The organosilane agent, namely 3-(N,N’-diisopropylguanidine)-propyltriethoxysilane, was firstly prepared by the reaction of diisopropylcarbodimide with (3-aminopropyl)triethoxysilane, and then employed for grafting guanidine base onto the surface of the mesoporous SBA-15 silica to afford an organic-inorganic hybrid catalyst. The prepared solid catalyst was fully characterized by various techniques such as small-angle X-ray power diffraction, Fourier transform infrared spectra, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption–desorption and elemental analysis techniques. The obtained results showed that the guanidine base was successfully tethered onto the SBA-15 silica and the ordered mesoporous structure of the SBA-15 material remained almost unchangeable after the orgnofunctionalization. The solid catalyst was found to have appreciable catalytic activities to the interesterification of soybean oil with methyl octanoate or methyl decanoate under solvent-free conditions. Influence of various reaction parameters, such as the substrate molar ratio, reaction temperature, catalyst loading and reaction time, on the catalytic interesterification was investigated to optimize the interesterification condition for the production of structured lipids containing medium-chain fatty acids. The hybrid solid catalyst was easily separated and reused for four runs without significant loss of catalytic activity.
Analysis of lard extracted from lipstick formulation containing castor oil has been performed using FTIR spectroscopic method combined with multivariate calibration. Three different extraction methods were compared, namely saponification method followed by liquid/liquid extraction with hexane/dichlorometane/ethanol/water, saponification method followed by liquid/liquid extraction with dichloromethane/ethanol/water, and Bligh & Dyer method using chloroform/methanol/water as extracting solvent. Qualitative and quantitative analysis of lard were performed using principle component (PCA) and partial least square (PLS) analysis, respectively. The results showed that, in all samples prepared by the three extraction methods, PCA was capable of identifying lard at wavelength region of 1200-800 cm–1 with the best result was obtained by Bligh & Dyer method. Furthermore, PLS analysis at the same wavelength region used for qualification showed that Bligh and Dyer was the most suitable extraction method with the highest determination coefficient (R2) and the lowest root mean square error of calibration (RMSEC) as well as root mean square error of prediction (RMSEP) values.
The goal of this study was to investigate the effect of heating and microwave treatment on the levels of volatile oxidation products and the stability of safflower (Carthamus tinctorius L.), sesame (Sesamum indicum) and canola (Brassica napus L.) cold-pressed oils. Cold-pressed oils were subjected to conventional heating (oven test) using air-forced oven at 60°C and microwave heating for 2 and 4 min. The changes in conjugated diene (CD) and conjugated triene (CT) values were monitored during treatments. As expected, heating generates an increase in CD and CT values. The volatile compounds in treated oils were determined using solid phase micro-extraction-gas chromatography/mass spectrometry (SPME-GC/MS). The obtained GC/MS data were used to characterize volatile compounds of cold-pressed oils during heating and microeave treatments. Under oven conditions, 2-heptenal and 2,4-heptadienal isomers were identified as major components in canola oil, while hexanal and 2-heptenal were found in high levels in safflower and sesame oils. Among volatiles, p-cymene was the dominant compound found in microwave-treated canola oil. In addition, hexanal and 2-hexenal were found at high amounts upon microwave treatment especially after 4 min of application.
Removal process of a fatty acid from four substrates was monitored using a quartz crystal microbalance (QCM). Model substrates included carbon, silica, and gold sputtered electrodes and a polymer film prepared on a gold sputtered electrode. Stearic acid (SA), a model solid oily contaminant, was deposited on the substrates as an ultra-thin layer using the Langmuir–Blodgett (LB) technique. Cleaning tests of the SA-LB films were performed in aqueous solutions containing sodium chloride (NaCl), sodium hydroxide (NaOH), and/or sodium dodecyl sulfate (SDS). The removal efficiency was calculated from the QCM frequency vs. time curve obtained during the cleaning process. The neutralization by NaOH was effective for removing the SA-LB film from all substrates, although the reaction was slow. In the absence of NaOH, minor amounts of the SA-LB film was removed from the substrates, with the exception of silica, even in the SDS solution. To increase the removal efficiency of the SA-LB film in the absence of NaOH, the SA-LB film deposited on the substrates was exposed to atmospheric-pressure plasma before the cleaning process. This treatment promoted the removal of the film in the NaCl and/or SDS solutions, which we interpreted to be due to the hydrophilization of both the surfaces of the substrates and the SA-LB film.
Quaternary ammonium salt-type cationic surfactants with an adamantyl group (hydrocarbon-type; CnAdAB, fluorocarbon-type; CmFC3AdAB, bola-type; Ad-s-Ad, where n, m and s represent hydrocarbon chain lengths of 8–16, fluorocarbon chain lengths of 4–8, and spacer chain length of 10–12) were synthesized via quaternization of N, N-dimethylaminoadamantane and n-alkyl bromide or 1, n-dibromoalkane. Conductivity and surface tension were measured to characterize the solution properties of the synthesized adamantyl group-containing cationic surfactants. In addition, the effects of hydrocarbon and fluorocarbon chain lengths and spacer chain length between headgroups on the measured properties were evaluated by comparison with those of conventional cationic surfactants. The critical micelle concentration (CMC) of CnAdAB and Ad-s-Ad was 2/5 of that for the corresponding conventional surfactants CnTAB and bola-type surfactants with similar number of carbons in the alkyl or alkylene chain; this was because of the increased hydrophobicity due to the adamantyl group. A linear relationship between the logarithm of CMC and the hydrocarbon chain length for CnAdAB was observed, as well as for CnTAB. The slope of the linear correlation for both surfactants was almost the same, indicating that the adamantyl group does not affect the CMC with variations in the hydrocarbon chain length. Similar to conventional surfactants CnTAB, the hydrocarbon-type CnAdAB is highly efficient in reducing the surface tension of water, despite the large occupied area per molecule resulting from the relatively bulky structure of the adamantane skeleton. On the other hand, the bola-type Ad-s-Ad resulted in increased surface tension compared to CnAdAB, indicating that the curved chain between adamantyl groups leads to poor adsorption and orientation at the air–water interface.
We discuss an alternate method for calcification in microcapillaries for fabricating calcium phosphate films using silicone molds and calcifying solutions. Calcium phosphate films with a line/space of 5–50 µm were fabricated by controlling the concentrations of calcium chloride and sodium phosphate solutions. Plate-type crystals of hydroxyapatite were grown when the calcium phosphate films were immersed in hydroxyapatite precursors. In the initial stage of hydroxyapatite crystal growth, the c-plane of the crystals was grown parallel to the substrates, and subsequently the growth followed with the c-plane growing perpendicular to the substrates. In narrow capillaries, dendritic structures were formed with a tendency to grow in a direction parallel to the direction of the microcapillaries. This technique is useful in the micropatterning of biocompatible ceramics with a minimized material consumption and a short fabrication time.
The degree of counterion binding (β) to micelles of aqueous n-alkylammonium chlorides (CnAC; H(CH2)nNH3Cl, n = 8-12) was evaluated from the ionic activity coefficient (γCl-), which was determined by use of a conventional chloride ion selective electrode at 25°C. In the γCl- plot of C12AC, a bend indicating the critical micelle concentration (cmc) was found, at concentrations above which the Botré plot was examined, and a value of 0.80 was determined for β. Very similar β values were obtained for the other alkylammonium chloride surfactants. The standard free energy of the micellization (ΔGm) of CnAC was estimated from the β and micellar aggregation numbers.
There is only a couple of reports indicating essential oil composition of Asphodelus species in the literature. However, from the members of this genus many non-volatile secondary metabolites were isolated. In Cyprus, Asphodelus aestivus Brot. can be found abundantly in all regions of the island. This plant has various ethnobotanical uses in Cyprus. There is no report on the volatiles nor the essential oil composition of A. aestivus. The smell of A. aestivus flowers resembles that of a cat pee which caught our attention. Therefore, we have carried out GC, GC/MS analysis of the essential oil (yield: 0.01 v/w) obtained from Asphodelus aestivus flowers. Seventeen compounds were identified in the essential oil comprising 96.2% of the oil. The major components of the essential oil were hexadecanoic acid 35.6%, pentacosane 17.4%, tricosane 13.4% and heptacosane 8.4%. In our results, we expected to see sulfur containing cat pee odorants due to the odor of the flower whereas high amounts of n-alkanes, saturated fatty acids and minor amounts of acyclic diterpenes were observed.
Two essential oil samples were obtained from the pericarp of Zanthoxylum bungeanum with the methods of hydrodistillation (HD) and supercritical fluid CO2 extraction (SFE), their chemical components were identified, and their bioactivities against Lasioderma serricorne adults were evaluated. In the process of testing, the two samples showed significant bioactivities against Lasioderma serricorne adults. For an example, the SFE-sample expressed relatively stronger fumigant toxicity on Lasioderma serricorne adults (LC50 = 3.99 μg/mL air) than that of the HD-sample (LC50 = 12.54 μg/mL air). According to GC-MS analysis, the chemical components between two samples were different. The major chemical components for HD included linalool (25.99%), limonene (19.34%), linalyl anthranilate (12.22%), 4-terpinenol (10.49%), eucalyptol (6.53%) and α-terpineol (5.02%), while for SFE included nonanoic acid (21.43%), γ-terpinene (14.51%), eucalyptol (13.45%), α-terpineol (5.83%) and caryophyllene oxide (5.48%). The results showed that different chemical components result in different bioactivities. This work provides theoretical basis for traditional Chinese concept of antagonistic storage, and it also provides important information for the development and comprehensive utilization of Zanthoxylum bungeanum.