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嵌合异硫氰酸罗丹明B核壳荧光纳米颗粒制备的新方法研究 总被引:4,自引:0,他引:4
随着纳米技术的发展,结合了纳米技术与材料制备技术而发展起来的荧光染料嵌合的核壳荧光纳米颗粒的制备为生物医学领域的研究提供了新的材料、技术和方法。何晓晓等以联钉吡啶配合物为核材料,制备了嵌合无机金属配合物的核壳荧光纳米颗粒,段菁华等用异硫氰酸荧光素FITC与蛋白质IgG相结合, 相似文献
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利用可控微乳液法合成粒径19~200 nm,且呈球状分布均匀的聚甲基丙烯酸甲酯/聚(异戊二烯-co-苯乙烯)(PMMA/PIS)核壳纳米粒子,通过水合肼产生原位氢的技术,对合成的PMMA/PIS乳液体系进行直接常压氢化,对影响氢化度的因素、聚合物氢化前后结构、热性能进行了研究.结果显示,聚合物粒径、水合肼及双氧水用量等都是影响聚合物的氢化度的因素.研究发现,氢化以PMMA为核,PIS为壳的核壳结构乳液可以显著提高PIS氢化程度,减少氢化过程中凝胶产生.利用FTIR、~1H-NMR、Na_2S_2O_3滴定法测定了乳液的氢化度.结果表明,当聚合物粒径小于200 nm时,乳液氢化度可达到95%以上,且无凝胶现象产生.GPC结果证明了反应是氢化而非凝胶过程.利用TEM、DLS测试了氢化后乳液的核壳结构和粒径.实验结果显示,PMMA/HPIS为核壳纳米结构.TGA结果显示,当氢化度为98%时,聚合物耐热性提高41°C. 相似文献
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纳米核壳式铜-锡双金属粉的制备及性能研究 总被引:7,自引:0,他引:7
A kind of novel core-shell Cu-Sn bimetallic nanoparticles has been prepared by a new method (displacement method), in which Sn was made to cover on the surface of Cu nano-core. The preparation method and reaction mechanism have been discussed. This reaction happened under the existence of coordinate agent-(NH2)2CS and protective agent PVP. The nanoparticles prepared were with a core-shell structure, granule diameter between 50~100 nm and good dispersing capability. The Cu-Sn nanoparticles proposed has better oxidation-resistant ability than Cu nanoparticles with corresponding granule diameter and can be applied as lubricant additives as well as antibacterial agent. When the additive amount is very low (0.1wt‰~0.5wt‰), it can improve the PB of the lubricant by 92%~106%, and also enhance its antiwear characteristics and friction-reducing properties. At the concentration of 1 000 ppm, it can reach an antibacterial ratio of 99.99%. 相似文献
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The Ni@Au core-shell nanoparticles had been successfully synthesized from aqueous solution by one-step route at room temperature. The Ni@Au nanoparticles can be an excellent catalyst for Ullmann reaction. The advantage of Ni@Au is that the catalyst does not need additional reducing agents. The Au shell can effectively protect the Ni core from oxidation. The Ni core and Au shell have both composited in structure and cooperated in function. 相似文献
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采用丙烯酸酯(AC)对水性聚氨酯(WPU)进行改性,合成了接枝型丙烯酸酯/聚氨酯(PUA)复合乳液。 随着共聚物中丙烯酸酯质量分数的增加,乳液外观由透明变为不透明,乳液粒径随之增大、分布变宽。 TEM显示,PUA乳胶粒子呈现清晰的核壳结构,且形态规整,粒径分布在60~120 nm之间。 FTIR测试表明,随着丙烯酸酯质量分数的增加,聚氨酯(PU)硬段氢键化作用先增强后减弱,硬段的有序度逐渐降低。 DSC分析表明,当AC的质量分数低于75%时,PU、聚丙烯酸酯(PA)两组分相容性较好,只出现一个玻璃化转变温度,并且随着PA质量分数的增加逐渐升高。 PA质量分数的增加,使胶膜的最大热失重速率从363 ℃提高至412 ℃,吸水率从11.3%降低至5.7%,弹性模量从16.4 MPa提高至47.6 MPa,拉伸强度从9.0 MPa提高至23.7 MPa,断裂伸长率从365%提高至408%,同时乳液的粘度下降,干燥时间变短,胶膜的附着力变好。 相似文献
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离子液体具有良好的溶解能力、稳定性、结构可调性、无明显的蒸汽压等优点,使其可以作为良好的有机反应介质和催化剂,但由于其价格昂贵且不易从反应体系中分离,应用受到限制。以超顺磁性纳米颗粒作为催化剂载体,利用其所提供的磁学特性,可通过外磁场对催化剂进行简单有效的分离。不过,超顺磁性纳米颗粒具有的高比表面能以及粒子间的偶极距作用,使其容易团聚,不能稳定分散于反应体系。若在磁性纳米颗粒表面包裹一层有机物或无机物形成核-壳结构复合材料,就既可以阻止其团聚又可以对其进行表面功能化。因此,将离子液体固载到核-壳结构磁性纳米颗粒表面,制备可回收并循环使用的多相催化剂的工作受到广泛关注。本文综述了近十年来核-壳结构磁性纳米颗粒负载离子液体催化剂的制备方法及其在有机合成方面的应用,并对其未来的应用前景进行了展望。 相似文献
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与传统的软、 硬模板法相比, 近期发展的自模板法具有反应步骤少和无需额外模板等众多优点, 同时, 介孔空心无机微/纳米结构在催化、 能源和医药等领域的巨大应用前景也使其制备方法备受关注. 本文根据不同的反应机理, 从Ostwald熟化、 表面保护刻蚀、 柯肯达尔效应和电偶置换反应4个方面分别综述了自模板法的最新研究进展和应用现状, 并展望了自模板法的研究与应用前景. 相似文献
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在聚乙烯吡啶修饰导电玻璃电极表面进行了金纳米粒子的二维单层结构组装,通过电沉积方法在金粒子表面制备了纳米汞壳层.研究结果表明,汞壳层的形成导致了内部金粒子表面等离子体共振的谱峰红移和强度衰减.吸附于汞壳表面的结晶紫分子因可承受被金核增强的电磁场,而使其拉曼散射得到极大的增强. 相似文献
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铟锡氧化物ITO纳米粉体的共沉淀法合成 总被引:2,自引:0,他引:2
Indium tin oxide (ITO) nanoparticles were synthesized by precipitation method from granulated indium and oxalate tin. The ITO particles were characterized by means of XRD, BET and TEM. The tin doping decreases the crystallite size, increases the specific surface area and decreases the lattice volume of the ITO nanoparticles. The absence of chlorine ions in the synthesis greatly increases the particles′ purity, decreases the agglomeration and improves the synthesis efficiency. This synthesis process to ITO nanoparticles is now in pilot-scale production in: Light & Future Advanced Material Co. LTD, Daegu, Korea. 相似文献
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纳米银的电化学合成 总被引:25,自引:0,他引:25
纳米颗粒因具有量子尺寸效应、表面效应和宏观量子隧道效应等不同于晶态体材料和单个分子的固有特性 ,显示出体材料不具备的导电特性、光电特性、光催化能力及随粒径变化的吸收或发射光谱 ,已被用于各种发光与显示装置[1] .其制备的化学方法主要有溶胶 -凝胶法、微乳法、化学沉淀法和醇解法等 [2 ] .近年来 ,新发展出一种电化学合成纳米粒子的方法 ,如 Braun等 [3]利用 DNA模板电化学合成了银纳米线 ,Yu等[4 ] 用电化学合成了金纳米棒 ,Zhu等[5] 利用超声电化学合成了半导体 Pb Se纳米粒子 ,Amigo等 [6 ]用电化学方法合成了 Fe-Sr氧化… 相似文献
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WANG Lili LIU Yanan PENG Xiaoxing SUN Yuanqing LIU Xiaohua LIU Huimin LIN Quan SUN Hongchen YANG Bai LI Xiangwei 《高等学校化学研究》2020,36(5):970-975
Residual bacteria and microleakage in a complicated root canal can often result in reinfection of the periapical tissues. To promote the antibacterial and sealing effects of a root canal filling, core-shell structured CaO/ZnO nanospheres were synthesized using a precipitation method based on a traditional root canal sealer, zinc oxide-eugenol(ZOE). The obtained CaO/ZnO particles had a size of 80-90 nm and a core-shell structure. The film thickness, flow rate, pH, and calcium ion release of the core-shell structured CaO/ZnO nanospheres-eugenol paste were tested. The pH and calcium ion release results showed a slight increase in the prepared nanospheres, with a flow rate of 24.22 mm and a formed film thickness of 30 μm, which are basically consistent with ISO 6876:2001 standards(regarding dental root canal sealing materials). Cytotoxicity tests showed that the cytocompatibility of the CaO/ZnO nanospheres-eugenol paste was much higher than that of the ZOE or iRoot SP groups(P<0.05). A comparison of the sealing ability and antibacterial activity showed that the core-shell structured CaO/ZnO nano-spheres-eugenol paste had significantly better effects than the ZOE and iRoot SP sealers(P<0.05). The core-shell structured CaO/ZnO nanosphere paste displayed excellent sealing and antibacterial properties, and it has promising application potential in endodontics. 相似文献
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Nano-sized HfO2, C and C/HfO2 powders obtained through hydrothermal process have been investigated by XRD, TEM and FTIR, and Different precursors, namely Hafnium(Ⅱ) oleate and Hafnium(Ⅱ) hydroxide derived from homogeneous precipitation method, have been chosen for the synthesis of nanometric HfO2 via hydrothermal process. The results indicate that using the former material as the precursor under identically hydrothermal process can yield finer HfO2 nanoparticles, compared to using the latter. Nano-sized Carbon of about 100 nm with square morphology and narrow size distribution can be obtained through hydrothermal reaction of sucrose solution at 200 ℃ for 6 h. The addition of as-synthesised Carbon nanoparticles into the hydrothermal process of HfO2 powder can produce C/HfO2 composite powders with core-shell structure. 相似文献
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ATO纳米粉体的燃烧合成研究 总被引:7,自引:1,他引:7
锑掺杂氧化锡(Antimony鄄dopedtinoxideATO)是一种新型多功能材料,具有耐高温、耐腐蚀、机械稳定性好的特点而被广泛应用。作为新型导电填料,可用于材料的抗静电,其效果优于传统的碳黑、金属粉体,表面活性剂等,性价比高于最近提出的碳纳米管导电材料。用于电致变色材料可以替代 相似文献
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超声化学制备单分散金属纳米钯 总被引:9,自引:0,他引:9
A simple sonochemical technique is used to synthesize palladium nanoparticles in a poly(ethylene glycol) (PEG) solvent at room temperature. The reaction based on chemical reduction of PdCl2 by ascorbic acid (AA). The as prepared Pd nanoparticles are highly dispersed and uniform in size (with average size of ~20nm). The products were characterized by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). 相似文献
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核壳型含氟丙烯酸酯共聚物的合成及性能 总被引:4,自引:1,他引:4
采用饥饿态半连续种子乳液聚合方法, 在十二烷基硫酸钠(SDS)/辛基苯基聚氧乙烯醚(TX-10)复合乳化剂的作用下, 分别选用甲基丙烯酸三氟乙酯(TFEM)、甲基丙烯酸六氟正丁酯(HFBM)和甲基丙烯酸十二氟庚酯(DFHM)为含氟单体, 合成以丙烯酸正丁酯(BA)、甲基丙烯酸甲酯(MMA)和含氟单体为原料的核壳型结构含氟丙烯酸酯共聚物乳液. FTIR, 1H NMR, TEM和DSC分析结果显示, 获得了BA/MMA/含氟单体的共聚物乳液, 且乳液具有明显的核壳结构. DSC, TGA和SEM-EDX的分析显示, 核壳型结构的共聚物具有优异的热力学稳定性能和成膜性能; 长侧链或短侧链含氟单体对共聚物的热稳定性影响不明显, 但侧链较长的含氟单体所获得的聚合物在成膜过程中更易向表面迁移, 更能体现含氟聚合物的优点. 相似文献