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1.
核/壳结构增韧剂对环氧树脂的抗冲改性   总被引:7,自引:0,他引:7  
张明耀  冯之榴 《应用化学》1996,13(1):112-113
核/壳结构增韧剂对环氧树脂的抗冲改性张明耀,张会轩,杨海东,冯之榴(吉林工学院化学工程系长春130012)(中国科学院长春应用化学研究所长春)关键词核/壳结构,增韧剂,环氧树脂,共混核/壳结构增韧剂是用分步乳液聚合技术制造的一种复合乳胶粒子,其核为橡...  相似文献   

2.
分别以硼氨配合物和硼氢化钠为还原剂合成了核壳结构的Cu@CoW三元合金催化剂和非核壳结构的CuCoW三元合金催化剂,25℃下,Cu0.4@Co0.5W0.1三元合金催化剂对于硼氨配合物水解反应的TOF(转换频率)值达到0.369 0 molH2·molcat-1·s-1,明显高于非核壳结构的Cu0.4Co0.5W0.1催化剂,接近Pt、Pd等贵金属的催化活性,反应的活化能为49 kJ·mol-1。与非核壳结构的CuCoW合金相比,核壳结构的Cu@CoW三元合金催化剂的催化性能及稳定性均有明显提高。  相似文献   

3.
以乳液聚合制备的聚苯乙烯乳液为种子,加入甲基三甲氧基硅烷(MTMS)水解溶液进行缩聚反应,合成亚微米级聚苯乙烯/聚硅氧烷核壳粒子,并以此作为光散射剂添加至聚甲基丙烯酸甲酯(PMMA)树脂中,制备了光散射材料;考察了亚微米级核壳粒子添加在PMMA树脂中的分散性。结果表明:经过双螺杆剪切作用的挤出加工后,可以实现核壳粒子在PMMA树脂中的良好分散。核壳粒子可以大幅度提高PMMA的雾度,当聚苯乙烯/聚硅氧烷核壳粒子(NS82)的含量为1%时,制得的PMMA样片(厚度为2 mm)的雾度为89%,透光率为69%,有效光散射系数为61%。  相似文献   

4.
利用反相微乳法, 以巯基乙酸修饰的水溶性CdTe量子点为核, 包覆SiO2, 制备得到核壳型CdTe@SiO2荧光纳米复合粒子. 用紫外-可见(UV-vis)分光光度计, 荧光(PL)分光光度计, 红外(FT-IR)光谱仪, 透射电子显微镜(TEM)等分析测试手段, 对得到的荧光纳米复合粒子的性能进行表征, 结果表明: 得到的CdTe@SiO2纳米复合粒子是核壳型结构, 由SiO2壳层包覆多个量子点, 其大小均匀, 水溶性好, 有效地提高了量子点的稳定性, 大大增强了其抗光漂白性能, 为该材料的进一步生物应用打下了良好的基础.  相似文献   

5.
6.
Wei K  Li Y  Lei X  Yang H  Teramoto A  Yao J  Abe K  Ko FK 《Macromolecular bioscience》2011,11(11):1526-1536
The effectiveness of a multifunctional scaffold produced by the electrospinning of emulsions composed of organic PLGA and aqueous collagen-like protein (denoted as Fol-8Col) solutions is demonstrated. The resultant Fol-8Col/PLGA fibrous scaffolds with homogeneous morphology have mean fiber diameters from 600 to 2,000 nm. A uniform distribution of encapsulated Fol-8Col in the fibers is observed by fluorescence microscopy. TEM is used to clarify the representative core/sheath structure of emulsion electrospun Fol-8Col/PLGA fibers. Preliminary release assessment of encapsulated Fol-8Col shows results of sustained release for more than one month from the Fol-8Col/PLGA fibrous mats. The cytocompatibility of fibroblast cell line L929 with the fibrous composite seems promosing.  相似文献   

7.
以磷酸、拟薄水铝石和硅溶胶为原料,三乙胺为模板剂,在不同晶化温度和晶化时间的实验条件下,分别采用水热合成法和气相转移法合成了一系列ZSM-5/SAPO-5核壳结构复合分子筛,并用X射线衍射、扫描电镜、X射线能量散射谱、红外光谱和N2吸附等手段对其进行了表征.结果表明,所合成的分子筛是以ZSM-5为核,以SAPO-5为壳的双结构复合分子筛.晶化温度的提高和晶化时间的延长有利于分子筛结晶度的提高.与水热合成法相比,采用气相转移法可以减小壳层SAPO-5的颗粒尺寸,减少脱离ZSM-5表面独立生长的SAPO-5的量,改善SAPO-5在ZSM-5表面的分布.重油裂化结果表明,核壳结构复合分子筛对生成低碳烯烃的催化性能优于机械混合的样品.  相似文献   

8.
TiO2 coated SiO2 materials as anode for lithium-ion batteries were synthesized via an in situ hydrolysis of tetraethyl orthosilicate under ultrasonic irradiation using nanometer-sized TiO2 colloids as precursors. The XRD patterns indicate that the as-prepared core/shell particles remain anatase after calcining below 800 ℃. TEM observation shows that the particle size of TiO2 / SiO2 composites is ca. 200 nm, and a homogeneous SiO2 layer is coated on the surfaces of TiO2 particles. FTIR spectra demonstrate that SiO2 could have been coated on the surfaces of TiO2 particles via a chemical bonding. In addition, the first specific charge and discharge capacities of the coated particle electrode were 66.4 mAh·g-1 and 90.7 mAh·g-1, respectively, which indicates that the TiO2 / SiO2 particles are more stable than the monodispersed TiO2. Meanwhile, the new material has good lithium intercalation-deintercalation performances.  相似文献   

9.
采用微乳液法制备出Ni0.5Zn0.5 Fe2O4纳米颗粒以及Ni0.5Zn0.5Fe2O4/PANI核壳结构复合纳米材料,借助FT-IR、XRD、SEM、TEM、VSM等分析手段研究了材料的形貌、结构与磁性能.结果表明:得到的Ni0.5Zn0.5Fe2O4纳米颗粒平均粒径为20hm左右,Ni0.5Zn0.5 Fe2O...  相似文献   

10.
本文用薄层色谱成功地将微交联核-壳结构聚苯乙烯微粒中的少量线性PS分子与微交联组分相分离,用凝胶色谱法测得线性PS的分子量为104-105数量级;0.2-1.6×10-6g的点样量,薄层扫描吸收峰面积与样品量成良好的线性关系;可直接由峰面积计算线性PS分子的含量;结合微粒的表观粘度,对微粒的核-壳结构进行了定性分析。  相似文献   

11.
This paper reports the use of polyhedral oligomeric silsesquioxane (POSS)‐based copolymers to stabilize the core/shell interface for the facile fabrication of electrospun core/shell fibers. For the poly[(propylmethacryl‐heptaisobutyl‐polyhedral oligomeric silsesquioxane)‐co‐(methyl methacrylate)] (POSS‐MMA)/poly(ε‐caprolactone) (PCL) system, the bicontinuity of hybrid core/shell fibers can be tuned by controlling the phase separation of POSS‐MMA/PCL in electrospinning solutions and therefore the size of PCL‐in‐POSS‐MMA emulsion droplets. Our results demonstrate the enhanced encapsulation capacity of POSS‐MMA copolymers as shell materials. Taking advantage of the rapid advancement of POSS‐based copolymer synthesis, this study can potentially be generalized to guide the fabrication of various other POSS‐based core/shell nano‐/microstructures by using single‐nozzle electrospinning or coaxial electrospinning.

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12.
Electrocatalysis is the most promising strategy to generate clean energy H2, and the development of catalysts with excellent hydrogen evolution reaction (HER) performance at high current density that can resist strong alkaline and acidic electrolyte environment is of great significance for practical industrial application. Therefore, a P doped MoS2@Ni3S2 nanorods array (named P-NiMoS) was successfully synthesized through successive sulfuration and phosphorization. P-NiMoS presents a core/shell structure with a heterojunction between MoS2 (shell) and Ni3S2 (core). Furthermore, the doping of P modulates the electronic structure of the P-NiMoS; the electrons transfer from the t2g orbital of Ni element to the eg empty orbital of Mo element through the Ni−S−Mo bond at the Ni3S2 and MoS2 heterojunction, facilitating the hydrogen evolution reaction. As a result, P-NiMoS exhibits excellent HER activity; the overpotential is 290 mV at high current density of 250 mA cm−2 in alkaline electrolyte, which is close to Pt/C (282 mV@250 mA cm−2), and P-NiMoS can stably evolve hydrogen for 48 h.  相似文献   

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