一种稠油原油污水处理破乳剂的合成及性能研究

通过保护与反保护的方法,合成了PAMAM稠油原油污水高效破乳剂。探讨了原油废水的pH值、温度,以及不同PAMAM代数对稠油原油污水破乳效果的影响,结果表明,在温度为20℃,pH值的范围为4.8~10.57的条件下,4代PAMAM树形分子投加20mg/L时,除油率达到96.9%。现场试验表明,PAMAM树形分子是一类性能优良的稠油原油污水破乳剂。     

紫外光辐照下以PAMAM树形分子为模板制备Ag纳米簇及光致发光性能研究

以G5．0-OHPAMAM树形分子为模板，用紫外光辐照法制备银纳米簇．用透射电子显微镜、紫外-可见吸收光谱和共振散射光谱等对所制备的银纳米簇进行了表征．结果表明：用紫外光辐照法可以制备尺寸分布均匀、稳定的银纳米簇；且辐照时间、PAMAM树形分子的浓度及Ag^＋／PAMAM树形分子的摩尔比都会对所制备的银纳米簇产生较大的影响．由于所制备的银纳米簇的粒径小于树形分子的流体力学半径，表明树形分子起到了“内模板”作用．同时研究了银纳米簇的尺寸对其光致发光性能的影响，发现通过调节银纳米簇的尺寸可实现其光致发光的可调性．     

树形高分子增强的高分子磁性颗粒的制备与表征

利用化学共沉淀法制备Fe3O4磁性纳米粒子;悬浮聚合的方法制备带有酰胺基的聚苯乙烯-丙烯酰胺磁性颗粒(NMP);发散法制备聚酰胺胺树形高分子(PAMAM)并与酰胺修饰聚苯乙烯磁性颗粒结合,得到树形高分子增强的磁性微粒。并对NMP和PAMAM-NMP的颗粒基质晶体结构、饱和磁化强度、表面官能团和微观结构以及各元素的百分含量进行表征。结果显示,Fe3O4磁核晶形完整,平均粒径为9 nm;PAMAM-NMP的红外图谱在3478 cm-1和3 300 cm-1处有吸收峰,证明存在胺基;经PAMAM增强后氮元素百分含量由0.225%增加到0.992%,证明PAMAM为NMP提供了更多的活性基团;在有无磁场存在时的沉淀时间分别为16 h和2112 h,证明PAMAM-NMP有良好的磁响应性和悬浮性。     

树枝状聚酰胺胺与线形聚合物共混的研究

介绍了聚酰胺胺(PAMAM)树状分子的独特结构和性能,综述了国内外有关聚酰胺胺树状分子与线形聚合物共混的研究进展。参考文献24篇,包括树枝状聚酰胺胺的分子结构,它的性能及其同PHE-MA、PVC、PVC和PVAC,尼龙6、聚马来酸酐、聚甲基乙烯基醚、环氧树脂等共混物。     

Electrochemistry of polyamidoamine dendrimers ester gel electrolytes

This paper described the first example of polyamidoamine dendrimers ester (PAMAM) used as a gel electrolyte with a short-chain polyethylene glycol (MPEG-400) as a plasticizer. The polymer films are solid and sticky. Background cyclic voltammetry (CV) shows a potential window between 0.7 and -0.7 V vs. Ag/AgCl. The voltammetry of ferrocene and 7,7,8,8-tetracyanoquinodimethane (TCNQ) indicates that diffusion coefficients are in the range of 10^-8-10^-9 cm^2/s.Ionic conductivities are approximately 10^-6 S/cm. Similar films using dimethyl sulfoxide (DMSO) as a plasticizer instead of MPEG-400 have demonstrated ionic conductivities of 10-4 S/cm and reversible voltammetry. However, UV spectropho-tometry shows that 70% of the DMSO is lost under vacuum, indicating the difficulty in quantifying the DMSO content when exposed to vacuum.     

改性天然橡胶MG-30和树枝状聚酰胺-胺对轮胎胎面胶耐磨性能的影响

研究甲基丙烯酸甲酯接枝改性的天然橡胶（NR）MG-30和树枝状聚酰胺-胺（PAMAM）对全钢子午线轮胎胎面胶耐磨性能的影响。结果表明：与生产配方胶料相比,加入MG-30后的NR胶料的门尼特性和硫化特性均无明显变化、物理性能有所提高,但邵尔A型硬度增大;加入PAMAM后,NR/MG-30并用胶的物理性能和耐磨性能明显提高,邵尔A型硬度减小。     

聚酰胺-胺的合成及在水处理中的应用

聚酰胺-胺(PAMAM)树枝状大分子作为一类三维的、分子尺寸和构型高度可控的高分子聚合物,因其具有无毒高效、易于修饰等优点,已在工业水处理领域引起了广泛的关注。本文介绍了PAMAM的主要合成路线及工艺优缺点,综述了近年来PAMAM及其改性衍生物在工业水处理中应用研究进展,分析其作用机理及影响因素,最后对未来的研究方向作以展望。     

星型高效复合主抗氧剂的合成与抗氧化性能

 以β-(3,5-二叔丁基-4-羟基苯基)丙酰氯(简称3,5-丙酰氯, 3,5-Propionyl chloride)和星型聚合物1.0代聚酰胺-胺(1.0G PAMAM)为原料,通过酰胺化缩合反应合成了结构新颖的星型高效复合主抗氧剂,并通过优化实验确定了该抗氧剂的最佳合成条件。采用元素分析、FT-IR、¹H NMR 和¹³C NMR 对星型高效复合主抗氧剂进行表征,并考察了该抗氧剂在聚烯烃树脂中的抗氧化性能。结果表明,当n(3,5-Propionyl chloride)/n(1.0G PAMAM)=5、 三氯甲烷为溶剂、 反应时间12 h、 滴加1.0G PAMAM的温度为15℃、反应温度为45℃时,星型高效复合主抗氧剂收率在65%以上,熔程为204.5~206.5℃。星型高效复合主抗氧剂在聚烯烃树脂中具有很好的抗氧化作用,在聚丙烯树脂(PP)中的抗氧化性能与市售抗氧剂1010和3114相近,在聚乙烯树脂(LLDPE)中的抗氧化性能优于抗氧剂1010和3114。     

Detection of aflatoxin B1 by aptamer-based biosensor using PAMAM dendrimers as immobilization platform

We report an aptamer-based biosensor for detection of aflatoxin B₁ (AFB₁), a mycotoxin identified as contaminant in food. The sensor is assembled in a multilayer framework that utilizes cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) for acquiring the signal response by means of redox indicators: K[Fe(CN)₆]^−3/−4. Poly (amidoamine) dendrimers of fourth generation (PAMAM G4) immobilized on gold electrode covered by cystamine, were employed for attachment of single stranded amino-modified DNA aptamers specific to AFB₁. The cystamine-dendrimers (Cys-PAMAM) layers were compared with other immobilization platforms such as cystamine (Cys), 11-mercaptoundecanoic acid (MUA) and 11-mercaptoundecanoic acid-dendrimers (MUA-PAMAM), being the first approach the most appropriate for producing sensitive and reproducible signal in the range of concentrations 0.1–10 nM AFB₁. The sensor was validated in certified contaminated peanuts extract as well as in spiked samples of peanuts-corn snacks and the sensing response was evaluated and compared in terms of the matrix effect. The aptamer specificity was analyzed by testing the sensor in other mycotoxins such as aflatoxin B₂ (AFB₂) and ochratoxin A (OTA). The limit of detection achieved by this sensor was LOD = 0.40 ± 0.03 nM, it was regenerable in 0.2 M glycine-HCl and it did not lose its stability up to 60 h storing at 4 °C. Atomic Force Microscopy (AFM) studies were also performed for illustrating individual steps of biosensor assembly.     

Dendrimer templates for heterogeneous catalysts: Bimetallic Pt–Au nanoparticles on oxide supports

Polyamidoamine (PAMAM) dendrimers were used to template Pt, Au, and bimetallic Pt–Au dendrimer encapsulated nanoparticles (DENs) in solution. Adjusting the solution pH allowed for slow, spontaneous adsorption of the nanoparticles onto silica, alumina, and titania. After dendrimer removal, the catalysts were characterized with infrared spectroscopy of adsorbed CO and tested with CO oxidation catalysis. Infrared spectroscopy of the monometallic Pt catalysts showed a slight shift in the CO stretching frequency for the different supports. For the bimetallic catalysts, infrared spectra showed CO adsorbed on both Pt and on Au sites. Spectra collected during CO desorption showed substantial interactions between the two bands, confirming the presence of bimetallic particles on all the supports. The bimetallic catalysts were found to be more active than the monometallic catalysts and had lower apparent activation energies. The titania supported Pt–Au catalyst was resistant to deactivation during an extended treatment at 300 °C. Correlations between IR spectra and catalytic activity showed differences between the mono- and bimetallic materials and implicated a bimetallic Pt–Au ensemble at the catalytic active site. This is the first study to show that DENs are appropriate precursors for studying support effects on catalysis by metal nanoparticles, although the magnitude of the effects were small.