溶胶-凝胶法制备生物活性玻璃陶瓷的研究

采用溶胶-凝胶法制备前驱体粉体,经高温煅烧制备了名义化学组成为MgO4．6,CaO44．9,SiO234．2,P2O516．3,CaF20．5(质量分数)的磷灰石-硅灰石生物活性玻璃陶瓷。用造孔工艺制备了其多孔型材料。通过实验观察、差热和热重分析。体积密度和气孔率的测量,粒度测试、X射线衍射分析。扫描电镜观测,FTIR转换红外光谱分析等方法。研究了玻璃陶瓷前驱体粉末的溶胶-凝胶制备工艺条件,玻璃陶瓷的烧结工艺条件;分析了材料的晶相结构和显微结构。实验结果表明：溶胶-凝胶法可制备出微细的非晶态前驱体粉末,经烧结后玻璃陶瓷主晶相为磷灰石及β-硅灰石。造孔后。多孔型材料具有良好的贯通孔隙结构：微观孔隙约2～3 μm,宏观孔隙约300～400 μm。鉴于其晶相组成及良好的微观结构,通过新型溶胶-凝胶工艺开发的生物活性玻璃陶瓷材料可望被用于骨修复材料及骨组织工程支架材料。     

溶胶–凝胶法制备Cu_2ZnSnS_4薄膜及其太阳能电池器件

以金属盐和硫脲为原料、水和乙醇的混合液为溶剂,采用溶胶–凝胶滴涂法制备出Cu2Zn Sn S4(CZTS)薄膜。结果表明:所得薄膜为Kesterite相CZTS纳米晶,但含有少量的Sn S2杂质,薄膜中含有大量的CZTS纳米棒,薄膜组成Cu:Zn:Sn:S的元素摩尔比为1.6:1.2:1.0:3.4,为贫铜富锌比例,但存在杂质Cl–,薄膜带宽约为1.56 e V。该薄膜未经硫化,即用于组装CZTS薄膜太阳能电池器件,其结构为钠钙玻璃/ITO/Ti O2或Zn O/Cd S/CZTS/Ag电极,器件中的Ti O2和Zn O均用溶胶–凝胶法制备。器件具有光伏效应,开路电压Uoc为267 m V,短路电流密度Jsc为0.025 m A/cm2,填充因子fF为32%。     

溶胶-凝胶法制备TiO2-SiO2-GeO2玻璃的研究

以GeCl4为原料合成了3－三氯锗丙酸,再以正硅酸乙酯,钛酸丁酯,3－三氯锗丙酸为前驱物,采用溶胶－凝胶法制备了TiO2-SiO2-GeO2玻璃,利用DTA,TG,XRD研究TiO-SiO2-GeO2溶胶向玻璃的转化,利用XPS研究了TiO2-SiO2-GeO2玻璃体系的微结构。     

二氧化锗-二氧化硅凝胶玻璃的溶胶-凝胶法制备及其光学性质研究

本文以二氧化锗为原料合成了3-三氯锗丙酸,再以它和正硅酸乙酯为原料用溶胶-凝胶方法制备了二氧化锗-二氧化硅凝胶玻璃.研究了凝胶的制备及其向玻璃的转化过程,确定了制备的工艺条件.研究了凝胶和凝胶玻璃的透射光谱.用X射线衍射和电子衍射确定凝胶玻璃的结构为非晶结构.     

TiO2-SiO2/SiO2双层复合薄膜制备及折射率调控EI北大核心CSCD

采用溶胶-凝胶法制备了具有W型减反特性的Ti O2-SiO2/SiO2复合薄膜,并分别调控了TiO2及TiO2-SiO2混合介质薄膜折射率,探索了不同制备条件对TiO2薄膜折射率的影响机理。通过场发射扫描电子显微镜、能谱仪、椭偏仪、紫外–可见-红外分光光度计研究了薄膜微观结构、薄膜组分、折射率和光学透过率,通过TFcal软件模拟了双层复合薄膜的光学透过率线型。研究表明:溶胶pH值对TiO2薄膜折射率影响显著,其影响的前驱体水解速率对折射率的影响占主要作用,并且随着pH值的增大薄膜折射率减小,而水/钛比对薄膜折射率影响不显著。在TiO2与Si O2混合溶胶中两者物质的量比为1.2:1.0时,获得可用于制备双层复合W型减反膜系底层的薄膜,其椭偏仪拟合测试折射率约为1.68。最终制备的复合TiO2-SiO2/SiO2薄膜实现了光学宽谱范围380~1100 nm的优良增透效果,最大透过率可达约97%。     

TiO_2-SiO_2/SiO_2双层复合薄膜制备及折射率调控

采用溶胶-凝胶法制备了具有W型减反特性的Ti O_2-SiO_2/SiO_2复合薄膜,并分别调控了TiO_2及TiO_2-SiO_2混合介质薄膜折射率,探索了不同制备条件对TiO_2薄膜折射率的影响机理。通过场发射扫描电子显微镜、能谱仪、椭偏仪、紫外–可见-红外分光光度计研究了薄膜微观结构、薄膜组分、折射率和光学透过率,通过TFcal软件模拟了双层复合薄膜的光学透过率线型。研究表明:溶胶pH值对TiO_2薄膜折射率影响显著,其影响的前驱体水解速率对折射率的影响占主要作用,并且随着pH值的增大薄膜折射率减小,而水/钛比对薄膜折射率影响不显著。在TiO_2与Si O_2混合溶胶中两者物质的量比为1.2:1.0时,获得可用于制备双层复合W型减反膜系底层的薄膜,其椭偏仪拟合测试折射率约为1.68。最终制备的复合TiO_2-SiO_2/SiO_2薄膜实现了光学宽谱范围380～1100 nm的优良增透效果,最大透过率可达约97%。     

纳米多孔二氧化钛薄膜的制备及其亲水性能的研究

分别采用溶胶-凝胶法,水热合成法,热雾喷解法制备了纳米多孔TiO2薄膜。以X射线衍射,扫描电镜等方法分析了不同制备方法所得薄膜结构与形貌。通过比较不同方法制备的TiO2薄膜的亲水性能,得知溶胶—凝胶法制备的薄膜和玻璃载体结合最紧,而且表面平整。热雾喷解法制备的薄膜具有最大的比表面积,其亲水性能也最好。同时表明,纳米多孔TiO2薄膜在紫外光照射以后,具有比一般薄膜更持久的亲水型。     

利用TeCl4非水解溶-凝胶法制备TeO2薄膜

利用四氯化碲与乙醇反应生成前驱体氯代乙醇碲,采用非水解溶胶-凝胶法制备了TeO2凝胶薄膜,通过热处理获得非晶态TeO2薄膜.利用差热分析、X射线衍射和Fourier变换红外光谱等测试手段研究了非水解TeO2的溶胶-凝胶机制、物相变化、以及薄膜制备过程中的析晶现象.结果表明:四氯化碲可与乙醇发生部分亲核取代反应,在非水解溶胶-凝胶体系中生成了含桥氧、桥氯的Te-O-Te和Te-Cl-Te网络结构,凝胶薄膜在热处理过程中有机物碳化和Te-Cl结构的不稳定性易导致Te4+被还原,而对凝胶薄膜煅烧前在200℃进行预烧处理可抑制金属碲的析出,进而获得厚度约150nm、折射率为1.86的TeO2非晶薄膜.     

溶胶-凝胶法制备梯度折射率玻璃涂层的研究

本文讨论了用溶胶-凝胶法制备Na_2O-B_2O_3-SiO_2系统梯度折射率减反射膜的实验方法。这类玻璃膜具有多孔的微观结构,拥有比基玻璃更小的密度和折射率,膜中微孔结构经过热处理和化学处理后,使薄膜的折射率呈现梯度变化,玻璃涂层在宽的波长范围内起到减反射作用。将它应用于太阳能电池系统中可提高电池效率10%。 文中讨论了膜的厚度影响因素。应用热分折、红外吸收光谱研究了凝胶转化为玻璃的过程,应用开口气孔模型讨论了烧结过程.     

磷灰石/硅灰石生物玻璃基骨水泥的溶-凝胶法制备及性能

为了获得高性能的玻璃摹骨水泥,采用溶胶-凝胶法制备了磷灰石/硅灰石(apatite/wollastonite,AW)生物玻璃,将其作为固相粉末与柠檬酸固化液均匀混合制得了AW玻璃基骨水泥(glass-based bone cement,GBC),探讨了溶胶-凝胶法制备的AW生物玻璃作为GBC固相粉末的可能性.用X射线衍射、红外光谱和强度测试仪对不同温度热处理的AW生物玻璃粉末的晶相转变以及骨水泥在人体模拟体液中浸泡不同时间后的晶相组成和抗压强度进行了研究.结果表明:AW生物玻璃粉末经700℃热处理后形成了硅灰石和羟基磷灰石晶相,且温度越高晶相越完整;以900℃热处理后的AW生物玻璃粉末作为固相所制备的GBC随着浸泡时间的增加,骨水泥固化体中生成了更多量的CaC03晶体及少量的羟基磷灰石晶体,且此种GBC的抗压强度最大.     

GeS_2-Ga_2S_3-AgCl微晶玻璃的制备及其光学性质

用熔融淬冷法制备了一系列GeS2-Ga2S3-AgCl三元系统硫卤玻璃。研究了样品的密度、热稳定性以及折射率随玻璃组分的变化规律。选取了75GeS2-10Ga2S3-15AgCl玻璃组分进行微晶化处理,并且在350℃下热处理得到了可见至红外透明的微晶玻璃样品。X射线衍射和扫描电子显微镜测试显示,玻璃中析出(Ga4Ge)S4和AgCl微晶相,晶粒尺寸为200～400nm。用Z扫描测量了微晶化前后玻璃样品在800nm波长下的三阶非线性特性,结果表明:在热处理后,玻璃的非线性折射率n2和非线性吸收系数β均明显增加,其中微晶玻璃的最大三阶非线性极化率χ(3)为8.619×10-11esu,是基质玻璃的2.2倍。     

Synthesis and characterization of low-birefringent crosslinkable fluorinated poly(arylene ether sulfide)s containing pendant phenyl moiety

Fluorinated poly(arylene ether sulfide) (FPAESI) and ethynyl-terminated fluorinated poly(arylene ether sulfide) (E-FPAESI) were synthesized via step-growth polymerization from prepared dihydroxy monomer and pentafluorophenylsulfide, then E-FPAESI was followed by a reaction with 3-ethynylphenol. The number-average molecular weights and polydispersities of FPAESI and E-FPAESI were in the range of 12,000-26,000 and 1.75-3.18, respectively. The glass transition temperatures of the polymers varied from 138 to 178 °C depending on the molecular weight of the polymer used and were changed to the range of 191-245 °C after curing. The FPAESIs and E-FPAESIs exhibited high thermal stability up to 445-450 °C and 457-462 °C, respectively. The refractive index and birefringence of spin-coated polymer films were determined by the prism-coupling method. The refractive indices and birefringences of the films were in the range of 1.5849-1.5880 and 0.0014-0.0035 at a 1550 nm wavelength, respectively. The effect of E-FPAESI structure on the birefringence is compared with various reported poly(arylene ether sulfide)s.     

Synthesis of KTiOPO4 (KTP) Thin Films Using Metallo-organics

Crack-free and highly transparent KTiOPO₄ (KTP) thin films were synthesized by the sol-gel method using a homogeneous precursor solution prepared from ("BuO)₂-P(O)(OH), Ti(OEt)₄, and KOEt in EtOH. Precipitated powders from the solution crystallized directly to KTP above 550°C. Polycrystalline KTP thin films were obtained at 600°C on various substrates. On NdAlO₃(100) substrates, KTP films with (101) and (240) preferred orientations were formed at 600°C. KTP films on glass substrates showed a refractive index of 1.75 and an absorption edge of 350 nm. KTP films exhibited the second harmonic generation of the 532 nm light on irradiaton with 1064 nm light.     

Preparation and Characterization of BaO–TeO2 Thin Films Obtained from Tellurium(VI) Alkoxide by a Sol–Gel Method

BaO–TeO₂ thin films were prepared from tellurium(VI) alkoxide by a sol–gel method and their structure was investigated by X-ray diffractometry, Fourier transform infrared spectrometry, and ¹²⁵Te static nuclear magnetic resonance. Their crystallization temperature ( T _c), optical transmittance, and dielectric constant were measured, and their refractive index was calculated from the transmission spectra. The results indicate that the BaO–TeO₂ thin films were composed of TeO₆ and TeO₄ units, and had a T _c of ∼520°C, refractive index of ∼1.79, dielectric constant of ∼20. These films had a T _c higher than the glass prepared by a melt-quench method, but their refractive index and dielectric constant were lower. These differences may be due to differences in their structural units.     

高分子梯度玻璃的研制和表征

利用溶胶凝胶法制备高分子梯度玻璃前体 ,在这个体系中加入钛酸丁酯 ,形成高分子梯度玻璃。采用X射线散射能谱 (EDAX)、吸收光谱仪、隧道扫描电子显微镜 (SEM)、射线衍射仪 (XRD)对产品进行了表征 ,发现在样品(棒状 )中钛离子浓度由中心向边缘逐渐降低 ,呈梯度分布 ,样品在可见光范围内无明显的吸收峰 ,说明样品有较好的光学透明性 ,材料的颗粒分布均匀 ,粒径的大小为 40～ 6 0nm ,说明其有机相和无机相是均匀混合的 ,材料中没有明显的晶态物质     

Influences of Mn doping on the microstructural,semiconducting, and optoelectronic properties of HgO nanostructure films

Mn-doped HgO nanostructured thin films (Hg_1-xMn_xO) have been prepared using electron beam evaporation technique on Corning glass (1022) substrate at room temperature with different concentrations x = 0, 0.015, 0.05, 0.1, 0.15, and 0.2. The microstructural, morphological, semiconducting, and optoelectronic properties of the films have been investigated. The X-ray diffraction spectra suggest a hexagonal wurtzite type structure with lattice parameters decreased with increasing Mn content. It was found that the average particle size of the films decreases with increasing Mn doping which is confirmed by FE-SEM and AFM micrographs. The optical band gap of the investigated Mn-doped HgO nanocrystalline films is determined from the absorption coefficient and found to increase with the increase of Mn concentration which is attributed to the sp-d exchange interaction and/or the quantum confinement effect. The refractive index and extinction coefficient of the Mn-doped HgO films are also reported. The refractive index dispersion n(λ) is analyzed by single-effective-oscillator dispersion model proposed by the Wemple–DiDomenico (WDD). The oscillator parameters were estimated. The obtained dispersion values are suitable for the design of optoelectronic devices.     

Optical properties,thermal stability,and forming region of high refractive index La2O3–TiO2–Nb2O5 glasses

The high refractive index La₂O₃–TiO₂–Nb₂O₅ glasses were prepared by containerless processing, and the glass‐forming region was determined. The refractive index showed the range from 2.20 to 2.32, and the values were much higher than those of most optical glasses. The completely miscible 30LaO_3/2–(70?x)TiO₂–xNbO_5/2 (0 ≤ x ≤70) system was fabricated to study the compositional dependence of refractive index and optical transmittance. The crucial determinants of the refractive index of oxide glasses, oxygen molar volume, and electronic polarizability of oxygen ions were calculated. The principle of additivity of glass properties was suitable for the calculation of refractive index between glass and compositional oxides. All the glasses were colorless and transparent in the visible to 6.5 μm middle infrared (MIR) region. These results are useful for designing new optical glasses with high refractive index and low wavelength dispersion in wide optical window.     

Gradient refractive index structure of phosphor-in-glass coating for packaging of white LEDs

A gradient refractive index (GRIN) structure, with a gradual increase in the refractive index from the glass substrate, was successfully obtained by multilayer screen printing for white light-emitting diodes (w-LEDs) packaging. Each phosphor-in-glass (PiG) coating consisted of B₂O₃–SiO₂–ZnO glass matrix and yellow phosphor. The gradually increased refractive index (1.62, 1.72, and 1.82) of glass matrices were obtained from higher molecular weight of La₂O₃ and WO_3. After sintering at 600°C, no obvious interface was observed and the phosphor particles were mixed thoroughly in the glass matrix. When the phosphor content was 50 wt%, the white-light emission was obtained. Compared with those based on the nongradient and low-refractive PiG coating, the luminous efficacy of w-LEDs constructed by the PiG coating with GRIN was enhanced. It shows that the GRIN structure is beneficial to improve the luminous efficacy of w-LEDs.     

Structural and optical properties of iodine-doped PMMA film

Poly(methyl methacrylate) (PMMA) film was cast from solution in benzene (4% W/V). Various samples of iodine-doped PMMA films were prepared by adding different amount of iodine, namely, 0.5, 1, 2, and 8% (w/w), respectively, to PMMA solution in benzene. The structures of pristine and doped PMMA were investigated using analysis of their infrared spectra and wide-angle X-ray diffraction analysis. The refractive index of pristine PMMA is almost equal to that of glass. Changes in the refractive index of various doped PMMA samples have been determined from their reflectance and transmission spectra in ultraviolet–visible range. It has been observed that the refractive index increases at low concentrations of doping, and it is maximum for 1% iodine doping. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 1627–1631, 1998