Nosaibah Ebrahimi

Removing synthetic and pernicious materials from industrial effluents to prevent their discharging into the environment, recovering valuable compounds in food residues to prevent their wasting, and quantification of target species in complex matrices are among significant reasons that necessitate developing effective extraction/separation methods. In this work, aqueous two-phase systems (ATPSs) constructed by polypropylene glycol (PPG) and tetraalkylammonium salts (tetramethylammonium bromide (TMAC), tetraethylammonium bromide (TEAB), and tetramethylammonium chloride (TMAC)) were used as benign liquid-liquid extraction platform. Liquid-liquid phase diagrams were determined in the temperature range of 298.15-318.15 K. The parameters controlling the phase separation in the ternary PPG-tetraalkylammonium halides aqueous systems were evaluated. It was found that the potential of ATPS formation increases with increasing temperature, increasing the anion charge density, and decreasing the cation alkyl chain length of tetraalkylammonium salts so that the ability to induce PPG-based ATPS formation decreases in the order TMAC > TMAB > TEAB. Tie-line data reveal that the water content of the salt-rich phase is more than that of the polymer-rich phase. The partition coefficient and extraction efficiency of two alkaloids (caffeine and codeine), a flavoring antioxidant (vanillin), a natural bioactive pigment (curcumin), and three textile dyes (methylene blue, rhodamine B, and sudan III) were addressed in the studied ATPSs. From the obtained results, except for codeine and methylene blue, which are enriched in the more hydrophilic salt-rich phase, the other analytes tend to migrate to the more hydrophobic PPG-rich phase. The selectivity index of PPG-tetraalkylammonium ATPSs in the selective separation of the alkaloids (caffeine and codeine) and the dyes (rhodamine B/methylene blue and sudan III/methylene blue) were explored. The effect of water content difference of the coexisting phases of the ATPSs, the hydrophilicity/hydrophobicity nature of the target analytes, and V_"ratio" (the ratio of the PPG-rich phase volume to the salt-rich phase volume) on the extraction performance were scrutinized. Finally, the PPG-tetraalkylammonium ATPSs were used to extract dyes from the actual textile wastewater, and satisfactory results, especially for sudan III, were obtained.

To develop the type V hydrophobic thymol-based Deep Eutectic Solvents (DESs) with low viscosity for liquid-liquid extraction, in this work, the ability of DES formation between thymol and different materials was investigated. For this purpose, 39 combinations of thymol with various amino acids, acids, carbohydrates, amides, alkylammonium halides, and others were examined. Two new thymol (THY): acetamide (ACM)/acetanilide (ACN)-based DESs were prepared. Various combinations of THY and ACM/ACN were prepared, and their abilities to form a stable liquid at room temperature were monitored to screen the molar ratios for the formation of DES. The solid-liquid equilibrium (SLE) phase diagrams of the studied mixtures were determined by the Differential Scanning Calorimetry (DSC) method. From the SLE phase diagrams, it was found that the mixtures with composition range (2.5:1-1.5:1) and (2.5:1-2:1) for THY: ACM and THY: ACN, respectively, formed stable liquid at ambient temperature. The mixture with a molar ratio of 2:1 was selected to study intermolecular interactions, characteristics, and applications in dye extraction. FT-IR and NMR analysis were used to investigate the structure and hydrogen bond formation between the DES components. The physicochemical properties of the prepared DESs, including melting point, density, speed of sound, refractive index, and viscosity, were measured at different temperatures. The prepared DESs were stable in aqueous solutions due to their hydrophobicity. Therefore, they can be used to extract various analytes in aqueous environments. The obtained solvents were applied to extract methylene blue, methyl orange, and rhodamine B from aqueous solutions and real textile wastewater. Finally, to achieve optimal conditions, the effect of various factors on extraction efficiency was investigated.

The aqueous ternary systems composed of amino acid and tetraalkylammonium bromide (TAAB) were subjected to vapor–liquid and solid–liquid equilibria (VLE and SLE) studies to investigate the soluting effects in these systems. The amino acids used are S(+)-serine and S(-)-proline, and the TAABs are tetramethylammonium bromide (TMAB), tetrapropylammonium bromide (TPAB), and tetrabutylammonium bromide (TBAB). The water iso-activity curves obtained from the VLE measurements reveal the negative deviations from the linear isopiestic relation (LIR), indicating unfavorable amino acid – TAAB interactions in aqueous media. The incompatibility between amino acid and TAAB leads to solid–liquid demixing above critical concentrations. The results of SLE experiments demonstrate reducing the water-solubility of TAABs in the presence of the amino acids, while the water-solubility of amino acids doesn’t significantly change with the addition of TAABs. According to both VLE and SLE measurements, the amino acids play the role of the soluting-out agents in the investigated systems. The soluting-out strength increases with increasing the hydrophilic character of amino acids and the hydrophobic character of TAABs. In order to expand the knowledge of the soluting-out/in phenomena occurring in aqueous solutions, in this work, several ternary systems of {water + amino acid + quaternary ammonium salt} were subjected to vapor-liquid equilibrium (VLE) measurements at 298.1 K. The deviations of water iso-activity curves from the semi-ideal behavior have been taken as a criterion to determine the soluting-out/in effect occurring in the investigated systems. The VLE results generally showed negative deviations from the semi-ideality, indicating that there are no favorable interactions between amino acids and quaternary ammonium salts in aqueous media, and aqueous solutions composed of these solutes undergo the soluting-out phenomenon (except for DL-alanine/S(-)-proline-TBAH aqueous ternary systems that show small positive deviation from the semi-ideality). For a given amino acid, the magnitude of negative deviations and the strength of the soluting-out effect increase with increasing the cation alkyl chain length (TBAB > TPAB > TMAB) and the hydrophobic character of the anion of the quaternary ammonium salts (TBAB > TBAC > TBAH). Amino acids act as the soluting-ou agent, and their soluting-out ability follows the order S(+)-serine > glycine > DL-alanine > S(-)-proline. In the following sections of this thesis, the type of salt cation in the aqueous ternary systems {amino acid + tetrabutylammonium bromide} and {amino acid + tetrabutylphosphonium bromide} was discussed and it was observed that the water iso-activity curves is higher in ternary systems {water + serine/glycine/alanine/proline + tetrabutyl-phosphonium bromide}, which corresponds to the hydrophobicity of the cation (ammonium < phosphonium).

In this work, the effect of organic and inorganic ammonium salts on the liquid-liquid phase behavior of the water-rich region of 1-butanol + water system has been investigated in the temperature range of 10-80 ◦C. The inorganic salts used are NH4Cl and NH4Br, and the organic ones are tetramethylammonium bromide (TMAB), tetraethylammonium bromide (TEAB), tetrapropylammonium bromide (TPAB), tetrabutylammonium bromide (TBAB), tetrabutylammonium chloride (TBAC), tetrabutylammonium hydrogen sulfate (TBAH), dodecyltrimethylammonium bromide (DTAB), and cetyltrimethylammonium bromide (CTAB). From the gathered results, the inorganic ammonium halides reduce the water-solubility of 1-butanol and induce the salting-out effect. As the concentration of inorganic ammonium salts increases, the strength of the salting-out effect and the area of the biphasic region increase. However, tetraalkylammonium salts increase the water-solubility of l-butanol and induce the salting-in effect. The extent of the monophasic region, and the intensity of the salting-in effect (co-solvency), enhance with increasing the concentration of tetraalkylammonium salts. At the same molality of the investigated salts (0.2 mol.kg-1), the biphasic region area of the clouding diagram of aqueous 1-butanol systems decreases in the order NH4Cl > NH4Br > pure water > TMAB > TEAB > TPAB > TBAB > TBAC > TBAH > CTAB > DTAB. This trend reveals that the higher the charge density of the salt anion, the stronger the salting-out effect of inorganic ammonium halides, as well as the salting-in effect of tetraalkylammonium halides on aqueous solutions of 1-butanol. In the case of tetraalkylammonium salts with the same anion and different alkyl chains length of cation, the delicate balance between self-association interactions driving the organic salt micellization and favorable butanol-salt interactions driving the solubility of 1-butanol in aqueous solutions determines the magnitude of the salting-in effect. The values obtained for the relative contribution of enthalpy and entropy to the clouding Gibbs free energy demonstrate that the clouding process of 1-butanol in aqueous solutions of inorganic ammonium salts and organic ammonium salts with smaller hydrocarbon portion is entropy-driven. However, the clouding process for 1-butanol in aqueous solutions of tetraalkylammonium salts with longer hydrocarbon chains is often enthalpy-driven.

Aiming at studying the soluting effects occurring in non-aqueous mixtures containing polymeric solutes, the vapor-liquid equilibrium behavior of ternary {polymer 1 + polymer 2 + ethanol}, {polymer 1 + polymer 2 + 2-propanol}, and {polymer 1 + polymer 2 + 1-butanol} were studies via the isopiestic method, at 298.15 K. The polymers used in this work are: polypropylene glycol with molecular masses of 400 and 1000 g.mol-1 (PPG400 and PPG1000), polyvinyl pyrrolidone with a molecular weight of 10000 g.mol-1 (PVP10000), polyethylene glycol dimethyl ether with molecular masses of 250 and 500 g.mol-1 (PEGDME250 and PEGDME500), and polyethylene glycol with a molecular weight of 400 g.mol-1 (PEG400). The impact of the type and molecular weight of polymers on the activity and vapor pressure of the organic solvents was investigated. The results showed that the solvophilic degree of the studied polymers in all three studied organic solvents follows a relatively similar trend. The dependence of solvent iso-activity curves on the type and activity of solvents, as well as the type and molecular weight of polymers, was evaluated. The deviations of the isopiestic equilibrium concentrations from the semi-ideal behavior (linear isopiestic relation) were calculated to find out the soluting-in or soluting-out effects governing the behavior of the investigated systems. None of the ternary systems of {polymer (1) + polymer (2) + ethanol/2-propanol/1-butanol} showed a meaningful negative deviation from the linear isopiestic relation. These findings indicate that unlike aqueous systems containing two polymeric solutes which can form an aqueous biphasic system, the organic systems investigated in this work do not undergo liquid-liquid de-mixing. The solvent iso-activity curves of {PVP + polymer (2) + ethanol/2-propanol/1-butanol} exhibit convex shape, that is, isopiestic equilibrium concentrations of these systems have positive deviations from the semi-ideal behavior. In these systems, due to the preferential interaction between PVP and polymer (2), adding one of the polymers to an organic solution containing another polymer leads to increased solubility and decreased activity coefficient of polymers (soluting-in effect). However, in other ternary systems investigated here, isopiestic equilibrium concentrations follow a linear isopiestic relation and have semi-ideal behavior. In such systems, adding the second polymer does not affect the solubility and activity coefficient of the first polymer.

This work systematically studies the effect of various additives on the liquid-liquid equilibrium behavior of water +1-butanol system at water-rich branch. For this purpose, the cloud point data have been obtained for ternary systems of 1-butanol in aqueous amino acids, polymers, imidazolium-based ionic liquids, primary propanol and secondary propanol solutions via the visual turbidity titration method, at temperatures ranging from 10°C to 80 °C. The investigated concentrations for amino acids and ionic liquids are 0.2, 0.4, and 0.6 mol.kg-1, and those for polymers and propanol are 5%, 10%, and 15% w/w. From the obtained phase diagrams, the solubility of 1-butanol in water decreases by the addition of the investigated amino acids (salting-out effect). As the amino acid molality increases, the space of the biphasic region increases, and at the same amino acid molality, the salting-out ability follows the order: serine > glycine > alanine > proline > glutamine. However, the clouding phase diagrams in the presence of ionic liquids (1-butyl-3-methyl-imidazolium bromide and 1-octyl-3-methyl-imidazolium bromide) and polymers (polyethylene glycol 400 and polyethylene glycol 10000) reveals the salting-in phenomenon. The studied ionic liquids and polymers can favorably interact with both water and butanol molecules, therefore increase the solubility of 1-butanol in water. The magnitude of the ionic liquid’s salting-in effect increases with an increase in their molality and cation alkyl chain length. Although, the salting-in effect increases with the increase in polymer’s mass percentage, its decreases by increasing polymer’s molecular weight. The obtained cloud point data for 1-butanol in aqueous propanol solutions reveals washing-out effect at lower temperatures and salting-in effect at higher temperatures. In fact, the favorable interactions between propanol and 1-butanol at low temperatures facilitate the separation of the organic phase from the aqueous phase; this type of biphasic region expansion is not due to the salting-out effect, but is called washing-out effect. As temperature increases, the simultaneous favorable propanol-water and propanol-butanol interactions lead to an increase in the water solubility of 1-butanol and therefore an expansion of the one-phase region (salting-in effect).

در این پایان نامه، از اصول نمک زدایی برای تولید انواع جدید سیستم های دوفازی آبی مبتنی بر پلیمر بهره برده شد. به این منظور، اثر نمک زدایی یا نمک افزونی انواع آمینواسیدها، کربوهیدرات ها و سورفکتانت های آنیونی بر محلول های آبی پلیمری، با تکنیک های مختلف بررسی شد. مکانیسم اثر نمک حل شونده های مختلف بر محلول های آبی پلیمری، از دیدگاه ترمودینامیکی مورد مطالعه قرار گرفت که منجر به یافتن رابطه ی پدیده های نمک زدایی و نمکافزونی با انحراف رفتار تعادل مایع – بخار از حالت شبهایدهال شد. در بخش اول این کار، سیستم های آبی پلیمر – آمینواسید با بررسی تعادل مایع – مایع، دمای ابری شدن، اسمومتری فشار بخار و خواص حجمی و تراکم پذیری مطالعه شدند. اثر دما، جرم مولکولی پلیمر و ساختار آمینواسید بر خواص ترمودینامیکی این سیستم ها بررسی شد. نتایج نشان می دهد که سیستمهای آبی پلی اتیلن گلیکول (PEG) – آمینواسید قابلیت دوفازی شدن ندارند؛ در حالی که سیستم های آبی پلی پروپیلن گلیکول (PPG) – آمینواسید بالاتر از غلظتهای بحرانی تشکیل سیستم دوفازی آبی می-دهند (اثر نمک زدایی). افزایش دما، افزایش جرم مولکولی PPG و کاهش سهم هیدروکربنی آمینواسید، پتانسیل تشکیل سیستم دوفازی آبی را افزایش می دهد. میزان انحراف منفی داده های اسمومتری فشار بخار سیستمهای آبی PPG - آمینواسید از حالت شبهایده ال، کاملا در توافق با رفتار تعادل فاز مایع – مایع این سیستم ها است؛ به طوری که هرچه انحراف منفی از حالت شبهایده ال بیش تر باشد، ناحیه ی دوفازی نمودار فاز مایع – مایع گسترده تر است. اثر آمینواسیدها بر حجم و تراکمپذیری مولی ظاهری رقت بی نهایت PPG و نیز اثر PPG بر حجم و تراکمپذیری مولی ظاهری رقت بینهایت آمینواسیدها، در محیط آبی، در دماهای مختلف بررسی شد و نتایج بر اساس استعداد نمکزدایی آمینواسیدها و انواع برهمکنشهای بین مولکولی توجیه شد. در بخش دوم این کار، سیستم های آبی پلیمر – کربوهیدرات با بررسی تعادل مایع – مایع و اسمومتری فشار بخار، بهطور سیستماتیک مطالعه شدند. اثر دما، نوع و جرم مولکولی پلیمر و نوع و شیمی فضایی کربوهیدرات بر رفتار تعادل های فاز مایع – مایع و مایع – بخار بررسی شد. در سیستم های آبی PEG – کربوهیدرات که قابلیت دوفازی شدن ندارند، داده های اسمومتری فشار بخار عمدتا دارای انحراف مثبت از رفتار شبهایده ال هستند(اثر نمک

این کار بر دو بخش متمرکز شده است: 1- مطالعه تجمع یونی و حلالپوشی مایع یونی 1-هگزیل-3-متیل ایمیدازولیوم کلراید، [Hmim]Cl، در حلالهای مولکولی متعدد؛ که به این منظور حجم سنجی، اندازه گیری صوتی، هدایت سنجی و اسمومتری فشار بخار برای مخلوط های دو تایی مختلف شامل مایع یونی [Hmim]Cl + حلال (متانول، اتانول، 1-پروپانول، 2-پروپانول، 1-بوتانول، استونیتریل و آب) انجام شد. 2- مطالعه اثر salting-out در نتیجه افزودن مایع یونی به محلول های آبی شامل پلیمرهای قابل حل در آب؛ که به این منظور اسمومتری فشار بخار برای محلول های شامل[Hmim]Cl در آب خالص و در محلول های آبی از پلیمر های PEG2000 و PEG6000 در دمای 15/308 کلوین انجام شد. بخش اول: با استفاده از داده های تجربی دانسیته و سرعت صوت، خواص مولی ظاهری مایع یونی در همه سیستم های مورد مطالعه در دماهای مختلف محاسبه شد. حجم مولی ظاهری رقت بی نهایت برای بررسی برهمکنش های حلال-حل شونده مورد استفاده قرار گرفت و معلوم شد که برهمکنش [Hmim]Cl با حلال های مورد بررسی از ترتیب متانول> استونیتریل>1-پروپانول> اتانول>2-پروپانول>1-بوتانول> آب پیروی می کند. با استفاده از داده های هدایت سنجی، هدایت الکتریکی ویژه و هدایت الکتریکی مولی مایع یونی در سیستم های مورد بررسی بدست آمد. در غلظت یکسان، هدایت الکتریکی [Hmim]Cl از ترتیب استونیتریل> آب> متانول> اتانول> 1-پروپانول> 2-پروپانول> 1-بوتانول پیروی می کند. ضرایب اسمزی تجربی در دمای 15/318 کلوین، به طور مستقیم از روش اسمومتری فشار بخار بدست آمد و با استفاده از آن، فعالیت، فشار بخار، کاهش فشار بخار و ضریب فعالیت حلال و هم چنین ضریب فعالیت مولی متوسط مایع یونی و انرژی آزاد گیبس مولی مازاد برای همه سیستم های مورد بررسی محاسبه شد. نتایج نشان داد که به استثنای محلول های غلیظ استونیتریلی، در همه محلول های مورد مطالعه، حلال دارای انحراف مثبت جزئی از رفتار محلول رقیق ایده ال است در حالی که حل شونده انحراف منفی شدیدی از حالت رقیق ایده ال نشان می دهد از این روست که مقادیر انرژی آزاد گیبس مولی مازاد برای همه محلول های بررسی شده منفی است. بخش دوم: داده های بدست آمده از روش اسمومتری فشار بخار نشان داد که کاهش فشار بخار برای سیستمهای سه تایی شامل ( مایع یونی+ PEG+ آب) به مقدار جزئی از مجموع فشار بخار سیستم های دوتایی متناظر