共查询到20条相似文献,搜索用时 15 毫秒
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以天然麦饭石为载体、铜离子为抗菌离子,在一定条件下通过液相离子交换反应,制备载铜麦饭石抗菌剂.运用ICP和XRD等现代分析方法对抗菌剂中银离子的含量以及银离子与载体的结合方式进行了分析,并对其抗菌性、耐久性和安全性能进行研究.结果表明,在Cu2+浓度是0.1 mol·L-1,搅拌时间是4 h,反应温度是60 ℃时,制备的麦饭石抗菌剂具有优异抗菌性、耐久性和安全性.究其原因主要在于Cu2+能从载体上缓慢地释放出来,与细菌细胞作用,杀灭细菌,从而赋予该抗菌剂良好的、持久的抗菌能力. 相似文献
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《分离科学与技术》2012,47(6-7):719-729
Abstract The liquid hydrocarbons hexadecane and pseudocumene (1,2,4-trimethyl-benzene) were removed from their O/W-type emulsions by flotation. The effect of different inorganic salts (NaCl, Na2SO4, Na3PO4) on the removal efficiency was investigated. It was shown that the inorganic salt effect on flotation efficiency is connected with their influence on the double-layer thickness and on the adsorption of surface-active ions. 相似文献
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本文提出了一种针对化工类一年级本科生的元素无机化学实验离子鉴定部分的考核方法,介绍了从未知样的选择、测试题编写、考核过程实施的全过程,分析了考核结果,并从教学效果、可操作性、难易程度等方面讨论了这种考核方法的特点。 相似文献
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A new supported liquid membrane (SLM) system was prepared for the selective transport of bismuth ions from the aqueous feed into the aqueous permeate phase. The support of the SLM was a thin porous polypropylene or polyvinylidene fluoride membrane impregnated with diisooctyldithiophosphinic acid (Cyanex 301) as mobile carrier in 4‐chloroacetophenon as organic solvent. Cyanex 301 acts as a highly selective carrier for the uphill transport of bismuth ions through the SLM. In the presence of HNO3 as a metal ion acceptor in the strip solution, the transport of bismuth ions into the strip side reached 70 % of the initial feed concentration after 3.5 hours. The selectivity and efficiency of bismuth transport from aqueous solutions containing different mixtures of cations were investigated. In the presence of P2O72– ions as suitable masking agent in the feed solution, the interfering effects of other cations were completely eliminated. The selective transport of bismuth through SLM is superior to liquid‐liquid extraction or through bulk liquid membranes. This is due to the high efficiency. The SLM reduces the solvent requirements, combines extraction and stripping operations in a single process and allows the use of highly selective extractants. The system may be applied to samples containing very low bismuth concentrations. 相似文献
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由于人类活动的影响,阴霾天的范围在不断扩大,并且两年频率越来越高,严重影响人们的生活及身体健康。PM2.5是造成阴霾天的主要原因,其中的可溶性无机离子组分的强吸水能力又加重了PM2.5对环境的污染程度。本文从现有的研究中总结我国PM2.5中可溶性无机离子组分的来源及特点,对于正确认识PM2.5的特征及今后开展相应研究有一定引导作用。 相似文献
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E. Potapova R. Jolsterå A. Holmgren M. Grahn 《Journal of surfactants and detergents》2014,17(5):1027-1034
Linear alkylbenzenesulfonates (LAS) are an important group of anionic surfactants within the detergent industry and have also been suggested for use in mineral flotation and enhanced oil recovery. Because of its great industrial importance, there are a number of publications on the adsorption of LAS on metal oxides; however, the effect of co‐adsorbing inorganic species on LAS adsorption has rarely been addressed. In this study we investigated the effect of calcium and carbonate ions on the adsorption of sodium dodecylbenzenesulfonate (DBS) onto hematite at pH 8 and 10.5 using in‐situ ATR‐FTIR spectroscopy. DBS adsorption on hematite was found to increase as pH was decreased from 10.5 to 8. Calcium ions promoted accumulation of DBS on hematite, with a larger amount of DBS on the surface at pH 10.5. Carbonate ions did not have any major effect on DBS adsorption on hematite. In the presence of both calcium and carbonate, the amount of DBS on the hematite surface was higher than without the two co‐adsorbing ions but lower than with calcium ions alone. Likely, precipitation of calcite reduced the total concentration of calcium ions available for the interaction with DBS on the hematite surface. The results presented in this work clearly indicate the importance of water chemistry for DBS adsorption and allow predicting adsorption behavior of DBS on iron oxides from natural and process waters of different chemistry, which is important for the industrial applications of DBS and the fate of DBS in the environment. 相似文献
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归纳和讨论了无机硫酸盐S2 Ox2 -型离子的构型和红外活性振动基频数 ,并对其红外光谱进行了吸收峰的指认 相似文献
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《分离科学与技术》2012,47(13):1926-1936
Hydrodesulfurization-treated (HDS-treated) gasoline with low sulfur content is an important source of primary fuel for fuel cells, although it contains sulfur compounds, thiophene (TP), benzothiophene (BTP), and thiophene alkylated derivatives, known as a poison for the reformer catalysts and the electrode catalysts of fuel cells. Adsorptive removal of TP from model organic liquid of HDS-treated gasoline was screened on different kinds of inorganic adsorbents: hydrous metal oxides, mixed metal oxides, aluminosilicates, acidic salts of multivalent metal, hetero polyacidic salt, and metal salts of iron hexacyanate. All the adsorbents showed very low TP uptake, less than 5% of the total TP amount when metal ions were not loaded on the adsorbent. On the other hand, some metal ion (Ag, Cu, and Ce) loaded adsorbents had good TP adsorptive properties. On simple metal oxides, Ag ion was better for the formation of adsorption center than Ce or Ni ions. In zeolite group, Ce-loaded Y-zeolite showed the largest TP uptake (99% of the total TP amount). Hydrous cerium oxide and the Ce-loaded adsorbents prepared from K4[Fe(CN)6], Silicagel, TiO2, and ZrO2 did not show TP selectivity. The effect of coexisting toluene on TP adsorption was studied from the TP solutions with and without toluene. 相似文献
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Wenhu Zhou Runjhun Saran Po‐Jung Jimmy Huang Prof. Dr. Jinsong Ding Prof. Dr. Juewen Liu 《Chembiochem : a European journal of chemical biology》2017,18(6):518-522
Ca2+ is a highly important metal ion in biology and in the environment, and thus there is extensive work in developing sensors for Ca2+ detection. Although many Ca2+‐binding proteins are known, few nucleic acids can selectively bind Ca2+. DNA‐based biosensors are attractive for their high stability and excellent programmability. We report a RNA‐cleaving DNAzyme, EtNa, cooperatively binding two Ca2+ ions but to only one Mg2+. Four DNAzymes with known Ca2+‐dependent activity were compared, and the EtNa had the best selectivity for Ca2+. The EtNa is 90 times more active in Ca2+ than in Mg2+. Phosphorothioate (PS) modification showed that both non‐bridging oxygen atoms at the scissile phosphate contribute equally to Ca2+ binding. The pH–rate profile suggests two concurrent deprotonation reactions. EtNa was further engineered for Ca2+ sensing, and found to have a detection limit of 17 μm Ca2+ and excellent selectivity. The detection of Ca2+ in tap water was performed, and the result was comparable with that by ICP‐MS. This study offers new fundamental insights into Ca2+ binding by nucleic acids and improved metal selectivity by having multiple cooperative metal binding sites. 相似文献
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Spectra of divalent transition metal ions in ZnCl2 , KOAc-Ca(OAc)2 , KNO3 -Ca(NO3 )2 , and K2 SO4 -ZnSO4 glasses are presented. Ions with low octahedral site preference energies (e.g. CO2+ ) can be used as "probes" for divalent cations in glass and can indicate the presence or absence of network structures. Thus ZnCl2 glass has a tetrahedral network structure, analogous to vitreous BeF2 , but KOAc-Ca(OAc)2 and KNO3 -Ca(NO3 )2 glasses contain potassium ions and discrete acetatocalcate(II) and nitratocalcate(II) "complex ions." The structure of acetate and nitrate glasses is discussed in terms of the ideal glass concept. 相似文献
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《分离科学与技术》2012,47(9):1303-1309
Trident molecules containing pyridyl groups have been prepared for use as novel extraction reagents to investigate their physicochemical properties for dissolution into the aqueous phase and their ability, together with their corresponding monomeric analogues, to extract precious metal ions. Differences in their behavior were related to the pK a values of the trident molecules and the position of the nitrogen atom in the pyridyl groups. The trident molecules exhibit the ability to selectively extract silver from mixtures of other precious metals. The extraction mechanism and the coordination site of the silver ion with a 2-pyridyl derivative were determined by slope analysis and peak shift of the 1H-NMR spectra of the extraction reagent before and after silver loading. 相似文献
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《分离科学与技术》2012,47(4):1135-1152
Abstract A process for the selective removal of heavy metal ions with macromolecular chelating agents or emulsified liquid ion exchange materials in combination with ultrafiltration is described. The theoretical limitations of the procedure are discussed, and several practical applications are presented. 相似文献
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Cinzia Perrino Maria Catrambone Carmela Farao Roberto Salzano Giulio Esposito Marco Giusto 《Aerosol science and technology》2013,47(7):521-530
A particle-into-liquid sampler coupled with ion chromatograph (PILS-IC) for the on-line measurement of inorganic ions has been modified by the insertion of two ion-exchange pre-concentration cartridges that enrich the sample during the period of the IC analysis. The limits of detection of the modified instrument were 10-15 times lower and the time coverage 24 times higher (from 2 to 48 min per hour) than those of the original PILS-IC setup. The instrumental performance in terms of recovery and break-through volume from the cartridges was satisfactory. The modified PILS-IC was operated in comparison with a diffusion denuder line and with a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) during a short intensive measurement period organized in the framework of the European Monitoring and Evaluation Programme (EMEP), a co-operative program for monitoring and evaluation of the long-range transmission of the air pollutants in Europe. The instrument showed a quantitative response in agreement with the results of the diffusion lines, and an ability to trace fine concentration variations not so different from the performance of the much more complex HR-TOF-AMS. From the time patterns of the ion concentrations measured by the modified PILS-IC, it was possible to obtain useful information about the variations in the air quality and in the strength of the particulate matter sources.Copyright 2015 American Association for Aerosol Research 相似文献
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研究了氯化钠和四丁基溴化铵分离金的行为及与一些金属离子分离的条件。实验结果表明,当溶液中氯化钠和四丁基溴化铵的浓度分别为2.5×10-3mol/L和4.0×10-4mol/L时,Au(Ⅲ)可与Ga(Ⅲ)、Co(Ⅱ)、Pd(Ⅱ)、Zn(Ⅱ)、Rh(Ⅲ)、Al(Ⅲ)、Cd(Ⅱ)、Ce(Ⅳ)、Fe(Ⅲ)、Ru(Ⅲ)、Cu(Ⅱ)、W(Ⅵ)、Ti(Ⅳ)、Pb(Ⅱ)、Sb(Ⅲ)、V(Ⅴ)、Pt(Ⅳ)、Mn(Ⅱ)I、n(Ⅲ)、Sn(Ⅳ)、Ni(Ⅱ)I、r(Ⅳ)和Cr(Ⅲ)离子定量分离,对合成水样中Au(Ⅲ)的分离和测定,结果满意。 相似文献