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1.
《Arabian Journal of Chemistry》2020,13(11):7598-7608
Zirconia ceramics have attained much consideration owing to the amazing mechanical strength and white color. These properties provide an opportunity for the use in biomedical applications. In the present study, an application oriented sol-gel route was adapted for synthesis of zirconia nanoparticles. ZrOCl2·8H2O was used as a precursor, iron oxide (Fe3O4) nanoparticles (pH 2 & pH 9) as a stabilizer and de-ionized water was used as a solvent. Sol-gel synthesized iron oxide stabilized zirconia nanoparticles were prepared by varying concentrations of iron oxide nanoparticles in the range of 2–10 wt%. X-ray diffraction results showed mixed phases at all wt% with acidic pH value, while pure tetragonal phase of zirconia was observed for stabilization with 6 wt% basic iron oxide. Maximum value of dielectric constant (~80 at log f = 4) and minimum value of tangent loss (~0.66 at log f = 4) were observed for zirconia stabilized with basic 6 wt% iron oxide. Maximum value of hardness (1410 ± 10 HV) along with high fracture toughness were observed with optimized stabilization. Very weak hemolytic activity and maximum scavenging (~76) antioxidant activity was observed under optimized conditions. Thus, it can be suggested that optimized nanoparticles, i.e. tetragonal zirconia stabilized with 6 wt% of basic Fe3O4, can be further useful for therapeutical and pharmaceutical applications.  相似文献   
2.
In this study, spectroelectrochemical (SPE) studies to monitor the electrochromic properties of electrochemically synthesized sub‐10 nm sized Prussian blue (PB) nanostructures (NSs) are employed. At the beginning the dark blue coloured device, shifts reversibly between translucent and dark‐blue while applying an applied bias between +1 to ?1 V with an opposite polarization. Amine functionalized silicate sol‐gel matrix (SSG) is used as a solid support and stabilizer for electrodepositing highly uniform sub‐10 nm PB NSs. The SSG's film thickness is suitably optimized through suitable controlled experiments. It is found that the SPE behaviour of sub‐10 nm sized PB NSs, suitably followed a colour modulation of PB into Prussian white (PW) and vice‐versa. SPE studies are used to investigate the redox switching between the PB and PW and which are responsible for an electrochromic function of a fabricated electrochromic device (ECD). Fabricated ECD has demonstrated an optical modulation at 680 nm with the moderate coloration efficiency of 115.8 cm2/C. Present study validates the SPE feature of sub‐10 nm PB NSs as an active electrochromic nanomaterial and demonstrating the applicability of SPE technique to investigate the variety of electrochromic nanomaterials, with consequences in both spectral and electrochemically active nanomaterials for electrochromic device applications.  相似文献   
3.
In this work we report an easy and efficient way to fabricate nanostructured cobalt oxide (Co3O4) thin films as a non-enzymatic sensor for H2O2 detection. Co3O4 thin films were grown on ITO glass substrates via the sol-gel method and characterized with several techniques including X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and optical absorbance. The Co3O4 thin films’ performance regarding hydrogen peroxide detection was studied in a 0.1 M NaOH solution using two techniques, cyclic voltammetry (CV) and amperometry. The films exhibited a high sensitivity of 1450 μA.mM−1.cm−2, a wide linear range from 0.05 μM to 1.1 mM, and a very low detection limit of 18 nM. Likewise, the Co3O4 thin films produced showed an exceptional stability and a high selectivity.  相似文献   
4.
利用溶胶-凝胶法制备了硅烷偶联剂KH560修饰的有机/无机杂化电光材料,分析了KH560的水解缩合的反应机理.对制备好的电光薄膜进行了表面形貌、折射率和电光特性的表征,并用反射法测量得出了该材料的电光系数为3.5pm/V.针对这种材料柔韧的特性,设计了上加载条形电光波导,并利用Opti-BPM软件模拟了二维和三维光场.摸索了其制备的加工工艺,制备了该结构的光波导,最后得到了这种波导的近场输出.  相似文献   
5.
采用溶胶-凝胶法制备了TiO2/Sm3+下转换薄膜,利用其下转换特性将紫外光转换为可见光,提高了可见光光照强度。利用X射线衍射和荧光光谱对TiO2/Sm3+粉体进行了表征,并对TiO2/Sm3+下转换薄膜进行了荧光光谱测试和紫外-可见分光光度计测试。荧光光谱显示,TiO2/Sm3+薄膜在受到395 nm紫外光照射时可发射出540~600 nm连续波长的可见光,具有下转换特性。二层TiO2/Sm3+下转换薄膜的可见光透过率与单纯的TiO2薄膜基本相同,利用其下转换特性使电池短路电流提高了13.2%,光电转换率提高了16.2%。  相似文献   
6.
Abstract

Organic-inorganic composite gel was prepared by using PEG-modified urethane acrylate (PMUA) gel and tetraethoxysilane (TEOS). PMUA gel was prepared by the phase-inversion emulsion polymerization of PMUA emulsion. The gelation of PMUA emulsion using this method enables PMUA gel to swell with H2O, TEOS, and ethanol. Hydrolysis and condensation reaction rates of the sol-gel process are strongly influenced by the pH controlled by catalysts such as HCl and NH4OH. Additionally, the morphology on the cross section of composite and the amount of silica ingredient incorporated into the composite gel were dependent on solvent, the molar ratio of H2O to TEOS, as well as the pH value.

As the silica content increased, due to hydrogen bonds interacting between PMUA gel and SiO2, particles, the tensile strength of composites considerably increased, whereas the elongation at break decreased. The incorporation of silica ingredient in PMUA gel/silica composites was verified with FTIR/ATR and SEM. The amount of the silica component in the composite was indirectly investigated by using TGA thermal analysis.  相似文献   
7.
纳米孔莫来石陶瓷材料的制备   总被引:2,自引:2,他引:0  
以正硅酸乙酯(TEOS)提供硅源、纳米氧化铝(d90=50 nm)提供铝源,通过溶胶-凝胶法与超临界干燥技术,制备了分散纳米氧化铝的SiO2气凝胶块体,所得复合气凝胶块体经1200℃、1300℃热处理后,得到了纳米孔莫来石陶瓷材料。XRD测试表明:凝胶体在1 200℃热处理后发生了莫来石化,1300℃莫来石化基本完成。压汞仪与场发射扫描电镜结果显示:凝胶块体经1 200、1 300℃热处理后,形成了具有纳米多孔结构的莫来石陶瓷材料,其骨架结构包含有200~400 nm的大孔,以及大量位于其孔壁上的6~30 nm的介孔。由于莫来石化的进行,热处理后的陶瓷材料的纳米孔结构具有更高的热稳定性。  相似文献   
8.
SiO2-PEG凝胶体系织构特性的研究   总被引:9,自引:0,他引:9  
采用溶胶-凝胶法,以正硅酸乙酯(TEOS)为前驱体,以不同分子量的聚乙二醇(PEG)为改性剂,制备结构可控的多孔SiO2干凝胶。结果表明:PEG好制了TEOS的 水解反应,进而对溶胶粒子的进行修饰,形成“粒子团-PEG”聚集体及短程有序的环状网络结构,由此对SiO2干凝胶的结构性质进行调控。经真空热处理后,PEG等有机残 留物被脱除的同时,SiO2-PEG干凝胶柔性骨架得到加强,孔分布更趋集中,干凝胶  相似文献   
9.
本文分别以钛酸丁酯的冰醋酸溶液和四氯化钛的乙醇溶液为钛源,硝酸铝的乙醇溶液为铝源,采用溶胶-凝胶法制备钛酸铝溶胶,通过分析溶胶的流变学特征和显微结构,研究了两种钛源对钛酸铝溶胶可纺性的影响.结果表明:以钛酸丁酯的冰醋酸溶液为钛源,制备的钛酸铝溶胶,由球形胶粒团聚体组成,呈非牛顿型流体的特性,溶胶不具有可纺性;而以四氯化钛乙醇溶液为钛源制备的溶胶,由线型聚合物构成,粘度为18.1~28 Pa·s,属于牛顿型流体,具有很好的可纺性.  相似文献   
10.
The solid host of a laser dye modifies its spectroscopic properties with respect to its liquid host. During the Sol-Gel process the dye molecules suffer from changing their environment. Two parameters affect this matter, the change in the concentration due to the evaporation of the solvent (drying) and the caging of dye molecules inside the pores or attachment to the silica network. Rhodamine 6G absorption and fluorescence spectra with different concentrations, during Sol-Gel time processing, have been studied. Both, absorption and fluorescence spectra of the dye in the solid host, for different concentrations, show a blue-shift relative to its liquid phase.  相似文献   
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