SBS as template to synthesize 3D siliceous mesostructured cellular foams

A mesostructured cellular foam (MCF) with three-dimensional (313) disordered strutlike structure is prepared by using triblock copolymer (poly(styrene-b-butadiene-b-styrene), SBS, M-W = 140K) as template under strong acid conditions. It is the first report to use triblock copolymer with both hydrophobic head and tail groups instead of hydrophilic head and hydrophobic tail copolymers to synthesize siliceous mesostructured cellular foams. The resulted materials have high pore volume (0.92 cm(3)/g) and relatively narrow pore size distributions with a large pore size of 7.9 nm, which will allow for the fixation of large active complexes, reduce diffusional restriction of reactants and enable reactions involving bulky molecules to take place, especially.

The first synthesis of a water-soluble alpha-cyclodextrin/C-60 supramolecular complex using anionic C-60 as a building block

A novel supramolecular inclusion complex of alpha-CD/C-60 was synthesized using anionic C-60. The reaction progress was monitored in situ by visible and near-IR spectroscopy. The obtained complex was characterized by UV-vis, C-13 NMR, MALDI-TOF, and cyclic voltammetry. The induction and dispersion forces are considered to be the major driving forces for the formation of a resulting alpha-CD/C-60(.-) inclusion complex.

Mercaptoethane sulfonate protected, water-soluble gold and silver nanoparticles: Syntheses, characterization and their building, multilayer films with polyaniline via ion-dipole interactions

Mercaptoethane sulfonate protected, water-soluble gold and silver nanoparticles (Au-MES and Ag-MES) are synthesized by one-phase method and characterized by TEM, TGA and XPS techniques, UV-vis and FTIR spectra. Both Au-MES and Ag-MES nanoparticles are soluble in the water up to 2.0 mg/ml and the stability of AU-MES is much better than that of Ag-MES. When dissolved in the water. they behave like a polyanion and can be used to build multilayer films with polyaniline (PANI) by way of layer-by-layer. A new approach is presented to fabricate the Multilayer films of Au-MES/PANI and Ag-MES/PAN]. The assembly mechanism of these multilayer films is also discussed. We anticipate highly conducting PANI films can be obtained by doping with these nanoparticles.

Effects of SBS addition and temperature on 3D siliceous mesostructured cellular foam

Siliceous mesostructured cellular foam with three-dimensional (3D) wormhole structure (MSU-type) is prepared by using triblock copolymer (poly(styrene-b-butadiene-b- styrene), SBS) with both hydrophobic head and tail group as template in strong acid condition via microemulsion method. The effects of SBS addition and temperature on the morphology and physicochemical properties, such as pore diameters, surface areas and pore volumes of the materials have been investigated by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscope (FE-SEM) and nitrogen adsorption-desorption analysis. The results show that the pore volumes, pore sizes and specific surface areas depend strongly on the SBS amount and forming micelles temperature. Moreover, the materials obtained with high wall thickness exhibit a relatively good thermal stability.

New high-dimensional networks based on polyoxometalate and crown ether building blocks

Three novel supramolecular assemblies constructed from polyoxometalate and crown ether building blocks, [(DB18C6)Na(H2O)(1.5)](2)Mo6O19.CH3CN, 1, and [{Na(DB18C6)(H2O)(2)}(3)(H2O)(2)]XMo12O40.6DMF.CH3CN (X = P, 2, and As, 3; DB18C6 = dibenzo-18-crown-6; DMF = N,N-dimethylfomamide), have been synthesized and characterized by elemental analyses, IR, UV-vis, EPR, TG, and single crystal X-ray diffraction. Compound 1 crystallizes in the tetragonal space group P4/mbm with a = 16.9701(6) Angstrom, c = 14.2676(4) Angstrom, and Z = 2. Compound 2 crystallizes in the hexagonal space group P6(3)/m with a = 15,7435(17) Angstrom, c = 30.042(7) Angstrom, gamma = 120degrees, and Z = 2. Compound 3 crystallizes in the hexagonal space group P6(3)/m with a = 15.6882(5) Angstrom, c = 29.9778(18) Angstrom, gamma = 120degrees, and Z = 2. Compound 1 exhibits an unusual three-dimensional network with one-dimensional sandglasslike channels based on the extensive weak forces between the oxygen atoms on the [Mo6O19](2-) polyoxoanions and the CH2 groups of crown ether molecules, Compounds 2 and 3 are isostructural, and both contain a novel semiopen cagelike trimeric cation [{Na(DB18C6)(H2O)(2)}(3)(H2O)(2)](3+). In their packing arrangement, an interesting 2-D "honeycomblike" "host" network is formed, in which the [XMo12O40](3-) (X = As and P) polyoxoanion "guests" resided.

用仪器化冲击仪研究HIPS/SBS共混物的冲击性能

用JJ-20型仪器化冲击仪研究了HIPS/SBS共混物在组成为100/0、100/5、100/10、100/15、100/20和100/25质量比下样品的Izod缺口冲击性能。结果表明，在组成范围内，随着SBS含量的增加，样品的Izod缺口冲击强度随之增加。质量比为100/25样品的Izod缺口冲击强度值(225.9J/m)比质量比为100/0的样品(108.7J/m)增加了1倍以上。通过对冲击断裂过程的分析表明，冲击强度的提高主要是由于缺口根部应力集中产生塑性区所消耗的裂纹引发能的提高引起的，而裂纹扩展能基本没有多大变化

Compatibilization effect of graft copolymer on immiscible polymer blends: 1. LLDPE/SBS/LLDPE-g-PS systems

compatibilizing effect of graft copolymer, linear low density polyethylene-g-polystyrene (LLDPE-g-PS), on immiscible blends of LLDPE with styrene-butadiene-styrene triblock copolymer (SBS) has been investigated by means of C-13 CPMAS n.m.r. and d.s.c. techniques. The results indicate that LLDPE-g-PS is an effective compatibilizer for LLDPE/SBS blends. It was found that LLDPE-g-PS chains connect two immiscible components, LLDPE and SBS, through solubilization of chemically identical segments of LLDPE-g-PS into the amorphous region of LLDPE acid PS block domain of SBS, respectively. It was also found that LLDPE-g-PS chains connect the crystalline region of LLDPE by isomorphism, with serious effects on the supermolecular structure of LLDPE. The effect of LLDPE-g-PS on the supermolecular structure of LLDPE in the LLDPE/SBS blends obviously depends on the composition of the blends, but has little dependence on the PS grafting yields of LLDPE-g-PS. (C) 1998 Elsevier Science Ltd. All rights reserved.

尼龙6／SBS共混物形态与性能的研究

尼龙６／ＳＢＳ共混物形态与性能的研究张皓瑜张维广陈长江吕树刚（中国科学院长春应用化学研究所，长春１３００２２）尼龙６是一种重要的大品种工程塑料，在汽车、家电等领域得到了广泛的应用，但由于其吸水率较高，使制品的尺寸稳定性变差，抗疲劳强底低，尤其是冲击韧…

PA6/SBS-g-MAH共混物的形态与力学性能

利用扫描电子显微镜、偏光显微镜对尼龙6/马来酸酐接枝SBS共混物的形态结构进行了研究,对其力学性能、吸水率进行了测试和表征。结果表明,用马来酸酐接枝的SBS与尼龙6有较好的相容性,其室温和低温下的缺口冲击强度比纯尼龙6有大幅度提高,吸水率有所降低。

用SBS或SBR或BR改进HIPS的冲击性能

采用机械共混法，在弹性体用量为５％～２５％时，研究了ＳＢＳ，ＳＢＲ，ＢＲ分别对ＨＩＰＳ的增韧效果。ＳＢＳ可使ＨＩＰＳ的冲击韧性大幅度提高，并随ＳＢＳ含量增加显著上升。ＳＢＲ也能提高ＨＩＰＳ的冲击韧性，但幅度不大。ＢＲ的加入使ＨＩＰＳ的冲击韧性下降。前两者的冲击试样断面平整而光洁，有明显的应力发白现象，属韧性断裂，后者的断面粗糙不平，无应力发白现象，属脆性断裂。改性ＨＰＳ的形态随着弹性体的不同以及含量的变化均有不同特点，与冲击韧性的变化相对应。

NMR研究LLDPE-g-PS对SBS/LLDPE的增容作用

最近,关于用接枝或嵌段共聚物作为增容剂来提高不相容聚合物共混体系相容性的研究越来越受到人们的重视因为这是开发新型高性能聚合物材料最简单最有效的方法之一.通常,适当选择接枝或嵌段共聚物,其链段可能同相应相区的链段相同,或者同某一相相容,因而可起到界面剂的作用:减小不相容组分的界

γ－射线辐照对HIPS／SBS共混物结构与性能的影响

采用６０Ｃｏγ－射线对ＨＩＰＳ／ＳＢＳ共混物以不同剂量和时间进行辐照，适当条件下，可改善共混物的性能，其中的丁二烯橡胶相可产生不同程度的交联，使抗张强度、弹性模量增加，热变形温度及硬度明显提高。并观察了交联后形态结构的变化。

α－甲基苯乙烯对HIPS／SBS共混物流变行为及力学性能的影响

用锥板式流变仪研究了α－ＭＳ对ＨＩＰＳ／ＳＢＳ共混物流动行为的影响，结果表明：不同α－ＭＳ用量的共混物和如曲线相似．均随增加τ＿ｗ增大、η＿ａ下降。流动指数，ｎ均小于１为非牛顿假塑性流体。加入少量（约２．５％）α－ＭＳ使共混物熔融指数提高３倍，其总体力学性能变化不大。

HIPS/SBS共混物的形态结构和性能

通常,高抗冲聚苯乙烯(HIPS)为多相体系,由连续聚苯乙烯(PS)相和分散的聚丁二烯(PB)颗粒组成。PB含量一般为5～15%,粒径范围为0.5～10μm,PB颗粒是交联的,同时含有接枝的PS,其内部结构由制备工艺决定。HIPS力学性能与其制备工艺、PB含量、PB分子结构、相区尺寸及内部结构密切相关。PS和PB嵌段共聚物(SBS)通常为热塑弹性体,由于PS段和PB段的不相容性而呈现微相分离的结构特征。SBS常用于与其它聚合物共混以增加后者的韧性。本工作研究了HIPS/SBS共混物的形态结构和力学性能。

Protective immunity induced by CpG ODNs against white spot syndrome virus (WSSV) via intermediation of virus replication indirectly in Litopenaeus vannamei

The worldwide shrimp culture is beset with diseases mainly caused by white spot syndrome virus (WSSV) and suffered huge economic losses, which bring out an urgent need to develop the novel strategies to better protect shrimps against WSSV. In the present study, CpG-rich plasmid pUC57-CpG, plasmid pUC57 and PBS were employed to pretreat shrimps comparatively to evaluate the protective effects of CpG ODNs on shrimps against WSSV. The survival rates, WSSV copy numbers, and antiviral associated factors (Dicer, Argonaute, STAT and ROS) were detected in Litopenaeus vannamei. There were higher survival proportion, lower WSSV copy numbers, and higher mRNA expression of Dicer and STAT in pUC57-CpG-pretreatment shrimps than those in pUC57- and PBS-pretreatment shrimps after WSSV infection. The Argonaute mRNA expression in pUC57-CpG-, pUC57- and PBS-pretreatment shrimps after WSSV infection was significantly higher than that of shrimps post PBS stimulation on the first day. The ROS levels in pUC57-CpG-pretreatment shrimps post secondary stimulation of PBS were significantly higher than those post WSSV infection on the first day. These results together demonstrated that pUC57-CpG induced partial protective immunity in shrimps against WSSV via intermediation of virus replication indirectly and could be used as a potential candidate in the development of therapeutic agents for disease control of WSSV in L. vannamei. (C) 2009 Elsevier Ltd. All rights reserved.