共查询到20条相似文献,搜索用时 15 毫秒
1.
《The Journal of Supercritical Fluids》2007,40(3):330-337
In this study, the extraction of jojoba seed oil obtained from jojoba seed using both supercritical CO2 and supercritical CO2+ethanol mixtures was investigated. The recovery of jojoba seed oil was performed in a green and high-tech separation process. The extraction operating was carried out at operating pressures of 25, 35 and 45 MPa, operating temperatures of 343 and 363 K, supercritical fluid flow rates of 3.33 × 10−8, 6.67 × 10−8 and 13.33 × 10−8 m3 s−1, entrainer concentrations of 2, 4 and 8 vol.%, and average particle diameters of 4.1 × 10−4, 6.1 × 10−4, 8.6 × 10−4 and 1.2 × 10−3 m. It was found that a green chemical modifier such as ethanol could enhance the solubilities, initial extraction rate and extraction yield of jojoba seed oil from the seed matrix as compared to supercritical CO2. In addition, it was found that the solubility, the initial extraction rate and the extraction yield depended on operating pressure and operating temperature, entrainer concentration, average particle size and supercritical solvent flow rate. The solubility of jojoba seed oil and initial extraction rate increased with temperature at the operating pressures of 35 and 45 MPa and decreased with increasing temperature at the operating pressure of 25 MPa. Furthermore, supercritical fluid extraction involved short extraction time and minimal usage of small amounts entrainer to the CO2. About 80% of the total jojoba seed oil was extracted during the constant rate period at the pressure of 35 and 45 MPa. 相似文献
2.
Melia azedarach L. is a plant with wide use in folk medicine since it contains many bioactive compounds of interest. The present study aimed to extract bioactive compounds from M. azedarach fruits by a sequential process in fixed bed using various solvent mixtures. Extractions were performed at 50 °C and 300 bar in four sequential steps using supercritical CO2 (scCO2), scCO2/ethanol, pure ethanol, and ethanol/water mixture as solvents, respectively. The efficacy of the extraction process was evaluated by extraction yield and kinetics, and analysis of extracts by: (1) thin layer chromatography (TLC), (2) phenolics content, (3) reduction of surface tension of water, (4) gas chromatography (GC–MS), (5) electrospray ionization mass spectrometry (ESI–MS) and (6) antiviral activity. The overall extraction yield reached 45% and TLC analysis showed extracts with different composition. extract obtained from CO2/ethanol mixture (SCEE) exhibited the greatest ability to reduce surface tension of water from 72.4 mN m−1 [1] of pure water to 26.9 mN m−1 of an aqueous solution of 40 g L−1. The highest phenolics contents were observed in both the hydroalcoholic extract and scCO2/ethanolic extract. Volatile oils were not detected in the supercritical extracts by GC–MS. MS analyses identified the fatty acids: linoleic, palmitic and myristic acid in the supercritical extract (SCE), and the phenolics: caffeic acid and malic acid in the other extracts. In addition, SCE and SCEE extracts showed significant inhibition percentage against Herpes Simplex Virus Type 1. The extraction process proposed in the present study produced extracts with significant potential for application in food and pharmaceutical industries. 相似文献
3.
Supercritical carbon dioxide (SC-CO2) extraction of lipid from Scenedesmus sp. for biodiesel production was investigated and compared to conventional extraction methods. The effect of biomass pre-treatment prior to extraction and extracting conditions, namely pressure in the range of 200–500 bar, temperatures in the range of 35–65 °C and CO2 flow rate in the range of 1.38–4.02 g min−1, on SC-CO2 extraction yield and quality of lipid were investigated. Three levels full factorial design of experiments and response surface methodology was used to model the system. A second order polynomial model was developed and used to predict the optimum conditions. Scaling up to a laboratory larger scale was also tested. The results indicated that SC-CO2 extraction was superior to other extraction techniques, but exhibited significant variations in yield with changes in operating parameters. In the developed model, it was found that the linear and quadratic terms of the temperature, as well as the interaction with pressure had a significant effect on lipid yield; whereas, their effect on lipid quality was insignificant. The best operating conditions, in the tested range, were 53 °C, 500 bar and 1.9 g min−1, in which lipid extraction yield of 7.41% (dry weight basis) was obtained. Negligible differences were observed when the fatty acid composition of SC-CO2 extracted lipid was compared to that extracted by the conventional methods. At the optimum conditions, SC-CO2 extraction was successfully scaled-up by eight-folds and the extracted lipid yield dropped by 16%. 相似文献
4.
The reported work aimed at the optimization of operating conditions of the supercritical fluid extraction (SFE) of spent coffee grounds (SCG) using pure or modified CO2, with particular emphasis on oil enrichment with diterpenes like kahweol, cafestol and 16-O-methylcafestol. The analysis comprised the application of Box–Behnken design of experiments and response surface methodology, and involved three operating variables: pressure (140–190 bar), temperature (40–70 °C) and cosolvent (ethanol) addition (0–5 wt.%). The best conditions to maximize total extraction yield are 190 bar/55 °C/5 wt.% EtOH, leading to 11.97% (goil/100 gSCG). In terms of the concentration of diterpenic compounds in the supercritical extracts, the best operating conditions are 140 bar/40 °C/0 wt.% EtOH, providing 102.90 mg g−1oil. The measurement of extraction curves near optimized conditions (140 bar/55 °C/0 wt.% EtOH and 190 bar/55 °C/0 wt.% EtOH) confirmed the trends of the statistical analysis and revealed that SFE enhances diterpenes concentration by 212–410% at the expenses of reducing the extraction yield between 39% and 79% in comparison to n-hexane extraction. 相似文献
5.
Extraction of protocatechuic acid from Scutellaria barbata D. Don using supercritical carbon dioxide
The use of supercritical carbon dioxide (SCCO2), with water as a modifier, was evaluated in this study as a method to extract protocatechuic acid (PA) from Scutellaria barbata D. Don. The highest extraction yield of PA, 64.094 ± 2.756 μg/g of dry plant, was achieved at 75 °C and 27.5 MPa, with the addition of 15.6% (v/v) water as a modifier. The mean particle size was 0.355 mm, the CO2 flow rate was 2.2 mL/min (STP) and the dynamic extraction time was 100 min. At pressures of 16.230.0 MPa and temperatures of 4575 °C, the mole fraction solubilities of PA in SCCO2 ranged from 2.829 ÿ 107 to 9.631 ÿ 107. The solubility data for PA fit well in the Chrastil model. It is evident that the SCCO2 extraction uses less solvent, saves both energy and time and is an environmentally friendly extract technology that can be used in the food, cosmetic and pharmaceutical industries. 相似文献
6.
Copper or cobalt incorporated TiO2 supported ZSM-5 catalysts were prepared by a sol–gel method, and then were characterized by XRD, BET, XPS and UV–vis diffuse reflectance spectroscopy. Ti3 + was the main titanium specie in TiO2/ZSM-5 and Cu–TiO2/ZSM-5, which will be oxide to Ti4 + after Co was doped. With the deposition of Cu or Co, the efficiency of the CO2 conversion to CH3OH was increased under low energy irradiation. The peak production rate of CH3OH reached 50.05 and 35.12 μmol g− 1 h− 1, respectively. High photo energy efficiency (PEE) and quantum yield (φ) were also reached. The mechanism was discussed in our study. 相似文献
7.
Enrichment of Nigella damascena extract with volatile compounds using supercritical fluid extraction
β-Elemene, germacrene A and damascenine were extracted from lady-in-a-mist (Nigella damascena L.) seeds with supercritical carbon dioxide at 10–30 MPa and 40–60 °C. The influence of supercritical fluid extraction (SFE) conditions on the yield and concentration of volatiles in the extract and the extraction kinetics were studied. The extraction yields and the apparent solubility of volatile compounds increased with increasing density of CO2. The highest total yield was obtained at 30 MPa and 40 °C but the selectivity for volatiles was low under these conditions. With respect to both yield of volatiles and their concentration in extract, the best results were at 12 MPa and 40 °C, either with one separator or with additional separator maintained at 5 MPa and 25 °C. The yields of β-elemene, germacrene A and damascenine reached 0.72, 3.31 and 3.65 mg g−1 and their concentration in the extract was 2.62, 12.04 and 13.28 wt.%, respectively. Though the yields of germacrene A and damascenine were by about 20% higher using Soxhlet extraction with hexane than using SFE, their concentration in the extract where fatty oil prevailed was only 1.19 and 1.20 wt.%, respectively. Under the conditions of hydrodistillation, partial conversion of germacrene A to β-elemene occurred and its yield was higher than using the other methods but the composition of volatiles in the SFE extracts better corresponds to the original raw material. 相似文献
8.
《Carbon》2014
Graphite electrodes were electrochemically cycled in Li-ion cells at 50 and 60 °C in order to determine the changes in their surface properties in comparison to the electrodes tested at 25 °C. A 17% drop in planar capacity occurred during the first cycle at 60 °C compared to a 40% at 25 °C and reduced the amount of damage that occurred to graphite due to a rapidly formed solid electrolyte interphase (SEI). During the following cycles, a planar capacity of 3.11 ± 0.12 mAh cm−2 was attained at 60 °C rather than 0.53 ± 0.03 mAh cm−2 at 25 °C. The SEI layer formed at 60 °C predominantly consisted of Li2CO3 and was devoid of residual LiClO4 detected at 25 °C. At 25 °C, the diffusion coefficient of Li+ (DLi+) was calculated as 1.07 × 10−8 cm2 s−1, whereas at 60 °C, DLi+ increased to 3.25 × 10−8 cm2 s−1. A pre-treatment conducted at 60 °C enhanced the cyclic performance of graphite subsequently cycled at 25 °C; a Li2CO3-enriched SEI, generated during the 60 °C pre-treatment, covered the graphite surface uniformly and resulted in a 28% increase in battery capacity at 25 °C. 相似文献
9.
《The Journal of Supercritical Fluids》2007,39(3):326-331
Extraction of sunflower oil from sunflower seeds (Heliantus annuus L.) using supercritical CO2 was studied. The shrinking core model was applied to the modeling of the packed-bed extraction process. The experimental data were obtained for extraction conducted at the pressures of 20, 30, 40, 50 and 60 MPa; the temperatures of 313, 333 and 353 K, the CO2 flow rates of 1–4, and 6 cm3 CO2 min−1; the mean particle diameters of 0.23, 0.55, 1.09, 2.18 mm. The supercritical CO2 extraction process was modeled by a quasi steady state model as a function of extraction time, pressure, temperature, CO2 flow rate, and particle diameter. The supercritical CO2 extraction process. The intraparticle diffusion coefficient (effective diffusivity) De was used as adjustable parameter. The model using the best fit of De was correlated the data satisfactorily. 相似文献
10.
Saponins are surfactants that reduce the surface tension of aqueous solutions, besides having pharmacological actions. In order to extract and fractionate saponins from Pfaffia glomerata roots and Hebanthe eriantha roots using supercritical technology, fractionated extracts were obtained from a sequential process in fixed bed using supercritical CO2 (scCO2), ethanol, and water as solvents. All extractions were carried out in four sequential steps, at 50 °C and 300 bar. In the first step, pure scCO2 was used as solvent, while (a) scCO2/etanol (70:30, w/w); (b) ethanol, and (c) ethanol/water (70:30, v/v) were used as solvents in the three subsequent steps. The extracts were analyzed by thin layer chromatography (TLC) and surface tension. The extraction yields of the four steps were 0.16, 0.55, 1.00, and 6.90% for P. glomerata roots, and 0.17, 0.58, 0.89, and 28% for H. eriantha roots, showing a predominance of high polarity compounds in these species. TLC analysis showed that the extraction process was selective according to the polarity of the solvent, and provided extracts containing different saponins, except for scCO2 extraction. The extracts from the extraction using ethanol + scCO2 (Step 2) showed the greatest ability to reduce the surface tension of water from 72 mN m−1 (pure water) to 25 mN m−1, suggesting that this step was the best for extraction of less polar saponins in the extracts. The critical micelle concentration (CMC) values were approximately 2 and 8 g L−1 for P. glomerata and H. Eriantha, respectively. These results confirmed the efficacy of the extraction process under study. 相似文献
11.
《The Journal of Supercritical Fluids》2003,25(1):33-44
The aim of this work was to assess and model supercritical carbon dioxide (ScCO2) extraction kinetics of pre-pelletized Jalapeño peppers (Capsicum annuum L.). Pepper flakes were conditioned to low moisture, ground finely and pelletized at high pressure, and pellets were subsequently ground and size classified. The effects of average sample particle size (Dp=0.28–3.19 mm) and superficial solvent velocity (Us=0.14–2.62 mm s−1) were evaluated at 40 °C and 120 or 320 bar. Extraction rate increased as a result of a decrease in Dp. It also increased as a result of an increase in Us at 120 bar, but the effect was almost negligible at 320 bar. Integral extraction yields of capsicum oleoresin and capsaicinoids were ≈0.102 g g−1 and ≈240 mg kg−1, respectively, independent of extraction conditions. External mass transfer coefficients (kf) increased with Us, but this effect was less pronounced than commonly reported in the literature. Values of kf increased as Dp or process pressure decreased, due respectively to increments in specific area and improvements in transport properties. Internal mass transfer coefficients, on the other hand, were 5.3×10−8 m s−1 at 40 °C and 120 bar, and 34.7×10−8 m s−1 at 40 °C and 320 bar. Solutes were effectively liberated from the original matrix with our multistage pretreatment, so that the fraction of free solute did not depend on Dp (α=0.46). Pseudosolubilities for capsicum oleoresin in ScCO2 (≈2100 mg l−1 at 40 °C and 120 bar; ≈13,700 mg l−1 solute/CO2 at 40 °C and 320 bar) were of the same order of magnitude as corresponding true solubilities of capsaicin (5600 and 11,800 mg l−1, respectively). Estimated true solubilities of chlorophyll-a in ScCO2 (2 mg l−1 at 40 °C and 120 bar; 18 mg l−1 at 40 °C and 320 bar), on the other hand, were orders of magnitude smaller, which justifies a much slower extraction rate for green pigments than pungent compounds. Thus, oleoresin obtained after 4 h at 40 °C and 120 bar had a very attractive light yellow tinge. 相似文献
12.
《Ceramics International》2017,43(4):3726-3733
Ta-doped lead-free 0.94NBT-0.06BT-xTa (x=0.0–1.0%) ceramics were synthesized by a conventional solid-state route. XRD shows that the compositions are at a morphotropic phase boundary where rhombohedral and tetragonal phases coexist. The depolarization temperature (Td) shifted to lower temperature with the increase of Ta content. The pyroelectric coefficient (p) of doped ceramics greatly enhanced compared with undoped material and reached a maximum of 7.14×10−4 C m−2 °C−1 at room temperature (RT) and 146.1×10−4 C m−2 °C−1 at Td at x=0.2%. The figure of merits, Fi and Fv, also showed a great improvement from 1.12×10−10 m v−1 and 0.021 m2 C−1 at x=0.0 to 2.55×10−10 m v−1 and 0.033 m2 C−1 at x=0.2% at RT. Furthermore, Fi and Fv show the huge improvement to 52.2×10−10 m v−1 and 0.48×10−10 m v−1 respectively at Td at x=0.2%. FC shows a value between 2.26 and 2.42 ×10−9 C cm−2 °C−1 at RT at x=0.2%. The improved pyroelectric properties make NBT-0.06BT-0.002Ta ceramics a promising infrared detector material. 相似文献
13.
This work uses a fully predictive mass transfer model to simulate the supercritical CO2 extraction of vegetable oils from prepressed oilseeds in the 1-m3 vessel of an industrial multi-vessel plant operating at 40 °C and 30 MPa with the purpose of minimizing the operational cost. The work analyses the effect of particle diameter (0.5, 1, 2, 3, and 4 mm), superficial CO2 velocity (2.76, 5.52, or 11.0 mm/s), and number of extraction vessels (2, 3, or 4) on optimal extraction time and minimal operational cost. Keeping other variables constants, cost diminishes as particle diameter decreases. Although the optimal superficial CO2 velocity increases as particle diameter decreases, in the case of small (≤1 mm) particles, substrate fluidization may place an upper limit to the superficial velocity. Within the studied region, best superficial CO2 velocities are 11.0 mm/s for particles smaller than 1–2 mm, 2.76 mm/s for particles larger than 3–4 mm, and 5.52 mm/s for particles in between. Keeping other variables constant, the cost of extraction of medium-to-large (≥2 mm) particles decreases as the number of extraction vessels increases, at the expense of an increase in extraction time. However, because of a sharp transition wave that develops when extracting small (≤1 mm) particles that separates fully extracted (downstream) from virtually unextracted (upstream) substrate within extraction vessels, two-vessel plants are best for small particles. The lowest operational cost observed in this work was USD 4.08 kg−1 oil for the extraction of 2-mm particles using 3.30 m3/h of CO2 (U = 2.76 mm/s) in a four-vessel plant. 相似文献
14.
Supercritical carbon dioxide extraction of Gac (Momordica cochinchinensis Spreng) aril was performed at pressures ranging from 200 to 400 bar, temperatures from 313 to 343 K and specific flow rates from 50 to 90 kg h−1 CO2 kg−1 Gac aril. Total oil recovery and carotenes concentration were investigated in the course of extraction. Mathematical modelling of oil solubility data was also performed. The results showed that at specific flow rate of 70 kg h−1 kg−1, pressure of 400 bar and temperature of 343 K, Gac oil recovery exceeded 95% after 120 min of extraction. Gac oil loading of supercritical carbon dioxide was successfully described by Chrastil's model. Carotenes concentration of extracted Gac oil was found at level of thousands of ppm. 相似文献
15.
The equilibrium solubilities of cefixime trihydrate and oxymetholone in supercritical carbon dioxide (CO2) were measured using a “static method”. Cefixime trihydrate is a cephalosporin antibiotic drug and Oxymetholone is a 17alpha-alkylated anabolic-androgenic steroid drug. The experimental measurements for cefixime trihydrate were performed at temperatures of 308, 318 and 328 K as well as pressure range from 183 to 335 bar. The solubility of oxymetholone was determined at 308, 318 and 328 K and pressure range from 121 to 305 bar. The experimental solubility data (mole fraction) for cefixime trihydrate and oxymetholone was greater than 1.6 × 10−7 and 1.6 × 10−5 and less than 3.02 × 10−7 and 1.49 × 10−4, respectively. The solubilities for two drugs in CO2 were correlated by using four semi-empirical models such as Bartle, Kumar and Johnstone (K–J), Mendez-Santiago and Teja (M–T) and Chrastil models. The results obtained from the semi-empirical models show that there is good agreement between the experimental data and the results of semi-empirical models. By using the correlation results, the heat of drug–CO2 solvation and heat of drug vaporization for cefixime–CO2 and oxymetholone–CO2 systems may be approximately estimated. Also, the Peng–Robinson (PR) cubic equation of state (CEOS) along with the van der Waals combining rule was applied to correlate the drugs solubilities in supercritical CO2. The average absolute deviation between the experimental data and the results of PR equation for cefixime trihydrate and oxymetholone was 11.92% and 11.74%, respectively. 相似文献
16.
The extraction of polyphenol compounds from jatoba (Hymenaea courbaril L. var stilbocarpa) bark using supercritical fluid extraction (SFE) with CO2 and cosolvents has been investigated. Among the solvent systems studied, SFE using CO2 and water (9:1, v/v), at 323 K and 35 MPa, presented the best results, with extract yield of 24%, and with high antioxidant activity (IC50 of 0.2 mg/cm3). This solvent system was used to determine global yield isotherms, which were built at 323 and 333 K, and 15, 25, and 35 MPa, using a second lot of jatoba. The highest yield was 11.5% at 15 MPa and 323 K, with maximum total phenolic compounds (TPC) of 335.00 mg TAE/g extract (d.b.) and total tannins content of 1.8 g/100 g raw material. A kinetic experiment was performed using optimized conditions, yielding 18% extract, and the kinetic parameters were used to scale-up the process from laboratory to pilot scale. Chemical analyses showed high content of phenolic compounds in the extracts of jatoba bark mostly due to the presence of procyanidins. 相似文献
17.
The objective of this work was to study production costs for the supercritical CO2 extraction of a pre-pressed oilseed (packed bed with 2-mm particles) in a 2-m3 industrial multi-vessel plant operating at 40 °C and 30 MPa, using a fully predictive mass transfer model to simulate the process. We modified the inner diameter (47.3 ≤ D ≤ 65.6 cm) and number (n = 2, 3, or 4) of extraction vessels, and the mass flow rate of CO2 (Q = 3000 or 6000 kg/h), thus changing the aspect ratio of the extraction vessels (3 ≤ L/D ≤ 8), and superficial velocity (2.71 ≤ U ≤ 10.8 mm/s) and specific mass flow rate (6 ≤ q ≤ 24 kg/h per kg substrate) of CO2. Production cost decreased when increasing the mass flow rate of CO2 or the number of extraction vessels (or when increasing q). Production cost did not depend on the geometry of extraction vessel for a constant specific mass flow rate of CO2, but it decreased with a decreasing of the L/D ratio of the vessel for a constant superficial velocity of CO2. For any given plant, the contribution of fixed cost items (capital, labor) to the production cost increased with extraction time, unlike that of variable cost items (substrate, CO2, energy), which decreased. Thus, there was an optimal extraction time that minimized production cost for each plant. This work proposes an expression for capital cost of an industrial multi-vessel plant as a function of the mass flow rate of CO2 (which defines the cost of the solvent cycle of the plant), and the volume of the extraction vessels (which together with number of extraction vessels define the cost of extraction section of the plant), with a scaling factor of 0.48 for both items. Under optimal conditions, capital cost represented 30–40% of the production cost, but uncertainties in capital cost estimates (about ±50% using the proposed expression) may largely affect these estimates. The lowest production cost estimated in this work was USD 7.8/kg oil for the extraction of prepressed oilseed in a four-vessel plant using 6000 kg/h of CO2. The mass flow rate of CO2 and number of extraction vessels also affected annual productivity that was about 360 ton oil for the same plant operating 7200 h per year. Oil yields were above 90% for both three- and four-vessel plants. 相似文献
18.
《中国化学工程学报》2014,22(11-12):1285-1290
The adsorption characteristics of UiO-66 (a Zr-containing metal–organic framework formed by terephthalate) for Rhodamine B (RhB), such as isotherms, kinetics and thermodynamics, were investigated systematically. The batch adsorption data conform well to the Langmuir and Freundlich isotherms. The adsorption kinetics of UiO-66 for RhB can be well described by the pseudo first-order model, and the adsorption thermodynamic parameters ΔG0, ΔH0 and ΔS0 at 273 K are − 6.282 kJ·mol− 1, 15.096 kJ·mol− 1 and 78.052 J·mol− 1·K− 1, respectively. The thermodynamic analyses show that the adsorption process of RhB on UiO-66 is more favorable at higher temperatures. UiO-66 can be regenerated by desorbing in DMF solution with ultrasonic for 1 h. UiO-66 can keep good performance for at least six cycles of sorption/desorption. 相似文献
19.
The influence of diverse factors on the supercritical fluid extraction (SFE) with supercritical CO2 (scCO2) of galanthamine from bulbs of Narcissus pseudonarcissus cv. Carlton was investigated. The parameters that were studied were CO2 density (temperature and pressure), flow rate and plant material particle size and pre-treatment. The highest yield (303 μg/g) was achieved by extracting 53–1000 μm particle-size powdered dried bulb material moistened with NH4OH (25%, v/v) at 70 °C, 220 bar (690 kg/m3) for 3 h. Other N. pseudonarcissus alkaloids such as O-methyllycorenine and haemanthamine were also obtained. N. pseudonarcissus alkaloids as free bases are highly soluble in CO2 at a high pH as opposed to the slightly soluble salt form in which they are generally found in plants. Therefore, plant material pre-treatment with a base is an essential step for galanthamine extraction. Scanning electron microscope (SEM) results also revealed that the desorption of N. pseudonarcissus alkaloids from the plant material rather than the solubility of the alkaloids in the scCO2 plays a major role in this scCO2 extraction. This extraction method has a good potential for industrial application. 相似文献
20.
《Journal of the European Ceramic Society》2014,34(12):2967-2976
Mn2+-doped Sn1−xMnxP2O7 (x = 0–0.2) are synthesized by a new co-precipitation method using tin(II)oxalate as tin(IV) precursor, which gives pure tin pyrophosphate at 300 °C, as all the reaction by-products are vaporizable at <150 °C. The dopant Mn2+ acts as a sintering aid and leads to dense Sn1−xMnxP2O7 samples on sintering at 1100 °C. Though conductivity of Sn1−xMnxP2O7 samples in the ambient atmosphere is 10−9–10−6 S cm−1 in 300–550 °C range, it increases significantly in humidified (water vapor pressure, pH2O = 0.12 atm) atmosphere and reaches >10−3 S cm−1 in 100–200 °C range. The maximum conductivity is shown by Sn0.88Mn0.12P2O7 with 9.79 × 10−6 S cm−1 at 550 °C in ambient air and 2.29 × 10−3 S cm−1 at 190 °C in humidified air. It is observed that the humidification of Sn1−xMnxP2O7 samples is a slow process and its rate increases at higher temperature. The stability of Sn1−xMnxP2O7 samples is analyzed. 相似文献