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采用脉冲电化学驱动壳聚糖原位调控制备了具有抗菌性的羟基磷灰石/银纳米复合涂层.考察了电解液中银离子浓度、钙磷盐浓度等对复合涂层的形貌及成分的影响.探讨了壳聚糖调控羟基磷灰石和银纳米粒子的形成机理,发现在本研究的较佳实验条件为电位-1.3 V,Ag~+浓度为0.06 g·L~(-1),Ca~(2+)浓度为5 mmol·L~(-1).在此基础上对复合涂层的生物活性、生理稳定性能、抗菌性能进行分析.结果表明:复合涂层呈纳米球状,由羟基磷灰石、银、壳聚糖三相组成,并且表面有一层壳聚糖覆盖.银纳米粒子和羟基磷灰石纳米粒子在复合涂层中均匀分布.将复合涂层浸泡在SCPS溶液中37°C浸泡矿化10天后,在复合涂层表面生产细针状排列整齐的羟基磷灰石,且在(002)晶面25.8°处发生显著择优生长,表明复合涂层在快速矿化液中能诱导磷灰石生成,生物活性好.将复合涂层浸泡在37°C PBS溶液中考察其生理稳定性,壳聚糖对复合涂层中Ca~(2+)和Ag~+实现双重离子释放,且降低了离子释放速度,涂层具有良好的生理稳定性.抗菌实验表明复合涂层对大肠杆菌和金黄色葡萄球菌抗菌率达到99%以上,抗菌能力强. 相似文献
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采用壳聚糖改性棉和涤纶织物,通过织物表面的壳聚糖原位吸附、还原银离子制备了纳米银抗菌织物.用场发射扫描电子显微镜(SEM)、X射线能谱(EDA)、X射线粉末衍射仪(XRD)和反射光谱等对纳米银织物进行了表征,研究了银离子浓度和壳聚糖浓度对纳米银织物的影响,并检测了纳米银织物的抗菌性能.结果表明,在无需任何还原剂的条件下,壳聚糖改性的棉和涤纶织物表面可以均匀地形成银纳米粒子,晶粒大小为5~10 nm,所制备的纳米银织物均具有优异的抗菌性能. 相似文献
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为了制得表面多孔且与基材结合强度高的羟基磷灰石(HA)涂层,实验中以正丁醇为分散介质,以SiO2粉末为添加剂,纯钛片为基材,电泳沉积制备羟基磷灰石/二氧化硅/壳聚糖/(HA/SiO2/CS)复合涂层,经后续热处理得到多孔HA/SiO2复合涂层,采用扫描电镜(SEM)、傅立叶红外光谱仪(FT-IR)、X射线衍射仪(XRD)、万能材料试验机对涂层的表面形貌、组成、结构和结合强度进行测试和表征,并通过模拟体液(SBF)浸泡法对复合涂层的生物活性进行评价.结果表明:当悬浮液中的HA/SiO2/CS质量比为1∶1∶1时,制得的HA/SiO2/CS涂层经700℃热处理后获得的HA/SiO2复合涂层孔洞分布均匀,大孔孔径在10~15μm,小孔孔径在1~5μm;涂层与基材的结合强度达到25.5 MPa;多孔HA/SiO2复合涂层在SBF中浸泡7 d后,涂层表面碳磷灰石化;说明实验中添加SiO2所制得的多孔HA/SiO2复合涂层与钛基材结合强度高,且具有良好的生物活性. 相似文献
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借助聚吡咯(PPy)的调控,采用脉冲电沉积法在生物医用金属钛表面制备出均匀的纳米HA/PPy/Ag抗菌复合涂层.考察了电解液中Py浓度、Ag~+浓度、钙磷盐浓度等对复合涂层的形貌及成分的影响.探讨了PPy聚合过程形成球形HA-NPs和Ag-NPs的形成机理,并对复合涂层的生物活性、生理稳定性及抗菌性能进行研究.研究结果表明,电解液中Py浓度的高低影响涂层的形貌,Py浓度为0.03 mol/L时有利于复合涂层的沉积.电解液中Ag~+浓度影响涂层的形貌、结晶,电解液中Ag~+浓度为0.3 mmol/L左右比较适合.电解液中Ca~(2+)浓度影响涂层的形貌及结晶,其浓度过高颗粒尺寸增大,Ca~(2+)浓度为5.0 mmol/L左右较适合.复合涂层能够诱导磷灰石的生成,使其沿着(002)晶面出现择优生长,具有较好的生物活性.PPy的加入大大降低了复合涂层中Ca~(2+)和Ag~+的释放速度,提高了复合涂层的生理稳定性.抗菌检测表明复合涂层具有良好的抗菌性. 相似文献
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电化学沉积羟基磷灰石过程晶体生长行为 总被引:9,自引:0,他引:9
采用恒电流电化学沉积方法从含钙与磷盐水溶液中直接在纯金属钛电极表面沉积纳米羟基磷灰石涂层,运用EDS、SEM、XRD、FTIR等方法对其进行表征. 重点考察了一种典型制备条件下钙磷沉积层的形貌、结构及组分随沉积时间的变化,进而探讨相应条件下电化学沉积羟基磷灰石涂层晶体生长过程的基本规律. 研究表明电化学沉积法可用于在医用金属表面直接涂覆含钙离子缺陷的纳米羟基磷灰石涂层,典型条件下涂层的生长规律为: (1)沉积过程中羟基磷灰石晶粒以c轴方向沿沉积面法线方向择优生长,且这一趋势延续整个沉积过程; (2)内层晶粒的生长受到外层晶粒生长的抑制, 对于同层的晶粒,当晶粒分布密集时,晶粒生长可能发生相互制约; (3)随沉积时间的延长,沉积量增加,而膜层的化学组成基本不发生变化. 相似文献
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采用复合电沉积和电泳沉积两步法在钛基体上制备了Co-YSZ/HAp纳米复合涂层, 与只采用电泳沉积法在钛基体上制备纳米HAp单一涂层进行了比较研究.采用场发射扫描电镜、X 射线衍射和能量散射谱对复合涂层的微观形貌, 纳米HAp外层表面形貌, 晶相, 复合涂层的断面形貌及元素组成分布进行分析研究. 通过粘结-拉伸实验测定了涂层与基体的结合强度, 结果表明, Co-YSZ/HAp 纳米复合涂层与钛基体的结合强度明显高于纳米HAp 单一涂层与钛基体的结合强度, 说明复合涂层具有更好的力学性能. 相似文献
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Uota M Arakawa H Kitamura N Yoshimura T Tanaka J Kijima T 《Langmuir : the ACS journal of surfaces and colloids》2005,21(10):4724-4728
A new surfactant-mediated approach was developed to synthesize hydroxyapatite (HAp) nanoparticles with high surface areas by calcination of their precursors encapsulated with calcium stearate using mixed surfactant-containing reaction mixtures. Acidic aqueous solution of calcium phosphate was mixed with both or either nonaoxyethylene dodecyl ether (C12EO9) and polyoxyethylene(20) sorbitan monostearate (Tween 60) and then was treated with aqueous ammonium at 25 degrees C. The C12EO9-based single surfactant system yielded an aggregate of platy HAp nanoparticles 20-40 nm in size, whereas the Tween 60-based single and mixed systems led to lath-shaped HAp nanoparticles 2-8 nm wide and encapsulated with calcium stearate. On calcination at 500 degrees C, the stearate-encapsulated HAp nanoparticles in the latter two systems were deorganized into high surface area HAp nanoparticles. Particularly, the HAp nanoparticles in the mixed system exhibited a specific surface area as high as 364 m2 g(-1) that is roughly 3 times larger than 160 m2 g(-1) for those in the single system. The significantly high surface area for the former is attributed to much less adhesion of decapsulated HAp nanoparticles, which originated from the particle-separating effect of the C12EO9 molecules adsorbed on the outer surface of the stearate-encapsulated HAp nanoparticles to inhibit their agglomeration or interfacial coordination. The present results demonstrate that the mixed use of two different surfactants as a source of encapsulating and templating agent and a particle-separating agent is specifically effective for the synthesis of high surface area HAp nanoparticles. 相似文献
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Biocomposites of hydroxyapatite, HAp, in conjunction with various binders including poly(vinyl alcohol), PVA, and collagen have the potential of serving in various tissue engineering applications, such as in bone repair and reconstruction tasks, especially if the nanoparticles of hydroxyapatite are used. Here, hydroxyapatite nanoparticles (n-HAp) were synthesized at the ultimate size range of 10-50 nm and then incorporated into PVA or in situ synthesized in collagen/PVA. The biocomposites of HAp with PVA exhibited relatively high elasticity (as revealed by the linear viscoelastic material functions, characterized upon small-amplitude oscillatory shear) especially upon cryogenic treatment. The incorporation of the collagen into the PVA/HAp biocomposite provided internal porosity to the biocomposite with the pores in the 50-100 nm range for collagen/HAp and 50-500 nm for the collagen/HAp/PVA. 相似文献
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Iwasaki M Miyamoto Y Ito S Furuzono T Park WK 《Journal of colloid and interface science》2008,326(2):537-540
Nanometer-sized TiO(2) island structure on the platy hydroxyapatite nanocrystals (HAp) has been accomplished by two-step emulsion process. At the first step, platy HAp nanocrystals, of which size was in the range of 70-200 nm after heat-treatment at 1078 K for 1 h, were prepared using the W/O emulsion system. Before the second step, HAp nanocrystals were immersed in NaH(2)PO(4) solution for the formation of hydroxyl group on their surface. In the following, titanium tetraisopropoxide reacted with the hydroxyl group of HAp surface to form TiO(2) nanoparticles on the surface of HAp nanocrystals, which were dispersed in the micrometer-sized methanol droplets of polyethylene cetylether-cyclohexane mixture (methanol/oil emulsion). The resulting hydroxyapatite nanocrystals loaded with TiO(2) nanoparticles showed the high photocatalytic activity comparing to the commercial TiO(2) catalyst. 相似文献
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维生素E绿色还原法制备银纳米粒子的研究 总被引:1,自引:0,他引:1
采用一种绿色还原法制备银纳米粒子,以维生素E为还原剂,淀粉为稳定剂,在液相中还原硫酸银,通过改变溶液的pH值和反应时间,得到不同粒径的黄色银纳米粒子,并分别采用透射电镜、红外光谱、紫外-可见吸收光谱、扫描电镜和电化学方法对银纳米粒子进行表征。结果表明:维生素E在溶液中被氧化生成苯醌,反应得到的银纳米粒子为球形,粒径为8~25 nm;在较强碱性条件下,得到的银纳米粒子尺寸较小,分布较均匀,其平均粒径约为10 nm;不同条件下生成的银溶胶分别在417、411、409、408 nm处出现紫外吸收峰,这些吸收峰均为银纳米粒子的表面共振吸收;生成的银纳米粒子具有很好的电化学性质,并对L-半胱氨酸的电化学反应显示了良好的催化活性。 相似文献
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MubarakAli D Thajuddin N Jeganathan K Gunasekaran M 《Colloids and surfaces. B, Biointerfaces》2011,85(2):579-365
Biosynthesis of nanoparticles is under exploration is due to wide biomedical applications and research interest in nanotechnology. Bioreduction of silver nitrate (AgNO(3)) and chloroauric acid (HAuCl(4)) for the synthesis of silver and gold nanoparticles respectively with the plant extract, Mentha piperita (Lamiaceae). The plant extract is mixed with AgNO(3) and HAuCl(2), incubated and studied synthesis of nanoparticles using UV-Vis spectroscopy. The nanoparticles were characterized by FTIR, SEM equipped with EDS. The silver nanoparticles synthesized were generally found to be spherical in shape with 90 nm, whereas the synthesized gold nanoparticles were found to be 150 nm. The results showed that the leaf extract of menthol is very good bioreductant for the synthesis of silver and gold nanoparticles and synthesized nanoparticles active against clinically isolated human pathogens, Staphylococcus aureus and Escherichia coli. 相似文献
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Vigneshwaran N Kathe AA Varadarajan PV Nachane RP Balasubramanya RH 《Langmuir : the ACS journal of surfaces and colloids》2007,23(13):7113-7117
A simple route for the synthesis of silver-protein (core-shell) nanoparticles using spent mushroom substrate (SMS) has been demonstrated in this work. SMS exhibits an organic surface that reduces silver ions and stabilizes the silver nanoparticles by a secreted protein. The silver nitrate solution incubated with SMS changed to a yellow color from 24 h onward, indicating the formation of silver nanoparticles. The purified solution yielded the maximum absorbance at 436 nm due to surface plasmon resonance of the silver nanoparticles. X-ray analysis of the freeze-dried powder of silver nanoparticles confirmed the formation of metallic silver. Transmission electron microscopic analysis of the samples showed a uniform distribution of nanoparticles, having an average size of 30.5 +/- 4.0 nm, and its corresponding electron diffraction pattern confirmed the face-centered cubic (fcc) crystalline structure of metallic silver. The characteristic fluorescence of the protein shell at 435 nm was observed for the silver nanoparticles in solution, when excited at 280 nm, while Fourier transform infrared (FTIR) spectroscopy confirmed the presence of a protein shell. The silver nanoparticles were found to be stable in solution for more than 6 months. It is observed that the reducing agents from the safflower stalks caused the reduction of silver ions while protein secreted by the fungus stabilized the silver nanoparticles. These silver nanoparticles showed excellent antibacterial activity against two representative bacteria, Staphylococcus aureus (Gram positive) and Klebsiella pneumoniae (Gram negative), in spite of the presence of an organic layer as a shell. Apart from ecofriendliness and easy availability, "SMS" as a biomanufacturing unit will give us an added advantage in ease of handling when compared to other classes of microorganisms. 相似文献
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Kalimuthu K Suresh Babu R Venkataraman D Bilal M Gurunathan S 《Colloids and surfaces. B, Biointerfaces》2008,66(1):150-153
The use of microorganisms for the synthesis of nanoparticles is in the limelight of modern nanotechnology. Using the bacterium Bacillus licheniformis, the biosynthesis of silver nanoparticles was investigated. These silver nanoparticles were characterized by means of UV-vis spectroscopy, scanning electron microscopy (SEM), electron diffraction spectroscopy (EDX) and X-ray diffraction (XRD). The nanoparticles exhibited maximum absorbance at 440 nm in UV-vis spectroscopy. The XRD spectrum of silver nanoparticles exhibited 2theta values corresponding to the silver nanocrystal. SEM micrographs revealed the formation of well-dispersed silver nanoparticles of 50 nm, and the presence of silver was confirmed by EDX analysis. 相似文献
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Green methods using biological extracts, in particular plant-based solutions, have shown great potential for silver nanoparticle synthesis. A microwave-assisted single-step phytosynthesis of silver nanoparticles is described in the present study. The aqueous extract obtained from the Rosa santana (rose) petals was used for the first time in the synthesis. The synthesized nanoparticles obtained after optimized microwave conditions for time and temperature were analyzed by ultraviolet–visible spectroscopy (UV–Vis), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and Zeta-size analysis. The results obtained from the characterization studies showed that the synthesized nanoparticles were nearly spherical in shape with sizes from 6.52?nm to 25.24?nm with an average particle size of 14.48?nm with a face-centered cubic structure. The antibacterial activities of the synthesized nanoparticles were evaluated and revealed that the silver nanoparticles displayed good inhibition against both Gram-negative and Gram-positive bacteria. Also, the cytotoxic effect of the silver nanoparticles on a mouse fibroblast cell line (L929) was studied by a cell viability assay. The results showed that phytosynthesized silver nanoparticles were nontoxic to the healthy normal cell line at all tested concentrations. 相似文献
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《Arabian Journal of Chemistry》2014,7(6):1099-1103
The Pepper leaves extract acts as a reducing and capping agent in the formation of silver nanoparticles. A UV–Vis spectrum of the aqueous medium containing silver nanoparticles demonstrated a peak at 458 nm corresponding to the plasmon absorbance of rapidly synthesized silver nanoparticles that was characterized by UV–Vis spectrophotometer. The morphology and size of the benign silver nanoparticles were carried out by the transmission electron microscope (TEM) and field emission scanning electron microscope (FE-SEM). The sizes of the synthesized silver nanoparticles were found to be in the range of 5–60 nm. The structural characteristics of biomolecules hosted silver nanoparticles were studied by X-ray diffraction. The chemical composition of elements present in the solution was determined by energy dispersive spectrum. The FTIR analysis of the nanoparticles indicated the presence of proteins, which may be acting as capping agents around the nanoparticles. This study reports that synthesis is useful to avoid toxic chemicals with adverse effects in medical applications rather than physical and chemical methods. 相似文献