共查询到17条相似文献,搜索用时 186 毫秒
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石质文物表面生物矿化保护材料的仿生制备 总被引:16,自引:0,他引:16
许多濒危石质文物急需进行保护处理. 但是, 调查表明已经使用过的表面防护材料很难令人满意, 探索新的石质文物保护材料已是当务之急. 本工作以石质文物表面天然生成的生物矿化膜为仿生合成目标, 依据生物矿化的原理, 以硫酸软骨素作为有机模板, 草酸钙的亚稳过饱和溶液作为无机前驱物, 室温下在石材表面仿生合成了主要成分为一水草酸钙的无机表面保护材料. 其制备工艺用正交试验进行了优化; 结构和形貌用X射线衍射分析仪和原子力显微镜进行了表征; 通过憎水性、耐污性和耐酸性试验进行了合成膜的保护性能测试, 效果良好. 本方法为开拓新的石质文物保护材料提供了思路. 相似文献
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将改性膨润土引入到丙烯酰胺基水凝胶体系中,通过控制组分比例、温度和反应时间等因素,成功构筑了粘接修复型膨润土基水凝胶(AR-gel)材料,并实现了对破损和断裂的砂岩文物的高效修复.AR-gel中膨润土的存在提高了其与砂岩文物之间的兼容性,展现出了极好的粘接性,且粘接修复完整的文物接缝处无明显粘接痕迹,无泛白变色现象,不影响被粘接文物的整体美观;同时,粘接过程中的溢胶,可用水轻易去除.修复过后的砂岩形貌与性能与砂岩对照样品基本一致,表明了AR-gel高粘接性能的同时,不会对砂岩基体造成二次破坏.通过严苛的冻融老化循环和盐结晶湿热循环老化试验验证了该AR-gel材料对砂岩的耐久性粘接保护,并分析了保护机理:砂岩与AR-gel间通过强氢键、Si-O-Si键、Si-O-M键、质子化和离子键、机械咬合等作用牢固结合在一起.此外,AR-gel对玻璃、金属、砂岩、陶瓷和陶器等各种材质的文物均具有极好的粘接性能.本研究工作为开发耐久性文物粘接修复保护材料提供了新方法和新思路. 相似文献
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食品安全是人类社会发展最重要的问题之一,随着食品种类的丰富和发展,快速即时、低成本、便捷化的食品安全检测方法日益受到关注。纸基分析方法具有低成本和简便化分析特点,经历了从试纸到微流控纸芯片的快速发展过程。以纸基材料结合各种分析方法形成的纸基分析装置,在食品快速检测方面显示出了良好的应用前景。本文首先介绍了纸基材料表面的功能化改性,综述了比色分析、荧光分析、电化学分析、表面增强拉曼分析等及其联用技术与纸基平台结合构建的分析方法在食品安全快速检测中研究和应用进展,最后讨论了其在食品安全快速分析检测中面临的挑战和发展前景。 相似文献
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以甲苯二异氰酸酯(TDI)中的-NCO基与纳米金属氧化物表面的羟基发生反应,得到改性纳米金属氧化物,并使其与肝素钠(Heparin)进行接枝反应生成肝素杂化材料,结合红外、热重、扫描电镜(SEM)等表征方法,确定纳米金属氧化物确实接枝到了肝素钠的表面。通过对体外凝血时间和复钙时间的测定,来初步研究肝素杂化材料的抗凝血性质。结果表明:肝素杂化材料的抗凝血时间和复钙时间均比肝素钠的要短,表明它的抗凝血性比肝素钠的抗凝血性要弱一些;但比纳米金属氧化物和空白组的抗凝血时间和复钙时间要长,说明肝素杂化材料的抗凝血性与其相比则有明显的提高。 相似文献
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有机硅化合物在α-D-葡二糖合成上的应用 总被引:2,自引:0,他引:2
三苯基硅基作为葡萄糖1-C位羟基保护基, 在对硝基苯甲酰基存在下形成和脱保护基反应均易进行, 而且有产率高、在反应过程中保持1-C构型不变等特点, 并研究了三苯基硅基保护基在葡二糖上的应用。 相似文献
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中空介孔材料,尤其是硅基和碳基中空介孔材料,由于其孔道结构丰富、孔径可调、高比表面积、可容纳客体分子、良好的热稳定性和化学稳定性等特点已被广泛应用于催化、能量储存等众多领域。模板法是目前为止制备中空介孔结构最有效的方法之一,其最大特点是可以通过对模板的调控来实现对中空介孔结构的控制。聚合物基模板种类繁多,主要包括嵌段共聚物、聚合物乳胶粒、天然/合成生物大分子及复杂结构高分子等;与传统的表面活性剂/无机氧化物模板相比,其自组装形态更加丰富,结构更易进行功能化修饰。同时,以聚合物为模板的合成反应条件更加温和可控,更有利于合成形态各异、功能丰富的中空介孔材料。本文综述了近年来不同聚合物基模板合成中空介孔材料的研究进展,并着重介绍了贵金属粒子负载的中空介孔材料在催化载体领域的应用;同时,指出了当前阻碍中空介孔材料发展的问题,并对其在催化领域的应用前景进行了展望。 相似文献
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Wolfram Khler 《Chemie in Unserer Zeit》2005,39(6):410-415
The sciences of chemistry, geology and arts are involved in the following project: You work limestone, marble and other materials of calcium carbonate which must be soluble in acid. This chemical reaction transforms a natural stone into a relief, a vase or an ashtray if the attac of the acid is aimed at particular targets. A resistent material (plastic film, lacquer) protects the natural stone, where its surface should not be removed. The acid dissolves only the uncovered part of the stone. – Chemical reactions can also coloure a stone: dissolved compounds of copper convert calcium carbonate into green copper carbonate which can be transformed into other coloured compounds. 相似文献
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Twenty-three highly-coloured lichen specimens belonging to the genera Candelariella, Aspicilia and Xanthoria from high altitude sites in the Atacama Desert, Chile, 2300-4500 metres, have been analysed non-destructively by Raman spectroscopy. The vibrational band assignments in the spectra of the specimens, which were still attached to their limestone or sandstone substrata, were accomplished by comparison with the chemical compositions obtained from wet chemical extraction methods. Carotenoids and chlorophyll were found in all specimens as major components and the characteristic spectral signatures of calcium oxalate monohydrate (whewellite) and dihydrate (weddellite) could be identified; chemical signatures were found for these materials even in lichen thalli growing on the non-calcareous substrata, indicating probably that the calcium was provided here from wind- or rain-borne sources. The Raman spectral biomarkers for a variety of protective biomolecules and accessory pigments such as usnic acid, calycin, pulvinic acid dilactone and rhizocarpic acid have been identified in the lichens, in broad agreement with the chemical extraction profiles. The present study indicates that some form of non-destructive taxonomic identification based on Raman spectroscopy was also possible. 相似文献
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Hideo Sawada Yasufumi Shikauchi Hiroshi Kakehi Yoshihiro Katoh Masashi Miura 《Colloid and polymer science》2007,285(5):499-506
Calcium chloride reacted with sodium carbonate in the presence of a variety of self-assembled molecular aggregates formed
by fluoroalkyl end-capped acrylic acid, 2-methacryloyloxyethane sulfonic acid, dimethylacrylamide, and acryloylmorpholine
oligomers in aqueous solutions to afford the corresponding fluorinated oligomers/calcium carbonate composites in excellent
to moderate isolated yields. These fluorinated calcium carbonate composites thus obtained were shown to have a good dispersibility
not only in water but also in traditional organic media including fluorinated solvents. Dynamic light scattering measurements
(DLS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that these fluorinated composites
are nanometer-size-controlled particles and well dispersed in these media. Cross-linked fluoroalkyl end-capped acrylic acid
co-oligomer containing poly(oxyethylene) units was also applied to the preparation of new cross-linked fluorinated calcium
carbonate nanocomposites under similar conditions. The obtained cross-linked fluorinated calcium carbonate nanocomposites
were found to have an extremely higher dispersibility in aqueous and organic media including fluorinated solvents, compared
to that of the corresponding fluoroalkyl end-capped oligomer nanocomposites. In particular, it was verified that these fluorinated
calcium carbonate nanocomposites are applicable to the dispersion above poly(methyl methacrylate) (PMMA) film surface. Interestingly,
field-emission SEM (FE-SEM) images of the cross-section of the modified PMMA films showed that calcium carbonate particles
dispersed into these PMMA films could be arranged regularly above the modified film surface. More interestingly, cross-linked
fluorinated oligomeric aggregates were able to provide suitable host moieties for the crystallization of calcium carbonate. 相似文献
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In contrast to extensive studies on hydroxyapatite thin films, very little has been reported on the thin films of carbonated apatite (dahllite). In this report, we describe the synthesis and characterization of a highly crystalline dahllite thin film assembled via a biomimetic pathway. A free-standing continuous precursor film of carbonated calcium phosphate in an amorphous phase was first prepared by a solution-inhibited templating method (template-inhibition) at an air-water interface. A stearic acid surface monolayer acted as the template, while a carbonate-phosphate solution composed a binary inhibition system. The precursor film formed at the air/water interface was heated at 900 degrees C and transformed into a dense crystalline film that retained the overall shape of the precursor. The crystalline phase was characterized by XRD and IR to be a single-phase carbonate apatite, with carbonate substitutions in both type A (OH-) and type B (PO4(3-)) lattice positions. 相似文献
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Thermal transformations of natural calcium oxalate monohydrate known in mineralogy as whewellite have been undertaken using a combination of thermal analysis and Raman microscopy with the use of a thermal stage. High resolution thermogravimetry shows that three mass loss steps occur at 162, 479 and 684 °C.Evolved gas mass spectrometry shows that water is evolved in the first step and carbon dioxide in the second and third mass loss steps. The changes in the molecular structure of whewellite can be followed by the use of the in situ Raman spectroscopy of whewellite at the elevated temperatures. The whewellite is stable up to around 161 °C, above which temperature the anhydrous calcium oxalate is formed. At 479 °C, the oxalate transforms to calcium carbonate with loss of carbon dioxide. Above 684 °C, calcium oxide is formed. 相似文献
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Villar SE Edwards HG Seaward MR 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(5):1229-1237
Seven highly-coloured lichen species belonging to the genera Caloplaca, Candelariella, Aspicilia and Xanthoria from ecclesiastical buildings in northern Spain have been analysed non-destructively by FT-Raman spectroscopy. The vibrational band assignments in the spectra of the specimens, which were still attached to their limestone or sandstone substrata, were accomplished with the assistance of the chemical compositions obtained from wet chemical extraction methods. beta-Carotene was found in all specimens as the major pigment, and the characteristic spectral signatures of calcium oxalate monohydrate (whewellite) and dihydrate (weddelite) could be identified; chemical signatures were found for these materials even in lichen thalli growing the non-calcareous substrata, indicating, probably, that the calcium was provided here from wind-or-rain-borne sources. The Raman spectral biomarkers found in the lichens broadly agreed with the chemical extraction profiles as expected, but the present study indicates that some form of non-destructive taxonomic identification based on Raman spectroscopy was possible. 相似文献
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Michael Maas Heinz Rehage Holger Nebel Matthias Epple 《Colloid and polymer science》2007,285(12):1301-1311
In this publication, we describe the growth of thin films of calcium carbonate beneath Langmuir monolayers of stearic acid.
The size and shape of the crystalline structures were systematically studied by means of different microscopic techniques
including Brewster angle microscopy, atomic force microscopy and scanning electron microscopy. In a series of experiments,
we explored the calcium carbonate crystallization process for different lipid monolayers and subphases. The observed phenomena
support a crystallization process which is induced by a thin, film-like structure of a precursor phase. The basic processes
of crystal and aggregate formation can be represented by a simple model which is based on electrostatic interactions between
the surfactant film and the inorganic calcium carbonate structures. 相似文献