共查询到20条相似文献,搜索用时 31 毫秒
1.
Yongli Zhang Yuding Huang Minghui Li Chao Liang Haifeng Zhu Yuan Zhong Nan Yang Zhi Zhou Mao Xia 《Journal of the American Ceramic Society》2020,103(8):4373-4383
To fulfil the demands of high-power plant growth lamps, cation co-doping is an effective way to tune the photoluminescence properties of manganese (Ⅳ)-activated aluminate phosphors. Therefore, we managed to synthesize a series of cations co-doped CaYAlO4:xMn4+, mSr2+, M+ (M+ = Li+, Na+, and K+) (CYAO:Mn, Sr, M) far-red-emitting phosphors. The excitation spectrum of these phosphors contained two excitation bands, and the opposite effects of these two bands on the luminescence intensity have been observed with the increase of Mn4+ concentration. By adding 0.1 mol Sr2+ ions to replace Ca2+ site, the emission intensity and thermal stability of CYAO:Mn phosphors can be enhanced. Furthermore, the luminescence properties of CSYAO:Mn can be further improved by co-doping monovalent alkali metal ions to serve as charge compensators, the increased number of Mn4+ luminescence centers. Moreover, 0.6 mol% Na+ can increase the initial emission intensity of the phosphors by 117% as the best ratio. The characteristic emission spectrum of the phosphors CYAO:Mn,Sr,M correspond to the phytochrome PFR of plants. These experiments and characterization results have certified that these phosphors have a potential application in indoor plants cultivation. 相似文献
2.
Influence of Substructures on the Spreading Ability and Hydrolysis Resistance of Double-Tail Trisiloxane Surfactants 总被引:2,自引:0,他引:2
Four types of novel double-tail trisiloxane surfactants of the general formula Me3SiOSiMeR1OSiMe3 (R
1 = –(CH2)3NR2CH2CH(OH)CH2(OCH2CH2)xOCH3; R
2 = –CH2CH(OH)CH2OCH2(CH2)yCH3, –CH2(CH2)3CH3, –CH2CH2CH(CH3)2; x = 8.4, 12.9, 17.5, 22; y = 2, 6), have been synthesized. Their structures were characterized by proton and carbon nuclear magnetic resonance. Most
of them are able to reduce the surface tension of water to less than 24 mN/m at concentration levels of 10−5 mol/L and 10−4 mol/L. The emphasis was on the influence of substructures on their spreading ability and hydrolysis resistance. The results
showed that a weaker hydrophilicity of a surfactant molecule, a larger molar ratio of methyl to methylene in the whole hydrophobic
groups, more flexible hydrophobic groups and introduction of a methyl group in the spacer can all improve the spreading ability
of the double-tail trisiloxane surfactant solutions on low-energy solid surfaces. The double-tail trisiloxane surfactants
1F and 2F are stable for more than 270 days in a neutral environment (pH 7.0). The hydrolysis resistance of the double-tail trisiloxane
surfactants can be improved by a weaker hydrophilicity of the surfactant molecule, and a larger volume of the hydrophobic
groups. 相似文献
3.
Tao Wang Feng Bao Yan Liu Bin Xing Zhe Tan Zhifang Tan Xing Qiang Lü 《Journal of Inorganic and Organometallic Polymers and Materials》2008,18(3):420-425
Abstract Two Ag+ complexes [Ag(HL)2(PF6)] (1) and [(AgL)
n
· n(CH2Cl2) · n(0.5H2O)] (2) (HL = 5-methyl-2-phenyl-4-[(2-o-tolylamino)-phenylmethylene]pyrazol-3(2H)-one) were synthesized and structurally characterized by EA analysis, IR spectra
and X-ray crystallography. The result shows that two expected coordination modes (Modes I and III in Scheme 1) of the HL ligand, can be observed in its Ag+ complexes, while not in other transition metal ions (Ni2+, Co2+ or Cu2+) complexes whether deprotonation or not for the HL ligand.
Graphical Abstract Three possible coordination modes (Modes I, II or III in Scheme 1) of the selected HL (HL = 5-methyl-2-phenyl-4-[(2-o-tolylamino)-phenylmethylene]pyrazol-3(2H)-one) ligand, can be adopted, in which Modes I and III can be observed in its two
Ag+ complexes [Ag(HL)2(PF6)](1) and [(AgL)
n
· n(CH2Cl2) · n(0.5H2O)] (2), while Mode II just observed in its transition metal ions (Cu2+, Ni2+, or Co2+) complexes, resulting from the deprotonatd form of the HL ligand and the coordination characters of transition metal ions.
相似文献
4.
Synthesis and Properties of Novel Double-Tail Trisiloxane Surfactants with High Spreading Ability 总被引:1,自引:0,他引:1
A new type of double-tail trisiloxane surfactants of the general formula R1NR2CH2CH(OH)CH2O(CH2CH2O)xCH3 (x = 8.4, 12.9, 17.5, 22; R
1 = Me3SiOSiMe(CH2)3OSiMe3, R
2 = CH2CH(OH)CH2OR3, R
3 = CH2CH(C2H5)CH2(CH2)2CH3) has been synthesized by reacting single-tail trisiloxane surfactants with 2-ethylhexyl glycidyl ether. Their structures
were characterized with 1H-NMR and 13C-NMR spectroscopy. These double-tail trisiloxane surfactants reduce the surface tension of water to less than 24 mN/m at
a level of 10−5 mol/L. The spreading ability (SA) of the double-tail trisiloxane surfactant solution on Parafilm (or Ficus microcarpa leaf) surfaces is better than that on polyethylene terephthalate surface. The SA of the solution of the double-tail trisiloxane
surfactants 1J with average ethoxy units of 8.4 is far better than the others, and its solution (5.0 × 10−3 mol/L) possesses an SA value of over 15 within 10 min on Parafilm and Ficus microcarpa leaf surfaces. The surface tension values of aqueous solutions (1.0 × 10−3 mol/L) of the double-tail trisiloxane surfactants 1J are still less than 25 mN/m over 21 days in an acidic environment (pH 4.0) and 139 days in an alkaline environment (pH 10.0),
respectively. It is suggested that the SA and hydrolysis resistance of double-tail trisiloxane surfactants are able to be
improved by changing the structure of the hydrophobic group, such as increasing the molar ratio of methyl to methylene. 相似文献
5.
Weiyong Zou Li Wang Baoyi Lu Hong Li Hongyu Chen 《Journal of Applied Electrochemistry》2009,39(10):2015-2020
The electrochemical assembly of [Ru(bpy)2tatp]2+ (where bpy = 2,2′-bipyridine, tatp = 1,4,8,9-tetra-aza-triphenylene) on the multi-walled carbon nanotubes-modified glassy
carbon electrode (MWNTs/GC) in the presence of anionic and cationic surfactants has been investigated. A diffusion-controlled
wave and three prewaves are exhibited on the differential pulse voltammogram of [Ru(bpy)2tatp]2+. The formal potential of the prewaves is found to be much negative than that of the diffusion-controlled wave. An appropriate
amount of anionic surfactants including dihexadecyl phosphate (DHP) and deoxyribonucleic acid (DNA) can prompt the assembly
of [Ru(bpy)2tatp]2+ on the MWNTs/GC electrode by using the method of repetitive voltammetric sweeping. In contrast, cationic surfactant such
as hexadecyl trismethyl ammonium chrolide (HTAC) dispersed on the MWNTs surface is found to inhibit the assembly of [Ru(bpy)2tatp]2+. Meanwhile, the assembled principle of [Ru(bpy)2tatp]2+ on the MWNTs/GC electrode with the participation of surfactants is discussed in detail. 相似文献
6.
To improve the hydrolysis resistant ability of trisiloxane surfactants, ethoxylated single-tail and double-tail trisiloxane
surfactants of the general formulas Me3SiOSiMeR1OSiMe3 (R
1 = (CH2)3NHCH2CH(OH)CH2(OCH2CH2)
x
OCH3; x = 8.4, 12.9, 17.5, 22) and Me3SiOSiMeR2OSiMe3 (R
2 = (CH2)3NR3CH2CH(OH)CH2(OCH2CH2)
x
OCH3; R
3 = CH2(CH2)
y
CH3; x = 8.4, 12.9, 17.5, 22; y = 2, 6) were synthesized. Their structures were characterized by 1H NMR and 13C NMR. The surface activity and hydrolysis resistant properties of the trisiloxane surfactants prepared were also studied.
The values of the critical micelle concentration of all trisiloxane surfactants prepared were at levels of 10−5 and 10−4 mol/L. They can reduce the surface tension of water to less than 24 mN/m. The hydrolysis resistant properties of double-tail
trisiloxane surfactants are superior to those of single-tail trisiloxane surfactants. The double-tail trisiloxane surfactants
1B (x = 8.4; y = 2) and 2C (x = 12.9; y = 6) can be stable for 8 days in an acidic solution (pH 4.0) and 11 days in an alkaline environment (pH 10.0). 相似文献
7.
A series of well-ordered lamellar mesoporous molybdenum oxides were prepared using gemini surfactant [C
n
H2n+1N+(CH3)2–(CH2)2–N+(CH3)2C
n
H2n+1] · 2Br−(denoted as C
n-2-n
, n = 12, 14 and 16) as the structure-directing agent and ammonium heptamolybdate tetrahydrate (NH4)6Mo7O24 · 4H2O as the precursor. The obtained samples were characterized by X-ray powder diffraction, thermal analysis, transmission electron
microscopy and nitrogen adsorption–desorption. Results showed that contrary to complete structure collapse after removing
tetradecyltrimethylammonium bromide (TTAB) from molybdenum oxide/TTAB composite, the lamellar mesostructure was retained after
removal of C
n-2-n
from corresponding composite. The effects of alkyl chain length and concentration of gemini surfactants on the structure
of the mesoporous molybdenum oxide were also investigated. The specific surface area of extracted sample was as high as 116 m2 g−1. The maintenance of the lamellar mesostruture was due to the strong self-assembly ability of gemini surfactants and the strong
electrical interaction between gemini surfactants and molybdenum oxide. 相似文献
8.
Amal A. Hafiz A. M. Badawi F. I. El-Deeb E. A. Soliman M. Y. El-Awady D. E. Mohamed 《Journal of surfactants and detergents》2010,13(2):165-172
A novel series of ferrocenyl surfactants was synthesized by the reaction of ferrocene disulfonic acid with different primary
and tertiary fatty amines to produce the corresponding ammonium salts Fc[SO3
−
+NH3(CH2)
n
CH3]2, where n = 9, 11, or 15 and Fc[SO3− +NH(CH3)2(CH2)
n
CH3]2, where n = 7 or 11, respectively, and where Fc = ferrocene. Chemical structures were confirmed by microelemental analysis, FTIR, and
1H NMR spectroscopy. The critical micelle concentration of each prepared surfactant was determined using equilibrium surface
tension. Furthermore, air/water interface parameters including effectiveness (π
CMC), efficiency (Pc20), maximum surface excess (Гmax), and minimum surface area (A
min) were determined at 30, 40, and 50 °C. Thermodynamic parameters (ΔG°, ΔS°, and ΔH°) for both micellization and adsorption processes were recorded. The new synthesized surfactants were screened as antimicrobial
agents against different bacterial and fungal organisms. 相似文献
9.
The field strength of modifier cations in boron‐containing oxide glasses has important but complex effects on boron coordination, and has long been known to have major effects on glass and liquid properties. With well‐constrained compositional and fictive temperature information in three binary borate glass series, we report how different modifier cations (Na+, Ba2+, Ca2+) affect boron coordination (11B MAS NMR), as well as glass transition temperatures and configurational heat capacities (DSC). Using estimated reaction enthalpies for converting a [4]B to a [3]B with an NBO from previous studies, we compare boron coordinations in glasses with different modifier cations on an isothermal basis. Temperature and modifier cation effects can thus be isolated. At low modifier contents [R = (Na2,Ca,Ba)O/B2O3<0.45], N4 is systematically higher in the order Na>Ba>Ca, suggesting the enhanced stabilization of NBO for the divalent cations, especially for the smaller Ca2+. At higher R values, N4 for Na borates drops below values for Ca and Ba borates. The trend in N4 with modifier field strength reverses at high R values (~ R > 0.7), with Ca > Ba > Na. The transition may be related to the enhanced stabilization of [4]B‐O‐[4]B groups by higher field strength cations in NBO‐rich glasses in which boron is the primary network component. 相似文献
10.
Peng Lv Zhao Sun Fugang Wang Yang Yu Fan Yang Shengjun Yue Mattias Edén Liang Chen Tieshan Wang 《Journal of the American Ceramic Society》2023,106(10):5766-5780
We examine the impact of the glass network-modifier cation field strength (CFS) on ion irradiation-induced mechanical property changes in borosilicate (BS) glasses for the ternary M2O–B2O3–SiO2 systems with M = {Na, K, Rb} and the quaternary [0.5M(2)O–0.5Na2O]–B2O3–SiO2 systems with M = {Li, Na, K, Rb Mg, Ca, Sr, Ba}. 11B nuclear magnetic resonance (NMR) experiments on the as-prepared BS glasses yielded the fractional population of four-coordinated B species (B[4]) out of all {B[3], B[4]} groups in the glass network, along with the fraction of B[4]–O–Si linkages out of all B[4]–O–Si/B bonds. Both parameters correlated linearly with the (average) CFS of the M+ and/or {M(2)+, Na+} cations. Both the nanoindentation-derived hardness and Young's modulus values of the glasses reduced upon their irradiation by Si2+ ions, with the property deterioration decreasing linearly with increasing Mz+ CFS, that is, for higher Mz+⋅⋅⋅O interaction strength. The irradiation damage of the glass network also increased linearly with the fraction of B[4]–O–Si linkages, which are the second weakest in the structure after the Mz+⋅⋅⋅O bonds. Our results underscore the advantages of employing BS glasses with high-CFS cations for enhancing the radiation resistance for nuclear waste storage. 相似文献
11.
Jin Wang Haoran Zhang Bingfu Lei Hanwu Dong Haiming Zhang Yingliang Liu Mingtao Zheng Yong Xiao 《Journal of the American Ceramic Society》2015,98(6):1823-1828
While the reddish‐orange emitting phosphors M2Si5N8:Eu2+(M = Ca, Sr) have been intensively investigated as potential materials for white‐light‐emitting diodes, in this study, optical energy storage properties of (Ca1?xSrx)2Si5N8: Eu2+, Tm3+ (x = 0–1) solid solutions were tuned by cation substitution, which was commonly used to tune color point for improving w‐LEDs. Partial substitution of either Ca by Sr or Sr by Ca resulted in a redshifted Eu2+ emission which had a demarcation point at x = 0.5. Furthermore, the (Ca1?xSrx)2Si5N8: Eu2+, Tm3+ materials exhibited similar persistent‐ and photostimulated luminescence behaviors with a maximum intensity at about x = 0.2. Such optical energy storage characters of the samples were attributed to the more appropriate trap depths (322–333 K) and higher density of energy level traps indicated by the thermoluminescence analysis. 相似文献
12.
Dale P. Prentice Lauren Gomez-Zamorano Magdalena Balonis Bartu Erdemli Kirk Ellison Narayanan Neithalath Dante Simonetti Gaurav Sant 《Journal of the American Ceramic Society》2020,103(10):6025-6039
Synthetic hydrotalcites were produced by a co-precipitation method. The hydrotalcites are represented by the general formula [MII(1-x)MIII(x)(OH)2][An−]x/n·zH2O, where MII is a divalent cation (eg, Mg2+or Ca2+), MIII is a trivalent cation (eg, Al3+) and An− is the interlayer anion. Herein, MII = Mg, and MIII = Al such that [Mg/Al] = [2, 3] (atomic units) and An−, represents intercalant species including: OH−, SO42− and CO32− anions. The thermochemical data of each compound including their solubility constants (Kso), density and molar volume were quantified at T = 25 ± 0.5°C, and P = 1 bar. The solubilities of the synthetic hydrotalcites, irrespective of their divalent-trivalent cation partitioning ratio, scaled as CO32− < SO42− < OH−; in order of decreasing solubility. The type of anion, very slightly, affected the solubility with less than ±1 log unit of variation for [Mg/Al] = 2, and ±2 log units of variation for [Mg/Al] = 3. The solubilities of these phases were strongly correlated with that of gibbsite (Al(OH)3); such that activity of the [AlO2−] species was solubility determining with increasing pH. The tabulated thermodynamic data were used to construct solid-solution models for phases encompassing both cation distribution ratios and to calculate stable phase equilibria relevant to alkali-activated slag (AAS) systems for diverse activator compositions. 相似文献
13.
Hideki Kurokawa Satoru Morita Michiko Matsuda Hidenori Suzuki Masa-aki Ohshima Hiroshi Miura 《Applied Catalysis A: General》2009,360(2):192-198
Supported catalysts consisting of Cp2ZrCl2 and cation-exchanged fluorotetrasilicic mica (Mn+-mica, Mn+ = Na+, Mg2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+) were prepared and employed in the ethylene polymerization or ethylene/1-hexene copolymerization in the presence of R3Al. The catalysts consisting of swellable Mg2+-mica and Zn2+-mica (both calcined at 200 °C) and Cp2ZrCl2 displayed high activity for the polymerization reaction. By contrast, when Mg2+-mica and Zn2+-mica were calcined above 250 °C, the swellability was lost, and the activities of Cp2ZrCl2 supported on these non-swellable micas were significantly reduced. The relationship between the activity and swellability of mica was clearly observed both in ethylene polymerizations employing (n-BuCp)2ZrCl2 in place of Cp2ZrCl2 and in ethylene/1-hexene copolymerizations using Cp2ZrCl2. The role of Mn+-mica for the activation of the metallocene complex was investigated by surface observation using a scanning electron microscope and by XRD measurements of the catalysts after polymerization of ethylene for a short time. The results of the surface observations indicated that polyethylene was produced on the edges of Mn+-mica lamellas at the initial stage of the polymerization. The XRD measurements show that the regularity of the stacked lamellas was immediately lost at this stage. The catalyst prepared by removing free Cp2ZrCl2 (i.e., unsupported Cp2ZrCl2, Cp2ZrCl2 dissolved into the catalyst slurry) showed extremely low activity, suggesting that the most of the active sites were formed through the reactions of Mn+-mica and free Cp2ZrCl2. These results indicate that the lamellas of Mn+-mica are peeled off at the initial stage of the polymerization and that exposed metal cations react with free-Cp2ZrCl2 to form additional active species. The swellability of Mn+-mica strongly affects the formation of additional active sites, and therefore the supported catalysts based on non-swellable Mn+-mica displayed only low activities. 相似文献
14.
《分离科学与技术》2012,47(11):1351-1360
Abstract Relative transport rates of metal cation nitrates (Na+, K+, Rb+, Cs+, Ag+, Tl+, Ca2+, Sr2+, Ba2+, and Pb2+) in a water-toluene-water emulsion membrane system were measured. The toluene component contained the surfactant Span 80 and the crown ether dicyclohexano-18-crown-6. The aqueous receiving phase contained Li4P2O7. When each metal cation was individually present in the aqueous source phase, metal extraction was complete within 10 min with the order of extraction being Tl+ > Cs+ > Ag+ > Rb+ > K+ ≥m Na+ and Pb+ > Ca2+ > Sr2+ > Ba2+ for uni-and bivalent cations, respectively. Significant extraction was found for all cations except Na+, K+, and Ba2+. Some metal ions were concentrated nearly 10-fold in a 10-min period. Relative transport rates were determined when binary cation mixtures of either Tl+ or Pb2+ were present at equal concentrations with each of the remaining metal ions in the source phase. Tl+, when present with either Na+, Cs+, or Rb+, was selectively extracted from the source phase. Complete and nearly exclusive extraction of Pb2+ was observed in the presence of all cations including Tl+. The enrichment ratios of Pb2+ in the binary mixtures were approximately 10 while those of the second cation were less than 0.5 except for Sr2+ which was 0.86. Corresponding separation factors for Pb2+ ranged from 1000 to > 6000. 相似文献
15.
Ozcan Ozmen Cigdem Ozsoy‐Keskinbora Ender Suvaci 《Journal of the American Ceramic Society》2018,101(3):1074-1086
In recent years, potassium sodium niobate (K0.5Na0.5NbO3, KNN) has become popular and promising among perovskite lead‐free piezoceramic systems. In this study, the chemical stability of KNN powders in aqueous medium was investigated as a function of pH, time, and powder surface area. To better understand the dissolution behavior of the complex KNN stoichiometry, subconstituents such as potassium niobate (KNbO3, KN) and sodium niobate (NaNbO3, NN) were investigated separately first. Results showed that all of the cations in the structure underwent dissolution in different values. Indicating that KNN undergoes incongruent dissolution in aqueous medium, the dissolution of A site cations was higher at lower pH while the dissolution of B site cations increased at higher initial pH. The order of released cation concentrations (CA1 = K > CA2 = Na > CB = Nb) fits with inverse relationship of cation field strength (FS) order, B = Nb5+FS > A2 = Na+FS>A1 = K+FS, at pH 4, 7 and 10 for NN, KN, and KNN. Calculated diffuse layer thickness from the ICP data confirmed to outer amorphous layer in TEM image. Also, the ratio of normalized cation concentration versus surface area of powders showed that incongruent dissolution kinetic was driven by the diffusion step. 相似文献
16.
Kinjal Gandha Mariappan Parans Paranthaman Haobo Wang Xubo Liu Ikenna C. Nlebedim 《Journal of the American Ceramic Society》2023,106(1):166-171
In this research, anisotropic NdFeB + SmFeN hybrid and NdFeB bonded magnets are additively printed in a polyphenylene sulfide (PPS) polymer binder. Printed NdFeB + SmFeN PPS bonded magnets displayed excellent magnetic properties (Br [remanence] = 6.9 kG [0.69 T], Hcj [coercivity] = 8.3 kOe [660 kA/m], and BHmax [energy product] = 9.9 MGOe [79 kJ/m3]) with superior corrosion resistance and thermal stability. The anisotropic NdFeB bonded magnet shows a high coercivity of 14.6 kOe (1162 kA/m) with a BHmax of 8.7 MGOe (69 kJ/m3). The coercivity and remanence temperature coefficients for NdFeB + SmFeN hybrid bonded magnets are −0.10%/K and −0.46%/K, and for NdFeB bonded magnets are −0.14%/K and −0.53%/K in the range of 300–400 K, indicating that the hybrid bonded magnets are thermally stable. The average flux aging loss for hybrid magnets was also determined to be very stable over 2000 h at 448 K (175°C) in air with 2.04% compared to that of NdFeB magnets with 3.62%. 相似文献
17.
Rui Yang Hongshen Liu Zhijie Ding Jinfeng Zheng John C. Mauro Seong H. Kim Qiuju Zheng 《Journal of the American Ceramic Society》2021,104(8):3973-3981
Glass for pharmaceutical packaging requires high chemical durability for the safe storage and distribution of newly developed medicines. In borosilicate pharmaceutical glasses which typically contain a mixture of different modifier ions (alkali or alkaline earth), the dependence of the chemical durability on alkaline earth oxide concentrations is not well understood. Here, we have designed a series of borosilicate glasses with systematic substitutions of CaO with MgO while keeping their total concentrations at 13 mol% and a fixed Na2O concentration of 12.7 mol%. We used these glasses to investigate the influence of R = [MgO]/([MgO] + [CaO]) on the resistance to aqueous corrosion at 80°C for 40 days. It was found that this type of borosilicate glass undergoes both leaching of modifier ions through an ion exchange process and etching of the glass network, leading to dissolution of the glass surface. Based on the concentration analysis of the Si and B species dissolved into the solution phase, the dissolved layer thickness was found to increase from ~100 to ~170 nm as R increases from 0 to 1. The depth profiling analysis of the glasses retrieved from the solution showed that the concentration of modifier ions (Na+, Ca2+, and Mg2+) at the interface between the solution and the corroded glass surface decreased to around 40%–60% of the corresponding bulk concentrations, regardless of R and the leaching of modifier cations resulted in a silica-rich layer in the surface. The leaching of Ca2+ and Mg2+ ions occurred within ~50 and <25 nm, respectively, from the glass surface and this thickness was not a strong function of R. The leaching of Na+ ions varied monotonically; the thickness of the Na+ depletion layer increased from ~100 nm at R = 0 to ~200 nm at R = 1. Vibrational spectroscopy analysis suggested that the partial depletion of the ions may have caused some degree of the network re-arrangement or re-polymerization in the corroded layer. Overall, these results suggested that for the borosilicate glass, replacing [CaO] with [MgO] deteriorates the chemical durability in aqueous solution. 相似文献
18.
Liwei Mi Weihua Chen Zhen Li Yaming Wang Guoqiang Zheng Yingguo Zhou Changchun Yang Jianmin Zhang Changyu Shen Hongwei Hou 《Journal of Inorganic and Organometallic Polymers and Materials》2010,20(4):847-855
A sandwich-like 2D infinite framework of {[Cd(pbbm)2(SO3FcSO3)]·(CH3OH)2·(H2O)6}
n
(1) with nanosized porous structure [Fc(SO3)2Na2 = ferrocene-1,1′-disulphonate, pbbm = 1,1′-(1,3-propylene)-bis-1H-benzimidazole] was prepared by combining d
10 Cd2+ ions with highly conjugated pbbm and disodium ferrocene-1,1′-disulfonate. Experimental results show that 1 could serve as a new fluorescent probe for the detection of many divalent metal ions in water, such as Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Ag+, Cd2+, Hg2+ and Pb2+, and trace organic solvents, including acetone, toluene, methylene chloride, ether, tetrahydrofuran, and methanol. The main
product was very different from previous chemosensory materials that only identify one or two metal ions. The powdery multipurpose
chemosensory materials proposed here could also sequester dangerous heavy metal ions, especially Pb2+. A computational study of ferrocene-1,1′-disulfonate and 1 gave insight into the process of ion exchange and sorption. This study introduces a promising new field of fluorescent chemosensors
based on nanoporous coordination polymers with free functional groups. 相似文献
19.
S. Cortés-Camargo P.E. Acuña-Avila D. Arrieta-Báez B. Montañez-Barragán A.I. Morato J.L. Sanz-Martín B.E. Barragán-Huerta 《Journal of surfactants and detergents》2021,24(5):773-782
A new biosurfactant was obtained from a moderately halophilic bacterium identified as Bacillus tequilensis ZSB10 that was isolated from a saline water pond located in Tehuacan-Cuicatlan valley, Mexico. A kinetic analysis of the bacterial growth of the ZSB10 strain showed a maximum growth at 24 h regardless of the initial pH (5, 7.4, and 9). The best results were found at pH = 7.4 in terms of bacterial growth, besides which the produced biosurfactant showed emulsifying and surfactant properties with an emulsification index (E24) and surface tension change (ΔST) of 54 ± 0% and 26 mN m−1, respectively. Extracted ZSB10 crude biosurfactant had a yield of 106 ± 6 mg L−1, an E24 = 58.4 ± 0.2%, and a ΔST = 26 mN m−1 with a critical micelle concentration (CMC) of 44.82 mg L−1. Also, its structure was characterized by MALDI-TOF mass spectrometry as a surfactin, iturin A, and fengycin mixture whose main isoform was leu/ile-7 C15 surfactin [M + Na]+. Finally, the ZSB10 crude biosurfactant showed antifungal activity against Helminthosporium sp., with a 79.3% growth inhibition and an IC50 of 1.37 mg per disc. Therefore, this biosurfactant could be used as biopesticide. 相似文献
20.
Cerem Piskin Levent Karacasulu Gloria Ischia Mauro Bortolotti Cekdar Vakifahmetoglu 《Journal of the American Ceramic Society》2022,105(6):3809-3819
Potassium–sodium niobates (KxNa1−xNbO3, 0 < x < 1, KNN) were hydrothermally synthesized under varying alkaline ratios (K+/Na+), total hydroxide concentration, reaction temperature, and time. Compositional surveys were developed by using Rietveld analyses derived quantitative volume fractions. The data demonstrated that phase pure KNN synthesis can be achieved by reacting the niobium source with the hydroxide solution having 6 M total hydroxide concentration, cation ratio (K+/Na+) of above 6 at temperatures ≥200°C for 24 h. Dissolution–precipitation events through intermediate products including hexaniobates were postulated as a plausible formation mechanism. It was shown also that the single-phase KNN approaching the morphotropic phase boundary (MPB) could be obtained by further incorporation of sodium ions into the crystal via post-annealing at 800°C/2 h, following the hydrothermal synthesis. 相似文献