显色剂2-(5-羧基-1,3,4-三氮唑偶氮)-5-二乙氨基苯甲酸与钯(Ⅱ)的显色反应研究

研究了显色剂2-(5-羧基-1,3,4-三氮唑偶氮)-5-二乙氨基苯甲酸(CTZDBA)与钯(Ⅱ)的显色反应。结果表明,Pd(Ⅱ)与CTZDBA生成稳定的1∶2的紫红色配合物,其最大吸收波长为548 nm,配合物的表观摩尔吸光系数为9.32×104L.mol-1.cm-1,Pd(Ⅱ)质量浓度在0.08~0.8 mg/L范围内符合比耳定律。该方法可不经分离直接测定钯碳催化剂和钯纳米碳催化剂中的微量钯,测定结果与原子吸收法(AAS)基本相符。     

2-氯-4-溴苯基重氮氨基偶氮苯光度法测定微量钯

研究了在Trion X-100存在下,钯(Ⅱ)与2-氯-4-溴苯基重氮氨基偶氮苯的显色反应。试验表明,在pH 10.0的硼砂-氢氧化钠缓冲溶液中,钯(Ⅱ)与试剂形成1∶2的暗红色配合物,表观摩尔吸光系数ε为1.29×105L.mol-1.cm-1。Pd(Ⅱ)含量在0~18μg/25mL范围内符合比耳定律。本法用于钯催化剂及矿样中微量钯的测定,结果满意。     

新显色剂2-[2-(6-甲基-苯并噻唑)偶氮]-5-二甲氨基苯磺酸与钯(Ⅱ)的分光光度研究及其应用

合成了新试剂2-[2-(6-甲基-苯并噻唑)偶氮]-5-二甲氨基苯磺酸,并研究了其与钯(Ⅱ)的显色反应。实验表明,该试剂与钯(Ⅱ)反应生成1:1蓝色水溶性络合物,在阴离子表面活性剂十二烷基硫酸钠(SDS)存在下可稳定24h,其最大吸收波长为615nm,表观摩尔吸光系数为7.94×10~4L·mol~(-1)·cm~(-1)。钯量在0～0。8μg/ml范围内符合比尔定律。本法是目前测定钯(Ⅱ)的高灵敏度显色反应之一,并具有良好的选择性。可不经预分离而直接测定催化剂中微量钯,回收率为97.00％～102.1％,结果令人满意。     

2-[2''''-(4''''-甲基-苯并噻唑)偶氮]-5-二甲氨基苯甲酸与钯(Ⅱ)显色反应的研究及应用

合成了新试剂2-[2'-(4'-甲基-苯并噻唑)偶氮]-5-二甲氨基苯甲酸,并研究了其与钯(Ⅱ)的显色反应.实验表明,在50%乙醇介质中,该试剂与钻(Ⅱ)反应生成1:l络合物,其最大吸收彼长为698nm,表观摩尔吸光系数为5.83×10~4L·mol~(-1)·cm~(-1).钯量在0~1.3μg/ml范围内符合比尔定律.本法可不经预分离而直接测定催化剂中微量钯,平均回收率为100.4%,结果满意.     

新试剂 N-庚基-N′-(对氨基苯磺酸钠)硫脲光度法测定微量钯(Ⅱ)的研究

研究了N-庚基-N′-(对氨基苯磺酸钠)硫脲(HPT) 与钯(Ⅱ) 的反应条件.结果表明:在 pH 4.8～5.8 的 HAc-NaAc 介质中,并有溴化十六烷基三甲胺(CTMAB) 存在下,试剂 HPT 与钯(Ⅱ) 形成稳定的黄色配合物,其最大吸收波长为 295.2nm,表观摩尔吸光系数为 2.98×105L*mol-1*cm-1.钯(Ⅱ) 浓度在 0.04～0.28mg/L 范围内符合比尔定律,相关系数 r=0.9989.方法简便、快速、选择性好,用于催化剂、贫钯矿中微量钯的测定,结果满意.     

1-(4-氨替比林)-3-(2-噻唑)-三氮烯的合成及其光度法测定钯(Ⅱ)

合成并用红外光谱和元素分析鉴定了一个新的三氮烯类试剂:1-(4-氨替比林)-3-(2-噻唑)-三氮烯(ATTA),研究了它与Pd2+的显色反应。结果表明,在OP存在下,ATTA与Pd(Ⅱ)在pH 9.5的Na2B4O7缓冲溶液中生成红褐色络合物,其最大吸收波长为480 nm。依此建立的新的测定钯的光度分析方法可检测0.010~1.60μg/mL的Pd(Ⅱ),其摩尔吸光系数为5.33×104L.mol-1.cm-1。方法具有较高的灵敏度,较宽的线性范围和较好的选择性。将其用于催化剂样品中钯的测定,所得结果与用AAS法测定结果基本一致。     

N-甲基-2-硫-咪唑树脂对钯吸附的研究

测定了N-甲基-2-硫-咪唑树脂对钯Pd(Ⅱ)吸附的容量,Pd(Ⅱ)与Fe~(3+)、Cu~(2+)、Ni~(2+)、Mn~(2+)的分离系数、吸附Pd(Ⅱ)的速率常数、Freundlich吸附常数。通过化学法、红外光谱等方法,分别确定树脂功能基对钯吸附的络合比,及吸附过程功能基与钯发生了配位键合.选用混合洗脱剂可定量洗脱钯,并证明此法在实际应用中,可富集、回收钯。     

对-偶氮苯重氮氨基偶氮苯磺酸与钯的显色反应研究及其应用

本文研究了对-偶氮苯重氮氨基偶氮苯磺酸在非离子表面活性剂Tween-80存在下,与钯(Ⅱ)显色反应适宜条件.实验结果表明,在pH10.80～11.10范围内钯(Ⅱ)与题示试剂形成1:4的橙红色络合物,其最大吸收峰位于533nm处,试剂最大吸收为440nm,其对比度达93nm.钯(Ⅱ)在0～30μg/25ml范围内遵守比耳定律,并由此计算出其表观摩尔吸光系数ε_(533)=1.0×10~5L.mol~(-1).cm~(-1)。该方法用于催化剂中微量钯的测定,获得了令人满意的结果。     

溴酸钾-5-溴-(2-吡啶偶氮)-二乙氨基酚体系催化动力学光度法测定钯(Ⅱ)

在H2SO4介质和室温条件下,痕量钯(Ⅱ)能灵敏地催化KBrO3氧化5-溴-(2-吡啶偶氮)-二乙氨基酚(5-Br-PADAP)的褪色反应。研究了该催化反应的最佳实验条件及动力学过程,建立了动力学光度法测定痕量钯的新方法。方法的线性范围为0~0.75 mg/L,检出限为7.62×10-8g/L。催化反应速率对于钯和5-Br-PADAP都为一级反应,表观活化能为88.64 kJ/moL。方法用于钯碳催化剂中钯量的测定,标准加入回收率为98.4%~104.9%。     

高选择性新试剂5-(2-羟基-5-磺酸基苯偶氮)罗丹宁与钯显色反应的研究及应用

介绍高选择性新试剂5-(2-羟基-5-磺酸基苯偶氮)罗丹宁(S-HBAR)与钯显色反应的研究与应用,建立了测定钯的新方法。在H_3PO_4介质中,在乳化剂OP存在下,S-HBAR与Pd(Ⅱ)形成稳定的红色配合物,最大吸收波长为500nm。钯浓度在0～70μg/25 mL范围内符合比耳定律。表观摩尔吸光系数ε=3.5×10~4 L/(mol·cm),选择性好。该方法无需加入掩蔽剂或其他分离手段,即可直接用于Pd-C催化剂和矿石中钯的测定。     

硅胶负载的双高分子-钯催化剂的研究——Ⅰ.硅胶负载的聚[4(2)-乙烯吡啶]-聚[苯乙烯-顺丁烯二酸]-钯催化剂的合成及其催化加氢性能

合成了硅胶负载的聚(4-乙烯吡啶)或聚(2-乙烯吡啶)-聚(苯乙烯-顺丁烯二酸)-钯催化剂(P4VP-PSM-Pd/SiO_2和P2VP-PSM-Pd/SiO_2),研究了合成条件、组成等对其催化性能的影响及对丙烯酸甲酯的催化加氢性能。发现,同时含两种高分子的催化剂比只含一种高分子的催化剂具有较高的催化活性,催化剂在常温常压下对丙烯酸甲酯的氢化反应具有很高的催化活性和选择性,且能重复使用,表现出良好的稳定性。同时还研究了其它因素对催化剂性能的影响。     

硅胶负载的双高分子-钯催化剂的研究——Ⅰ.硅胶负载的聚[4(2)-乙烯吡啶]-聚[苯乙烯-顺丁烯二酸]-钯催化剂的合成及其催化加氢性能

 合成了硅胶负载的聚(4-乙烯吡啶)或聚(2-乙烯吡啶)-聚(苯乙烯-顺丁烯二酸)-钯催化剂(P4VP-PSM-Pd/SiO₂和P2VP-PSM-Pd/SiO₂),研究了合成条件、组成等对其催化性能的影响及对丙烯酸甲酯的催化加氢性能。发现,同时含两种高分子的催化剂比只含一种高分子的催化剂具有较高的催化活性,催化剂在常温常压下对丙烯酸甲酯的氢化反应具有很高的催化活性和选择性,且能重复使用,表现出良好的稳定性。同时还研究了其它因素对催化剂性能的影响。     

Electroless deposition of nickel on fluoropolymers modified by surface graft copolymerization

Surface modification of Ar plasma-pretreated poly(tetrafluoroethylene) (PTFE) and poly(vinylidene fluoride) (PVDF) films via UV-induced graft copolymerization with 4-vinylpyridine (4VP), 2-vinylpyridine (2VP) or 1-vinylimidazole (VIDz) was carried out. Electroless deposition of nickel could be carried out on these graft-modified fluoropolymer surfaces after PdCl₂ activation. The surface compositions of the graft-modified films were studied by X-ray photoelectron spectroscopy. The adhesion strength between the surface graft-copolymerized fluoropolymer film and the electrolessly deposited nickel was affected by the type of monomers used for graft copolymerization and the graft concentration. The optimum T-peel adhesion strengths of the electrolessly deposited Ni on the 4VP graft-copolymerized PTFE and PVDF surfaces were about 7 and 13 N/cm, respectively. The metal/fluoropolymer assemblies delaminated by cohesive failure inside the fluoropolymer substrates. The enhanced adhesion between the electrolessly deposited Ni and the surface-modified fluoropolymers is attributable to the interfacial charge transfer interactions between the grafted polymer chains and the deposited metals (Pd and Ni), the spatial distribution of the graft chains into the metal matrix and the covalent tethering of the graft chains on the fluoropolymer surface.     

Synthesis of poly(4-vinylpyridine) and block copoly (4-vinylpyridine-b-styrene) by atom transfer radical polymerization using 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazamacrocyclotetradecane as ligand

Poly(4-vinylpyridine) (P4VP) and block copolymer, poly(4-vinylpyridine-b-styrene) (P4VP-b-PSt) were prepared by atom transfer radical polymerization (ATRP) using 1-phenylethyl chloride as initiator, CuCl and 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazamacrocyclotetradecane (Me₆[14]aneN₄) as catalyst and ligand. The polymerization of 4VP was carried out in 2-propanol at 40 °C. GPC and NMR studies show that the plot of ln([4VP]₀/[4VP]) against the reaction time is linear, and the molecular weight of the resulting P4VP increased linearly with the conversion. Within 3 h, the conversion can reach almost 90%. P4VP-b-PSt amphiphilic block copolymer with low polydispersity index (M_w/M_n ≈ 1.2) is also obtained by ATRP of St in DMF at 110 °C using P4VP-Cl as macroinitiator, CuCl/ Me₆[14]aneN₄ as catalyst.     

PtBMA-b-P4VP的ATRP合成及其化学转变

以α-氯代丙酸乙酯(ECP)为引发剂,N,N,N′,N″,N″-五甲基二亚乙基三胺(PMDE-TA)为配体,在N,N′-二甲基甲酰胺(DMF)溶液中引发甲基丙烯酸叔丁酯(tBMA)进行原子转移自由基聚合(ATRP),调节聚合反应时间得到了端基为氯原子,数均分子量为1.8×103~6.4×103的聚甲基丙烯酸叔丁酯(PtBMA-Cl)大分子引发剂。采用合成的5,5,7,12,12,14-六甲基-1,4,8,11-四氮杂环化合物(Me6[14]aneN4)为配体,使PtBMA-Cl引发4-乙烯吡啶(4VP)进行ATRP反应,得到了PtBMA-b-P4VP两嵌段共聚物,可使P4VP的收率达到60%。通过对PtBMA-b-P4VP的不同链段进行季铵化和水解反应,得到了聚甲基丙烯酸-b-季铵化聚4-乙烯吡啶(PMAA-b-QPVPB)亲水性嵌段共聚物。傅里叶变换红外光谱(FT-IR)、核磁共振(1H-NMR)和凝胶渗透色谱(GPC)分析表明:所得嵌段共聚物的结构明确,可将PtBMA与P4VP的链段长度之比调整在1∶0.5~1∶1的范围内。     

Multiple morphological micelles formed from the self-assembly of poly(styrene)-b-poly(4-vinylpyridine) containing cobalt dodecyl benzene sulfonate

A series of supramolecular block copolymers were prepared using poly(styrene)-b-poly(4-vinylpyridine)(PS-b-P4VP) which coordinated with cobalt dodecyl benzene sulfonate (Co(DBS)₂) in tetrahydrofuran (THF). Fourier transformation infrared spectroscopy (FTIR), UV-vis absorption spectroscopy (UV) and differential scanning calorimetry (DSC) showed that Co(DBS)₂ coordinated to the lone electron pairs of the pyridine nitrogens in the P4VP block and leaded to complexes. The supramolecular block copolymers could self-assemble into nanosized micelles with different shapes and dimensions in THF, depending on the number of Co(DBS)₂ groups per 4-vinylpyridine (repeat unit was denoted by n) and the ratio between PS block length and P4VP block length. Transmission electron microscopy (TEM) results showed that when the number of repeat units of P4VP was more than that of PS, micelles with different interesting shapes such as spheres, rods, vesicles, large compound vesicles (LCVs) and the large compound micelles (LCMs) were observed if increasing the content of the Co(DBS)₂ in PS-b-P4VP copolymer/THF solution; When the number of repeat units of P4VP was less than that of PS, the micelle morphologies changed from spheres to rods, bi-layer, and LCMs if the Co(DBS)₂ content was increased progressively.     

四臂星型聚苯乙烯-聚4-乙烯基吡啶嵌段共聚物纤维状胶束及负载金纳米粒子的研究

通过两步原子转移自由基聚合,制备了4种不同嵌段长度的四臂星型嵌段共聚物苯乙烯-聚4-乙烯基吡啶嵌段共聚物(PS-b-P4VP)4.在选择性溶剂甲苯中,随着嵌段长度的变化,自组装胶束的形态从球型到短棒状和纤维状的转变,其中(PS25-b-P4VP90)4自组装形成的以P4VP为核,以PS为花瓣型壳的纤维状胶束.以这种纤维状胶束作为模板,制备了金纳米粒子均匀分布的一维纳米材料     

一种侧基横挂偶极单元的聚苯撑乙炔的光学性质

以对苯二乙炔和2,5-二溴苯衍生物为单体,无水N,N-二甲基甲酰胺（DMF）为溶剂,通过Sonogashira偶联反应,采用2种Pd催化剂（Pd(PPh₃)₄和PdCl₂(PPh₃)₂）合成了一种侧基带有偶极基团的聚苯撑乙炔。 单体的化学结构通过IR、NMR和元素分析等测试技术得到确证。 聚合物外观为黄色粉状固体,室温下溶于CHCl₃和THF等有机溶剂。 2种Pd催化剂对合成聚合物的分子量以及光学性质影响不大,但对聚合物的发光效率影响较大,由Pd(PPh₃)₄催化得到的聚合物分子链具有较高的立构规整性,因此,具有较高的发光效率。 不同溶剂环境以及聚合物固体膜的紫外以及荧光光谱研究结果表明,侧基偶极基团的相互静电排斥力,可以有效阻止大分子链之间的聚集,从而有效地抑制了聚苯撑乙炔聚集体的形成。     

Synthesis and antibacterial activity of copper-immobilized membrane comprising grafted poly(4-vinylpyridine) chains

Poly(4-vinylpyridine) (P4VP) brushes were grafted onto microporous polysulfone (PSF) membranes via surface-initiated atom transfer radical polymerization (SI-ATRP) and then immobilized copper (II) ions on the modified membrane. Copper-loaded membranes exhibited excellent antibacterial properties with the added advantage of repeated use. The chemical composition and surface morphology of the functionalized membrane was characterized by ATR-FTIR, XPS, SEM, and AFM. The results showed that P4VP brushes clustered to rod-shaped covering and the sub-layer of membrane maintained sponge-like structures at the same time. Additionally, the kinetic study of SI-ATRP reaction revealed that the chain length of P4VP brushes increased linearly as the polymerization time increased. The antibacterial effects of copper-loaded CMPSF-g-P4VP membrane against Escherichiacoli were examined and the antibacterial efficiency reached 100% when 2.49wt.% of copper (II) ions was immobilized on membrane. The presented results could serve as a good starting point for the fabrication of antibacterial CMPSF membranes for waste-water treatment applications.     

Thermal degradation of poly(vinylpyridine)s

The thermal stability and the temperature at which maximum degradation yields are detected were quite similar for both poly(2-vinylpyridine) (P2VP) and poly(4-vinylpyridine) (P4VP). However, considerable differences among the thermal degradation products of both polymers were detected indicating a correlation between the polymer structure and the degradation mechanism. Direct pyrolysis mass spectrometry analyses revealed that P2VP degrades via a complex degradation mechanism, yielding mainly pyridine, monomer, and protonated oligomers, whereas depolymerization of P4VP takes place in accordance with the general thermal behaviour of vinyl polymers. The complex thermal degradation behaviour for P2VP is associated with the position of the nitrogen atom in the pyridine ring, with σ-effect.