聚合硅酸硫酸铝的合成、改性及结构表征

以硫酸铝,水玻璃和铝酸钠为原料制备了聚合硅酸硫酸铝(PASS),以聚二甲基二烯丙基氯化铵对聚合硅酸硫酸铝进行了改性。并通过红外光谱和X-射线衍射技术对聚合硅酸硫酸铝及其复合絮凝剂的结构特征进行了研究。

含阳离子表面活性剂高吸水性树脂的性能

采用含有烯丙基结构的长链烷基季铵盐阳离子表面活性剂和丙烯酰胺为原料,以N,N′-亚甲基双丙烯酰胺为交联剂,水溶液聚合法合成一种新型的高吸水性树脂。探讨了交联剂用量、单体中季铵盐的含量等对共聚树脂吸水率的影响;并对共聚树脂的溶胀速率及抗菌性能进行了测试。实验结果表明:在聚合体系中加入一定量的长链烷基季铵盐,共聚树脂在去离子水和质量分数为0 9%NaCl的水溶液中的最大吸水量分别由415g/g和48g/g提高到535g/g和62g/g;共聚树脂还具有抗菌杀菌性能,对金黄色葡萄球菌、大肠杆菌和白色念珠菌等微生物菌株均有不同程度的杀灭和抑制其生长的作用,树脂中季铵基团的含量越高、烷基链越长,树脂的抗菌效果越好。

Accurate ab initio Predictions of Ionization Energies and Heats of Formation for Cyclopropenylidene, Propargylene and Propadienylidene

The ionization energies （IEs） of cyclopropenylidene （c-C3H2）, propargylene （HCCCH） and propadienylidene （H2CCC） have been computed using the CCSD（T）/CBS method, which involves the approxixnation to the complete basis set （CBS） limit at the coupled cluster level with single and double excitations plus quasi-perturbative triple excitation effect （CCSD（T））. The zero-point vibrational energy correction, the core-valence electronic correction, the scalar relativistic effect and the high level correction beyond the CCSD（T） excitations have also been made in these calculations. The CCSD（T）/CBS values for the IN（c-C3H2） and IE（HCCCH） of 9.164, 8.987 eV are in good agreement with the experimental values of （9.15±0.03） and （8.96±0.04） eV. The CCSD（T）/CBS calculations yield the IE values of 10.477 and 10.388 eV for the ionization transitions H2CCC→H2CCC^＋ （^2A1, C2v） and H2CCC→H2CCC＋ （^2A＇, Cs）, respectively. On the basis of the Franek-Condon factor consideration, the IE of （10.43±0.02） eV determined in the previous single-photon ionization experiment most likely corresponds to the ionization threshold for the H2CCC→H2CCC^＋（^2A1, C2v） transition. Although the precision of the experimental IN measurements fpr c-C3H2, HCCCH, and H2CCC is insufficient to pin down the accuracy of the theoretical calculations to better than ±30 meV, the excellent agreement between the experimental and theoretical IE values observed in the present study indicates that the CCSD（T）/CBS calculations together with high-order correlation corrections are capable of yielding reliable IE predictions for simple hydrocarbon carbenes and bi-radicals. We have also reported the heats of formation at 0 K （△H^of0） and 298 K （△H^of298）for c-C3H2/c-C3H2^＋, HCCCH/HCCCH^＋, and H2CCC/H2CCC^＋, The available experimental △H^of0 and △H^of298 values for c-C3H2/c C3H2^＋, HCCCH/HCCCH^＋ are found to be in good accord with the CCSD（T）/CBS predictions after taking into account the experimental uncertainties.

A New Disulfide from Garlic

从大蒜 (AlliumsativumL .)环己烷提取物中分得了一个新的二硫化物 :E 丙烯醛基烯丙基二硫化物 (1) ;两个新的阿霍烯类化合物 :E 4,5 ,9 三硫 1,7,11 三烯 9,9 二氧化物 (2 ) ,Z 2 ,3,7 三硫 4,9 二烯 7 氧化物 (3) 。

Structural Dynamics of 3-Dimethylamino-2-methyl-propenal in S2（ππ^＊） State

The photophysics of 3-dimethylamino-2-methyl-propenal （DMAMP） after excitation to the S2 （ππ^＊） electronic state was studied using the resonance Raman spectroscopy and complete active space self-consistent field method calculations. The transition barriers of the ground state tautomerization reactions between DMAMP and its three isomers were determined at B3LYP/6-311＋＋G（d,p） level of theory. The vibrational spectra were assigned. The A- band resonance Raman spectra were obtained in acetonitrile with excitation wavelengths in resonance with the first intense absorption band to probe the structural dynamics of DMAMP. The B3LYP-TD computation was carried out to determine the relative A-band resonance Raman intensities of the fundamental modes, and the result indicated that the vibronic-coupling existed in Franck-Condon region. Complete active space self-consistent field （CASSCF） calculations were carried out to determine the excitation energies of the lower-lying singlet and triplet excited states, the conical intersection points and the intersystem crossing points. The A-band short-time structural dynamics and the corresponding decay dynamics of DMAMP were obtained by analysis of the resonance Raman intensity pattern and CASSCF computations. It was found that a sudden de-conjugation between C1=O6 and C2=C3 occurred at the Franck-Condon region of the S2（ππ^＊） state, while the enhancement of the conjugation interaction between C3 and N（CH3）2, and between C1 and C2 evolutions shortly after the wavepacket leaves away the Pranck-Condon region via the excited state charge redistribution. The de-conjugation interaction between C1=O6 and C2=C3 made the rotation of C3=N（CH3）2 group around the C2-C3 bond much easier, while the enhanced conjugation between C1 and C2, and between C3 and N（CH3）2 made the rotation around the C1-C2 bond and C3-N5 more difficult. It was revealed that the initial structural dynamics of DMAMP was predominantly towards the CI-I（S2/S0） point, while the opportunities towards either CI-2（S2/S0） or CI-3（S2/S0） point were negligible. Two decay channels of DMAMP from S2,FC（ππ^＊） to So or Tl,min via various CIs and ISCs were proposed.

Quantum chemical study on asymmetric allylation of benzaldehyde in the presence of chiral allylboronate

The quantum chemical method is employed to study the modified asymmetric allylation of benzaldehyde controlled by diisopropyl D-(-)-tartrate auxiliary. All the structures are optimized completely at the B3LYP/6-31G(d,p) level. The (R)-secondary alcohol can be achieved mainly through a six-membered ring chair-like transition state structure. From the relative reaction rates theory the main product configuration predicted is in agreement with the experiment result.

Structures of Silk Fibers Grafted with Hexafluorobutyl Methacrylate

The relationship between the graft yield and the effect of hexafiuorobutyl methacrylate graft treatment on the structural changes of the silk fibers was studied on the basis of the results of scanning electron micrograph photographs （SEM）, infrared spectroscopy （IR）, Raman spectrum, wide-angle X-ray diffraction patterns （WAXD）, nuclear magnetic resonance（NMR） and amion acid analysis. The results showed that the crystalline regions of grafted fibers were hardly affected and the fiber fission occurred on the cross sections of grafted fibers. The surface of fibers was covered with a high polymer film. The Raman spectrum showed there was little change in the conformation of grafted fibers which mainly remained β-sheet conformation. The IR of the grafted silk fibers showed new absorption of bands occurred which belonged to the stretching-vibrationabsorption-peak bands of Vo-o and VC-F of aliphatic ester species. The CF3-, -CF2- and -CFH- grafted silk macromodecul were verified in the NMR spectrum. The amion acid analysis indicated fluoride monomers were inclined to graft with TYR, ARG and CLU silk fibers.

Direct fabrication of carbon nanotube-graphene hybrid films by a blown bubble method

Hybridization of carbon nanotubes （CNT） with graphene provides a promising means of integrating the attributes of both materials, thereby enabling widespread application. Here, we present a method to directly assemble hybrid CNT- graphene films by a blown bubble method combined with selective substrate annealing. We use polymethylmethacrylate （PMMA） as the polymeric matrix to blow bubbles containing self-assembled multi-walled CNT arrays, and then transform the bubble film into a CNT-graphene hybrid film by thermal annealing on a Cu substrate; PMMA serves as the carbon source for growing single to few-layer graphene among the CNT network until a continuously hybridized structure is formed. Compared to the bare （non-hybridized） CNT networks, the hybrid films exhibit improved electrical conductivity and structural integrity. Our method also enables the fabrication of a multi-walled CNT-Si solar cell, which has high power conversion efficiency, through the assembly of hybrid CNT-graphene structures.

Crystal structure of trans-3-phenyl-2-propenoic acid

The title compound of trans-3-phenyl-2-propenoic acid （C9H802）, a main active organic acid of cinnamon bark and styrax, was obtained by oxidization from trans-3-phenyl-2-propenaldehyde and characterized by X-ray diffraction analysis. It crystallizes in monoclinic system, space group P21/n with a = 5.55916（10）, b = 17.4870（3）, c = 7.70677（13） A, V = 744.89（2） A3, Z= 4, Dc= 1.321 g/cm3, Mr = 148.15, F（000） = 312, and/t μ=0.764 mm-1. A total of 2661 reflections with 1447 unique ones （Rint = 0.0137） were collected, in which 1447 were observed （I〉2σ（/））. There were two C9H802 molecules in an asymmetric unit. The structural unit was a dimer formed by the hydrogen bonding of the oxygen atom of carbonyl group and the hydrogen atom of hydroxyl group. A 3D layer structure was formed through hydrogen bonds and Van der Walls＇ forces.