Sub-5 keV electron-beam lithography in hydrogen silsesquioxane resist

We fabricated 9-30 nm half-pitch nested Ls and 13-15 nm half-pitch dot arrays, using 2 keV electron-beam lithography with hydrogen silsesquioxane (HSQ) as the resist. All structures with 15 nm half-pitch and above were fully resolved. We observed that the 9 and 10-nm half-pitch nested Ls and the 13-nm-half-pitch dot array contained some resist residues. We obtained good agreement between experimental and Monte-Carlo-simulated point-spread functions at energies of 1.5, 2, and 3 keV. The long-range proximity effect was minimal, as indicated by simulated and patterned 30 nm holes in negative-tone resist.     

原花青素降低脂质过氧化作用的研究

以高、中、低三种剂量的原花青素喂食小鼠45d,对照组给予等体积的蒸馏水,测定各项指标.实验结果是高剂量组与老龄对照组比较,MDA含量明显降低,血清SOD活力明显升高(P＜0.05),表明原花青素具有降低脂质过氧化作用.     

POSS-based hybrid thermosets via photoinduced copper-catalyzed azide–alkyne cycloaddition click chemistry

An efficient approach for the preparation of inorganic/organic hybrid thermosets via photoinduced copper-catalyzed azide–alkyne cycloaddition click chemistry is established. Highly cross-linked thermoset polymers have been practically obtained by this technique using multifunctional compounds, tri-alkyne (1,1,1-tris[4-(2-propynyloxy) phenyl]-ethane) with octakis-azido-POSS or tri-azide (3,3′-((2-((3-azido-2-hydroxypropoxy)methyl)-2-ethylpropane-1,3-diyl)bis(oxy))bis(1-azidopropan-2-ol)) in the presence of Cu(II)Br₂/N,N,N′,N″,N?-pentamethyldiethylenetriamine/2-dimethoxy-2-phenyl acetophenone. The homogeneously distributed POSS nanoparticles are clearly detected in the TEM micrographs; whereas the TGA analysis shows that the obtained hybrid thermosets are thermally stable up to 360 °C and begin to lose weight at higher temperatures with a char yield of 23–50% at 800 °C.     

接枝法制备聚苯乙烯/笼型倍半硅氧烷复合材料

以工业级的3-氯丙基三氯硅烷和七聚(苯基)倍半硅氧烷三硅醇钠为原料,通过顶端封角法合成了含有一个3-氯丙基、七个苯基的单官能团POSS(3-氯丙基POSS),并以其作为聚苯乙烯的添加剂,采用化学接枝的方法制备POSS/PS复合材料.利用傅立叶转变红外光谱(FT-IR)、核磁共振(1H-NMR、29Si-NMR)和X-射...     

PC/POSS复合材料的制备及热性能

合成及表征了八苯基倍半硅氧烷（PH-POSS）、γ-甲基丙烯酰氧丙基倍半硅氧烷（MA-POSS）,并利用差示扫描量热（DSC）和热重分析（TGA）分别研究其在聚碳酸酯（PC）体系中对体系热性能的影响。研究结果表明,复合材料Tg随着PH-POSS含量的增加而降低;而随着MA-POSS含量的增加基本不受影响。在氮气中,复合...     

金属硅倍半氧烷的合成及其应用研究进展

本文以金属元素的种类为切入点, 首先详细介绍了现存的元素周期表中几乎所有已经被成功合成的金属元素的各种笼形金属硅倍半氧烷及其精确的分子结构。然后从合成工艺角度出发, 综述了近20年间多个国际和国内课题组关于笼形金属硅倍半氧烷制备方法的研究历程。随着不完全缩聚笼形低聚硅倍半氧烷的成功合成, 利用其硅羟基和金属形成配位键合成含有不同金属元素的笼形低聚硅倍半氧烷变得更加容易。关于笼形金属硅倍半氧烷的合成方法, 一种是通过“顶角-盖帽”的制备方法可以将几乎所有金属元素引入到硅倍半氧烷的笼形结构中, 其中多价金属离子可以充当笼中缺失的顶点, 从而制备出具有精确分子结构的笼形金属硅倍半氧烷; 另一种是利用高浓度的无机碱和烷氧基硅烷发生反应, 进一步加入氯化多价金属盐, 制备出含有Cu、 Co、 Fe等的笼形金属硅倍半氧烷; 另外, 本文简略地指出了现已发展成熟的笼形金属硅倍半氧烷的各种合成方法的优缺点。最后, 详细介绍了多种笼形金属硅倍半氧烷在催化和阻燃领域的应用现状, 并指出了现阶段笼形金属硅倍半氧烷的研究重点以及未来可能的发展方向。     

Syntheses, thermal properties, and phase morphologies of novel benzoxazines functionalized with polyhedral oligomeric silsesquioxane (POSS) nanocomposites

We have successfully synthesized a novel benzoxazine ring-containing polyhedral oligomeric silsesquioxane (BZ-POSS) monomer by two routes: (1) hydrosilylation of a vinyl-terminated benzoxazine using the hydro-silane functional group of a polyhedral oligomeric silsesquioxane (H-POSS) and (2) reaction of a primary amine-containng POSS (Amine-POSS) with phenol and formaldehyde. The benzoxazine-containing POSS (BZ-POSS) monomer can be copolymerized with other benzoxazine monomers through ring-opening polymerization under conditions similar to that used for polymerizing pure benzoxazines. Thermal properties of these POSS-containing organic/inorganic polybenzoxazine nanocomposites have been improved over the pure polybenzoxazine analyzed by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The BZ-POSS monomer is poorly miscible with the benzoxazine monomer and tends to aggregate and forms its own domains, both before and after polymerization. At a higher BZ-POSS content, gross aggregation occurs and results in a lower than expected improvement in the thermal properties.     

Modification of hydrogenated Bisphenol A epoxy adhesives using nanomaterials

Color-stable hydrogenated Bisphenol A (HBA) epoxy adhesives, containing organic-inorganic hybrid nanomaterials, were prepared and their properties investigated. Poly(propylene glycol)bis(2-aminopropyl ether) (D230) was used as the room temperature curing agent, and functional organic-inorganic hybrid nanomaterials, to tailor the adhesives, were prepared by a sol-gel reaction of 3-glycidoxypropyltrimethoxysilane and tetraethoxysilane. The commercial polyhedral oligomeric silsesquioxanes (POSS) having epoxy functional groups were also used. The concentration dependence of different nanomaterials, containing epoxy functional group for HBA/D230 adhesives, was studied. The tensile strength increased with the addition of nanomaterials having glycidyl epoxy group; however, the dependence varied with the size, the number of functional groups, and the amount of the addition. HBA/D230 adhesives containing different amounts of nanomaterials, whose compositions are similar to that of granite, were applied to the Korean granite and the results were compared with those obtained by using commercial adhesives, which have the problem of significant color change and high viscosity. The mechanical properties of HBA/D230 adhesives, containing POSS having glycidyl epoxy group, are found to be similar to those of commercial adhesives. Besides, it has low viscosity and long-term color stability.