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药物在有序介孔氧化硅纳米孔道中组装与控缓释研究进展 总被引:3,自引:0,他引:3
有序介孔纳米氧化硅材料是一种越来越受到重视的新型药物控缓释栽体材料.综述了其与作为药物控缓释载体用途相关的控制性合成的进展以及其纳米孔道结构特性对纳米孔道中药物分子组装、控缓释行为的影响,为控缓释药物研究人员研究药物分子的控缓释行为和药物分子组装技术及开发新型药物分子载体材料提供研究依据. 相似文献
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有序中孔炭球的自组装合成及其结构控制 总被引:2,自引:0,他引:2
以间苯二酚糠醛低聚物为炭前驱体,三嵌段共聚物F127为结构导向剂,通过悬浮辅助的蒸发诱导自组装乳化成球,高温炭化后得到有序中孔炭球. 考察了乳化剂用量和搅拌速度对有序中孔炭球的粒径和表面形貌影响,嵌段共聚物F127与间苯二酚摩尔比(F127/R)及间苯二酚糠醛反应时间对有序中孔炭球的微观结构影响. 结果表明:当乳化剂用量从0.1vol%增加到2.0vol%,有序中孔炭球的粒径从400μm减小到100μm;在乳化剂用量相同时,搅拌速度从100r/min增加到600r/min, 有序中孔炭球的粒径从341μm减小到60μm;当 F127/R的比值为0.008、0.015和0.025时,分别制得三维体心立方、二维六方和无序蠕虫结构的中孔炭球. 相似文献
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采用蒸发诱导自组装方法,在导电玻璃基体上制备了具有高热稳定性、高比表面积的TiO_2薄膜。运用扫描电子显微镜、X射线衍射分析仪对TiO_2薄膜的形貌和结构进行了分析,表明制备出的纳米晶TiO_2薄膜具有多孔的锐钛矿结构,晶粒平均尺寸d为29.2nm。以D102染料敏化的TiO_2薄膜为阳极,0.3mol/L KI溶液为电解液,铂电极为阴极,组成太阳能电池,通过电流-电压曲线研究了太阳能电池的性能。结果表明:太阳能电池的J短路为17.80mA·cm-2,U开路为0.60V,填充因子FF为0.54,光电转换效率为0.39%。 相似文献
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纳米材料在纳米尺度展现出的特殊性质, 相较于宏观尺度材料表现出众多优异特性, 在力学、声学、光学、磁学、电学、热学等各种领域具有良好的应用前景。纳米材料的仿生自组装技术模拟活体生命活动, 使纳米材料基于非共价键的相互作用, 自发形成稳定结构, 现已成为制备纳米材料的主要方法之一。仿生自组装技术是“自上而下”方法中的重要技术手段, 这种合成方式有望代替传统的“自上而下”加工技术, 实现单个原子或分子在纳米尺度上构造特定结构和功能的器件。另外, 仿生自组装技术虽然以化学过程为主, 但又有物理过程, 并且结合了“仿生学”的优点, 具有定向构造纳米材料的特点, 是众多交叉学科的热门研究手段。本文重点介绍了纳米材料在形貌和性能调控中不同的仿生自组装合成策略, 包括屏蔽效应的位相选择自组装、双相界面协同效应的仿生自组装、场诱导定位效应的功能器件一体化制备、光诱导自组装以及羟基氢键驱动的分相自组装, 总结了仿生自组装纳米材料的特性, 归纳了自组装技术在传感器、表面拉曼散射、生物医疗等领域的应用, 并对纳米材料仿生自组装技术的发展前景进行了展望。 相似文献
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以单一组分醋酸纤维素(CA)为成膜材质,不添加任何添加剂条件下,利用水蒸气辅助法层-层自组装制备了三维蜂窝状CA多孔膜。利用扫描电镜观察了多孔膜形貌;研究了溶剂、环境湿度和浓度等因素对所成多孔膜结构影响。实验结果表明,以二氯甲烷为溶剂,制备得到的孔结构规整、排列紧密;环境湿度由43%增加到91%,孔径大小由(1.36±0.24)μm增加到(3.71±0.18)μm;CA的质量分数为1%~2%有利于规整孔的形成。扫描电镜断面观察发现CA膜内部全部成孔,且内部孔径大小为(1.09±0.13)μm,约为表面孔径大小的一半。利用界面能最小化理论解释了三维蜂窝孔的形成机理。此三维多孔膜有利于细胞的粘附、铺展、分化和增殖,可作为一种良好的组织工程支架材料使用。 相似文献
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以单一组分醋酸纤维素(CA)为成膜材质,不添加任何添加剂条件下,利用水蒸气辅助法层-层自组装制备了三维蜂窝状CA多孔膜。利用扫描电镜观察了多孔膜形貌;研究了溶剂、环境湿度和浓度等因素对所成多孔膜结构影响。实验结果表明,以二氯甲烷为溶剂,制备得到的孔结构规整、排列紧密;环境湿度由43%增加到91%,孔径大小由(1.36±0.24)μm增加到(3.71±0.18)μm;CA的质量分数为1%~2%有利于规整孔的形成。扫描电镜断面观察发现CA膜内部全部成孔,且内部孔径大小为(1.09±0.13)μm,约为表面孔径大小的一半。利用界面能最小化理论解释了三维蜂窝孔的形成机理。此三维多孔膜有利于细胞的粘附、铺展、分化和增殖,可作为一种良好的组织工程支架材料使用。 相似文献
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微纳米钛酸钡陶瓷(BaTiO3)是多层陶瓷电容器(Multilayer ceramic capacitors, MLCCs)的关键材料,其可控合成受到研究者的广泛关注。本工作采用自组装烧结法制备了具有不同晶粒尺寸的微纳米BaTiO3陶瓷,从样品的相对密度、晶粒尺寸和介电性能研究了该方法在可控合成微纳米BaTiO3陶瓷时的效果和适用范围。结果表明,采用二元粒径自组装烧结法,通过合理选择BaTiO3粉体尺寸和组合方式,实现了可控合成不同晶粒尺寸的陶瓷;采用三元和四元粒径自组装烧结法,虽然提高了陶瓷的相对密度,但是降低了晶粒尺寸的可控性。因此,采用二元粒径自组装烧结法有利于可控合成微纳米BaTiO3陶瓷。 相似文献
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自组装单层膜(SAMs)技术是制备纳米尺寸超薄膜材料的一种极具应用前景的新型高效、环境友好的绿色制膜技术.本文首先比较详细地介绍了自组装单层膜技术(SAMs)的发展历程和研究现状,然后对SAMs技术诱导沉积纳米晶态无机薄膜的机理进行了综述,接着比较了SAMs技术与生物矿化的异同,最后对SAMs技术的应用做了一定的展望. 相似文献
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Cetyltrimethylammonium bromide (CTAB) templated mesoporous silica thin films were deposited on glass slides by evaporation-induced self-assembly (EISA) process using a dip-coating method. The effects of sol aging on the mesophase structure of the thin films organization were investigated. Identification of the structures was accomplished by coupling X-ray diffraction (XRD) and transmission electron microscope (TEM) investigations, and corresponding sol was characterized by 29Si solution state nuclear magnetic resonance (29Si NMR) and UV-Vis spectrophotometer for studying the mesophase structure evolution. Results indicate that sol aging has great effects on the mesophase structure of the films organization, which includes degree of order and phase transformation of mesoporous silica thin films. To obtain a better understanding of the effects of sol aging on the mesophase structure, the theories of apparent mass fractal dimension and charge density matching were introduced to explain the self-assembly process. 相似文献
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Mesoporous silica films with a thickness of 500-900 nm were synthesized on a titanium substrate by the evaporation-induced self-assembly method (with 900-1200 rpm for 90 s) using cetyltrimethylammonium bromide (CTAB) as structure-directing agent and tetraethyl orthosilicate as the silica source. Prior to coating deposition, the titanium substrate was oxidized to increase the surface roughness up to 500 nm and to produce a thin titania layer. Just before the synthesis, the titania layer was made super hydrophilic by an UV treatment for 2 h to provide a better adhesion of the silica film to the substrate. Films with hexagonal and cubic mesostructures with a uniform pore size of 2.8 nm and a surface area of 1080 m2/g were obtained and characterized by different methods. An alternative approach for surfactant removal by gradual heating up to 250 °C in vacuum was applied. Complete removal of CTAB from the as-synthesized silica films was confirmed by infrared spectroscopy. 相似文献
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Takanori Maruo Shunsuke Tanaka Hugh W. Hillhouse Norikazu Nishiyama Yasuyuki Egashira Korekazu Ueyama 《Thin solid films》2008,516(15):4771-4776
Mesoporous silica films have been prepared by a vapor phase method using tetraethoxysilane (TEOS) in a batch reactor and in a continuous flow reactor. The TEOS molecules penetrated into a triblock copolymer films and then a triblock copolymer/silica composite structure was formed. A two dimensional grazing-incidence small angle X-ray scattering pattern and field emission scanning electron microscopy images of the films indicated that the films possess ordered and disordered regions. The tortuous pore channels in the wormhole-like disordered structure run parallel to the film surface. The mesostructured triblock copolymer/silica composite films were treated with a trimethylethoxysilane (TMES) vapor before and after calcination. The vapor infiltration treatments effectively improved mechanical strength and hydrothermal stability of the films. The dielectric constant of the TMES-treated mesoporous silica films was reduced into the 1.5–1.7 range. 相似文献
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Choi SY Mamak M Speakman S Chopra N Ozin GA 《Small (Weinheim an der Bergstrasse, Germany)》2005,1(2):226-232
Herein we report the first kinetic study of the intrachannel wall phase-transition of amorphous titania to nanocrystalline anatase for periodic mesoporous titania thin films, monitored by time-resolved in situ high-temperature X-ray diffraction. Structural transformations associated with the phase transition are further probed by high-resolution scanning electron microscopy and transmission electron microscopy. The model found to be most consistent with the kinetic data involves 1D diffusion-controlled growth of nanocrystalline anatase within the spatial confines of the channel walls of the mesostructure. The observation of anisotropic, rod-shaped anatase nanocrystals preferentially aligned along the channel axis implies that the framework of the liquid-crystal-templated mesostructure guides the crystal growth. 相似文献
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Sang-Bae Jung 《Thin solid films》2007,515(16):6521-6525
Ordered mesoporous silica thin films using block copolymer have drawn an attention for low-k application due to its ordered pore structure. From the respect of dielectric and mechanical properties of the film, there is trade-off between pore size and wall thickness. In this work, factors for increase of wall thickness were investigated. It was found that body-centered cubic structure was maintained irrespective of the concentration of catalytic acid. The catalytic acid thickens the framework wall because counterion reduces the repulsion force between silicic acids. The highly ordered mesoporous silica films were obtained although high concentration of acid was added to the silica sol. However, wormlike micelle exists more with high HCl concentration due to fast gellation rate. And excess water, which has the role similar to the humid atmosphere, also increases the thickness of silica wall. However, large amount of excess water at the micelle interface disrupts organic-inorganic electrostatic interaction. As a conclusion, optimization of HCl concentration in the silica sol and control of humidity during spin coating can simultaneously increase the framework thickness while maintaining the pore periodicity. 相似文献
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Gold nanoparticles (NPs) incorporated mesoporous silica thin films (MSTFs) of varied gold contents from 4.64 to 29.15 wt.% were synthesized through a refined chemical modification to the mesopore surface using different amounts of silane with amino end group. The microstructures of the composite thin films were characterized and the off-resonant third-order optical nonlinearities of the composite thin films were investigated by Z-scan technique at 1064 nm. The resultant composite thin films showed increased third-order optical nonlinear susceptibility (χ(3)) from 4.26 × 10−11 to 9.24 × 10−10 esu at increased gold contents. The dependence of χ(3) on gold content have been discussed, which can be described by an exponent function y = y0 + Ae−x/t when the gold contents of the composite thin films were below 30 wt.%. 相似文献
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Mehdi A Dourdain S Bardeau JF Reyé C Corriu RJ Gibaud A 《Journal of nanoscience and nanotechnology》2006,6(2):377-381
Optically transparent and highly ordered mesoporous organosilica thin films functionalized with two different organic groups in various proportions were synthesized by templated-directed cocondensation of tetraethylorthosilicate (TEOS) and a mixture of two distinct and functional organotriethoxysilanes [NC(CH2)3Si(OEt)3 and O=P(OEt)2(CH2)3Si(OEt)3]. The mesostructured films obtained by evaporation induced self-assembly (EISA) approach were deposited on glass or silicon substrates by dip-coating. They were characterized by Grazing Incidence Small Angle X-ray Scattering (GISAXS) and X-ray reflectivity. We showed that whatever the proportion in organic groups, only 2D hexagonal phase having p6m symmetry was observed for all the materials indicating a good compatibility between the organic groups. The bi-functionalization of the internal pores surface by the organotriethoxysilanes groups was clearly evidenced by using micro-Raman spectroscopy. 相似文献
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Lee J Kim J Kim J Jia H Kim MI Kwak JH Jin S Dohnalkova A Park HG Chang HN Wang P Grate JW Hyeon T 《Small (Weinheim an der Bergstrasse, Germany)》2005,1(7):744-753
Hierarchically ordered mesocellular mesoporous silica materials (HMMS) were synthesized using a single structure-directing agent. The mesocellular pores are synthesized without adding any pore expander; the pore walls are composed of SBA-15 type mesopores. Small-angle X-ray scattering revealed the presence of uniform pore structures with two different sizes. Using HMMS as a nanoscopic template, hierarchically ordered mesocellular mesoporous carbon (HMMC) and polymer (HMMP) materials were synthesized. HMMS was used as a host for enzyme immobilization. To improve the retention of enzymes in HMMS, we adsorbed enzymes, and then employed crosslinking using glutaraldehyde (GA). The resulting crosslinked enzyme aggregates (CLEAs) show an impressive stability with extremely high enzyme loadings. For example, 0.5 g alpha-chymotrypsin (CT) could be loaded in 1 g of silica with no activity decrease observed with rigorous shaking over one month. In contrast, adsorbed CT without GA treatment resulted in a lower loading, which further decreased due to continuous leaching of adsorbed CT under shaking. The activity of crosslinked CT aggregates in HMMS was approximately 10 times higher than that of the adsorbed CT, which represents a 74-fold increase in activity per unit weight of HMMS due to higher CT loading. 相似文献