, translocation, subcellular distribution and chemical forms between two radish cultivars (Raphanus sativus L.)

Cadmium (Cd) absorption and accumulation vary greatly not only among plant species but also among cultivars within the same species. In order to better understand the mechanisms of Cd absorption, transportation and distribution, we examined the differences of Cd absorption, translocation, subcellular distribution and chemical forms between L19, a Cd-tolerant genotype, and H4, a Cd-sensitive genotype, using kinetic analysis and soil culture experiment. Kinetic assays showed that the different Cd concentrations between the two cultivars might be ascribed to root absorption and translocation from root to shoot. The investigations of subcellular distribution and chemical forms verified that Cd concentrations of all subcellular fractions in H4 were all higher than in L19. Meanwhile, most of the Cd was associated with cell walls in the root of H4, but the Cd in the root of L19 and leaf of the two cultivars was mainly stored in soluble fraction, which could be one possible mechanism of tolerance to Cd toxicity. In addition, Cd fractions extracted by 1M NaCl and 2% HAC were predominant in root and leaf of both cultivars and the concentrations and proportions extracted by water and 80% ethanol in root and 1M NaCl in leaf were all higher in H4 than in L19. These results indicate that the Cd in H4 is more active than L19, which could be responsible for the sensitivity of H4 to Cd damage.

Molecular arrangement between electrolyte and alcohol at the air/water interface

While it is conventionally believed that interaction between electrolytes and surfactants at the air/water interface can have profound impact on surface tension, a quantitative description remains elusive. In this study, the surface arrangement of MIBC at 1M and 2M NaCl solution was investigated by molecular dynamics. The main aim of simulation was to explore the molecular arrangement and explain the synergistic effect, which was evidenced by existing experimental data. The simulation was able to confirm experimental results as well as the underlying molecular arrangement. Specifically, it was found that Na+ and Cl− has an opposite effects on surface tension. The net effect of Na+/Cl− on surface tension is determined by the relative ratio between the two ions near the interface. This relative ratio, in turn, depends on MIBC concentration. As a result, NaCl decrease tension at low MIBC and increase tension at high MIBC. The mechanism should be the same governing principle for other surfactant/electrolyte mixture. The findings lay an important foundation for mixed surfactant/electrolyte systems.

Purification, characterisation and salt-tolerance molecular mechanisms of aspartyl aminopeptidase from Aspergillus oryzae 3.042

A salt-tolerant aspartyl aminopeptidase (approximately 57kDa) from Aspergillus oryzae 3.042 was purified and identified. Specific inhibitor experiments indicated that it was an aminopeptidase containing Zn2+. Its optimal and stable pH values and temperatures were 7 and 50°C, respectively. Its relative activity remained beyond 30% in 3M NaCl solution for 15d, and its Km and Vmax were slightly affected in 3M NaCl solution, indicating its excellent salt-tolerance. A comprehensive analysis including protein homology modelling, molecular dynamics simulation, secondary structure, acidic residues and hydrophobicity of interior residues demonstrated that aspartyl aminopeptidase had a greater stability than non-salt-tolerant protease in high salinity. Higher contents of ordered secondary structures, more salt bridges between hydrated surface acidic residues and specific basic residues and stronger hydrophobicity of interior residues were the salt-tolerance mechanisms of aspartyl aminopeptidase.

Revisiting the influence of carboxylic acids on emulsions and equilibrated SOW systems using the PIT-slope method

The influence of various carboxylic acids (from C2 to C18) one equilibrated and emulsified surfactant/oil/water (SOW) systems is investigated. The PIT-slope method, based on the influence of an additive on the PIT of the C10E4/n-octane/10−2M NaCl(aq) reference emulsion, shows that from butanoic to hexadecanoic acids, the PIT of the system is decreased. A breakdown on dPIT/dx (considering the molar fraction x) or a minimum on dPIT/dC (taking into account the weight percentage C) is obtained with octanoic acid. The phase behavior of the C10E4/carboxylic acid/n-octane/0.01M NaCl(aq) system maintaining a molar fraction of carboxylic acid xCA=0.2 shows that from octanoic acid, the solubility of the system is clearly enhanced explaining the breakdown obtained in the PIT-slope. The Span 80/carboxylic acid/oil/10−2M NaCl(aq) system at a water-to-oil ratio equal to 1 is able to form O/W emulsions in the presence of some carboxylic acids, of which the alkyl chain modifies the partition of the different oligomers of Span 80. Finally, the PIT-slope method is applied to mixtures of lauric acid/sodium laurate providing a linear behavior of the PIT-slope dPIT/dx as a function of the acid/salt ratio.