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1.
金属络阴离子在笼形聚氨肟树脂上的吸附行为   总被引:1,自引:0,他引:1  
研究了Ce(NO3)_6~3-、VO_3~-、Cr2O_7~2-、CrO_4~2-、MoO_4~2-、WO_4~2-、MnO_4~-、Fe(CN)_6~2-、Fe(CN)_6~3-、和PtCl_6~2-等金属络阴离子在笼形聚氨肟树脂(CAO)上的吸附行为。发现Ce(NO3)-6~2-离子在强酸性介质中不被CAO树脂吸附但被还原为Ce3+。其它金属络阴离子被酸处理笼形聚氨肟树脂(ACAO)所吸附,吸附容量顺序是:MnO_4~->Fe(CN)_6~2->Cr2O_7~2->MoO_4~2->PtCl_6~2->CrO_4~2->VO_3~->Fe(CN)_6~3->WO_4~2-减处理笼形聚氨肟树脂(BCAO)不吸附CrO_4~2-离子,但可吸附Cr2O_7~2-、MnO_4~2-和PtCl_6~-等离子。吸附容量顺序:MnO_4~->Cr2O_7~2->PtCl_6~2-根据吸附动力学研究结果,认为ACAO树脂通过离聚体的离子场对外来给阴离子进行多层吸附,但金属络阴离子在BCAO树脂大分子场力作用下在树脂表面形成单吸附层。  相似文献   

2.
以对氨基苯磺酸、苯酚、甲醛为基本原料,设计并合成了内盐结构稳定、对 (NH4)2SO4有较大亲合力的新型两性吸附树脂-PSN树脂,研究了PSN树脂对 (NH4)2SO4的吸附性质,同时研究了PSN树脂对 (NH4)2SO4的吸附等温线的静态性能。实验结果表明,PSN树脂对 (NH4)2SO4的吸附是以分子吸附形式进行,常温下PSN树脂对与自身结构相似的 (NH4)2SO4饱和吸附量可达3.16mmol/g干树脂,吸附等温线符合Langmuir等温方程。  相似文献   

3.
纤维素基磁性聚偕氨肟树脂吸附Mn(Ⅶ)   总被引:2,自引:0,他引:2  
用酸处理的纤维素基磁性聚偕氨肟树脂(AMAO)在溶液中吸附KMnO4,发生氧化还原反应的几率在2%以下;用碱处理的树脂(BMAO)作吸附剂,KMnO4还原为Mn(OH)4的比例剧增,达到或超过10%,并且与溶液的pH有关。但是,Mn(Ⅶ)被还原为Mn(Ⅳ)的量基本上不受KMnO4起始浓度、吸附剂添加量和吸附时间变化的影响。BMAO树脂吸附KMnO4的量是树脂偕氨肟基含量的5倍以上。超当量吸附现象反映了物理吸附的本质。  相似文献   

4.
H2PtCl6可被一系列的酸处理定形聚偕胺肟树脂所吸附,吸附容量的大小与处理树脂的质子酸的Pka值有关.认为是解高度低的酸所处理的树脂上的伯胺基成盐的机会较少,即树脂的吸附中心保留着较多的空穴,有利于H2PtCl6的接近而被吸附下来.吸附动力学的研究表明化学反应是吸附速度的控制因素。  相似文献   

5.
考查了无机酸、羧酸和酚类化合物处理的笼形聚偕胺肟树脂吸附酸性溶液中H_2PdCl_4的能力,其中H_3BO_3/ACAO、HSCH_2CO_2H/ACAO和p-NH_2C_6H_4H/ACAO树脂对H_2PdCl_4的吸附容量分别是2.023、2.368和2.083mmol/g-R或215、252和222mgPd/g-R。优于相同条件下的碱处理树脂(BCAO吸附容量为1.828mmol/g-R)。研究了吸附动力学,讨论了吸附机理。  相似文献   

6.
用羧酸处理的笼形聚偕胺肟树脂(RCO2H/ACAO)吸附Pd(Ⅱ)、Ir(Ⅳ)、Pt(Ⅳ)、Ag(Ⅰ)、Au(Ⅲ)离子的能力与羧酸性质有关,巯其乙酸/ACAO树脂对Pd(Ⅱ)、Ir(Ⅳ)和Au(Ⅲ)吸附容量较高,乙二酸/ACAO树脂则对Ag(Ⅰ)和Pt(Ⅳ)离子有稍强的吸附能力。除Pd(Ⅱ)外,RCO2H/ACAO树脂吸附贵金属离子的能力低于笼形聚偕胺肟树脂(CAO)和碱处理笼形聚偕胺肟树脂(BC  相似文献   

7.
CL-TBP萃淋树脂吸附分离镓(Ga)研究   总被引:7,自引:0,他引:7  
本文研究了 Cl- TBP萃淋树脂从酸性溶液中吸附分离镓的性能 ,结果表明 ,在 6mol· L-1HCl介质中 ,树脂对镓有良好的吸附性能。可有效地从含镓溶液中分离富集镓。被吸附的镓可用 NH4 Cl溶液定量洗脱 ,对吸附过程机理进行了初步研究 ,证实吸附为离子交换过程。  相似文献   

8.
笼形聚偕氨肟树脂的研究:酸处理树脂的吸附性能   总被引:5,自引:3,他引:5  
笼形聚偕氨肟树脂(CAO)经盐酸处理垢,伯胺基转变成胺盐。酸处理笼形聚偕氨肟树脂(ACAO)对Mg^2+,Ca^2+,Ba^2+,Mn^2+,Co^2+,Ni^2+离子不吸附;对Zn^2+,Cd^2+,Cu^2+,Pb^2+离子的吸附效率在20%以下,但对Hg^2+离子的吸附效率则高达71.2%;对一些金属络阴离子的吸附效率顺序是Fe(CN)^2-6>Cr2O^2-7>MoO^2-4>PtCl^2  相似文献   

9.
酚醛型吸附树脂对VB_(12)的吸附性能研究   总被引:2,自引:0,他引:2  
研究了酚醛型吸附树脂JDW 1、JDW 2 (自制 )和DuoliteS 76 1对VB12 的静态和动态吸附 .结果表明 ,JDW 1对VB12 的吸附量达 84mg g ,明显优于DuoliteS 76 1;吸附VB12 的初始阶段 ,即达到 4 3%~6 9%平衡吸附时 ,吸附速率数据和半经验速率方程很吻合 ;酚醛型吸附树脂等温吸附VB12 的平衡吸附数据符合Langmuir方程 ,相关系数在 0 99以上 ,因此 ,酚醛型吸附树脂吸附VB12 属单分子层吸附 ;在动态条件下 ,用含甲醇 80 %溶液以 1 1BV h来洗脱吸附VB12 的JDW 2 ,在 4 2、6 4个床体积的洗脱率分别是 92 2 0 %、95 93% ,这表明酚醛型吸附树脂具有良好的洗脱性能 ,用含甲醇为 80 %溶液作洗脱剂从JDW 2洗脱VB12 ,效果很好  相似文献   

10.
研究NJ-8、AM-1、Amberlite XAD-4、JX-101 4种吸附树脂对对硝基苯乙酮和对硝基苯甲酸的静态吸附行为。结果表明:江苏南大戈德环保科技有限公司研制的NJ-8和AM-1两种吸附树脂对硝基化合物的吸附效果较好。并研究NJ-8型吸附树脂的动态吸附和脱附行为,结果显示:NJ-8型吸附树脂对对硝基苯甲酸的吸附容量为128mg/g干树脂,对对硝基苯乙酮的吸附容量为383mg/g干树脂。用8%NaOH:乙醇(体积比1:1)洗脱吸附酸的树脂,用甲醇或乙醇洗脱吸附酮的树脂,体积为5BV时,温度分别为333K和313K,脱附率均接近100%。  相似文献   

11.
The oxidation of hydroxylamine by [IrCl6]2- has been studied spectrophotometrically in deoxygenated aqueous solutions in the range of pH 4-9 at 25 degrees C. The reaction is catalyzed by Cu2+, Fe2+, and impurities of aquochloroiridium complexes. Oxalate is a very effective inhibitor of catalysis by copper and iron ions. With excess hydroxylamine, the reaction follows pseudo-first-order kinetics, and the stoichiometric ratio (DeltanIr(IV)/Deltanhydroxylamine) is 1.05 at pH 5.9. Over the pH range 4.2-8.8, the empirical rate law is -d[IrCl(6)2-]/dt=k[IrCl6(2-)][NH2OH]tot, with k=k1Ka1/([H+]+Ka1)+k'Ka1/([H+]([H+]+Ka1)), where Ka1 is the dissociation constant of NH3OH+. Least-squares fitting yields k1=(17.05+/-0.47) M-1 s(-1) and k'=(2.59+/-0.09)x10(-6) s(-1) at ionic strength of 0.1 M (adjusted by NaClO4) and 25 degrees C. The kinetic isotope effects (KIE) (kH/kD) for k1 and k' are 4.4 and 9.8, correspondingly. A mechanism is inferred in which k1 corresponds to concerted proton-coupled electron transfer (PCET) and k' corresponds to electron transfer from NH2O-. In this mechanism, the large KIE for k' is due almost entirely to the equilibrium isotope effect for the pKa of NH2OH.  相似文献   

12.
Chen Z  Xie S  Shen L  Du Y  He S  Li Q  Liang Z  Meng X  Li B  Xu X  Ma H  Huang Y  Shao Y 《The Analyst》2008,133(9):1221-1228
The interactions between Hela cells and silver nanoparticles (AgNPs) have been studied by scanning electrochemical microscopy (SECM) with both IrCl(6)(2-/3-) and Fe(CN)(6)(3-/4-) as the dual mediators. IrCl(6)(2-), which can be produced in situ and react with AgNPs, is used as the mediator between the AgNPs on the cells and the SECM tip. Another redox couple, Fe(CN)(6)(3-/4-), which has a similar hydrophilicity to IrCl(6)(2-/3-), but cannot react with AgNPs, is also employed for the contrast experiments. The cell array is cultured successfully onto a Petri dish by microcontact printing (muCP) technique, which can provide a basic platform for studying of single cells. The approach curve and line scan are the two methods of SECM employed here to study the Hela cells. The former can provide the information about the interaction between Hela cells and AgNPs whereas the later gives the cell imaging. The permeability of cell membranes and morphology are two main factors which have effects on the feedback mode signals when K(3)Fe(CN)(6) is used as the mediator. The permeability of the cell membranes can be ignored after interaction with high concentration of AgNP solution and the height of the Hela cells is slightly decreased in this process. The kinetic rate constants (k(0)) between IrCl(6)(2-) and Ag on the Hela cell can be evaluated using K(3)IrCl(6) as the mediator, and they are increased with the higher concentrations of the AgNP solutions. The k(0) is changed about 10 times from 0.43 +/- 0.04 x 10(-4) to 1.25 +/- 0.07 x 10(-4) and to 3.93 +/- 1.9 x 10(-4) cm s(-1) corresponding to 0, 1 and 5 mM of AgNO(3) solution. The experimental results demonstrate that the AgNPs can be adsorbed on the cell surface and detected by SECM. Thus, the amount of AgNPs adsorbed on cell membranes and the permeability or morphology changes can be investigated simultaneously using this approach. The dual mediator system and cell array fabricated by muCP technique can provide better reproducibility because they can simplify experiments, and provide a platform for further single cell detection.  相似文献   

13.
The electron-donating properties of N-heterocyclic carbenes ([N,N'-bis(2,6-dimethylphenyl)imidazol]-2-ylidene and the respective dihydro ligands) with 4,4'-R-substituted aryl rings (4,4'-R=NEt2, OC(12)H(25), Me, H, Br, S(4-tolyl), SO(4-tolyl), SO2(4-tolyl)) were studied. Twelve new N-heterocyclic carbene (NHC) ligands were synthesized as well as the respective iridium complexes [IrCl(cod)(NHC)] and [IrCl(CO)2(NHC)]. Cyclic voltammetry (DeltaE1/2) and IR (nu (CO)) can be used to measure the electron-donating properties of the carbene ligands. Modifying the 4-positions with electron-withdrawing substituents (4-R=-SO(2)Ar, DeltaE1/2=+0.92 V) results in NHC ligands with virtually the same electron-donating capacity as a trialkylphosphine in [IrCl(cod)(PCy3)] (DeltaE1/2 =+0.95 V), while [IrCl(cod)(NHC)] complexes with 4-R=NEt2 (DeltaE1/2= +0.59 V) show drastically more cathodic redox potentials and significantly enhanced donating properties.  相似文献   

14.
钴(II)-丁二酮肟-亚硝酸盐体系极谱催化波的机理研究   总被引:1,自引:0,他引:1  
倪亚明  李玲  高小霞 《化学学报》1988,46(7):651-656
在氨性底液(PH8)中, 钴(II)-丁二酮肟(DMG)-亚硝酸盐体系产生高灵敏的极谱催化波. 利用吸附伏安法, 测定下限可达1×10^-^1^1mol.dm^-^3Co. 我们用多种电化学方法和紫外可见分光光度法证明, 吸附在汞电极表面的[NH4]2[Co(DMG)2(NO2)2]是有很高电活性的混配化合物, 在复杂的电还原过程中, 不仅Co(II)和DMG被催化还原, 而且NO2^-也被催化还原, 从而产生很大的催化电流, 本文再一次证明, “活性钴"在催化波的形成过程中起着重要的作用.  相似文献   

15.
Raman spectroscopic studies on thiourea (TU) in highly acidic media (e. g. >3 mol/L HC1O4) show that TU as a solution species is protonated through its sulphur atom and forms complex with anions. However, as an adsorbed species, TU is protonated via the nitrogen atom and adsorbed at the silver electrode surface through the sulphur atom. The distinct effects of pH and anions of the solution on the surface enhanced Raman (SER) spectra of TU were investigated. In acidic and neutral solutions, TU is coadsorbed with anions through its NH3 and - NH2 groups respectively.  相似文献   

16.
The surface interrogation mode of scanning electrochemical microscopy (SI-SECM) was used for the detection and quantification of adsorbed hydroxyl radical ˙OH((ads)) generated photoelectrochemically at the surface of a nanostructured TiO(2) substrate electrode. In this transient technique, a SECM tip is used to generate in situ a titrant from a reversible redox pair that reacts with the adsorbed species at the substrate. This reaction produces an SECM feedback response from which the amount of adsorbate and its decay kinetics can be obtained. The redox pair IrCl(6)(2-/3-) offered a reactive, selective and stable surface interrogation agent under the strongly oxidizing conditions of the photoelectrochemical cell. A typical ˙OH((ads)) saturation coverage of 338 μC cm(-2) was found in our nanostructured samples by its reduction with the electrogenerated IrCl(6)(3-). The decay kinetics of ˙OH((ads)) by dimerization to produce H(2)O(2) were studied through the time dependence of the SI-SECM signal and the surface dimerization rate constant was found to be ~k(OH) = 2.2 × 10(3) mol(-1) m(2) s(-1). A radical scavenger, such as methanol, competitively consumes ˙OH((ads)) and yields a shorter SI-SECM transient, where a pseudo-first order rate analysis at 2 M methanol yields a decay constant of k'(MeOH) ~ 1 s(-1).  相似文献   

17.
采用湿法浸渍-再干燥法将K2O和K2SO4担载到低温SCR催化剂V1/AC上,模拟研究了烟气中超细碱金属颗粒物对V1/AC催化剂脱硝活性的影响。结果表明,两种含K化合物的引入均导致了该催化剂的失活,明显抑制了NH3在催化剂上的吸附,尤其是热稳定性较低的吸附;K2SO4的抑制作用明显小于K2O,这与它们对催化剂SCR活性的影响规律相一致。K2O的担载对催化剂表面的氧化性能影响较小,但由于其能抑制NH3的吸附而引起催化剂的失活;K2SO4的担载则增加了催化剂表面吸附态的NH3在O2气氛中被过度氧化为NO的可能性。  相似文献   

18.
研究了笼形聚偕胺肟树脂(CAO)和酸式(ACAO)及碱式(BCAO)树脂对于苯酚、对-氨基酚、对-硝基酚、对-甲氨基酚和对-苯二酚的吸附和吸留作用,测定了酚处理树脂的中和当量。它反映了笼形树脂吸留外来物的特性。酚处理树脂有效地吸附Ag 、AuCl4-、PtCl62-、PdCl42-和IrCl62-等贵金属离子,吸附方式似乎与溶液的pH值有关。SEM观察表明,Ag 、Au-Cl4-和IrCl62-离子在吸附过程中被还原为零价态,在树脂表面生成形态各异的结晶。  相似文献   

19.
Reaction of [Cp*IrCl2]2 (1) with dpmp in the presence of KPF6 afforded a binuclear complex [Cp*IrCl(dpmp-P1,P2;P3)IrCl2Cp*](PF6) (2) (dpmp =(Ph2PCH2)2PPh). The mononuclear complex [Cp*IrCl(dpmp-P1,P2)](PF6) (4) was generated by the reaction of [Cp*IrCl2(BDMPP)](BDMPP =PPh[2,6-(MeO)2C6H3]2) with dpmp in the presence of KPF6. These mono- and binuclear complexes have four-membered ring structures with a terminal and a central P atom of the dpmp ligand coordinated to an iridium atom as a bidentate ligand. Since there are two chiral centers at the Ir atom and a central P2 atom, there are two diastereomers that were characterized by spectrometry. Complexes anti-4 and syn-4 reacted with [Cp*RhCl2]2 or [(C6Me6)RuCl2]2, giving the corresponding mixed-metal complexes, anti- and syn- [Cp*IrCl(dppm-P1,P2;P3)MCl2L](PF6) (6: M = Rh, L = Cp*; 7: M = Ru, L = C6Me6). Treatment with AuCl(SC4H8) gave tetranuclear complexes, anti- and syn-8 [[Cp*IrCl(dppm-P1,P2;P3)AuCl]2](PF6)2 bearing an Au-Au bond. Reaction of anti- with PtCl2(cod) generated the trinuclear complex anti-9, anti-[[Cp*IrCl(dppm-P1,P2;P3)]2PtCl2](PF6)2. These reactions proceeded stereospecifically. The P,O-chelated complex syn-[Cp*IrCl(BDMPP-P,O)] (syn-10)(BDMPP-P,O = PPh[2,6-(MeO)2C6H3][2-O-6-(MeO)C6H3]2) reacted with dpmp in the presence of KPF6, generating the corresponding anti-complex as a main product as well as a small amount of syn-complex, [Cp*Ir(BDMPP-P,O)(dppm-P1)](PF6) (11). The reaction proceeded preferentially with inversion. The reaction processes were investigated by PM3 calculation. anti- was treated with MCl2(cod), giving anti-[Cp*Ir(BDMPP-P,O)(dppm-P1;P2,P3)MCl2](PF6)(14: M = Pt; 15: M = Pd), in which the MCl2 moiety coordinated to the two free P atoms of anti-11. The X-ray analyses of syn-2, anti-2, anti-4, anti-8 and anti-11 were performed.  相似文献   

20.
A series of new iridium complexes, IrCl(COD)(TMOPP) (1) [COD=1,5-cyclooctadiene, TMOPP=tris(4- methoxyphenyl)phosphine], IrCl(COD)(TFMPP) (2) [TFMPP = tris(4-trifluoromethylphenyl)phosphine], IrCl(COD)(BDNA) (3) [BDNA= 1,8-bis(diphenylphosphinomethyl)naphthalene], IrCl(COD)(BISBI) (4) [BISBI= 2,2'-bis(diphenylphosphinomethyl)biphenyl] and IrCl(COD)(BDPB) (5) [BDPB= 1,2-bis(diphenylphosphinomethyl)benzene], were synthesized and characterized by NMR spectra and elemental analyses. In order to obtain the relationships between complex structures and their catalytic properties, IrCl(COD)(DPPM) (6) [DPPM = bis(diphenylphosphino)methane], IrCl(COD)(DPPE) (7) [DPPE= 1,2-bis(diphenylphosphino)ethane], IrCl(COD)(DPPP) (8) [DPPP=1,3-bis(diphenylphosphino)propane] and IrCl(COD)(TPP) (9) [TPP=triphenylphosphine], were also synthesized according to the reported methods. The hydrogenation results showed that the low electronic density at the central metal was favorable to increase the catalytic activity for the hydrogenation of avermectin, but decrease the selectivity to ivermectin. The complex with a large chelating ring and a bulky chelating backbone would easily cause the cleavage of C-O bond in avermectin to give a byproduct avermectin aglycon.  相似文献   

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