无纺布上的偕胺肟基团鳌合物的氧化还原反应的研究

 采用各种分析方法系统研究了含偕胺肟基因维尼无纺布与Ａｎ³⁺进行氧化还原反应时的化学结构变化、氧化还原与鳌合吸附的关系以及还原产物的结晶结构和形态．结果表明，含偕胺肟基无纺布与Ａｕ³⁺反应时，开始主要是偕胺肟基被氧化成为酰胺基．此外，有部分偕胺基因被氧化成为羧基．Ａｎ³⁺被还原的同时生成约相等当量的氢离子．反应后期或反应温度高时，氢离子生成量增大．实验结果还表明，在反应起始阶段，Ａｕ³⁺与偕胺肟基因会发生鳌合作用．还原生咸的单质Ａｎ形成“玫瑰花”状的小晶粒粘附于无纺布纤维表面．     

螯合纤维的研究：Ⅱ.含偕胺肟基螯合纤维的吸附性能

本文系统地研究了通过枝共聚和偕胺肟化反应制备的以聚乙烯醇缩甲醛（ＰＶＦ）无纺布为基体的含偕胺肟基螯合纤维对碱土，过渡贵重，稀土和放射性金属离子的螯合吸附行为，测定了在不同温度下的吸附速率曲线。并且首次发现这种螯合基团有氧化－还原性性质，能将高价金属离子如Ａｕ＾３＾＋还原成价态，即还原成元素金。     

氧化还原功能纤维的研究──Ⅴ．含胺基及乙二胺基功能纤维的合成及其对Au~（3＋）的吸附性能

本文以反应性氯甲基化纤维为基体，合成丁氮含量分别为４．０６、４．９２ｍｍｏｌ／ｇ的含胺基（－ＮＨ２）及乙二胺基（－ＮＨＣ２Ｈ４ＮＨ２）功能纤维．静态吸附实验结果表明：在ｐＨ２．０乙二胺基纤维对Ａｕ３＋的吸附量达最大（６２０ｍｇ／ｇ），含胺基纤维的吸附量为２４８ｍｇ／ｇ；ＷＡＸＤ证实它们对Ａｕ３＋都有还原作用；含乙二胺基纤维对吸附态Ａｕ３＋的还原百分率最大值为９１％（ｐＨ４．０），而含胺基纤维在ｐＨ２．０的还原百分率为１００％，但ｐＨ＜０．６后，含乙二胺基纤维对Ａｕ３＋无还原作用；含乙二胺基纤维对Ａｕ３＋的吸附量随溶液温度升高而增大；在乙醇、１、４－氧六环、乙酸乙酯中含乙二胺基纤维对Ａｕ３＋的吸附量分别为４２、１４３、０ｍｇ／ｇ，且在乙醇中它对Ａｕ３＋有还原作用．吸附动力学实验结果表明：吸附初期为快速离子交换过程，中期为螯合吸附占主导地位，后期则是氧化还原吸附占优势．在扫描电子显微镜可观察到部分吸附在含乙二胺基纤维上的金聚集成粒状．     

氧化还原功能纤维的研究Ⅵ．含胺基及乙二胺基功能纤维与Au~（3＋）的氧化还原反应机理

本文通过红外光谱分析、元素分析及光电子能谱分析等实验手段证实胺基及乙二胺基纤维中氧原子与Ａｕ３＋未发生氧化还原反应，而邻近的碳原子被氧化成羟基碳或羰基碳，并伴有氮原子的脱落，而部分吸附态Ａｕ３＋最终被还原成Ａｕ０。     

用含偕胺肟基螯合纤维吸附、还原Au^3＋的研究（Ⅱ）：—氧化还原过程的初步研究

讨论了含偕胺肟基螯合纤维对Au^3 的还原过程及螯合与还原反应间的关系。结果表明，含偕胺肟基螯合纤维在吸附Au^3 的过程中，功能基螯合Au^3 之后再将其部分还原成单质金，而偕胺肟基则先被氧化成酰氨基进而变成羧基，吸附了Au^3 的纤维经径高温灼烧后合理使可得到海绵金。     

纤维素基磁性聚偕胺肟树脂的研究——溴在树脂上的氧化还原反应

用羟胺作模拟物与溴反应，测定了吸溴前后的酸式纤维素基磁性聚偕胺肟树脂的红外光谱，结合Ｆｒｅｕｎｄｌｉｃｈ及Ｌａｎｇｍｕｉｒ等温吸附方程的分析和吸溴前后树脂重量变化的测定，证明纤维素基磁性聚偕胺肟树脂吸溴后随即发生氧化还原反应，偕胺肟基被氧化为羧基，溴则被还原为溴离子，在溴浓度较高时，纤维素葡萄糖单元上的羟基被溴代或被氧化成羰酸，若葡萄糖苷键氧化断裂，将导致大分子降解。     

笼形聚偕胺肟树脂的研究──(NH_4)_2IrCl_6在碱式树脂上吸附与还原过程

超当量吸附是碱式笼形聚偕胺肟树脂（BCAO）吸附氯铱酸铵的特征之一．被吸附的氯铱酸铵与浴液中树脂的偕胺肟基的摩尔比为3．0，表明物理吸附在吸附过程中起主导作用．吸附结果是氯铱酸铵和偕胺肟基结合而成1：1络合物，并且发生了氧化还原反应，后者从扫描电镜观察得到证实。     

氧化还原功能纤维的研究：VI.含胺基及乙二胺基功能纤维与Au^3…

本文通过红外光谱分析、元素分析及光电子能谱分析等实验手段证实胺基及乙二胺基纤维中氧原子与Ａｕ＾３＋未发生氧化还原反应，而邻近的碳原子被氧化成羟基碳或羰基碳，并伴有氮原子的脱落，而部分吸附态Ａｕ＾３＋最终被还原成Ａｕ＾０。     

纤维素基磁性聚偕胺肟树脂的研究──(NH_4)_2IrCl_6在树脂上的吸附

碱式纤维素基磁性聚偕胺肟树脂（ＢＭＡＯ）吸附（ＮＨ４）２ＩｒＣｌ６是快速过程，属超当量吸附。吸附结果生成ＡＯ－Ｉｒ和ＡＯ２－Ｉｒ３络合物，随后Ｉｒ（Ⅳ）被偕胺肟基还原为Ｉｒ（０），聚集成球状晶簇附着在树脂表面。     

纤维素基磁性聚偕胺肟树脂研究：HAuCl4在树脂上的吸附与还原

研究了ＨＡｕＣｌ４在碱式纤维素基磁性聚偕胺肟树脂上的吸附动力学。吸附容量与吸附时间关系在初吸附的３０ｍｉｎ内可表示为Ｑ＝０．６４ｔ＾０．４。粒内扩散是吸附速度的控制阶段。在吸附过程中，同时发生氧化还原反应，Ａｕ（０）以不同聚集态附着在树脂表面。     

笼形聚偕氨肟树脂的研究──Ag(Ⅰ)在树脂上的吸附过程

测定了Ag+离子在笼形聚偕胺肟树脂（CAO）及其酸、碱处理产物（ACAO、BCAO）上的吸附容量．Ag+离子在BCAO树脂上吸附容量较高,但同非选择性吸附,在ACAO上的吸附容量则与处理树脂的酸的pKa值有关．用高pKa值的硼酸、苯酸和对氨基酚处理所得的ACAO树脂的吸附容量接近BCAO树脂的水平,认为是胶后胺肟基发生互变异构所致．吸附动力学表明Ag+离子在H3BO3/ACAO和C6H5OH/ACAO树脂上进行多层吸附．在吸附中伴随有氧化还原反应并生成Ag（O）微晶的过程．     

Gold nanoparticles attached NH2+ ion implantation-modified indium tin oxide electrode: Characterization and electrochemical studies

An NH2+ ion implantation-modified indium tin oxide film was prepared and the implantation of amino groups on the indium tin oxide substrate was verified by X-ray photoelectron spectroscopy analysis.The gold nanoparticles attached surface could be obtained by self-assembly of different sized colloidal gold nanoparticles onto the NH2+ ion implantation-modified indium tin oxide surface.By scanning electron microscopy and electrochemical techniques,the as-prepared AuNPs attached NH2+ ion implantation-modified indium tin oxide electrode was characterized and compared with bare indium tin oxide electrode.Using a [Fe(CN)6]3 /[Fe(CN)6]4 redox probe,the increasingly facile heterogeneous electron transfer kinetics resulting from the attached gold nanoparticle arrays was observed.The gold nanoparticle arrays exhibited high catalytic activity toward the electro-oxidation of nitric oxide,which could provide electroanalytical application for nitric oxide sensing.     

接枝型偕胺肟树脂/SiO_2功能复合微粒的制备

用偶联剂γ-(甲基丙烯酰氧)丙基三甲氧基硅烷(KH-570)对微米级硅胶进行了表面化学改性,采用溶液聚合法,在改性硅胶微粒表面接枝丙烯腈(AN),制备了接枝微粒PAN/SiO2。用盐酸羟胺对接枝PAN进行偕胺肟(AO)化转变,制得了接枝有偕胺肟树脂(PAO)的复合型功能微粒PAO/SiO2。采用红外光谱(FT-IR)、热失重(TGA)及扫描电子显微镜(SEM)等测试技术,对接枝微粒PAN/SiO2以及功能微粒PAO/SiO2进行了表征,考察了制备条件对AN的接枝聚合过程及对PAN的偕胺肟化转变过程的影响规律。结果表明,适宜的接枝聚合条件为:引发剂质量分数为1.5%,反应温度为75℃。接枝聚合5h可制得接枝度为0.14g/g的接枝微粒PAN/SiO2。受偕胺肟基团空间位阻的影响,PAN的偕胺肟化转变反应不能进行彻底,适宜的PAN/SiO2偕胺肟化转变反应条件为:介质pH值为6～7,温度70℃,反应时间4h。所制得的功能微粒PAO/SiO2腈基转化率约为78%。     

Surface plasmon resonance spectroscopy and electrochemistry study of 4-nitro-1,2-phenylenediamine: a switchable redox polymer with nitro functional groups

Electrochemistry and electrochemical surface plasmon resonance (SPR) spectroscopy have been applied to study the electrochemical deposition and the redox transition of poly(4-nitro-1,2-phenylenediamine) (P4NoPD) on gold disk. It was shown that SPR can be the signal transducer for the different redox states of P4NoPD. Using a model biomolecular system, involving streptavidin, biotinylated DNA, and its complementary target DNA, it was found that the presence of nitro groups in P4NoPD allows the biorecognition events to be modulated by voltages. There is minimal nonspecific binding of biomolecules on oxidized (+0.2 V) or as-prepared P4NoPD, and binding occurs more significantly on the reduced P4NoPD (-0.2 to -0.6 V) with the presence of amine groups. The electrochemical deposition of P4NoPD film was also conducted on boron-doped diamond (BDD) electrode. The stability of the reduced P4NoPD film on gold and BDD was comparatively evaluated by electrochemical impedance spectroscopy (EIS). The result showed that BDD allows the electrochemical reduction of the P4NoPD film at wider cathodic limits than gold.     

Potential-dependent chemiluminescence of luminol on the gold electrode modified with ferrocenylalkanethiol self-assembled monolayer

Self-assembled monolayer of ferrocenylundecanethiol (FcC11SH) on gold electrode was used for the potential-dependent catalyst for chemiluminescence of luminol. Ferrocene head groups adsorbed on gold were oxidized to ferricinium cation species electrochemically and catalyzed the chemiluminescence of luminol. As the redox state of ferrocene group can be regulated by electrode potential, chemiluminescence response can also be controlled electrochemically. The presented system was adopted for detection of glucose in the presence of glucose oxidase since the light emission was detected even in the neutral and weak acid solution.     

杂多酸K7Fe^3^+P2W17O62H2对硫醇-磷脂杂化双层膜通透性的影响

利用涂抹冷冻法制备了硫醇-磷脂杂化双层膜,采用循环伏安和交流阻抗方法,研究了硫醇-磷脂杂化双层膜与杂多酸K7Fe^3^+P2W17O62H2作用前后通透性的变化,发现该种杂多酸能够诱导硫醇-磷脂杂化双层膜产生一些孔洞,降低了膜电阻,增加了膜电容,也增加了探针Fe(CN)^3-/4-~6与电极的电子传递。同时对产生该现象的机理进行了初步的探讨。     

Study of the oxidation dynamics of ethyl cysteinate dimer in solution by ultra‐performance liquid chromatography with tandem mass spectrometry

Diaminodithiol (N₂S₂)‐type compounds readily oxidize to produce disulfides. We found that some ligands failed to produce a prospective protonated molecular ion peak but gave a peak of [M–2+H]⁺, whereas others produced both [M+H]⁺ and [M–2+H]⁺ peaks in electrospray ionization mass spectra. In this study, an important N₂S₂ ligand, the ethyl cysteinate dimer (ECD), was investigated with high‐resolution accurate mass measurements and tandem mass spectrometric analysis. The elemental compositions of ECD and its oxidized product were analyzed. The oxidation of ECD was confirmed. An ultra‐performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method in multiple reaction monitoring mode was developed, and ECD and its oxidized product were quantitated in solution. The dynamic oxidation process of ECD in solution was studied in detail. The full time course of the decrease in ECD and the increase in its oxide was observed; the oxidation procedure followed first‐order kinetics, and the half‐life time of ECD was 51 min. Copyright © 2009 John Wiley & Sons, Ltd.