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.
The PMA/Eu2O3 porous and layered nanocomposite was prepared by in situ polymerization and characterized by means of X-ray diffraction （XRD）, transmission electron microscopy （TEM）, scanning electron microscope （SEM）, and inflared ray （IR）. Microscopic investigation of the nanocomposite was carded out by atomic force microscopy （AFM）. The results showed that the shape of the composite was layered and porous. Eu2O3 was grafted when methyl acrylate （MA） polymerized; thus Eu2O3 particles appeared on both sides of the chains of polymeric methyl acrylate （PMA）.
MO ZunliLIU YanzhiWANG KunjieLI HejunCHEN HongSUN Yinxia
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 aplasticizer. The polymer films are solid and sticky. Background cyclic voltammetry (CV) shows apotential window between +0.7 and -0.7 V vs. Ag/AgCl. The voltammetry of ferrocene and7,7,8,8-tetracyanoquinodimethane (TCNQ) indicates that diffusion coefficients are in the range of10^(-8) -10^(-9) cm^2/s. Ionic conductivities are approximately 10^(-6) S/cm. Similar films usingdimethyl sulfoxide (DMSO) as a plasticizer instead of MPEG-400 have demonstrated ionicconductivities of 10^(-4) S/cm and reversible voltammetry. However, UV spectropho-tometry shows that70% of the DMSO is lost under vacuum, indicating the difficulty in quantifying the DMSO contentwhen exposed to vacuum.
