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1.
The Omega-3 Index, a measure of long-chain omega-3 fats in red blood cell membranes, predicts heart disease mortality in adults,
but its association with cardiovascular risk factors in younger populations is unknown. We determined the Omega-3 Index in
adolescents participating in the Western Australian Pregnancy (Raine) Cohort, assessed associations with diet, lifestyle and
socioeconomic factors, and investigated independent associations with cardiovascular and metabolic risk factors. Red blood
cell fatty acid analysis was determined for 1,301 adolescents aged 13–15 years. Risk factors examined were blood pressure,
fasting blood insulin and glucose concentrations, and fasting blood lipids including ratios. The mean Omega-3 Index was 4.90 ± 1.04%
(range 1.41–8.42%). When compared with categories identified in adults, 15.6% of adolescents were in the high risk category
(Index < 4%). Age (P < 0.01), maternal education (P < 0.01) and BMI (P = 0.05) were positively associated with the Omega-3 Index. The Index was positively associated with dietary intakes of eicosapentaenoic
and docosahexaenoic acid (P < 0.01), protein (P < 0.01), omega-3 fats (P < 0.04), and food groups of fish and wholegrains (both P < 0.01), and negatively associated with intakes of soft drinks and crisps (both P < 0.01). In boys, the Omega-3 Index was independently associated with total (β = 0.06, P = 0.01) and HDL-cholesterol (β = 0.03, P = 0.01), and diastolic blood pressure (β = −0.68, P = 0.04). The predictability of the Index for the risk of cardiovascular disease later in life warrants further investigation
in the adolescent population. 相似文献
2.
Postprandial lipemia impairs insulin sensitivity and triggers the pro-inflammatory state which may lead to the progression
of cardiovascular diseases. A randomized, crossover single-blind study (n = 10 healthy men) was designed to compare the effects of a high-fat load (50 g fat), rich in palmitic acid from both plant
(palm olein) or animal source (lard) versus an oleic acid-rich fat (virgin olive oil) on lipemia, plasma glucose, insulin
and adipocytokines. Serum triacylglycerol (TAG) concentrations were significantly lower after the lard meal than after the
olive oil and palm olein meals (meal effect P = 0.003; time effect P < 0.001). The greater reduction in the plasma non-esterified free fatty acids levels in the lard group compared to the olive
oil meal was mirrored by the changes observed for serum TAG levels (P < 0.05). The magnitude of response for plasma glucose, insulin and adipocytokines [interleukin-6 (IL-6), tumor necrosis factor-α
(TNF-α), interleukin-1β (IL-1β) and leptin] were not altered by the type of dietary fats. A significant difference in plasma
IL-1β was found over time following the three high fat loads (time effect P = 0.036). The physical characteristics and changes in TAG structure of lard may contribute to the smaller increase in postprandial
lipemia compared with palm olein. A high fat load but not the type of fats influences concentrations of plasma IL-1β over
time but had no effect on other pro-inflammatory markers tested in the postprandial state. 相似文献
3.
An anionic gemini surfactant was synthesized under microwave irradiation conditions. The optimum reaction conditions were
obtained by the reaction of maleic anhydride, glycol, isooctyl alcohol and sodium sulfite. The first step esterification reaction
was carried out at 90 °C and 100 W microwave power for 20 min with a ratio a n
maleic anhydride:n
glycol = 2.1:1, and 1.0 wt% of catalyst. The second step esterification reaction was carried out at 80 °C for 25 min and 100 W microwave
power. Optimum sulfonation was carried out with n
sodium sulfite:n
glycol bismaleic anhydride bisester = 2.25:1 and 1.5% catalyst for 25 min at 60 °C. It is found that microwave-assisted synthesis is an efficient means of preparation
of this anionic gemini surfactant with shorter reaction times and higher yields. The title compound structure was confirmed
by IR. The critical micelle concentration of the title compound is 6.2 × 10−4 mol L−1, γCMC is 25.7 mN m−1, and benzene emulsion persistence was 2 days. 相似文献
4.
Mayson H. Alkhatib Douglas G. Hayes Volker S. Urban 《Journal of surfactants and detergents》2009,12(3):277-283
The phase behavior of microemulsion systems containing water (or 1.0 wt% NaClaq), isooctane, and the binary surfactant system consisting of n-octyl-β-d-glucopyranoside, C8βG1, and the acid-cleavable alkyl ethoxylate, 4-CH3O (CH2CH2O)7.2, 2-(CH2)12CH3, 2-(CH2)CH3, 1,3-dioxolane, or “cyclic ketal” (“CK-2,13”), was determined. Large temperature-insensitive one, two, and three-phase microemulsion-phase
regions were obtained when equal masses of the two surfactants were employed, suggesting that C8βG1 reduces the temperature sensitivity of CK-2,13’s ethoxylate group. Addition of C8βG1 to CK-2,13 greatly improves the latter’s low efficiency, evidenced by the formation of a three-phase microemulsion system
for surfactant concentrations at low fractions of total surfactants for systems with equal mass ratios of water to oil and
CK-2,13 to C8βG1. Analysis of the phase diagrams also suggests that CK-2,13 and C8βG1 impart hydrophobic and hydrophilic character, respectively, to the surfactant mixture, and that addition of salt further
increases the hydrophilicity of C8βG1, presumably because of the salting-in of the latter. Analysis of small-angle neutron scattering data revealed that the mixed
surfactant system formed spherical oil-in-water microemulsions, and that increasing the CK-2,13 fraction among the surfactants
reduced the critical microemulsion concentration but slightly increased the nanodroplet size.
相似文献
Douglas G. HayesEmail: |
5.
Anilú?Rubio-Ríos Bethsy?Adriana?Aguilar-Castillo Sergio?Flores-Gallardo Claudia?Alejandra?Hernández-Escobar Erasto?Armando?Zaragoza-Contreras
The development of photoluminescent materials based on the incorporation of quantum dots (QDs) into polymeric latexes has
gained importance due to the multiple potential applications. Through the process of miniemulsion polymerization it is possible
to encapsulate quantum particles into polymer matrix to provide both chemical stability and to maintain emission properties.
The polymerization process was achieved with continuous magnetic stirring and nitrogen atmosphere. Cetyl trimethylammonium
bromide (CTAB) was used as surfactant at concentration levels of 1.3 × 10-3, 3.2 × 10-3 and 5.4 × 10-3 M. The initiator 2,2-azobisisobutyronitrile (AIBN) was used at 0.50 and 0.75 wt% and CdSe QDS were used at 0.075, 0.15 and
0.225 wt%, both in relation to monomer content. A STEM study on the composite latexes and later a statistical study on the
measurement of polymer particle diameter let us corroborate that the increment in surfactant concentration produces a decrement
in polymer particle size. The obtained composite latexes were stable and showed fluorescence by excitation with UV light.
The spectrofluorometry studies indicated that in composite latexes fluorescent emission was a function of polymer particle
size, showing higher intensity those formulations with smaller surfactant concentrations and bigger polymer particle size. 相似文献
6.
Coumarin and 7-hydroxycoumarin (7HC) were photo-dimerized in an aqueous solution of polymeric β-cyclodextrin (PβCD) to investigate the effect of the photo-dimerization on the viscosity of PβCD solution. PβCD was prepared by cross-linking β-cyclodextrin (βCD) using epichlorohydrin. The content of βCD residues in PβCD, determined by a colorimetric method using phenolphthalein as an indicator, was 28.8 wt%. The solubility of coumarin increased
with increasing concentration of PβCD, because the benzene ring of coumarin was included in the hydrophobic cavity of βCD residue. PβCD also increased the solubility of 7HC, but the solubilizing effect on 7HC was much less than that on coumarin, possibly
because the hydroxy group on the benzene ring was likely to suppress the inclusion in the cavity of βCD. And, the photo-dimerization degree of 7HC in an aqueous solution of PβCD was about half than that of coumarin, possibly because the vinyl ether of pyrone group of 7HC could be concealed in the
cavity of βCD. The photo-dimerization of coumarin in an aqueous solution of PβCD could significantly increase the viscosity of the solution. One coumarin dimer would hydrophobically interact with two
βCD residues so it can act as a cross-linker for PβCD. 相似文献
7.
Francisco Carvajal-Ramos Alejandro González-Álvarez J. Roger Vega-Acosta Donato Valdez-Pérez Víctor Vladimir Amilcar Fernández Escamilla Emma Rebeca Macías Balleza J. Félix Armando Soltero Martínez 《Journal of surfactants and detergents》2011,14(2):269-279
The temperature–composition phase diagram in the diluted region of the cationic surfactant cetyldimethylbenzylammonium salicylate/water
system was studied with a battery of techniques. The Krafft temperature (T
k = 33 ± 1 °C) was measured by differential scanning calorimetry, polarizing microscopy, conductimetry, viscosimetry, and rheometry.
The critical vesicle concentration (cvc, ~0.002 wt%) and a vesicle–micellar transition (cvm, ~0.005 wt%) was detected at a
temperature of 35 °C. Below T
k and concentrations ≤2 wt%, a transparent solution is formed (I). Above 2–8.5 wt%, a lamellar (L1) phase forms. At higher concentrations and up to 12 wt%, a second lamellar phase (L2) is detected. From 12.4 to 15.5 wt%, an emulsion phase (E) is formed. Rheological dynamic measurements for the I phase indicate
that the system exhibits a predominantly viscous behavior (G′ < G″) for concentrations lower than the overlap or entanglement concentration (C
e, ~0.75 wt%). At higher concentrations, wormlike micelles form and the elastic behavior predominates (G′ > G″). The elastic (G′) modulus collapses in a concentration–time master curve in the whole reduced frequencies range ωτ
c examined, whereas the viscous modulus (G″) collapses only at reduced frequencies lower than 0.1. Reduced stress plotted as a function of the reduced shear rate yields
a good superposition of the curves at the different concentrations up to the onset of the non-linear behavior. 相似文献
8.
Zhongni Wang 《Journal of surfactants and detergents》2010,13(1):97-102
Surface tensions were determined for a mixture of an anionic fluorinated surfactant and a PEO-PPO-PEO triblock copolymer.
The interactions between the two surfactant molecules in the mixed monolayer and the mixed micelle were studied through molecular
interaction parameters (β
σ, β
M) and the molecule exchange energy (ε, ε
m). It was noted that synergism and strong attractive interactions took place between the anionic fluorinated surfactant and
the triblock copolymer molecules in both mixed micelles and mixed monolayers, reflected by the interaction parameter values
of between −10 and −18 for all mixtures investigated. Moreover, it can be seen from the value of (ε − ε
m) that when the mixture has a small amount of triblock copolymer, the formation of mixed micelle results in a greater decrease
in energy than does the formation of a mixed monolayer. With an increase in the mole fraction of the triblock copolymer in
the mixture, in order to obtain the lowest surface energy, surfactants tend to form mixed monolayers first, and then form
mixed micelles. 相似文献
9.
Maternal dietary conjugated linoleic acid alters hepatic triacylglycerol and tissue fatty acids in hatched chicks 总被引:1,自引:0,他引:1
The effects of feeding CLA to hens on newly hatched chick hepatic and carcass lipid content, liver TAG accumulation, and FA
incorporation in chick tissues such as liver, heart, brain, and adipose were studied. These tissues were selected owing to
their respective roles in lipid assimilation (liver), as a major oxidation site (heart), as a site enriched with long-chain
polyunsaturates for function (brain), and as a storage depot (adipose). Eggs with no, low, or high levels of CLA were produced
by feeding hens a corn-soybean meal-basal diet containing 3% (w/w) corn oil (Control), 2.5% corn oil +0.5% CLA oil (CLA1),
or 2% corn oil +1.0% CLA oil (CLA2). The egg yolk content of total CLA was 0.0, 1.0, and 2.6% for Control, CLA1, and CLA2,
respectively (P<0.05). Maternal dietary CLA resulted in a decrease in chick carcass total fat (P<0.05). Liver tissue of CLA2 chicks had the lowest fat content (P<0.05). The liver TAG content was 8.2, 5.8, and 5.1 mg/g for Control, CLA1, and CLA2 chicks, respectively (P<0.05). The chicks hatched from CLA1 and CLA2 incorporated higher levels of cis-9,trans-11 CLA in the liver, plasma, adipose, and brain than Control (P<0.05). The content of 18∶0 was higher in the liver, plasma adipose, and brain of CLA1 and CLA2 than Control (P<0.05), but no difference was observed in the 18∶0 content of heart tissue. A significant reduction in 18∶1 was observed in
the liver, plasma, adipose, heart, and brain of CLA1 and CLA2 chicks (P<0.05). DHA (22∶6n−3) was reduced in the heart and brain of CLA1 and CLA2 chicks (P<0.05). No difference was observed in carcass weight, dry matter, or ash content of chicks (P>0.05). The hatchabilities of fertile eggs were 78, 34, and 38% for Control, CLA1, and CLA2, respectively (P<0.05). The early dead chicks were higher in CLA1 and CLA2 than Control (18 and 32% compared with 9% for Control), and alive
but not hatched chicks were 15 and 19% for CLA1 and CLA2, compared with 8% for Control (P<0.05). Maternal supplementation with CLA leads to a reduction in hatchability, liver TAG, and carcass total fat in newly
hatched chicks. 相似文献
10.
In present study, novel composite nanocarriers comprised of O-carboxymethyl chitosan/β-cyclodextrin (O-CMC/β-CD) nanoparticles (NPS) were prepared and used to improve the bioavailability of hydrophobic drugs. Ibuprofen (IBU) was selected
as a model drug and chitosan/β-CD (CS/β-CD) NPS were also prepared as control. The prepared NPS were characterized by FT-IR spectroscopy and X-ray diffraction. IBU
entrapment of up to 93.25 ± 2.89% was obtained as determined by UV spectrophotometer. The NPS were spherical in shape with
average particle sizes of 166 nm. The in vitro release studies were performed in simulated gastric medium (pH 1.2) and simulated
intestinal medium (pH 6.8). The release rate of IBU from the O-CMC/β-CD NPS was slower than CS/β-CD NPS in simulated gastric medium. However, the converse tendency was observed in simulated intestinal medium. These results
suggested that O-CMC/β-CD NPS were more suitable for the oral delivery of hydrophobic drugs compared with the CS/β-CD NPS. 相似文献
11.
Wai-Fun Leong Kok-Whey Cheong Oi-Ming Lai Kamariah Long Yaakob B. Che Man Misni Misran Chin-Ping Tan 《Journal of the American Oil Chemists' Society》2011,88(5):717-725
The purpose of this study was to optimize the production parameters for water-soluble phytosterol nanodispersions. Response
surface methodology (RSM) was employed to model and optimize three of the processing parameters: mixing time (t) by conventional homogenizer (1–20 min), mixing speed (v) by conventional homogenizer (1,000–9,000 rpm) and homogenization pressure (P) by high-pressure homogenizer (0.1–80 MPa). All responses [i.e., mean particle size (PS), polydispersity index (PDI) and
phytosterols concentration (Phyto, mg/l)] fitted well to a reduced quadratic model by multiple regressions after manual elimination.
For PS, PDI and Phyto, the coefficients of determination (R
2) were 0.9902, 0.9065 and 0.8878, respectively. The optimized processing parameters were 15.25 min mixing time, 7,000 rpm
mixing speed and homogenization pressure 42.4 MPa. In the produced nanodispersions, the corresponding responses for the optimized
preparation conditions were a PS of 52 nm, PDI of 0.3390 and a Phyto of 336 mg/l. 相似文献
12.
This study was conducted to investigate the effects of fish oil (FO) supplements on fatty acid composition and the expression
of ∆6 desaturase and elongase 2 genes in Jade Tiger abalone. Five test diets were formulated to contain 0.5, 1.0, 1.5, 2.0
and 2.5% of FO respectively, and the control diet was the normal commercial abalone diet with no additional FO supplement.
The muscle, gonad and digestive glands (DG) of abalone fed with all of the five test diets showed significantly high levels
of total n-3 polyunsaturated fatty acid (PUFA), eicosapentaenoic acid (EPA), docosapentaenoic acid n-3 (DPAn-3), and docosahexaenoic
acid (DHA) than the control group. In all three types of tissue, abalone fed diet supplemented with 1.5% FO showed the highest
level of these fatty acids (P < 0.05). For DPAn-3 the higher level was also found in muscle and gonad of abalone fed diet supplemented with 2% FO (P < 0.05). Elongase 2 expression was markedly higher in the muscle of abalone fed diet supplemented with 1.5% FO (P < 0.05), followed by the diet containing 2% FO supplement. For ∆6 desaturase, significantly higher expression was observed
in muscle of abalone fed with diet containing 0.5% FO supplement (P < 0.05). Supplementation with FO in the normal commercial diet can significantly improve long chain n-3 PUFA level in cultured
abalone, with 1.5% being the most effective supplementation level. 相似文献
13.
Víctor M. Ovando-Medina Piedad S. Pi?a-García Miguel A. Corona-Rivera Paola E. Díaz-Flores René D. Peralta Hugo Martínez-Gutiérrez Tania E. Lara-Ceniceros 《Polymer Bulletin》2012,68(9):2313-2322
Semicontinuous heterophase polymerization was used to copolymerize methyl methacrylate (MMA) with reactive surfactant HITENOL
BC10 (HBC10) at 60 °C using sodium dodecyl sulfate as pre-stabilizing agent and potassium persulfate as initiator. The mixture
of MMA and HBC10 was added at constant rate in continuous mode varying the MMA/HBC10 ratio. High-polymerization rates were
observed, decreasing as the MMA/HBC10 ratio decreased. Latexes with polymer content near 20% and polymer to surfactant (P/S)
weight ratios between 5 and 15 were obtained. Particle sizes distribution were bimodal in all cases with a tendency to be
monomodal as HBC10 concentration increased which was ascribed to enhanced particle stabilization by the presence of HBC10.
The average particle diameters at the end of polymerizations for the first and second populations were around 10 and 50 nm,
respectively. Very high average molecular weights were observed (1.4 × 106 ≤ M
w
≤ 2.1 × 106 g/mol), which decreased when HBC10 concentration increased. The corresponding polydispersity indexes (M
w
/M
n
) were in the range of 1.45–2.24. 相似文献
14.
Ana Paula de Queiroz Mello Isis Tande da Silva Aline Silva Oliveira Valéria Sutti Nunes Dulcineia Saes Parra Abdalla Magnus Gidlund Nágila Raquel Teixeira Damasceno 《Lipids》2010,45(7):619-625
Dyslipidemias and physicochemical changes in low-density lipoprotein (LDL) are very important factors for the development
of coronary artery disease (CAD). However, pathophysiological properties of electronegative low-density lipoprotein [LDL(−)]
remain a controversial issue. Our objective was to investigate LDL(−) content in LDL and its subfractions (phenotypes A and
B) of subjects with different cardiovascular risk. Seventy-three subjects were randomized into three groups: normolipidemic
(N; n = 30) and hypercholesterolemic (HC; n = 33) subjects and patients with CAD (n = 10). After fasting, blood samples were collected and total, dense and light LDL were isolated. LDL(−) content in total
LDL and its subfractions was determined by ELISA. LDL(−) content in total LDL was lower in the N group as compared to the
HC (P < 0.001) and CAD (P = 0.006) groups. In the total sample and in those of the N, HC, and CAD groups, LDL(−) content in dense LDL was higher than
in light LDL (P = 0.001, 0.001, 0.001, and 0.033, respectively) The impact of LDL(−) on cardiovascular risk was reinforced when LDL(−) content
in LDL showed itself to have a positive association with total cholesterol (β = 0.003; P < 0.001), LDL-C (β = 0.003; p < 0.001), and non-HDL-C (β = 0.003; P < 0.001) and a negative association with HDL-C (β = −0.32; P = 0.04). Therefore, LDL(−) is an important biomarker that showed association with the lipid profile and the level of cardiovascular
risk. 相似文献
15.
T. Helgason T. S. Awad K. Kristbergsson D. J. McClements J. Weiss 《Journal of the American Oil Chemists' Society》2008,85(6):501-511
Solid lipid nanoparticle (SLN) suspensions, which consist of submicron-sized crystalline lipid particles dispersed within
an aqueous medium, can be used to encapsulate, protect and deliver lipophilic functional components. Nevertheless, SLN suspensions
are susceptible to particle aggregation and gelation during their preparation and storage, which potentially limits their
industrial utilization. In this study, we examined the aggregation and gelation behavior of SLN suspensions composed of 10 wt%
tripalmitin particles (r < 150 nm) stabilized by 1.5% Tween 20. The tripalmitin and aqueous surfactant solution were homogenized above the lipid melting
temperature and cooled under controlled conditions to initiate SLN formation. The aggregation and gelation of SLN suspensions
during storage was then examined by shear rheometry, differential scanning calorimetry (DSC), light scattering and microscopy.
Rheology measurements indicated that gelation times decreased with increasing storage temperature, e.g., samples formed weak
gels after 62, 23, and 10 min at 1, 5, and 10 °C, respectively. DSC revealed increasingly rapid α- to β-polymorphic transformations
in SLN dispersions stored at 1, 5, and 10 °C, respectively. We propose that the observed aggregation and gelation of SLN suspensions
are associated with a change in the shape of the nanoparticles from spherical (α-form) to non-spherical (β-form) when they
undergo the polymorphic transition. When they change shape there is no longer sufficient surfactant present to completely
cover the lipid phase, which promotes particle aggregation through hydrophobic attraction. Our results have important implications
for the design and fabrication of stable SLN suspensions. 相似文献
16.
Donald F. Steenson David B. Min 《Journal of the American Oil Chemists' Society》2000,77(11):1153-1160
The relative oxidative stability of soybean oil samples containing either thermally degraded β-carotene or lycopene was determined
by measuring peroxide value (PV) and headspace oxygen depletion (HOD) every 4 h for 24 h. Sobyean oil samples containing 50
ppm degraded β-carotene that were stored in the dark at 60°C displayed significantly (P<0.01) higher HOD values compared with controls. Lycopene degradation products (50 ppm) in soybean oil significantly (P<0.05) decreased HOD of samples when stored in the dark. PV and HOD values for samples containing 50 ppm of either β-carotene
or lycopene degradation products stored under lighted conditions did not differ significantly from controls (P<0.05). However, soybean oil samples containing 50 ppm of unheated, all-trans β-carotene or lycopene stored under light showed significantly lower PV and HOD values than controls (P<0.01). These results indicated that during autoxidation of soybean oil held in the dark, β-carotene thermal degradation products
acted as a prooxidant, while thermally degraded lycopene displayed antioxidant activity in similar soybean oil systems. In
addition, β-carotene and lycopene degradation products exposed to singlet oxygen oxidation under light did not increase or
decrease the oxidative stability of their respective soybean oil samples. 相似文献
17.
Dhanapalan Karthikeyan Nachiappan Lingappan Bommasamudram Sivasankar 《Korean Journal of Chemical Engineering》2008,25(5):987-997
Bifunctional catalysts containing (0.1–0.5 wt%) Nickel and 0.1 wt% of Pd supported on H-β zeolite were synthesized by incipient wetness impregnation method and characterized by XRD, TEM, XPS, TPD and TPR techniques.
The catalytic activity of Ni containing and Ni free Pd/H-β Catalysts was studied, and it was found that Ni up to a threshold value (0.3 wt% on β) produced increased the n-decane conversion and isomerization selectivity. When Ni content exceeds the threshold value, the
conversion increases but isomerized products decrease. Moreover, Ni containing Pd/H-β showed increased sustainability and favored the protonated cyclopropane (PCP) intermediate mechanism in n-decane isomerization.
The catalyst containing 0.3 wt% Ni 0.1 wt% Pd is adjudged as one performing better than other catalysts studied because of
the isomerized mixture from it shows better octane number. 相似文献
18.
Aniruddha S. Deshpande Ramdas B. Khomane Bhalchandra K. Vaidya Renuka M. Joshi Arti S. Harle Bhaskar D. Kulkarni 《Nanoscale research letters》2008,3(6):221-229
Sulfur nanoparticles were synthesized from hazardous H2S gas using novel biodegradable iron chelates in w/o microemulsion system. Fe3+–malic acid chelate (0.05 M aqueous solution) was studied in w/o microemulsion containing cyclohexane, Triton X-100 and n-hexanol as oil phase, surfactant, co-surfactant, respectively, for catalytic oxidation of H2S gas at ambient conditions of temperature, pressure, and neutral pH. The structural features of sulfur nanoparticles have
been characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive spectroscopy (EDS),
diffused reflectance infra-red Fourier transform technique, and BET surface area measurements. XRD analysis indicates the
presence of α-sulfur. TEM analysis shows that the morphology of sulfur nanoparticles synthesized in w/o microemulsion system
is nearly uniform in size (average particle size 10 nm) and narrow particle size distribution (in range of 5–15 nm) as compared
to that in aqueous surfactant systems. The EDS analysis indicated high purity of sulfur (>99%). Moreover, sulfur nanoparticles
synthesized in w/o microemulsion system exhibit higher antimicrobial activity (against bacteria, yeast, and fungi) than that
of colloidal sulfur. 相似文献
19.
Zheng-gang Cui Hong-xing Song Jun-jie Yu Jian-zhong Jiang Feng Wang 《Journal of surfactants and detergents》2011,14(3):317-324
Alkali-surfactant-polymer (ASP) flooding has been considered to be one of the useful tertiary oil recovery techniques. However,
field tests in China have revealed that serious side effects may occur due to using alkali. Thus alkali-free SP flooding is
more favorable in China. Unfortunately, surfactants effective in ASP flooding are usually ineffective in the absence of alkali
and new surfactants need to be designed. In this paper N-(3-Oxapropanoxyl)dodecanamide as a pure compound and a mixture of homologues with narrow EO number distribution, synthesized
by the reaction of lauroyl chloride with diglycolamine and addition of one ethylene oxide to coconut monoethanolamide respectively,
are examined for their adaptability in SP flooding. It is found that, when mixed with betaines, both products can reduce Daqing
crude oil/connate water interfacial tension to a magnitude of 10−3–10−4 mNm−1 at 45 °C in a wide surfactant concentration range, 0.01–0.5 wt%, and oil displacement tests using natural cores indicates
that a tertiary oil recovery of 18.6 ± 0.4% OOIP can be achieved by SP flooding with the N-(3-Oxapropanoxyl)dodecanamide as the main surfactant without adding any alkaline agent and neutral electrolyte. N-(3-Oxapropanoxyl)dodecanamide, as a nonionic surfactant without a cloud point and producible industrially from renewable
materials, is an ideal surfactant for SP flooding in the absence of an alkaline agent. 相似文献
20.
Razia Sultana Rubina Saleem Nighat Sultana Farhana Afshan Tahsin Gulzar 《Journal of the American Oil Chemists' Society》2012,89(6):1021-1027
Caesalpinia bonducella is an oilseed that is indigenous to Pakistan. The hexane-extracted oil content from the seed kernel was 17.3 ± 1.0% DM (dry matter). The proximate analysis of C. bonducella seed estimated protein, fiber and ash contents to be 20.8 ± 1.4, 5.3 ± 1.0 and 4.6 ± 0.8%, respectively. Trace metals were determined comparable to commonly consumed legume seeds. α-Tocopherol was the predominant tocopherol ranging from 345.10 to 460.21 mg/kg of oil, followed by γ- and δ-tocopherol. The major sterols were β-sitosterol, stigmasterol, campesterol, Δ5-avenasterol, Δ7-stigmastenol and Δ7 avenasterol. The kernel oil was found to contain a high level of linoleic acid (72.7 ± 1.0%) followed by oleic, stearic and palmitic acids. The high percentage of linoleic acid revealed that this oil is a potential source for the manufacture of cosmetics, paints, varnishes, soaps, liquid soaps and other products including biodiesel. These investigations suggest that C. bonducella oil is potentially an important dietary source of essential fatty acids and protein which could be employed for edible and commercial applications in various industries of Pakistan. 相似文献