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1.
环取代基对金属化聚苯胺衍生物膜修饰电极性能的影响   总被引:1,自引:0,他引:1  
通过比较聚2,5-二甲氧基苯胺(PDMAn)、聚邻甲基苯胺(POT)和聚间氯苯胺(PmClAn)膜修饰电极的氧化还原电位、沉积在这3种聚合物上的铂微粒的表面形态与晶面取向以及异丙醇在分散Pt微粒的聚苯胺膜修饰电极上的氧化行为,从电子效应和立体效应探讨了聚合物电化学性质与环取代基的关系以及不同聚合基质对Pt沉积机理和有催化性能的影响,结果表明,在硫酸溶液中PDMAn膜修饰电极的氧化还原电位最负、POT次之、PmClAn最正,Pt在PDMAn和POT膜上的电沉积机理与在PmClAn膜上的不同,聚合物膜上沉积的Pt微粒呈现(200)晶面择优取向,其中POT膜上择优取向度最大,PDMAn次之,Pm-ClAn最小,异丙醇在金属化聚合物膜电极上的氧化电位取决于聚苯胺的本质,在POT膜修饰电极上异丙醇的电氧化主要发生在POT的活性电位区,而在PDMAn与PmClAn膜上的电氧化则主要发生在Pt上的氧化电位区,说明聚合物膜不仅作为Pt微粒的分散介质,而且本身有产生催化作用。  相似文献   

2.
聚苯胺衍生物膜修饰电极的电化学和催化性质   总被引:4,自引:0,他引:4  
采用聚 2,5 二甲氧基苯胺(PDMAn)、聚邻甲苯胺(POT)膜修饰电极,以异丙醇(i P)氧化为模型反应,研究功能性膜电极的电催化性能.两种聚合物的伏安行为都表现为两对氧化还原峰;与镀铂的Pt电极比较,Pt金属化的PDMAn和POT修饰电极,大大提高了i P氧化电流密度,而且随着循环次数增加,氧化电流不断增大,表明功能性膜修饰电极具有较高的催化活性. POT修饰电极在较低的铂含量下就表现出对i P的强烈催化活性,而且对低浓度i P的氧化,具有较高的响应灵敏度;此外POT还具有良好的环境稳定性,可望成为一种具有实际应用前景的电化学传感器.  相似文献   

3.
掺杂质子酸的类型对聚苯胺结构和电导率的影响   总被引:18,自引:4,他引:18  
采用化学氧化聚合法以苯胺为单体,过硫酸铵为氧化剂,在不同质子酸的水溶液中合成聚苯胺,考察质子酸对聚苯胺电性能影响,并通过傅立叶红外吸收光谱(FTIR)和紫外可见光吸收光谱(UV-vis)研究聚苯胺掺杂前后结构的变化。结果表明,龙质子酸掺杂后聚 胺具有导电性是因为其分子链上电荷离城形成了共轭结构,具有不同质子酸中生成的聚苯胺氧化程度不同;分子链共轭程度与掺杂酸对阴离子大小有关,掺杂质子酸对阴离子越大,聚苯胺分子链共轭程度越大,电导率也就越高。  相似文献   

4.
掺杂和取代对聚苯胺导电性能影响机制的研究   总被引:4,自引:0,他引:4  
在导电聚合物的研究中,聚苯胺及其衍生物一直是人们相当感兴趣的课题.此类聚合物既可用氧化剂掺杂,也可进行质子酸掺杂,掺杂后其电导率可提高约十个数量级{1,’];利用在主链上引入取代基等化学修饰方法,可方便地调节其溶解性、加工性等物理化学性能.已有的研究结果表明,主链的化学修饰往往给聚苯胺的导电性能带来不利影响*.因此,如何使聚苯胶类导电聚合物保持高的电导率且同时具备优良的物理加工性能使成为此类导电聚合物研究中的一个亟待解决的问题一本文利用鼻子化学EHMO-CO方法对掺杂和取代影响聚苯胺及其衍生物导电性…  相似文献   

5.
钟昀  章伟光  张启交  谭民裕  王素籣 《化学学报》2003,61(11):1828-1833
合成了3个二硫代氨基甲酸锌配合物[Zn_2(S_2CNBu_2~n)_4],[Zn(S_2CNBy_2) _2](2)和[Zn(S_2CNBy_2)_2Py] (3) (Bu~n = 正丁基,By=苄基,Py=吡啶)。测定 了它们的晶体结构,红外光谱和热稳定性。1为单斜晶系,空间群C2/c,晶胞参数 a=2.3329(3)nm, b=1.7090(2)nm, c=1.6115(2)nm. α=90 °β=127.560(10) °, γ=90 °.2为正交晶系,空间群Pbcn,晶胞参数a=1.62193(11)nm, b=1.90010(12) nm, c=0.93795(6)nm. α=90 °,β=90 °,γ=90 °.3为三斜晶系,空间群P-1, 晶胞参数a=0.86418(6)nm, b=1.31156(9)nm, c=1.66238(11)nm. α=106.398(1) °,β=92.633(1) °,γ=107.461(1) °.1为二聚体,属典型的荒氨酸金属配合物 结构类型。2为一单核匹配位化合物,而在荒氨酸金属配合物中(除Ln,Ac系外)该 结构类型非常少见。2中引入吡啶环得到3,3为一五配位化合物,吡啶环的引入说 明2的中心离子处于配位不饱和状态,这与以往报道相吻合。1的热稳定性质研究发 现其在251 ℃有升华现象,可作为MOCVD的前驱物。  相似文献   

6.
合成了双核铜配合物[Cu(μ-Cl)(Cl)(C13H10N2S)2]2,并对其进行了光谱表征和晶体结构测定.晶体属单斜晶系,空间群P21/n,a=1.3322(2)nm,b=1.5051(2)um,c=1.3591(2)nm;α=γ=90°,β=110.15(1)°,Z=2.在配合物中,每个铜原子与2个桥连氯原子,l个端基氯原子以及2个互为位置异构体的双取代毗唑环上氮原子配位,而使钢原子具有畸变三角双锥构型.  相似文献   

7.
用三苯基氯化锡与1,5-戊二酸二钠以2:1摩尔比反应,合成了1,5-戊二酸 双(三苯基锡)酯,并进行了红外光谱、核磁共振氢谱及质谱表征。X射线单晶衍 射表明,该化合物属正交晶系,空间群C222(1),晶胞参数:a=1.5075(5)nm, b=4.8021(17)nm,c=2.8944(9)nm,α=90°,β=90°,γ=90°,V=20.953(12) nm^3,Z=8,Dc=1.316g/cm^3,μ=1.226mm^-1,F(000)=8280,R1=0.0546,wR2=0. 1182。晶体结构中存在5种化学环境不同的三角双锥构型的锡原子,由于配体中两 个羧基在不同方向的交联作用,使化合物呈现三维骨架结构,并且在骨架结构中存 在沿a轴和c轴方向伸展的规则的大环直孔道。  相似文献   

8.
掺杂聚苯胺溶致液晶相的产生和表征   总被引:1,自引:0,他引:1  
聚苯胺(PAN)具有共轭结构,从理论上满足形成液晶相的基本条件[1,2].但由于聚苯胺难溶、难熔,长期以来对于聚苯胺溶液(尤其是浓溶液)或熔体的研究甚少.近年来,人们采用具有“增塑作用”的大分子功能质子酸对聚苯胺进行掺杂,获得可溶于多种有机溶剂中的掺杂态聚苯胺[3~5].然而,聚苯胺溶液的结构与性能的特点及能否产生溶致液晶相等问题目前尚未见报道.为此,我们研究了十二烷基苯磺酸(DBSA)掺杂聚苯胺在有机溶剂中形成液晶相的条件,探讨了不同掺杂方法对PAN-DBSA的溶解性及形成液晶棺的影响;采用差式扫描量热分…  相似文献   

9.
借助沉积聚合辅助的“无模板”法在玻璃基片上制备出水杨酸掺杂的微/纳米结构的聚苯胺.实验发现,微/纳米结构的形貌及其浸润性依赖于掺杂剂与单体的摩尔比和沉积时间.当低分子量的聚苯胺微米球和纳米球共存时,其沉积的表面呈现出高的疏水性(接触角θ=148.0°),这主要来源于微/纳米共存的结构导致高的表面粗糙度,能捕获更多的空气所致.FTIR,紫外-可见光谱和X光射线衍射表征了微/纳米球的分子结构及其结晶性.  相似文献   

10.
用Co2(CO)8与CH3CSNH2反应制得产物Ⅰ,又用Na2Fe(CO)4与Ⅰ反应制得产物Ⅱ(Ⅰ:Co3(μ3-S)(CO)7(CH3CSNH),Ⅱ:Co2Fe(μ3-S)(CO)7(CH3CSNH).通过元素分析。IR、UV、1HNMR、MS表征并用X射线衍射法测得Ⅱ的单晶结构.该簇合物属三斜晶系、PT空间群,晶胞参数:a=0.9203(1),b=1.1296(2),c=1.1425(2)nm;α=116.40°(2),β=101.92°(2),γ=92.58°(1);z=2,V=1.2162nm3,Dc=1.698cm3,μ=21.89cm-1.结构分析表明,Co2FeS构三角锥分子骨架,所有CO均为端基配体,S1为面桥基配体,CH3CSNH为双齿配体,与Co、Fe形成五元环结构.  相似文献   

11.
Poly(o‐methoxyaniline) (POMA) and poly(o‐toluidine) (POT) salts doped with different acids (methanesulphonic acid (MeSA), trifluoroacetic acid (TFA), and hydrochloric acid (HCl)) were synthesized by using solid‐state polymerization method. The polymers were characterized by Fourier transform infrared (FTIR) spectra, ultraviolet–visible (UV–Vis) spectrometry, X‐ray diffraction (XRD), cyclic voltammetry (CV), and conductivity measurements. Transmission electron microscopy (TEM) was done to study the morphologies of POMA and POT salts. The FTIR and UV‐Vis absorption spectra revealed that the reduced phase was predominant in POMA salts, and the pernigraniline phase was predominant in POT salts. It was found that POMA salts displayed higher doping level and conductivity. In contrast, POT salts were lower at doping levels and conductivity. In accordance with these results, the electrochemical activity was also found to be lower in POT salts. The XRD patterns showed that the POMA salts displayed higher crystallinity than POT salts. The results from TEM revealed that the morphologies of POMA salts were different from those of POT salts. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

12.
Polyaniline as the first commercially available conducting polymer has recently received great attention from both academic and industrial communities. Although there have been quite a few reports on substituted polyanilines, none of them are concerning about the amino- and alkylthio-substituted polyanilines. Unlike other substituted polyanilines, the attempts in synthesizing poly(alkylthioaniline) directly from the alkylthioaniline monomer via chemical and electrochemical oxidative-coupling chemistry were all fail. On the other hand,we have recently discovered that the amino and alkylthio functional groups can be easily introduced to the backbone of emeraldine polyaniline via the concurrent reduction and substitution chemistry. Further combination of electrochemistry and the concurrent reduction and substitution chemistry can provide us a facile and versatile tool for preparing functional polyanilines. Different functional groups can be introduced sequentially to the same polymer backbone. The concentrations of each substituents can be easily controlled. This new process provides us a useful utility for tailoring the molecular and the electronic structures of polyanilines to render them with appropriate and possibly new material properties suitable for many different potential applications.  相似文献   

13.
UV-vis spectra of homopolymers and copolymers of 2-aminobenzoic acid (OAB) and 2-methoxyaniline (OMA) were analyzed in order to obtain information about the oxidation state and proton doping level of these polymers. Dimethyl sulfoxide (DMSO) was used as a solvent in which protonated forms of polyanilines are preserved and a mixture of N-methyl-2-pyrrolidone and triethylamine (0.5 %) as a solvent (NMP/TEA) in which polyanilines are assumed to be non-protonated. Polymers were prepared in the emeraldine salt form, externally doped with HCl. It was found that only external doping is eliminated in NMP/TEA while internal doping by carboxylate groups bound in OAB units remains operative. Since doped quinoid units do not contribute to the quinoid band (Q-band at 630 nm), the intensity ratio of the Q-band and benzenoid band (B-band at 320 nm) cannot be simply correlated with the oxidation state of poly(OMA-co-OAB) copolymers in contrast to poly(OMA) and polyaniline. Spectra of copolymers with less than 60 % of OMA units as well as those of poly(OAB) in DMSO and NMP/TEA are almost identical due to internal doping, which is proposed to lead to structures in which main-chain protons are coulombically bound with immobile carboxylate anions. In the spectra of copolymers with less than 60 % of OMA units, a well-resolved band occurs at 500 nm, which can be ascribed to alternating or close-to-alternating sequences of OMA and OAB units.  相似文献   

14.
PmClAn基膜修饰电极的电化学及催化性质研究   总被引:2,自引:0,他引:2  
聚苯胺作为电极修饰材料 ,已在传感器上显示出广泛的应用前景[1~ 4 ] .异丙醇 ( i- P)氧化[5,6 ] 是个较简单的反应 ,被广泛作为电催化研究的模型反应 .目前 ,i- P电化学氧化的研究集中于 Pt的多晶或单晶电极[7~ 9] ,Gonzales等 [10 ] 报道了 Pt- Sn共沉积的 PAn膜修饰电极上的异丙醇电氧化 ,但对复合材料的微观结构仍欠研究 .本文讨论 Pm Cl An基质性质对 Pt电沉积的影响 ,并探讨了 i- P在沉积 Pt微粒的 Pm Cl An功能膜电极上的氧化情况 .1 实验部分1 .1 电极的制备 聚间氯苯胺 ( Pm Cl An,本征态 ud,HCl掺杂态 d)采用乳液聚…  相似文献   

15.
聚甲基丙烯酸甲酯辐射裂解和消旋的空间立构效应   总被引:1,自引:1,他引:1  
本文研究了三种不同空间立构聚甲基丙烯酸甲酯的辐射效应,提出裂解过程是一种裂解与重合的动态平衡过程。分子量降低和消旋作用对温度的依赖性,是由于分子运动和笼罩效应以及重合的空间位阻效应所致。辐照温度愈高,裂解产额愈大。相同条件下辐照,全同立构比无规立构试样的裂解产额更大。 全同立构聚甲基丙烯酸甲酯辐照后,不仅分子链断裂,而且空间立构也发生很大变化。随着辐照剂量的增加,全同立构含量逐渐减少,而无规立构含量和间同立构含量却逐渐增加。  相似文献   

16.
Two polyaniline (PANI) samples of various molecular masses were used for the preparation of palladium catalysts (with 2 mass % of Pd). The physicochemical features of starting polyanilines were found to substantially affect the size and extent of palladium nanoparticles aggregation. Strongly aggregated large palladium particles appeared in the PANI sample of more compact morphology (PANI-H), higher crystallinity and lower specific surface area. Pd nanoparticles of a definitively smaller size were formed in the more amorphous PANI sample of looser morphology (PANI-L) and the extent of particles aggregation was markedly lower. The catalytic properties of Pd/PANI samples were studied in a liquid phase hydrogenation of unsaturated triple bond (C≡C) in alkynes reactants, phenylacetylene, and cyclohexylacetylene. The 2 mass % Pd/PANI-L catalyst prepared using polymer of less compact texture exhibited much higher activity in both reactions. In the presence of the 2 mass % Pd/PANI-L catalyst, alkene products were formed with a high selectivity (approximately 90 %) attained at the almost complete conversion of alkynes. This highly selective hydrogenation of the C≡C to the C=C bond was related to the presence of an electroactive polymer, PANI, in close proximity with Pd active sites. Polyaniline could have a role in a steric effect as well as in a modification of adsorptive properties of Pd centres.  相似文献   

17.
单一手性烯烃铜(Ⅰ)配位聚合物   总被引:1,自引:0,他引:1  
The solvothermal reaction of CuCl with R-(-)-1-allyl-3-methylpiperazine at 70 ℃ gives one-dimensional chain Cu-coordination polymer through olefin moiety binding to Cu atoms formulated as [Cu(C8H16N2)Cl]. It is interesting to note that through Cu2Cl2 dimer unit 1 results in a supramolecular 3-dimensional coordination polymer. Powdered sample measurement of 1 reveals that 1 is second-harmonic generation (SHG) active compound. Crystal parameters for 1, space group P212121, a=0.763 1(9) nm, b=0.891 0(10) nm, c=1.494 6(17) nm, α=90°, β=90°, γ=90°, V=1.016(2) nm3, Z=2, M=478.44, Dc=1.564 Mg·m-3. CCDC: 650193.  相似文献   

18.
聚噻吩取代效应的理论研究   总被引:3,自引:0,他引:3  
用自洽场晶体轨道法(SCF CNDO/2-CO)对聚噻吩的一些一取代物和二取代物的电子结构进行了研究,计算的取代基包括-CH3,-C2H5,-OCH3和-CN。计算结果表明,这些取代基基本没有影响聚噻吩主链的平面结构,除聚-3,4-二甲基噻吩的主链发生了40°的扭转外,其它衍生物的主链仍处于同一平面。根据各取代高分子的电子特性我们得到结论:给电子基团和吸电子基团的取代教师将使能隙(Eg)减小,价带  相似文献   

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