Study on Interaction Energy of PAMAM/Lanthanide（ Ⅲ ） by Molecular Dynamics Method

PAMAM/lanthanide （Ⅲ） nanocomposite was studied by molecular simulation method. Molecular simulation enabled study of the lanthanide tetrad effect at atomic level. However, PAMAM dendrimer exhibiting unique properties such as nanometer size and highly functionalized terminal surface provided a novel space for lanthanide （Ⅲ） to show their peculiar tetrad effect. The results showed that total energies of PAMAM/lanthanide（Ⅲ） nanocomposites presented obvious tetrad effect and special double-double effect. Nd, Gd, and Er fell to the lower point and Gd fell to the lowest point in the TE-Ln curve with four groups. In order to explain the tetrad effect, kinetic energy （KE） and potential energy （PE） were analyzed. The KE curve consisted of three W-type parts （La - Pm, Pm - Tb, Tb - Tm, and the latter two W-type part were axial symmetry） and an exception part （Yb - Lu）. It also showed that the KE of odd atomic number was higher than the even one＇s with exception of Yb and Lu. Furthermore, decomposed potential energies gave out the atomic-level subtle difference of lanthanide which present more regulations for Eu（Ⅲ） - Lu（Ⅲ） compared with La（Ⅲ） - Sm（Ⅲ）. And also Ho-valley and three platforms （Sm - Eu, Td - Dy, Er - Tm） were discovered that refect the regular change of nanocomposite structures. Additionally, there are distinct correlations between Ebond and EInversion, EAngle and EVDW, Eworsion and ECoul, respectively. Therefore, PAMAM could be used in separation of lanthanide by changing conditions.     

海上平台快速除油剂的制备与应用

针对赵东平台采油污水量大、污水含油量高、平台处理时间短等问题,以二乙烯三胺和丙烯酸甲酯为原料制得3代聚酰胺-胺超支化聚合物,再与二甲胺和环氧氯丙烷反应制得枝状聚酰胺-胺类聚阳离子类除油剂KYOR,研究了KYOR支化度对除油率的影响,考察了KYOR与现场用破乳剂DGF-18B的配伍性,并在赵东平台以连续注入方式进行了现场应用。结果表明,在超支化聚胺类的球形结构中,用季铵盐进行封端及改性可提高其亲水性和分子量;KYOR系列产品中,支化度最高的3.0代聚酰胺-胺制备的KYOR-3的除油效果最好,30 mg/L的KYOR-3可使污水含油量由202.8 mg/L降至17.8 mg/L,20 min除油率为91.22%。KYOR-3与赵东平台现场用破乳剂DGF-18B的配伍性良好,对原油脱水无影响。KYOR-3现场处理赵东平台注入水后,含油量、悬浮固体含量和粒径中值均明显降低,达到赵东平台回注污水水质指标要求。     

Composites membranes based on Nafion and PAMAM dendrimers for PEMFC applications

The aim of this work consists in to incorporate organic compounds as PAMAM (Poly-amidoamine) dendrimers into the polymeric Nafion matrix to prepare composite membranes as a possible alternative to reduce methanol crossover effect. Composite Nafion membranes were prepared using a 3 wt% of Generation-4 hydroxyl-terminated PAMAM (G4OH) dendrimers containing 64-terminal OH-functional groups. The influence of PAMAM-(G4OH) dendrimer on chemical–physical properties of the composite membrane was highlighted resulting in a reduction of the methanol permeability (1.05 × 10⁻⁶ cm² s⁻¹) if compared to a recast bare Nafion membrane (8.19 × 10−6 cm² s⁻¹), used as a reference. Good proton conductivity was also observed for PAMAM-(G4OH) composite membrane. The polarization curves carried out at 100 °C in the presence of 2 M methanol have revealed the higher performance of the PAMAM-(G4OH) membrane when compared to a recast Nafion membrane.     

Oxygen reduction and diffusion in electroactive nanostructured membranes (ENM) using a layer-by-layer dendrimer-gold nanoparticle approach

The fabrication of an electroactive nanostructured membrane (ENM) for oxygen reduction, made of layer-by-layer (LbL) films comprising Au nanoparticle-containing amine-terminated G4 PAMAM dendrimer alternated with poly(vinylsulfonic acid) (PVS) layers is reported. Electrochemical impedance spectroscopy and cyclic voltammetry show that electrodes with PVS/PAMAM-Au multiple bilayers are efficient for oxygen reduction and diffusion. A linear increase of oxygen reduction current occurs for up to 3 bilayers, with no further significant increase occurring for more than 3 bilayers. The 3-bilayer PVS/PAMAM-Au electrode, as an Au-ENM, is an attractive new system with potential for building diverse electrocatalytic devices with high molecular control.     

微波法制备3．5GPAMAM树状大分子保护的金纳米粒子

以3．5GPAMAM（3．5代聚酰胺一胺型）树状大分子为保护剂，利用微波法还原HAuCl4溶液制备金纳米粒子．考察了当3．5GPAMAM与HAuCl4物质的量的比一定时，微波照射不同时间对金纳米粒子大小及形状的影响；以及同一照射条件下，3．5GPAMAM与HAuCl4不同的物质的量比值对金纳米粒子大小及形状的影响．利用紫外可见分光光度计、透射电子显微镜对其进行了表征．结果表明，当3．5GPAMAM与HauCl4物质的量的比值一定时，金纳米粒子的形状和大小受微波照射时间长短的影响不大；适当延长照射时间，制得的金纳米粒子的分散性较好．在相同照射条件下，随着3．5GPAMAM与HAu—C14物质的量比值的减小，得到的金纳米粒子粒径逐渐变大，且分散性变差．     

金属配位树枝状大分子鞣剂的合成及表征

以乙二胺和丙烯酸甲酯为原料合成了 0 .5～ 3 .5代的树状聚酰胺大分子 ,在碱性条件下水解 ,将其外围官能团转变为羧基 ,并与CrCl3 配位得到金属配位树状大分子鞣剂。利用红外光谱、核磁共振、紫外光谱等手段对合成产物进行了表征。     

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。