Quantitative gas liquid chromatographic analysis of butterfat triglycerides

Gas liquid chromatographic triglyceride separation by carbon number, and integration of the area response obtained in the hydrogen flame ionization detector, has permitted the calculation of the following molar proportions for the various triglyceride types in a blended butterfat sample: C₂₄ 0.5, C₂₅ 0.08, C₂₆ 0.57, C₂₇ 0.18, C₂₈ 0.81, C₂₉ 0.17, C₃₀ 1.15, C₃₁ 0.2, C₃₂ 3.1, C₃₃ 0.34, C₃₄ 5.41, C₃₅ 1.0, C₃₆ 10.6, C₃₇ 1.2, C₃₈ 12.8, C₃₉ 1.15, C₄₀ 10.7, C₄₁ 1.0, C₄₂ 6.1, C₄₃ 0.58, C₄₄ 5.15, C₄₅ 0.6, C₄₆ 5.8, C₄₇ 1.0, C₄₈ 6.45, C₄₉ 1.47, C₅₀ 8.5, C₅₁ 1.43, C₅₂ 6.95, C₅₃ 1.05, C₅₄ 4.0. The validity of these estimates was verified by similar determinations performed on molecular distillates of butterfat and on butterfats with known amounts of added saturated and unsaturated long chain triglycerides. The fatty acid carbon recoveries estimated on the basis of the observed triglyceride peak proportions were of the order of 95% or better. A comparison of the experimentally determined triglyceride type distributions with those calculated on the basis of a completely random fatty acid arrangement for the blended and the molecularly distilled samples showed considerable differences, the most apparent of which was the greater proportion of both short and long chain triglycerides consistently predicted for the random population. On the basis of these studies, it is suggested that butterfat possesses a non-random fatty acid distribution which is reflected in its triglyceride type distribution. Presented at the AOCS meeting in Toronto, Canada, 1962     

Contact angle of surfactant solutions on precipitated surfactant surfaces

In this study, the contact angle of a saturated aqueous surfactant solution onto the surface of a precipitate of that surfactant is investigated. Those precipitates include fatty acids (C₁₀, C₁₂, C₁₄, C₁₆, and C₁₈), sodium salts of fatty acids (C₁₄, C₁₆, and C₁₈), calcium salts of fatty acids (C₈, C₁₀, C₁₂, C₁₄, C₁₆, and C₁₈). On virgin surfaces, free fatty acids and calcium salts of fatty acids have advancing contact angles (θ_A) between 77 and 92°, with little dependence on alkyl chain length for C₁₂ and higher alkyl chains. The sodium salt of a fatty acid has a lower θ_A than the free fatty or the calcium salt of the soap. The calcium salt of dodecyl sulfate has a lower θ_A than the calcium salt of dodecanoic acid (θ_A = 46 vs. 82°), but the calcium salt of the 18-carbon hydrophobes showed nearly the same contact angle for the soap and the alkyl sulfate. Greasiness, or slipperyness, or a scummy feel of a precipitated surfactant does not necessarily correspond to a hydrophobic surface.     

Understanding the adsorption of calcium sulfate on tetracalcium aluminoferrite and tricalcium aluminate surfaces

Calcium sulfate (CaSO₄), an essential retarder in cement, retards the hydration of tricalcium aluminate (C₃A) and tetracalcium aluminoferrite (C₄AF) phases. However, its retarding mechanism remains unclear. This paper focused on the adsorption of CaSO_4f on C₄AF and C₃A surfaces based on isothermal calorimetry, the measurement of the ionic concentrations in a diluted system, and density functional theory to enhance the understanding of the retardation mechanism. The results showed that the retarding effect of CaSO₄ on C₄AF was stronger than that on C₃A due to the slower CaSO₄ consumption rate, lower driving force for CaSO₄ adsorption, and surface coverage of Fe(OH)₃ gel. The adsorption of CaSO₄ hindered Ca dissolution more markedly on C₄AF than C₃A, which was pronounced on Fe-free C₄AF surfaces. The adsorption of CaSO₄ weakened the affinity of water on C₄AF and C₃A surfaces, lowering the driving force for H₂O adsorption. The adsorption of H₂O and CaSO₄ promoted the dissolution of Al on the [AlO₆] octahedral surface of C₄AF, which may be responsible for the maintenance of a higher Al concentration in the solution. Based on the above results, the adsorption of CaSO₄ on initial C₄AF and C₃A hydration was explained.     

Über einige Lipoid-Inhaltsstoffe aus den Früchten von Pimpinella anisum (L.) und Carum carvi (L.)

Component Lipids of the Fruits of Pimpinella anisum (L.) and Carum carvi (L.) Following substances could be isolated from the lipid portion of the fruits of Pimpinella anisum (L.) and Carum carvi (L.) by extraction with ether followed by fractionation on an aluminium oxide column: Fructus anisi: a mixture of fatty acids (C₁₆?, C₁₈?, C₂₀?, C₂₂?, C₂₄?, C₂₆?, C₃₀? and > C₃₀?acids), stigmasteryl palmitate and stearate, free stigmasterol and the coumarins bergaptene, umbelliprenine, umbelliferone and scopoletin; Fructus carvi: glycerides of C₁₆?, C₁₈?, C₁₈ ^{= 1}-, C₁₈ ^{= 2}- and C₁₈ ^{= 3}-acids, one sterol(?) and the coumarins umbelliferone, scopoletin and herniarin(?).     

One-step purification of ethylene from acetylene and carbon dioxide by ultramicroporous carbons

The one-step adsorptive separation of high-purity ethylene (C₂H₄) from a ternary gas mixture (C₂H₂/C₂H₄/CO₂) is challenging and has not been reported on porous carbons. Herein, we report camphor seeds husk-derived ultramicroporous carbons (CSHs) show high affinities toward acetylene (C₂H₂) and carbon dioxide (CO₂) over C₂H₄. The optimized CSH-2-700 with high heteroatom contents and centered pore size distributions shows high C₂H₂ adsorption capacity (2.24 mmol g⁻¹) and record ideal adsorbed solution theory (IAST) C₂H₂/C₂H₄ selectivity (10.2) among one-step C₂H₄ purification adsorbents. Meanwhile, CSH carbons are the only carbon adsorbents that preferentially adsorb CO₂ over C₂H₄, with a CO₂/C₂H₄ selectivity of 1.9 under ambient conditions. Furthermore, dynamic breakthrough experiments verified its feasibility for one-step C₂H₄ purification from a three-component C₂H₂/C₂H₄/CO₂ gas-mixture.     

Deposition of C60, C70 and C84 fullerene molecules, in benzene via a change of the fluid state, from a gas–liquid two phase region to the critical point

We dissolve C₆₀, C₇₀ or C₈₄ molecules in benzene and change the fluid state from a gas–liquid two-phase region (25.0 °C) to the critical point (289.0 °C) and from the critical point to the original state (25.0 °C) along the gas–liquid coexistence curve. We find that particle-like and whisker-like nano/micro clusters, which are composed of C₆₀ molecules, deposit on the surface of a silicon substrate placed vertically in C₆₀/benzene solution during the temperature change, whereas no appreciable clusters are detected on the silicon substrate in either C₇₀/benzene or C₈₄/benzene solutions. The clusters, in which fcc lattice structures are formed by C₆₀ molecules, remain stable in the solution. The present result suggests that C₆₀ molecules can be separated and extracted from a mixture of C₆₀, C₇₀ and C₈₄ molecules dissolved in benzene.     

Direct partial oxidation of methane over ZSM-5 catalyst: effects of additives

Previously, it was reported that the direct partial oxidation (DPO) of CH₄ with O₂ over HZSM-5 catalysts produces C₅₊ hydrocarbon liquids when the feed contains a propane or propene additive. This work studies additive effects on C₅₊ production in this system by processing a CH₄/C₃H₈ feed with subsequent removal of the C₃ additive and by processing natural gas feed. Results show C₅₊ production is maintained at constant yields for HZSM-5 catalysts having different zeolitic Al contents after removal of the C₃ additive. Mechanistic implications are discussed. Natural gas DPO consistently produced C₅₊ liquids due to the presence of C₂₊ components in the feed. While C₅₊ yields from natural gas DPO are higher than those observed for CH₄/C₃ feeds, increasing feed O₂ concentration, and thus conversion, deleteriously affected C₅₊ selectivity.     

Separation of fullerenes C60 and C70 using a crystallization‐based process

A crystallization‐based process that separates pure fullerenes C₆₀ and C₇₀ from their mixture using o‐xylene as the solvent has been developed. Isothermal solid–liquid equilibrium phase diagrams of the C₆₀‐C₇₀‐o‐xylene ternary system for a number of temperatures were first determined at 1 atm. Taking advantage of the shift in solvent‐free composition of the C₆₀‐C₇₀ double saturation point with temperature and based on the solid solution‐forming phase behavior between C₆₀ and C₇₀, the flowsheet of a general crystallization process was then synthesized. It involved the fractionation of a C₆₀‐C₇₀ fullerene mixture into C₆₀‐rich and C₇₀‐rich solid solutions using temperature‐swing crystallization, followed by purification of the solid solutions with multistage crystallization into pure C₆₀ and C₇₀ solids. To demonstrate process feasibility, bench‐scale batch experiments were performed using a commercially available fullerene mixture that was pretreated by adsorption to remove higher fullerenes. C₆₀ and C₇₀ solids of purity higher than 99 wt % were obtained. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

Water-retaining ability of diacylglycerol

The water-in-oil emulsification characteristics and the adsorption properties of DAG at the oil/water interface were investigated for DAG having different FA compositions. The water-retaining ability of DAG is dependent on the FA composition but is not dependent on the interfacial tension at the oil/water interface in a simple way. The water-retaining ability is very different between uni-chain DAG (two FA have the same chain length) and complex-chain DAG (one FA is oleic acid and the other has a shorter alkyl chain). Uni-chain DAG, having long FA chains (R=C₁₂ or C_18∶1) have the ability to emulsify water at the volume fraction of 80% (ϕ80%), but uni-chain DAG with short or medium chain-length FA (R=C₃, C₄, C₆, C₈) show little ability to retain water. For complex-chain DAG, all the DAG studied here (R₁=C_18∶1, R₂=C₂−C₁₂) have the ability to emulsify water at ϕ80%. The stability of the emulsions, however, varies with the chain length of the R₂ FA (R₂ stability order: C₂, C₃>C_18∶1, C₁₀>C₈>C₄, C₆). The relationship between the water-retaining ability and the molecular structure of DAG is discussed from the viewpoint of intra- and intermolecular interactions between the FA chains.     

Combined effect of lignosulfonate and carbonate on pure portland clinker compounds hydration. V. Hydration of dicalcium silicate alone and in the presence of tricalcium aluminate

The effect of sodium carbonate and/or sodium lignosulfonate on the hydration of C₂S alone and in the presence of C₃A has been examinated by DTG and TG curves and by zeta potential measurements. The combined addition of sodium carbonate and lignosulfonate retards the C₂S hydration to a lower extent than that observed for the C₃S hydration. The retarding effect on the C₂S hydration is significantly lower in the presence of 20% C₃A. On the other hand, the early C₃A hydration is completely blocked by admixtures simultaneously added. Addition of 0.9% sodium carbonate without lignosulfonate blocks the early hydration of both C₃A and C₂S. This effect was not found in the C₃SC₃A system.     

Effect of thermal molecular motion on pervaporation behavior of comb-shaped polymers with fluorocarbon side groups

Summary Thermal molecular motion of a series of comb-shaped polymers with heptadecafluorodecyl side chains (C^F ₈C₂-) has been studied based on dynamic viscoelastic measurement. The main chain of comb-shaped polymers was poly(fumarate), poly(methacrylate), and poly(acrylate). Poly(fluoroalkylfumarate) with heptadecafluorodecyl group, P(C^F ₈C₂-iPF) was amorphous polymer, whereas poly(acrylate) and poly(methacrylate) with C^F ₈C₂-, P(C^F ₈C₂-Acr) and P(C^F ₈C₂-MAcr) showed mesomorphic behavior. The pervaporation behavior of water/organic mixtures through amorphous polymer, P(C^F ₈C₂-iPF), and mesomorphic one, P(C^F ₈C₂-Acr), were investigated. The distinct increase in permselectivity has been observed at the mesomorphic transition of P(C^F ₈C₂-Acr).     

Effect of melt composition on tricalcium silicate: Its formation and composition

This study describes the effect of several clinker melt phases on the kinetics of tricalcium silicate (C₃S) formation. At a given burning temperature, a maximum amount of C₃S was apparently formed for a given melt. The iron-rich melt phases promoted the consumption of lime and the rate of formation of C₃S in the order C₂F > C₄AF > C₆A₂F > C₃A. Results of the microprobe analyses of C₃S and melt phases suggest that iron and alumina entered the C₃S lattice during clinkering. Silica also apparently entered the melt phase, although conclusive evidence could not be obtained.     

Thermodynamic and structural analyses and mechanisms of the crystallisation of multi-alkane model mixtures similar to petroleum cuts

Thermodynamic and structural analyses were carried out by X-ray diffraction and differential thermal analyses as functions of the temperature on multi-alkane samples whose distribution of mole fractions shows a shape of the ‘exponential decreasing’ type, as observed in petroleum cuts. Nine samples, whose number of normal-alkanes, C_ns, varied from 15 up to 23, were studied with continuous distributions of mole fractions going from the C₂₂–C₃₆ series to the C₁₄–C₃₆ series: C₂₂ and C₁₄ corresponding respectively to the first C_ns of the two terminal series and C₃₆ is always the last C_n of each series: each mixture differed from the previous sample by the addition of a lighter C_n−1. At the solid state and according to literature, the multi-alkane samples of C₂₂–C₃₆, C₂₁–C₃₆ and C₂₀–C₃₆ series are in a two-phase solid thermodynamic state, C₁₉–C₃₆ to C₁₅–C₃₆, three-phase, the broader distribution C₁₄–C₃₆, four-phase and the mixtures with numbers of C_ns≤11, single-phase. Thus, the C_ns crystallise in the solid phase, where the thickness of molecule layers is compatible with their own chain length. The results allow for extracting the recurring structural and thermodynamic properties for these types of mixtures during crystallisation, and to clarify the molecular mechanisms involved in the number of observed solid phases, in the order of their appearance and in their thermodynamic and structural behaviour during the course of cooling from the liquid state.     

Recovery of the N,N-Dibutylimidazolium Chloride Ionic Liquid from Aqueous Solutions by Electrodialysis Method

Ionic liquids (ILs), named also as liquid salts, are compounds that have unique properties and molecular architecture. ILs are used in various industries; however, due to their toxicity, the ILs’ recovery from the postreaction solutions is also a very important issue. In this paper, the possibility of 1,3-dialkylimidazolium IL, especially the N,N-dibutylimidazolium chloride ([C₄C₄IM]Cl) recovery by using the electrodialysis (ED) method was investigated. The influence of [C₄C₄IM]Cl concentration in diluate solution on the ED efficiency was determined. Moreover, the influence of IL on the ion-exchange membranes’ morphology was examined. The recovery of [C₄C₄IM]Cl, the [C₄C₄IM]Cl flux across membranes, the [C₄C₄IM]Cl concentration degree, the energy consumption, and the current efficiency were determined. The results showed that the ED allows for the [C₄C₄IM]Cl recovery and concentration from dilute solutions. It was found that the [C₄C₄IM]Cl content in the concentrates after ED was above three times higher than in the initial diluate solutions. It was noted that the ED of solutions containing 5–20 g/L [C₄C₄IM]Cl allows for ILs recovery in the range of 73.77–92.45% with current efficiency from 68.66% to 92.99%. The [C₄C₄IM]Cl recovery depended upon the initial [C₄C₄IM]Cl concentration in the working solution. The highest [C₄C₄IM]Cl recovery (92.45%) and ED efficiency (92.99%) were obtained when the [C₄C₄IM]Cl content in the diluate solution was equal 20 g/L. Presented results proved that ED can be an interesting and effective method for the [C₄C₄IM]Cl recovery from the dilute aqueous solutions.     

Hydrocarbons detected in irradiated shell eggs during storage

Hydrocarbons produced by γ-radiation of shell eggs were analyzed to determine how irradiation affects their production. Shell eggs were nonirradiated or irradiated at 0.5, 1, and 3 kGy and the stored at 5°C for 8 wk or at 30°C for 10 d. Hydrocarbons were determined by a sequential procedure of lipid extraction by hexane, Florisil column chromatography, and gas chromatography. Hydrocarbons C_15:0, C_14:1, C_17:0, C_16:1, C_17:1, C_16:2, C_17:2, and C_16:3 were detected in shell eggs irradiated at 0.5 kGy or higher, but not in nonirradiated ones except C_15:0 and C_17:0. Storage of nonirradiated or irradiated eggs had little effect on detection levels of hydrocarbons. The detection levels in all the samples irradiated at 1 and 3 kGy were in the order of C_16:2+C_17:1, C_15:0+C_14:1, C_17:2+C_16:3, and C_17:0+C_16:1 from the highest to the lowest.     

Composition of Cuticular Waxes on Osmunda regalis Fronds

The chemical composition of rodlet-shaped wax crystals on fronds of Osmunda regalis was analyzed. In all, 139 compounds belonging to 14 homologous series were detected in the surface extract. They included typical plant wax constituents: alkanes (C₂₅–C₃₃), alkyl esters (C₃₈–C₅₀), primary alcohols (C₂₂–C₃₂), secondary alcohols (C₂₇ and C₂₉), ketones (C₂₇–C₃₃), aldehydes (C₂₄–C₃₄), fatty acids (C₂₄–C₃₂), and -sitosterol. Additionally, bifunctional C₂₉ compounds (-diketone, ketols, diols) were identified. Nonacosan-10-one as the most abundant single compound, together with its bifunctional derivatives, is likely to form the wax crystals found on O. regalis fronds. Hence, a new type of wax crystals is defined morphologically and chemically. The occurrence of comparable wax aggregates on surfaces of higher plants is discussed.     

Electrochemistry of double-wall carbon nanotubes encapsulating C60 and their spectral characterization

Electrochemistry of double-wall carbon nanotubes (DWCNTs) encapsulating C₆₀ (C₆₀@DWCNT) have been studied by preparing a C₆₀@DWCNT modified electrode, and three pairs of reversible electro-reduction waves corresponding to electron transfer reactions of C₆₀ inside DWCNTs have been obtained in a mixed solvent of toluene and acetonitrile (4:1, v:v) containing tetrabutylammonium cation as supporting electrolyte, which indicates that DWCNTs act as molecular wires to allow electrical communication between the underlying electrode and the redox-active guest C₆₀. The influencing factors on the electrochemistry of C₆₀@DWCNT modified electrodes have been investigated. The results suggest that the voltammetric behavior of C₆₀@DWCNT is dependent on the nature of the supporting electrolyte and the solvent system. In addition, spectral characterization of the C₆₀@DWCNT modified electrodes before and after electrochemical scanning reveals interaction between C₆₀ and DWCNT and verifies the reduction of C₆₀ encapsulated in DWCNTs. C₆₀ molecules inside DWCNTs retains their redox activity, and can also act as an electron-transfer mediator to electrocatalyze the reduction of halohydrocarbon.     

Methane-Propylene homologation and reactivity of surface carbon on modified Ni-Al2O3 catalysts

Modified Ni catalysts supported on alumina and reduced in CH₄ have been investigated for the synthesis of C₄ hydrocarbons from CH₄ and C₃H₆. Addition of K or P to the Ni/Al₂O₃ catalyst increased C₄ selectivity and C₃H₆ conversion. A maximum selectivity to the desired C₄ product of 9 mol % was obtained at 350°C and 101 kPa with a feed gas composition of 90 mol% CH₄/10 mol% C₃H₆, but the catalyst activity declined rapidly with time-on-stream. Large amounts of unreactive carbon were deposited on the catalyst surface following reduction in CH₄ and reaction in CH₄/C₃H₆. However, the relative amount of a much more reactive species identified from Temperature-Programmed-Surface-Reaction that was formed in the presence of CH₄ and C₃H₆, is shown to correlate with the catalyst C₄ yield. Both the C₄ yield and the relative amount of this low temperature carbonaceous species increased in the order Ni<Ni/P<Ni/K.     

Twinning in β-dicalcium silicate

βC₂S was prepared by cooling α′C₂S or αC₂S. In both cases the βC₂S contained many twin lamellae with a (100) twin plane. βC₂S produced from á′C S contained lamellae on a single plane in each grain, but βC₂S produced from αC₂S contained smaller domains of twins. Dislocations were observed at a domain boundary. The observations are explained by the hypothesis that the twin lamellae form by lattice transformation shear strains.     

Über einige Lipoid-Inhaltsstoffe aus den Früchten von Anethum graveolens (L.) und Coriandrum sativum (L.)

Some Lipid Containing Substances from Fruits of Anethum Graveolens L. and Coriandrum Sativum L. From the lipid part of fruits from anethum graveolens L. and coriandrum sativum L. the following substances could be isolated by ether extraction followed by fractionation on an aluminium oxide column: Fructus anethi: a wax (composition: C₁₆-, C₁₈-, C₂₂-, C₂₄-, C₂₆- and C₂₈-acids and C₂₄-, C₂₆-, C₂₈-, C₃₀- and C₃₂- alcohols), the coumarins bergapten and umbelliprenin, an unidentified compound (phytofluen?) as well as γ-sitosterol. Fructus coriandri: an unidentified compound (phytofluen?), γ-sitosterol, umbelliferone and scopoletin.