Reactive Extraction of o-Aminophenol Using Trialkylphosphine Oxide

Extraction of o-aminophenol （OAP） using trialkylphosphine oxide （TRPO） was studied with different diluents The neutral OAP was extracted using TRPO under an equilibrium pH in the range of 6-7.5, and a maximum distribution coefficient occurred. It was confirmed that the pH value and the TRPO concentration are the key factors that affect distribution coefficient. Nonpolar diluents could provide better extraction distribution coefficient for the extraction of OAP and the order is： kerosene 〉n-octanol 〉chloroform.     

A Study of the γ-Radiolysis of N,N-Didodecyl-N′,N′-Dioctyldiglycolamide Using UHPLC-ESI-MS Analysis

Solutions of N,N-didodecyl-N′,N′-dioctyldiglycolamide in n-dodecane were subjected to γ-irradiation in the presence and absence of both an aqueous nitric acid phase and air sparging. The solutions were analyzed using ultra-high-performance liquid chromatography-electrospray ionization-mass spectrometry (UHPLC-ESI-MS) to determine the rates of radiolytic decay of the extractant as well as to identify radiolysis products. The DGA concentration decreased exponentially with increasing dose, and the measured degradation rate constants were uninfluenced by the presence or absence of acidic aqueous phase, or by air sparging. The identified radiolysis products suggest that the bonds most vulnerable to radiolytic attack are those in the diglycolamide center of these molecules and not in the side chains.     

The Development of Ginger Drying Using Tray Drying,Heat Pump–Dehumidified Drying,and Mixed-Mode Solar Drying

Mature ginger was pretreated by soaking in citric acid prior to drying in a single layer in a tray and heat pump dehumidified dryer at three temperatures of 40, 50, and 60°C and in a mixed-mode solar dryer at 62.82°C and a radiation intensity of 678 W/m². The drying data were applied to the modified Page model. Diffusivities were also determined using the drying data. Quality evaluation by color values, reabsorption, and 6-gingerol content showed best quality for ginger with no predrying treatment and dried at 40°C in a heat pump–dehumidified dryer. At drying temperature of 60 to 62.82°C, no pretreated dried ginger from mixed-mode solar dryer provided the shortest drying time and retained 6-gingerol as high as heat pump–dehumidified dryer.     

Extraction of Ternary Beta‐Diketonates of Uranyl Ion Using Some Substituted Monoamides

Abstract

The extraction behavior of uranyl ion from dilute nitric acid medium employing 1‐phenyl‐3‐methyl‐4‐benzoyl‐5‐pyrazolone (HPMBP)/2‐thenoyl‐ trifluoroacetone (HTTA) in toluene and their mixture with several structurally modified monoamides viz. di‐2‐ethylhexyl acetamide (D2EHAA), di‐2‐ethylhexyl propanamide (D2EHPrA), di‐2‐ethylhexyl isobutyramide (D2EHiBA), and di‐2‐ethylhexyl pivalamide (D2EHPvA) was investigated. The species of the type UO₂(A)₂ and UO₂(A)₂·B were extracted for the binary and ternary extraction systems respectively where A = PMBP/TTA and B = D2EHAA, D2EHPrA, D2EHiBA, or D2EHPvA. The extraction constants (log K _ex) for the binary species UO₂(A)₂ were determined to be ?2.32 ± 0.03 for HTTA and 0.21 ± 0.02 for HPMBP, which was an inverse function of their pK _a value. The overall extraction constants (log K) for the ternary species UO₂(A)₂·B were determined as 4.70, 4.22, 4.00, 3.61, 2.65, 2.39, 2.32, and 1.76 for UO₂(PMBP)₂·D2EHAA, UO₂(PMBP)₂·D2EHPrA, UO₂(PMBP)₂·D2EHiBA, UO₂(PMBP)₂·D2EHPvA, UO₂(TTA)₂·D2EHAA, UO₂ (TTA)₂·D2EHPrA, UO₂(TTA)₂·D2EHiBA, and UO₂(TTA)₂·D2EHPvA, respectively. A linear correlation was observed between the basicity of the amide and the corresponding adduct's formation constants.     

Copper-Catalyzed α-Arylation of Sulfoxonium Ylides Using Hypervalent Iodine Compounds

A Cu(I)-catalyzed synthesis of α-arylated sulfoxonium ylides has been achieved from mesitylene-derived diaryliodonium salts and α-carbonyl sulfoxonium ylides. The reaction is believed to proceed via an electrophilic Cu(III)-aryl intermediate that can be trapped upon nucleophilic attack of the sulfoxonium ylide precursor. The reaction was tolerant to both α-keto and α-ester-derived sulfoxonium ylides, to drug-derived ylide motifs and to electronically-diverse arenes, and enabled the direct synthesis of 32 α-aryl-sulfoxonium ylides in 42–85% yield.     

Selective Growth of α-Sexithiophene by Using Silicon Oxides Patterns

A process for fabricating ordered organic films on large area is presented. The process allows growing sexithiophene ultra-thin films at precise locations on patterned Si/SiO(x) substrates by driving the orientation of growth. This process combines the parallel local anodic oxidation of Si/SiO(x) substrates with the selective arrangement of molecular ultra-thin film. The former is used to fabricate silicon oxide arrays of parallel lines of 400 nm in width over an area of 1 cm(2). Selective growth arises from the interplay between kinetic growth parameters and preferential interactions with the patterned surface. The result is an ultra-thin film of organic molecules that is conformal to the features of the fabricated motives.     

Removal of Humic Acid Using PEI‐Modified Fungal Biomass

Abstract

A modified fungal biomass was prepared through the adsorption of polyethylenimine (PEI) and subsequent crosslinking with glutaraldehyde on the biomass surface. FTIR result verified that the amine groups were introduced on the biomass surface. As a large number of amine groups are present on the biomass surface and can be protonated in solution, the modified biomass was positively charged at pH<10.3. The modified biomass was used as an adsorbent to remove humic acid in a series of batch adsorption experiments. The amount of humic acid adsorbed on the biosorbent decreased with increasing solution pH, and the electrostatic interaction between the positive protonated amine groups on the biomass surface and the negative carboxyl groups in the humic acid molecules played an important role in humic acid adsorption. The time‐dependent sorption of humic acid on the biomass can be described well by the Fickian diffusion model at the initial stage and the pseudo‐second‐order equation over 10 h. Using the Langmuir adsorption isotherm, the maximum sorption capacity of the modified biomass for humic acid at pH 5 was 96.5 mg/g. The desorption experiments showed that the humic acid loaded biomass could be easily regenerated in a 0.1 M NaOH solution, and the regenerated biomass possessed good adsorption capacity up to the fifth cycle. The PEI‐modified biomass with polyamine chains shows the potential for application in water treatment for the removal of humic substances.     

Using a β-Cyclodextrin-functional Fe3O4 as a Reinforcement of PLA: Synthesis,Thermal, and Combustion Properties

In this work, Fe₃O₄ nanoparticles were chemically grafted with β-cyclodextrin (β-CD@Fe₃O₄). Fe₃O₄ nanoparticles were modified using N,N-dimethylformamide as a solvent, β-cyclodextrin as a modifier, and 3-glycidoxypropyltrimethoxysilane as a coupling agent at room temperature. The obtained modified Fe₃O₄ were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis techniques. β-CD@Fe₃O₄ was incorporated into a poly(lactic acid) matrix to prepare new green nanocomposites with modified properties. β-CD@Fe₃O₄ showed good dispersion in the poly(lactic acid) matrix and thermal and combustion properties of the nanocomposites were improved.     

Self-Assembly of Nanostructures on Surfaces Using Metal–Organic Coordination

Layer-by-layer (LbL) assembly of multilayers is an established method for the construction of layered nanostructures on surfaces, affording control of the thickness, composition, and organization in the vertical direction. Binding between layers is accomplished using various types of interactions, including electrostatic binding, hydrogen bonding, covalent bonding, metal–organic coordination, host–guest interactions, biospecific interactions, and others. Here we focus on LbL assembly using metal–organic coordination, and specifically on layered nanostructures based on bishydroxamate–M⁴⁺ binding. The coordination approach offers attractive features, such as a simple reaction, a defined geometry, and reversibility under certain conditions. The basic scheme includes self-assembly of a ligand (anchor) monolayer on the surface, followed by alternate binding of metal ions and multi-functional ligand layers, to form a coordination multilayer. This approach is demonstrated by the construction of a variety of coordinated nanostructures, including bilayers, multilayers, dendrimers, and nanoparticle assemblies, prepared on gold and oxide substrates.     

Low Temperature Hydrolysis of Carbonyl Sulfide Using γ-Alumina Catalysts

The hydrolysis of COS using alumina as catalyst in the temperature range 10–80°C is described in detail. The rate of COS hydrolysis is found to be approximately first order in [COS] but is significantly inhibited with increasing [H₂O]. Addition of CO₂ is also found to have an inhibiting effect on the rate of hydrolysis, but no marked effect is observed when additional H₂S is present in the feedstock. The reaction in this temperature range is contrasted with the previous studies at higher temperatures and it is suggested that the reaction proceeds via reaction of adsorbed COS with surface hydroxyl groups on the alumina. Supporting evidence for this is provided from experiments in which water was not co-fed with COS, or the flow of water vapour was interrupted. In both cases, an initial increase in the rate of COS hydrolysis is observed. The rate of COS hydrolysis can be significantly enhanced by the addition of Fe, Co, Ni, Cu and Zn to the alumina.     

Improving Suction Performance of Centrifugal Pumps by Using Jetting Device

Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pump can be improved with jetting device and be used for delivering the liquid media requiring high suction performance, whereas the efficiency and head of the pump will decrease a little. The effect of feed-back jetting on suction performance is the most obvious at design point. The suitable rate of feed-back flow is 2%-5%.     

Affinity Dialysis–A Method of Continuous,Rapid Metal Ion Separation Using Dialysis Membranes and Selective,Water-Soluble Polymers as Extractants

Abstract

A membrane process utilizing dialysis and selective complexation by water-soluble polymers has been developed. This process, termed affinity dialysis, has been shown to selectively extract and concentrate both cations and anions in a manner similar to ion exchange or solvent extraction. The selective removal of calcium from sodium with selectivity of about 30, removal of chromate ion from dilute streams, and separation of transition metal ions such as Cu/Fe and Cu/Zn have all been successfully demonstrated. Effects of different polymers, polymer concentration, temperature, and flow rates have been studied. The effect of increased polymer concentration is to increase product concentration if appropriate changes in feed, polymer solution, and strip flow rates are made. A continuous polymer solution recycle and regeneration system has been constructed and operated with Cu/Zn and chromate/chloride feed streams. Removal of over 95% of the desired ion in one pass and concentration factors of product over effluent in excess of 100 have been achieved at feed flow rates of 24 gal/d. Product concentrations of greater than 3% from as little as 400 ppm feed have been demonstrated in a continuous process. In addition, the degree of polymer loss to the effluent stream has been shown to be less than 0.01%/d for a typical system. Metal removal from typical feeds is about 0.9 g/m² per 1000 ppm metal in the feed. It is expected that this technique may be useful in the separation of organic and biological materials, as well as for ionic species     

Effect of the Additive Fire Retardants on the Properties of Rigid Polyurethane Foams,Obtained Using Hydroxyethyl Derivatives of Oxamide and Polymeric 4,4′-diphenylmethane Diisocyanate

The present work investigates the effect of polyol structure and physical addition of boric acid and N,N′-bis(2-hydroxyethyl)oxamide on the properties of rigid polyurethane foams. The product of hydroxyalkylation of oxamide by ethylene carbonate has been used as a polyol component. The new polyol has been foamed using polymeric 4,4′-diphenylmethane diisocyanate, water, and triethylamine. To decrease the flammability of the foams, boric acid, and N,N′-bis(2-hydroxyethyl)oxamide were used as the additive flame retardants. It has been found, that chemical modification of the foam structure by means of oxamide groups decreases their flammability only to a small extent, whereas physical addition of N,N′-bis(2-hydroxyethyl)oxamide does not influence the flammability. However, the addition of boric acid to the foam composition resulted in a distinct decrease of foam flammability, according to the amount of boric acid added. All the foams, modified and nonmodified by boron, have been categorized into flammability class HF-1, according to the applicable standard. The introduction of flame retardants had its impact on the properties of polyurethane foams obtained, as described in this work.     

Removal of Parabens from Aqueous Solution Using β-Cyclodextrin Cross-Linked Polymer

The removal of four parabens, methyl-, ethyl-, propyl-, and benzyl-paraben, by β-cyclodextrin (β-CD) polymer from aqueous solution was studied. Different β-CD polymers were prepared by using two cross-linkers, i.e., hexamethylene diisocyanate (HMDI) and toluene-2,6-diisocyanate (TDI), with various molar ratios of cross-linker. β-CD-HMDI polymer with molar ratio of 1:7 and β-CD-TDI polymer with ratio 1:4 gave the highest adsorption of parabens among the β-CD-HMDI and β-CD-TDI series, and were subsequently used for further studies. The adsorption capacity of β-CD-HMDI is 0.0305, 0.0376, 0.1854 and 0.3026 mmol/g for methyl-, ethyl-, propyl-, and benzyl-paraben, respectively. β-CD-TDI have higher adsorption capacities compared with β-CD-HMDI, the adsorption capacity are 0.1019, 0.1286, 0.2551, and 0.3699 mmol/g methyl-, ethyl-, propyl-, and benzyl-paraben respectively. The parameters studied were adsorption capacity, water retention, and reusability. Role of both cross-linker in adsorption, hydrophobicity of polymers, and adsorption capacity of different parabens were compared and discussed. All experiments were conducted in batch adsorption technique. These polymers were applied to real samples and showed positive results.     

Calculation of Viscosities of Liquid Mixtures Using Eyring’s Theory in Combination with Cubic Equations of State

1 INTRODUCTON The viscosity, particularly that of liquid mixtures is very important in engineering calculations involved in the process design for petroleum and other chemica industries. Since the successful development of a one-parameter equation for correlating the liquid vis cosity of nonpolar mixtures by Grunberg and Nissan[1] many other models have been proposed. Most of them are based on the corresponding state principle, the absolute rate theory of Eyring[2], or the free volume the…     

Experimental Study of CMC Evaluation in Single and Mixed Surfactant Systems, Using the UV–Vis Spectroscopic Method

In this study, the critical micellar concentration (CMC) of anionic, cationic and nonionic surfactants was determined using the UV–Vis spectroscopic method. Sodium lauryl sulfate (SDS) as anionic, hexadecyl-trimethyl-ammonium bromide as cationic, tert-octylphenol ethoxylates TOPEON (with N = 9.5, 7.5 and 35) and lauryl alcohol ethoxylate (23EO) as nonionic surfactants have been used. Concentration of surfactants varies both from below and above the CMC value in the pyrene solution. In addition, the amount of the CMC was determined using the values from the data obtained from the graph of absorbance versus concentration of surfactants. A comparative study was conducted between the results of the present study and the literature which shows a good agreement, in particular for TOPEO9.5 and LAEO23. Furthermore, the CMC value of SDS (as an ionic surfactant) in the presence of nonionic surfactants was also examined. The result reveals that with addition of small amount of nonionic surfactant to the anionic SDS surfactant, a decline in the CMC value of the anionic–nonionic system relative to the CMC of pure anionic surfactant was observed. In addition and for the first time, the effect of UV irradiation on the size of the micelle formations was studied. It was found that UV irradiation causes the formation of smaller micelles which is of prime concern in membrane technology.     

Estimation of Separation of Electrolytes and Organic Compounds by Nanofiltration Membranes Using an Irreversible Thermodynamic Modei

Nanofiltration separation has become a popular technique for removing large organic molecules and inorganic substances from water. It is achieved by a combination of three mechanisms: electrostatic repulsion, sieving and diffusion. In the present work, a modei based on irreversible thermodynamics is extended and used to estimate rejection of inorganic salts and organic substances. Binary systems are modeled, where the feed contains an ion that is much less permeable to the membrane as compared with the other ion. The two modei parameters are estimated by fitting the modei to the experimental data. Variation of these parameters with the composition of the feed is described by an empirical correlation. This work attempts to describe transport through the nanofiltration membranes by a simple model.     

Using the Sol–Gel Technology for the Treatment of Barley Seeds

Silica sols obtained by acidic or alkaline hydrolysis of tetraethoxysilane in an excess of water or ethanol in the presence of a number of salts and/or acids are used to treat the surface of barley seeds. The surface state and the elemental composition of the seeds are studied before and after their treatment in silica sols. The conditions of the sol–gel synthesis of silica sols, their effect on the state and chemical composition of the seed surface, and the sowing characteristics are analyzed. The plant’s resistance to phytopathogen, the causative agent of root rot is studied.     

Separation and Determination of Wax Content Using 100-Å Phenogel Column

Rice bran wax (RBW) is a by product of rice bran oil refinery. Crude RBW from refineries in Thailand had only 20–40% of the wax ester. The major impurity was triglyceride (TG). Purification of RBW requires a rapid and reliable method of analysis. In this study, a modified size exclusion HPLC column (100-Å Phenogel) was reported. Degree swellings of the gel matrix were controlled by isooctane–toluene mobile phase ratio. With pure toluene as the mobile phase, the gel matrix is fully swollen. Wax and TG could not be separated. With 65:35 (v/v) of isooctane–toluene, wax and TG as well as other lipids were baseline separated. The resolution (Rs) between wax and TG was greater than 1.5. Acetic acid (0.1% or higher) in the mobile phase could suppress peak tailing and improved separation of the lipid containing active hydroxyl groups such as free fatty acid, diglyceride and monoglyceride without affecting retention times of the wax and the TG. Separation of lipids in crude RBW could be completed in a single run on the modified Phenogel column (100 Å) with the total analysis time less than 15 min. The relationship between the amount of wax in the sample and the peak area was linear with the R ² greater than 0.98.