Solubility In Acetone Research Articles

Synthesis and characterization of Luffa cylindrica fatty acids-based alkyd resins

The work reports on preparation of three grades of alkyd resins using a two-stage alcoholysis-polyesterification method. Phthalic anhydride, glycerol and Luffa cylindrica seed oil were used in the formulation of the alkyds. The oil was extracted with n-hexane and 30.30 % was obtained. The fatty acids and physicochemical analyses of L. cylindrica seed oil revealed 77.78 % unsaturated fatty acids with linoleic acid (50.25 %), oleic acid (27.30 %), palmitic acid (13.40 %), and stearic acid (6.38 %) being the most abundant; and iodine value, 153 mg I2/g respectively. Properties of the alkyds having oil content of 40 % (I), 50 % (II) and 60 % (III) were evaluated. The acid value was observed to decrease as the reaction progressed. FTIR spectra of the alkyds revealed ester linkages and olefenic hydrogen stretch at 1737.92–1734.06 and 3064.99–3007.12 cm−1 respectively. Evaluation of prepared alkyds by determination of acid values, iodine values, solubility in xylene, toluene and acetone; resistance of dry film to acid, alkali and water; scratch and gouge film hardness and drying time revealed that L. cylindrica seed oil is a potential raw material for the coatings industry.

Solubility of 2,5-Di-tert-butylhydroquinone and Process Design for Its Purification Using Crystallization

The solubility of 2,5-di-tert-butylhydroquinone (DTBHQ) in acetone, ethyl acetate, methanol, and the mixtures of ethanol and water was measured and correlated in the temperature range between 278.95 K and 346.15 K. It was found that the solubility in acetone increases more rapidly with increasing temperature than in other solvents. The data was correlated using the modified Apelblat, Buchowski-Ksiazczak λh, and Van’t Hoff equations, with a maximum relative average deviation of less than 2.74 %. The obtained thermodynamic models were used in designing a crystallization process and synthesizing a flowsheet for effective purification of crude DTBHQ from the byproduct of tertiary butylhydroquinone (TBHQ).

Solubility of tridecanedioic acid in pure solvent systems: An experimental and computational study

Solubility has been extensively investigated by the phase equilibria approach at the mesoscale level, but its origin on the molecular and electronic levels is poorly understood. This study explored the solubility behaviour of crystalline solid in selected pure solvents with various functional groups by using both phase equilibria and molecular modelling methods. The model compound tridecanedioic acid (TDDA) solubility in methanol, ethanol, acetic acid, acetone, and ethyl acetate was determined from T=(283.15 to 323.15)K by a static method. It was found that almost all solutions studied exhibit non-ideal behaviour and deviate positively from Raoult’s law indicating the important role of homo-molecules interactions. Thermodynamic analyses of solution suggest that both enthalpy and entropy of solution govern the dissolution process. Computational studies on solubility behaviour were performed by using both density functional theory (DFT) calculations and molecular dynamic (MD) simulations. The results conclude that the (solute+solvent) interaction is not the only factor determining solubility, and (solvent+solvent) interaction also plays an important role. The simulated results are found to be qualitatively consistent with experimental values. Finally, solubility values were correlated by the empirically modified Apelblat equation and two local composition models of Wilson and NRTL.

A New CCM/MPL Structure for High Power Density Polymer Electrolyte Fuel Cells

High power density operation is one path of cost reduction and commercialization of polymer electrolyte fuel cells (PEFCs), and mass transport limitations, particularly of oxygen hinders the operation at required high current densities. Most of the mass transport limitation in a PEFC occur in the gas diffusion layers (GDL), particularly of cathode. Conventional GDLs are typically comprised of highly porous carbon paper or cloth substrate; a small amount of hydrophobic material (usually PTFE) is applied to the GDL to enhance its water removal capabilities. In the last decade, micro-porous coatings (e.g. micro-porous layer, MPL) have been developed to both improve the electrical/thermal contact between the GDL and the catalyst layers, and water management.Kotaka et. al. recently introduced a GDL, where the carbon paper substrate is removed and the entire gas diffusion layer consists of the MPL only [1]. The MPL in their concept is manufactured separately and assembled similar to a conventional GDL. Here, we present a similar concept where the MPL is directly fabricated on the catalyst coated membrane (CCM), forming the GDL. A schematic of the assembly is shown in Fig. 1(a). Due to much smaller thickness and heat/electron conduction cross-section of this GDL, a micro-channel flow field is utilized.The MPL is directly deposited onto both sides of the CCM via spray deposition with a hot plate maintained at 100°C as shown in Fig. 1(b). Poly(vinylidene fluoride) (PVDF)-based copolymer is used as the wet proofing agent because of its lower sintering temperature and high solubility in acetone compared to conventional PTFE and PVDF homopolymer. In order to prepare the MPL solution, carbon particles are added to a PVDF solution obtained by dissolving in dimethylformamide (DMF), and then mixed in an ultrasonic water bath with a homogenizer for 6 hours and stirring for 24 hours. The MPL solution can be applied to the CCM by spraying, screen printing, or doctor blade methods with a thin layer; however spray deposition with a hot plate found to be the most suitable method to avoid damage to the Nafion membrane in the CCM by DMF. Acetone is also added to the MPL solution to accelerate evaporation rate before spraying onto the CCM. A spray station with controlled X-Y table is used to make a uniform MPL surface onto both sides of the CCM. The desired thicknesses of the MPL are between 50 and 100µm to provide enough mechanical stability while maintaining minimal mass transport resistance. After spraying the carbon solution to either side of the CCM, the MPL/CCM/MPL (MCM) is dried at 100°C to evaporate all remaining solvents for 30 min, and then heated between two hot flat plates for 3 hours with a temperature of 170°C to distribute homogeneously PVDF throughout the MPL.Figure 2 shows the SEM image and EDX maps of the CCM with the MPL deposited on one side. A highly porous structure is observed in the deposited MPL layer, which results in open pathways for fuel and oxygen to the CL. Pore size distribution, permeability (with Gurley method), cell performance and electrochemical impedance spectroscopy (EIS) are used to characterize the new diffusion layer structure. Acknowledg e ments Financial support from National Science Foundation (CBET-0748063) is greatly acknowledged.

Solubilities of 4-Bromo-1,8-naphthalic Anhydride in Different Pure Solvents and Binary Solvent Mixtures with the Temperature Range from (278.15 to 333.15) K

The solubilities of 4-bromo-1,8-naphthalic anhydride in organic solvents of acetone, methanol, ethanol, and acetic acid and in the binary mixtures of acetone and ethanol were determined over the temperature range of (278.15 to 333.15) K by using the analytical stirred-flask method. The solubilities of 4-bromo-1,8-naphthalic anhydride in these solvents increased with the increasing temperature. The experimental results showed that 4-bromo-1,8-naphthalic anhydride presents a higher solubility in acetone and the solubility in acetone had the strongest positive temperature dependency. The modified Apelblat equation, the combined nearly ideal binary solvent/Redlich–Kister (CNIBS/R–K) equation, and the modified Jouyban–Acree model were proposed for correlating the experimental data. The values for the apparent molar enthalpy and entropy were calculated by using the van’t Hoff equation. The experiment results and correlation models could be useful in the reaction and purification process of 4-bromo-1,8-naphthalic anhydride.

Synthesis and properties of conjugated fluoroalkyl ether-substituted polythiophenes prepared in organic solvent and supercritical carbon dioxide

A number of new fluoroalkyl ether-containing polythiophenes are synthesized via oxidative polymerization in supercritical CO2 (scCO2) and chloroform. In both cases, high-molecular-mass polymers with high yields are prepared. The properties of the polymers synthesized in scCO2, such as molecular mass, polydispersity, conjugation, and UV absorption, are similar to the properties of the polymers obtained in chloroform. All poly(fluoroalkyl ether thiophenes) show solubility in DMF, toluene, THF, chloroform, and acetone. The glass-transition temperatures of the polymers are in the range 58–82°C, and the temperatures corresponding to 10% loss in their weight are in the ranges 248–294 and 260–303°C for poly(fluoroalkyl ether thiophenes) synthesized in scCO2 and chloroform, respectively. All polymers fluoresce in the blue region with emission maxima at 506 to 526 nm. Because of the unique combination of fluoroalkyl and carbonyl groups, poly(fluoroalkyl ether thiophenes) feature good solubility in scCO2, which is a promising alternative solvent for the oxidative polymerization of fluoroalkyl ether thiophenes.

Determination and Correlation of Solubility Data and Dissolution Thermodynamic Data of l-Lactide in Different Pure Solvents

The solubility of l-lactide in pure ethanol, ethyl acetate, acetone, isopropanol, methanol, and methylbenzene from (278.15 to 338.15) K was determined by dynamic method with a laser monitoring technique. It was found that l-lactide is sparingly soluble in ethanol, isopropanol, methanol, and methylbenzene while it has high solubility in ethyl acetate and acetone. The solubility data of l-lactide in different solvents increase with the increasing of temperature. The measured solubility data of l-lactide were correlated by using the modified Apelblat, Wilson, nonrandom two-liquid (NRTL), and universal quasichemical (UNIQUAC) models, respectively. It was found that NRTL equations give the best correlation results for most solvents except for ethanol. The dissolution enthalpy, entropy of l-lactide, and the free Gibbs energy change of l-lactide in these solvents were obtained by using the van’t Hoff equation. From solubility data, melting point, fusion enthalpy, and entropy of l-lactide and d-lactide, it was pr...

Growth and Characterization of New Non Linear Optical Bis-Glycine Hydro Bromide (BGHB) Single Crystal

A new non linear optical material, Bis-Glycine Hydro bromide (BGHB), has been synthesized. Single crystals of BGHB have been grown successfully by slow evaporation method. The solubility of the material was measured in various solvents such as ethanol, acetone and water. It was found to have extremely low solubility in ethanol and acetone. The grown crystals were characterized by recording the powder diffraction and identifying the diffracting planes. Using single crystal diffractometer the morphology of BGHB crystal was identified. Fourier transform infrared (FTIR) spectroscopic studies, optical behavior such as UV-visible-NIR absorption, Thermogravimetic (TG) and differential scanning calorimetric (DSC) analyses have been performed to show that BGHB is thermally stable up to 168.5℃ and there is no phase transition and decomposition till 168.5℃. Anisotropy in the hardness behavior has been observed while measuring at different crystal planes by Vicker hardness test.

Supercritical extraction of organic solutes from aqueous solutions by means of membrane contactors: CFD simulation

This work presents mass transfer modeling of solvent extraction by means of membrane contactors. Model was based on solving conservation equations for solutes in the membrane contactor. The system considered here was a polymeric membrane contactor, an aqueous solution of ethanol or acetone, and a dense solvent. The equations of the model were solved by numerical method using CFD techniques. The simulation results for ethanol and acetone showed an average deviation of 15.6% and 2.5% with the experimental data, respectively. Simulation results indicated that the extraction of acetone is higher than ethanol due to higher solubility of acetone in the solvent. The simulation results revealed that decreasing feed velocity and increasing solvent velocity increase solute removal. The developed mass transfer model is more accurate than other models and represents a general approach for simulation of membrane-based solvent extraction.

PHBV microspheres – PLGA matrix composite scaffold for bone tissue engineering

Polymer scaffolds, particularly in the form of microspheres, have been employed to support cells growth and deliver drugs or growth factors in tissue engineering. In this study, we have established a scaffold by embedding poly (β-hydroxybutyrate-co-β-hydroxyvalerate) (PHBV) microspheres into poly ( l-lactic-co-glycolic acid) (PLGA) matrix, according to their different solubility in acetone, with the aim of repairing bone defects. PLGA/PHBV scaffolds had good pore parameters, for example, the porosity of PLGA/30% PHBV scaffold can reach to 81.273 ± 2.192%. Besides, the pore size distribution of the model was evaluated and the results revealed that the pore size mainly distributed between 50 μm and 200 μm. With increasing the amount of PHBV microspheres, the compressive strength of the PLGA/PHBV scaffold enhanced. The morphology of the hybrid scaffold was rougher than that of pure PLGA scaffold, which had no significant effect on the cell behavior. The in vitro evaluation suggested that the model is suitable as a scaffold for engineering bone tissue, and has the potential for further applications in drug delivery system.

Uptake of acetone, acetaldehyde and ethanol in cold sulfuric acid solutions containing organic material: Carbon accretion mechanisms

The solubilities of acetone, ethanol and acetaldehyde in cold ternary solutions composed of 38.4–75.0 wt% sulfuric acid in water with additional dissolved organic material have been measured over the temperature range 214.4–238.5 K using a Knudsen cell reactor. The solubility of acetaldehyde in H 2SO 4/H 2O is enhanced by an order of magnitude by the presence of ethanol or acetone. The reactive uptake of acetaldehyde is enhanced by the presence of formaldehyde in acid solution. No significant formation of acetals from ethanol with carbonyl partners was observed. The solubility of acetone is unaffected by the presence of ethanol in solution and vice versa. Only polymerization of small aldehydes offers a potentially significant route to the accretion of organic material into acidic particles in the upper troposphere. The acid-catalyzed polymerization of aldehydes, RC(H) O + R′C(H) O, proceeds through the hydrated forms of the aldehydes, is optimized at acidities around 40 wt% H 2SO 4, and can potentially accumulate significant amounts (>20%) of organic material by mass in upper tropospheric particles.

On the Metastable Zone Width of 1,3-Dipalmitoyl-2-oleoylglycerol, Tripalmitoylglycerol, and Their Mixtures in Acetone Solutions

The extensive experimental data reported by Smith et al. (Eur. J. Lipid Sci. Technol. 2005, 107, 583−593) on the metastable zone width of 1,3-dipalmitoyl-2-oleoylglycerol, (POP) tripalmitoylglycerol (PPP), and their mixtures in acetone are analyzed using a novel approach based on classical three-dimensional nucleation theory (Sangwal, K. Cryst. Growth Des. 2009, 9, 942−950) and a self-consistent Nývlt-like approach (Sangwal, K. Cryst. Res. Technol. 2009, 44, 231−247) to obtain quantitative information on the processes of nucleation of these systems. The relevant equations of the above approaches are (i) (T0/ΔTmax)2 = F(1 − Z ln R) and (ii) ln(ΔTmax)/T0) = Φ + β ln R, where T0 is the saturation temperature and F and Φ are, respectively, the values of (T0/ΔTmax)2 and ln(ΔTmax)/T0) when ln R = 0, whereas Z is a parameter characteristic of the crystallizing system and the constant β is inverse of the apparent nucleation order m in the Nývlt approach. It was found that (1) the value of parameters β and Z is relatively insensitive to saturation temperature T0 but depends on the investigated compound and the technique used for the measurement of maximum supercooling ΔTmax and the presence of PPP impurity in POP solutions; (2) the values of β and Z for PPP and POP decrease with an increase in their solubility in acetone; and (3) the data of Φ and ln(F1/2) as a function of saturation temperature T0 follow the Arrhenius-type relation with an activation energy Esat. Analysis of the results revealed that (1) the values of β and Z are directly connected with the solid−liquid interfacial energy γ; (2) the value of Esat depends on the nature of ions/molecules participating in diffusion; (3) maximum supercooling ΔTmax measured by turbidimetry corresponds to a nucleation event alone, but that obtained from growth exotherm includes some contribution of growth of stable nuclei after nucleation; and (4) PPP impurity in POP solutions promotes crystallization by acting as growth centers for heterogeneous nucleation.

HOMOGENEOUS SYNTHESIS OF HIGH-AMYLOSE STARCH ACETATES AND THEIR ULTRAFINE FIBERS PREPARED BY ELECTROSPINNING

High-amylose starch can dissolve effectively in a room temperature ionic liquid 1-allyl-3-methylimidazolium chloride (amimCl). By using amimCl as the reaction medium,high-amylose starch acetates with a relatively wide range of degree of substitution (DS) were homogeneously synthesized by a one-step method in the absence of any catalyst.The effects of reaction time and acetic anhydride/anhydroglucose unit (AGU) molar ratio on the DS of starch acetates were investigated.These starch acetates exhibited different solubility in water,acetone and DMAc,depending on the DS value.Finally,the fibrous membranes composing of continuous and smooth fibers with diameters in a range from several tens to several hundreds nanometers were successfully produced via electrospinning of starch acetate solution.

Hydrophilic polystyrene/maleic anhydride ultrafine fibrous membranes

AbstractPolystyrene/maleic anhydride (PSMA) was synthesized to reach a viscosity‐average molecular weight of 700 kDa and fabricated into ultrafine fibrous membranes consisting of fibers with an average diameter of 300 nm. These ultrafine PSMA fibers were rendered insoluble in organic solvents by reactions with hydrazine and ethylenediamine (ED). The highly efficient incorporation of diamines into the fibrous membranes was easily achieved by brief immersions in either dilute (0.5 wt %) hydrazine for 1 min or ED ether solution for 2 min. Heating at 150°C for 5 min produced crosslinked PSMA with very little or no solubility in acetone with the retention of the fibrous membrane structure. The ED‐crosslinked membranes were particularly stable to both bases and acids as well as hydrophilic solvents, had a 46° water contact angle, and absorbed 22 times the amount of water as the as‐spun fibrous membrane. This post‐fiber‐formation crosslinking approach was robust, highly efficient, and fast and required very little crosslinking reagent. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Cellulose/chitosan hybrid nanofibers from electrospinning of their ester derivatives

A facile approach has been established to generate cellulose/chitosan hybrid nanofibers with full range of compositions by electrospinning of their ester derivatives, cellulose acetate (CA) and dibutyryl chitin (DBC), followed by alkaline hydrolysis to cellulose (Cell) and chitosan (CS). DBC was synthesized by acid-catalyzed acylation of chitin (CHI) with butyric anhydride and the newly formed butyl groups on C3 and C6 were confirmed by FT-IR and 1HNMR. DBC had robust solubility in acetone, DMAc, DMF, ethanol, and acetic acid, all except ethanol were also solvents for CA, allowing mixing of these ester derivatives. Fiber formation by electrospinning of either DBC or CA alone and together in these common solvents and their mixtures were studied. The 1/1 acetone/acetic acid was found to be the optimal solvent system to generate fibers from either DBC or CA as well as their mixtures at all CA/DBC ratios, resulting in hybrid fibers with diameters ranging from 30 to 350 nm. DBC and CA were well mixed and showed no phase separate in the hybrid fibers. Alkaline hydrolysis (NaOH) of the equal mass CA/DBC nanofibers regenerated Cell and CHI readily via O-deacylation, then proceeded to further deacetylate CHI to CS via N-deacetylation at higher alkaline concentrations and/or temperatures. Under conditions studied, hydrolysis with 5N NaOH at 100 °C for 3 h was optimal to regenerate cellulose/chitosan hybrid nanofibers.

Copolymerization of Styrene and Ethylene at High Temperature with Titanocenes Containing a Pendant Amine Donor

The copolymerization of ethylene and styrene at 120 °C was investigated with a series of titanocenes: Cp′TiCl2L [1, 2: Cp′ = cyclopentadienyl (Cp) versus 3, 4: Cp′ = {2-(dimethylamino)ethyl}cyclopentadienyl (CpN); 1, 3: L = Cl versus 2, 4: L = 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO)], in combination with methylaluminoxane (MAO). At 120 °C, titanocenes bearing a pendant amine ligand (3 and 4) are effective catalysts for the ethylene-styrene (ES) copolymerization, whereas complexes lacking the pendant group (1 and 2) afford only mixtures of polyethylene (PE) and atactic polystyrene (aPS). At these temperatures, copolymerization with complexes 3 and 4 yields mixtures of ES copolymers and atactic polystyrene that are not readily separated by solvent extraction or gel permeation chromatography as both components of the mixture exhibit similar molecular weights and solubility in THF and acetone. The source of the atactic polystyrene was the autopolymerization of styrene as deduced by carrying out the copolymerization in the presence of a catalytic chain transfer agent, cobalt tetraphenylporphyrin (Co(tpp)). The addition of Co(tpp) caused a decrease in the molecular weight of the atactic polystyrene but had no effect on the molecular weight of the ES copolymer.

Effect of calcium chloride on the liquid-liquid equilibria of the water-acetone system

Liquid-liquid phase equilibrium is mainly a result of intermolecular forces. Therefore hydroxylic compounds very often show a good affinity with water, due to hydrogen bonding. Consequently the ionic forces taking place when salt is added to an aqueous solution may affect this phase equilibrium. This is the main scope of this study, considering this salt effect. The effect of the addition of calcium chloride (CaCl 2) on the liquid-liquid equilibrium data of the binary system water-acetone has been studied experimentally at 23°C, for different salt weight percentages of 5, 10, 15 and 20. A two- phase region has been created, decreasing the acetone solubility in water. From this study it can be concluded that ‘salting-out’ takes place with the presence of calcium chloride.

Grafting of ethylene–ethyl acrylate–maleic anhydride terpolymer with amino‐terminated polydimethylsiloxane during reactive processing

AbstractAn ethylene–ethyl acrylate–maleic anhydride copolymer (EEAMA) is grafted with aminopropyl polydimethylsiloxane (PDMS) via melt reactive mixing at 140°C. The materials produced split into two components based on their solubility in acetone. The acetone soluble material is highly enriched in PDMS, whereas the insoluble material contains levels of PDMS that are lower than the proportions added to the reaction mixture. It was found that for all reaction mixtures the PDMS content in the acetone insoluble solids increases with mixing time. Molecular weight distributions of materials become narrower as the amount of PDMS increases. Rheological testing shows that the level of PDMS in the mixtures and the presence of the acetone soluble fractions give rise to significant changes in the complex viscosity and elastic moduli for the polymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4230–4237, 2006

Growth of mercuric iodide crystals

Mercuric Iodide (HgI2) is a semiconductor candidate for the construction of X- and gamma-ray detectors for digital medical imaging due to its high atomic number (Z Hg = 80, Z I = 53). Also, HgI2 has a wide optical band-gap (2.13 eV) and high photon absorption coefficient for high-energy radiation. Different structures can lead to varying electrical and optical properties of the final material. In this work, HgI2 crystals were produced by the solvent evaporation technique. The solvents used were ethanol (solubility around 20 mg/ml at 25ºC), ether (solubility around 3.5 mg/ml at 25ºC) and acetone (solubility around 24mg/ml at 25ºC). The evaporation conditions were varied in order to produce different final crystals. The Bérnard cells are responsible for crystallites formation due to the Bérnard-Maragoni convection in the liquid. Millimeter-sized crystals can be obtained as seen by Scanning Electron Microscopy.

Direct nanoimprint of inorganic-organic hybrid glass

Inorganic-organic hybrid glass nanoimprint has been demonstrated by the transformation of polysilane polymer into SiO2-based material. The proposed technique has the advantages of low temperature and very short processing time over conventional inorganic patterning methods. Line and space structures ranging from 50nmto25μm could be precisely patterned, and an aspect ratio of 4.8 was achieved for an optimized imprint condition. Only 5% shrinkage of the structure was confirmed after heat treatment at 350°C. The patterned film shows little solubility in acetone, acid, or alkali solution. Furthermore, only a very small change is observed when it is dipped in hydrofluoric acid. It was demonstrated that the proposed process enables nanopatterning of inorganic-organic hybrid glass with good thermal and chemical durabilities.