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1.
利用Ag^+-Na^+离子交换法形成了Ag^+离子基底,在此基础上镀上PDMA/PMMA膜并在Y型波导分支上进行局部紫外聚合,从而制成了较理想的通道波导。测定了PDMA/PMMA的线性折射率及Ag^+离子基底的折射率,实现了较理想的复合波传输。  相似文献   

2.
利用聚丙烯等离子体接枝甲基丙烯酸甲酯共聚物(PP-g-PMMA)作增容剂,研究了其在聚丙烯/聚偏氟乙烯(PVDF)共混体系中的作用。增容是通过PMMA与PVDF的偶极-偶极相互作用实现的。接枝共聚物使共混体系的抗张强度和模量均有提高,由不同等离子体处理时间所得的PP-g-PMMA,接枝率在7.7%~300%具有最好的增容效果;而由不同后聚合时间所得的共聚物,接枝率在30%~80%具有最好的增容效果。  相似文献   

3.
陈瑞川  万桢 《应用化学》1998,15(6):25-28
以电化学聚合法在石墨电极上获得聚间苯二胺膜(PMPD),并建立了快速、灵敏的膜质量检验方法:辣根过氧化物酶(HRP)标记PMPD膜-邻苯二胺(OPD)反应法,对聚合、活化等条件作了研究;进一步制成了检测乙肝表面抗原(HBsAg)和检测鼠免疫蛋白(MIgG)的免疫电极,对血清样品作了检测.结果表明:2.5V电池电压下,于含0.12mol/LMPD的1.2mol/LH2SO4中聚合20min,再以30g/L浓度的戊二醛活化4h,所得HRP标记电极及免疫电极重现性好;检测HB-sAg和MIgG的线性范围分别为0.1~3.2mg/L及0.1~10mg/L  相似文献   

4.
甲醇在CM-3-1催化剂上脱水生成二甲醚的本征动力学   总被引:9,自引:0,他引:9  
采用等温积分反应器研究了常压下甲醇在CM31催化剂上脱水生成二甲醚反应的本征动力学,得到Langmiur均匀吸附双曲型动力学方程:rM=1.587×1012exp122984RTPM1PDPWKP2M1+1.103×109exp81760RTPM2,mol/(g·h)  相似文献   

5.
4-(H酸偶氮)-1-苯基-3-甲基吡唑酮光度法测定铝   总被引:1,自引:0,他引:1  
研究了新试剂4-(H酸偶氮)-1-苯基-3-甲基吡唑酮(HAPMP)与铝的显色反应,在pH4.6的HAc-NaAc缓冲介质中,CTMAB存在下,HAPMP和Al(Ⅲ)反应生成2∶1红色络合物,λmax=555nm,ε=1.34×105L·mol-1·cm-1,铝的含量在0~3.5μg/25mL内符合比尔定律,方法已用于天然水样中铝的测定。  相似文献   

6.
采用DMA和TEM系统研究了聚丁二烯-聚甲基丙烯酸甲酯的嵌段共聚物(PBD-b-PMMA)与聚氯乙烯(PVC)共混体系的相容性问题。结果表明:PVC/PBD-b-PMMA共混体系具有部分相溶性。相容的程度与共混体系的组成、组分聚合物的分子量以及共聚物中PBD和PMMA嵌段的比例密切相关。  相似文献   

7.
聚合物-锂改性蒙脱石复合材料离子迁移   总被引:1,自引:0,他引:1  
以聚合物(PEO,PEO-PMMA)和锂改性蒙脱石作为主要原料,采用聚合物粉末直接熔融嵌入的方法,制备聚合物-蒙脱石复合材料.利用NMR、AC阻抗等分析方法探讨了复合材料中聚合物链对 Li+离子迁移的影响.结果表明,聚合物(PEO)嵌入蒙脱石层间,层间聚合物链的无序度增大,有利于Li+离子迁移.PMMA引入对PEO链的改性,进一步加大聚合物链的无序度,更易于层间Li+离子迁移;复合材料的常温离子电导率接近10-2S·cm-1,且具有良好的温度稳定性.  相似文献   

8.
聚醋酸乙烯酯与铜(Ⅱ)离子的配位反应及其催化作用   总被引:1,自引:1,他引:1  
以ESR、UV和IR表征Cu(2+)离子与PVAC的配位反应。根据CUCl2·2H2O乙醇溶液与PVAc-CuCl2·2H2O乙醇溶液的电导率差值随Cu(2+)离子摩尔浓度变化的明显转析点得知,1个Cu(2+)离子大约能与PVAc4个链节单元配位。证实MMA在Cu(Ⅱ)-PVAc配合物/Na2SO3体系的聚合体是无规PMMA,得率为70%。讨论了MMA在Cu(Ⅱ)-PVAc配合物/Na2SO3体系络合催化引发下的游离基反应历程。  相似文献   

9.
报道了以氨三乙酸为活化剂,以N-十二烷基二甲基铵基乙酸(DDMAA)为增敏剂,高碘酸钾氧化酸性品红催化光度法测定痕量锰的新方法,在DDMAA存在下,灵敏度提高了7倍(Mn2+量为1.2~2.4μg/L)和14倍(Mn2+量为2.4~5.2μg/L),相对标准偏差为2.0%,检出限为1.4×10-7g/L,可用于茶叶中锰的测定。  相似文献   

10.
4—(H酸偶氮)—1—苯基—3—甲基吡唑酮光度法测定铝   总被引:4,自引:1,他引:3  
研究了新试剂4-(H酸偶氮)-1-苯基-3-甲基吡唑酮(HAPMP)与铝的显色反应,在pH4.6的HAc-NaAc缓冲介质中,CTMAB存在下,HAPMP和Al(Ⅲ)反应生成2:1红色络合物,铝的含量在0 ̄3.5μg/25mL内符合比尔定律,方法已用于天然水样中铝的测定。  相似文献   

11.
Silver nanoparticles were formed in situ along with poly(2,5‐dimethoxyaniline) (PDMA) in an interconnected network matrix (reactor), comprising the electronic conductive polymer, PDMA, and a polyelectrolyte, poly(styrene sulfonic acid) (PSS), through the simultaneous reduction of Ag+ ions and polymerization of 2,5‐dimethoxyaniline. In situ ultraviolet‐visible spectroscopy showed that peaks corresponding to the plasmon resonance of silver nanoparticles at 411 nm and the polaronic transition of PDMA at 438 nm provided evidences for the simultaneous formation of silver nanoparticles and PDMA. Transmission electron microscopy and size distribution analysis revealed the presence of spherical silver nanoparticles with an average diameter of 12 nm in the composite. X‐ray photoelectron spectroscopy showed that the amine units in PDMA changed to imine units upon the formation of silver nanoparticles. A comprehensive mechanism for the formation of the PDMA‐PSS‐Ag nanocomposite is proposed. A 10‐fold increase in the conductivity was noticed for the PDMA–PSS–Ag nanocomposite (1 S/cm) in comparison with the PDMA–PSS composite (0.1 S/cm). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3843–3852, 2006  相似文献   

12.
A poly(2,5-dimethoxyaniline) (PDMA) film was coated on the iron surface by the electropolymerization of 2,5-dimethoxyaniline in neutral buffer solution (pH?6.86). The PDMA film strongly adhered to the surface because of the polar methoxy groups of the PDMA molecules. The fact that no electrochemical response of the PDMA film-coated iron electrode to dissolved Fe2+ exhibited that the PDMA film was less permeable to dissolved species, acting as a diffusion barrier against agents causing corrosion such as H2O and O2. The PDMA film coating greatly lowered the anodic current peak ascribed to the anodic dissolution of iron and the corrosion current in strongly acidic medium, 0.5?M H2SO4 aqueous solution (1?M?????mol?dm??) as well as neutral medium (pH?6.86). The high anti-corrosion ability was due to a hybrid effect of the PDMA film not only as the diffusion barrier, but also as an in situ oxidant in spite of the slight redox activity of PDMA. In addition, the PDMA film is much more durable and adhesive than polyaniline film against over-oxidation.  相似文献   

13.
The similarities and differences in the adsorption behavior of diblock poly(2-(dimethylamino)ethyl methacrylate)-b-poly(2-(diethylamino)ethyl methacrylate) (XqPDMA-PDEA, where X refers to a mean degree of quaternization of the PDMA of either 0, 10, 50, or 100 mol%) copolymers at the mica/ and silica/aqueous solution interfaces have been investigated. These diblock copolymers form core-shell micelles with the PDEA chains located in the cores and the more hydrophilic PDMA chains forming the cationic micelle coronas at pH 9. These micelles adsorb strongly onto both mica and silica due to electrostatic interactions. In situ atomic force microscopy (AFM) has demonstrated that the mean spacing and the dimension of the adsorbed micelles depend on both the substrate and the mean degree of quaternization of the PDMA blocks. In particular, the morphology of the adsorbed nonquaternized 0qPDMA-PDEA copolymer micelles is clearly influenced by the substrate type: these micelles form a disordered layer on silica, while much more close-packed, highly ordered layers are obtained on mica. The key reasons for this difference are suggested to be the ease of lateral rearrangement for the copolymer micelles attached to the solid substrates and the relative rates of relaxation of the coronal PDMA chains.  相似文献   

14.
Poly(2,5‐dimethoxyaniline) (PDMA)–Ag composites were successfully obtained through the oxidative polymerization of 2,5‐dimethoxyaniline in poly(styrene sulfonic acid) with CH3SO3Ag and AgNO3 as oxidants. In situ ultraviolet–visible spectroscopy results showed that the growth rate of PDMA was strongly affected by CH3SO and NO. The coupling reaction of PDMA and NO was proposed to explain the lower growth rate of PDMA with AgNO3 as the oxidant in comparison with CH3SO3Ag. X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were used to validate the proposed coupling reaction through the monitoring of the side products and oxidized state of PDMA. The results showed that there were more side products and lower oxidized states for the composite structure in the presence of NO than in the presence of CH3SO, and this agreed with the proposal. Transmission electron microscopy showed that the Ag nanoparticles had almost the same size, regardless of the anions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6624–6632, 2006  相似文献   

15.
The mixtures of two polymers, poly (N,N-dimethylacrylamide) (PDMA) and polyvinylpyrrolidone (PVP) were synthesized and used as the separation medium for double-stranded and single-stranded DNA fragments by capillary electrophoresis with UV detector. On optimal conditions, 2%w/v PDMA 2%w/v PVP can be used to separate the doublet 123/124bp in pBR322/Hae Ⅲ Markers.  相似文献   

16.
在Ag(NH3)2+溶液中,在钛基体上电沉积出树枝状纳米银颗粒,研究了沉积电位对树枝状纳米银颗粒形成的影响,探讨了这种树枝状纳米银颗粒形成的机理,并研究了这种钛基树枝状纳米银电极(Ag/Ti)在碱性溶液中对甲醛氧化的电催化活性。结果表明,在30 mmol/LAg(NH3)2+以及沉积电位在-1.8~-1.2 V(vsAg)时,形成了形态为树枝状的纳米银颗粒。在沉积电位为-1.6 V(vs Ag),Ag(NH3)2+浓度为30 mmol/L的溶液中,电沉积制备的这种树枝状纳米银电极(Ag/Ti)对甲醛氧化具有强的电催化活性。循环伏安曲线表明,在0.1 mol/LNaOH溶液中以及甲醛的浓度范围在0~40 mmol/L,甲醛浓度和它的氧化峰电流密度呈现良好的线性关系,检测下限达到0.662 mmol/L,这种新型的树枝状纳米银电极有望作为甲醛检测的传感器。  相似文献   

17.
Ag nanoparticles grown on reduced CeO2-x thin films have been studied by X-ray photoelec-tron spectroscopy and resonant photoelectron spectroscopy of the valence band to understand the effect of oxygen vacancies in the CeO2-x thin films on the growth and interfacial elec-tronic properties of Ag. Ag grows as three-dimensional particles on the CeO2-x(111) surface at 300 K. Compared to the fully oxidized ceria substrate surface, Ag favors the growth of smaller particles with a larger particle density on the reduced ceria substrate surface, which can be attributed to the nucleation of Ag on oxygen vacancies. The binding energy of Ag3d increases when the Ag particle size decreases, which is mainly attributed to the final-state screening. The interfacial interaction between Ag and CeO2-x(111) is weak. The resonant enhancement of the 4f level of Ce3+ species in RPES indicates a partial Ce4+→Ce3+ re-duction after Ag deposited on reduced ceria surface. The sintering temperature of Ag on CeO1.85(111) surface during annealing is a little higher than that of Ag on CeO2(111) surface, indicating that Ag nanoparticles are more stable on the reduced ceria surface.  相似文献   

18.
将以铂微粒修饰玻碳电极(GC)为基体的聚2,5-二甲氧基苯胺膜(PDMA)形成修饰电极(Pt/PDMA/GC).循环伏安实验表明,Pt/PDMA/GC电极对甲醇氧化比分散于玻碳电极上的铂催化活性更大。讨论了PDMA膜厚度、铂微粒含量及甲醇浓度对催化活性的影响。这种电极在酸性甲醇溶液中具有良好的稳定性。  相似文献   

19.
To realize the spectral analysis of molecules on the opaque substrate, we proposed non-contact optical waveguide (NOW) spectroscopy. The cyt.c was adsorbed on the carbon substrate by dipping method. This was fixed above the optical waveguide. The gap between the carbon substrate and the waveguide was controlled by latex beads with a diameter of 120 nm as a spacer. A clear NOW spectrum based on the adsorbed cyt.c on the carbon substrate was observed. The cyt.c was easily adsorbed on the carbon surface with an oxidized form by the dipping method. The electrochemical cell system constructed on the waveguide enabled the dynamic analysis on the redox reaction of the adsorbed cyt.c on the carbon electrode. The adsorbed cyt.c showed stable redox reaction without the dislocation or re-dissolution in an aqueous solution.  相似文献   

20.
关英  张拥军 《高分子科学》2017,35(10):1212-1221
A strategy was developed for the synthesis of highly ordered 2D arrays of Ag-PNIPAM hybrid microgel.The highly ordered 2D arrays of PNIPAM microgel were prepared by dispersing PNIPAM microgel on a charge-reversible substrate.The microgel spheres self-assembled into a 3D colloidal crystal,and the first 111 plane was fixed in situ onto the substrate as a result of spontaneous charge reversal of the substrate,leaving a high-quality 2D array of PNIPAM microgel.Ag nanoparticles were then synthesized in situ inside the microgel spheres by introduction of Ag+ ions into the microgel spheres and reduction with sodium borohydride.The resulting 2D arrays are highly ordered.The inter-particle distance in the array can be tuned.In addition,the method allows the synthesis of large size arrays and the use of nonplanar substrate.  相似文献   

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