溶胶-凝胶生物活性玻璃的纳米结构分析研究

利用溶胶-凝胶低温合成法制备了CaO-P2O5-SiO2系统生物活性玻璃骨修复及骨组织工程材料.利用SEM、BET及XRD等方法对溶胶-凝胶生物活性玻璃的微观结构及其组成对材料微观结构的影响进行了分析,并同目前已临床应用的45S5生物活性玻璃进行了比较.研究发现由溶胶-凝胶法制备的生物活性玻璃是由纳米级微球构成,其高比表面积是由其纳米微球之间的孔隙所致.这种高比表面积对于提高材料的表面吸附能力及生物矿化功能具有重要作用.根据等大球体最紧密堆积原理建立了溶胶-凝胶生物活性玻璃纳米孔隙尺寸近似计算模型,并对其孔隙结构进行了分析计算.     

纳米氧化铪粉体的制备及表征

以HfOI4为原料.NaBH4为沉淀剂,聚乙二醇(PEG)为表面活性剂,分别采用溶胶-凝胶法和沉淀法制备出HfO3纳米粉.并采用TG一DTA、XRD、SEM方法,对制备的前驱体、纳米粉体进行了分析和表征.研究了不同的制备方法对粉体粒径、粒子的影响.结果表明:溶胶-凝胶法制备出纳米粉体呈单斜晶型,平均粒径为20nm左右,粒子为球形,分散性较好,加入表面活性剂聚乙二醇,粒径变大,分散性变差,而化学沉淀法制备出纳米粉体,有少量晶须生成,晶须直径30nm,长度200nm.     

溶胶-凝胶法制备粒径可控的纳米钛酸铅

纳米钛酸铅是一种应用广泛的压电材料。采用溶胶-凝胶法研究了纳米钛酸铅的制备,考察了凝胶的煅烧温度、反应物的浓度及溶胶的反应温度对纳米颗粒粒径的影响和变化规律。研究表明,控制钛酸丁酯-醇溶液浓度为0.100～1.000 mol/L、醋酸铅-醋酸浓度为0.500～1.500 mol/L、溶胶反应温度为70～90℃、凝胶煅烧温度为400～800℃,可制备出平均粒径在20～50 nm范围的近似球形的四方相纳米钛酸铅。制备条件对纳米钛酸铅的粒径有显著影响:随溶胶反应温度和凝胶煅烧温度的升高,所制备纳米钛酸铅平均粒径增大;当醋酸铅-醋酸溶液浓度为1.500 mol/L,随钛酸丁酯-醇溶液浓度由0.100 mol/L增大至1.000 mol/L,所制备纳米钛酸铅粒径先增大后减小。制备粒径可控的纳米钛酸铅对其性能及应用具有重要的价值。     

聚乙二醇分子量对氧化锆粉体粒径的影响研究

为了控制纳米氧化锆粉体的粒径并降低制备成本,以不同分子量(MW)的聚乙二醇(PEG)作为分散剂,采用辅助溶胶-凝胶法制备纳米氧化锆粉体。利用傅里叶变换红外光谱对凝胶体进行了表征,采用激光粒度仪、X射线衍射仪和扫描电镜对纳米氧化锆粉体进行表征。实验结果证明,不同分子量的PEG具有不同的碳转化率,分解所得的碳颗粒所形成的碳隔离作用有助于控制粉体的团聚,纳米氧化锆的粒径与分散剂的碳转化率成反比。     

综合化学实验“溶胶-凝胶法制备锐钛矿二氧化钛”的改进*

对综合化学实验中“溶胶-凝胶法制备锐钛矿二氧化钛”的实验进行改进。本实验采用溶胶-凝胶法,通过钛酸丁酯水解,在反应物中加入少量螯合剂乙酰丙酮制备二氧化钛纳米微粒。样品的结构和粒径通过XRD、TEM、QESL、IR、UV-Vis 进行表征,结果表明,改进的溶胶-凝胶法制得的纳米二氧化钛为锐钛矿型晶体结构,分散度较好,粒径约为5-10 nm。     

二氧化钛纳米薄膜溶胶-凝胶法制备研究

研究了在清洁的玻璃表面采用溶胶-凝胶法制备锐钛矿相二氧化钛纳米薄膜,重点研究了薄膜制备过程中的关键工艺如溶胶配制及其稳定性、溶胶陈化及胶粒长大、提拉法涂膜次数及是否添加稳定剂对薄膜表面形貌均匀性的影响等.对所制备的薄膜的X射线衍射、光学显微镜、扫描电子显微镜及能谱分析表明,该薄膜为典型锐钛矿相二氧化钛,薄膜中二氧化钛纳米颗粒分布均匀、致密,纳米颗粒大小分布窄,直径约为30 nm,薄膜厚度约为300 nm.     

纳米氧化钛多孔薄膜的溶胶-凝胶法制备及其结构特征

采用溶胶-凝胶技术，以钛酸丁酯[Ti(OC4H9)4]为前驱体，加入聚乙二醇(polyethylene glycol，PEG)作为模板剂，在玻璃基片上制备了纳米氧化钛多孔薄膜。通过SEM观察了多孔薄膜的表面形貌，通过IR及XRD的测试分析表征了材料的结构，探讨了样品在溶胶-凝胶及烧结过程中的物理化学变化，测定了氧化钛的晶相成分。实验结果表明：通过调整H2O／Ti(OC4H9)4摩尔比及PEG的添加量可得到孔径范围在50～500nm且孔径可调的多孔氧化钛纳米薄膜，此外成膜过程中的升温速率是决定薄膜孔结构优劣的一个重要因素。     

多层陶瓷电容器用的SrTiO3纳米粉体制备

采用溶液-溶胶-凝胶法,从Sr(NO3)2-Ti(OC4H9)4-H2O-C2H5OH体系制备多层陶瓷电容器用的纳米SrTiO3粉体.用热重-差示扫描分析研究了由前驱体干凝胶形成纳米SrTiO3粉体的加热过程.用X射线衍射等方法研究了醋酸、水、温度对凝胶化、纳米SrTiO3粉体的粒径和比表面积的影响.用扫描电镜和透射电镜观察了纳米SrTiO3粉体的形貌和颗粒大小.所制备的SrTiO3粉体分散性好,粒径为40～50 nm,比表面积为9～10 m2/g.     

稀土离子掺杂碲酸盐发光薄膜的制备及其荧光增强

利用直流电场辅助固态膜离子交换技术,将金属银引入硅酸盐玻璃基片中,制备了表层含银纳米颗粒的改性硅酸盐玻璃基片。以1,2-丙二醇碲和硝酸锌、硝酸铒、硝酸镱为原料,通过非水解溶胶-凝胶法制备稀土离子掺杂的碲酸盐发光薄膜材料。利用X射线衍射、透射电镜、差热分析、场发射扫描电镜、原子力显微镜、荧光光谱仪、立体显微镜等测试手段,研究了玻璃基片中的银纳米颗粒及其形貌、薄膜的物相、形貌、发光性能及改性基片的荧光增强效应。结果表明:改性硅酸盐玻璃基片表层含有粒径为10～20nm的银纳米颗粒;制备的Er~(3+)-Yb~(3+)掺杂的碲酸盐发光薄膜为无定形态,薄膜的微观形貌良好,厚度约200nm;在改性玻璃基片上制备的薄膜在980nm激光泵浦下,可在410,527,547,660nm和1540nm附近发射荧光,其发光强度显著提高,最大可提高180倍。     

不同硅源对溶胶凝胶法制备莫来石纤维可纺性和结构的影响

采用铝粉和结晶氯化铝作为铝源,分别加入硅溶胶、硅溶胶与纳米氧化硅(7 nm、15 nm)的混合物作为硅源,采用溶胶-凝胶法,制备莫来石纤维。研究了不同硅源对莫来石前驱体溶胶纺丝性能、并对纤维晶化温度和结构的影响。结果表明加入纳米氧化硅后,溶胶纺丝性能下降;全部加硅溶胶制备的溶胶,纺丝性能最好,凝胶纤维长度大于500 cm。不同硅源凝胶纤维,在1200℃煅烧后主要物相为莫来石。加入纳米氧化硅(7 nm和15 nm)的试样,在1600℃煅烧后,有硅线石生成。加入纳米二氧化硅为硅源,纤维致密度明显增高,晶粒得到细化,孔隙率降低。     

Electrochemical Deposition of 58SiO2‐33CaO‐9P2O5 Nanobioactive Glass Particles on Ti‐6Al‐4V Alloy for Biomedical Applications

The nanobioactive glass (58SiO₂‐33CaO‐9P₂O₅) powders were synthesized by simple sol–gel method. The prepared samples reveal amorphous nature, agglomerated spherical morphology with particle size of 100–150 nm. The specific surface area of nanobioactive glass (NBG) particle is 147 m²/g. The NBG samples were coated on titanium (Ti‐6Al‐4V) alloy through electrochemical deposition method. The particle size of the NBG‐coated surface was in the order of 200–300 nm, and it was confirmed by atomic force microscopy (AFM) analysis. In vitro and AFM studies reveal the existence of higher bioactivity and uniform coating of NBG on implants at 80 V for 1 h.     

锌灰制备碱式碳酸锌和超细氧化锌及表征

室温下采用氨浸出锌灰制得碱式碳酸锌,再经煅烧制得超细氧化锌。研究了在合成碱式碳酸锌过程中表面活性剂对碱式碳酸锌和氧化锌颗粒尺寸与形貌的影响。结果表明,聚乙二醇（PEG20000）和聚乙烯吡咯烷酮（PVP-K30）这两种表面活性剂对颗粒的分散效果最好,制得的碱式碳酸锌颗粒为无定形片状且分散均匀,平均粒径为1 μm,煅烧后的氧化锌颗粒为六方晶系纤锌矿结构,粒径约为0.7 μm。添加PVP-K30比添加PEG20000的碱式碳酸锌热分解温度高。添加PEG和PVP的碱式碳酸锌反应活化能分别为139.9 kJ/mol和146.8 kJ/mol。     

A study of the electrophoretic deposition of bioactive glass-chitosan composite coating

Bioactive glass is coated on implant's surface to improve corrosion resistance and osseointegration, when placed in the body. Bioactive glass particles were synthesized through a sol-gel process and deposited along with chitosan to form a composite coating on a stainless steel substrate using electrophoretic deposition technique. Stable suspensions of chitosan-bioactive glass were prepared using bioactive glass particles (<1 μm) and 0.5 g/l chitosan solution. The influence of ethanol-water ratio on deposition yield was investigated. For all process conditions, best results were achieved with suspension of 30 vol% water in ethanol-water containing 2 g/l bioactive glass. FTIR studies showed that chitosan was absorbed on ceramic particle surface via hydroxyl and amid bonds. In order to evaluate the coating, its structure and electrochemical properties were studied. It was concluded that increasing the process voltage led to an increase in particle size and porosity, but induced cracks in the coating. In the presence of the polymer-bioactive glass coating, current density in artificial saliva was decreased by 52% and corrosion potential shifted toward more noble values.     

Preparation and characterization of stable and high solid content St/BA emulsifier-free latexes in the presence of AMPS

Stable and high solid content (about 50 wt%) St/BA emulsifier-free latexes were successfully synthesized using emulsifier-free emulsion polymerization with the addition of a small amount of reactive emulsifier AMPS. Properties of the latexes, such as the average particle diameter and its distribution, the morphology of latex particles, and stability were investigated. Physical properties of the latex films, i.e., glass transition temperature (T _g), water resistance, and solvent resistance were investigated as well. The size of latex particles is 400–600 nm in diameter, which is larger than that prepared by conventional emulsion polymerization. And the particle size distribution is narrow and uniform. It was found that the diameter of the latex particles decreases with the increasing content of the initiator KPS and the reactive emulsifier AMPS. Compared with the film prepared by conventional emulsion polymerization, water resistant and solvent resistant of the films prepared by emulsifier-free emulsion polymerization are improved greatly.     

Bioactive glass nanoparticles with negative zeta potential

The purpose of this work was to produce and characterize SiO₂–CaO–P₂O₅ bioactive glass nanoparticles with negative zeta potential for possible use in biomedical applications. 63S bioactive glass was obtained using the sol–gel method. X-ray fluorescence (XRF) spectroscopy and dispersive X-ray analysis (EDX) confirmed the preparation of the 63S bioactive glass with 62.17% SiO₂, 28.47% CaO and 9.25% P₂O₅ (in molar percentage). The in vitro apatite forming ability of prepared bioactive glass was evaluated by Fourier transform infrared spectroscopy (FTIR) after immersion in simulated body fluid (SBF). The result showed that high crystalline hydroxyapatite can form on glass particles. By the gas adsorption (BET method), particle specific surface area and theoretical particle size were 223.6 ± 0.5 m²/g and ∼24 nm, respectively. Laser dynamic light scattering (DLS) indicated particles were mostly agglomerated and had an average diameter between 100 and 500 nm. Finally, using laser Doppler electrophoresis (LDE) the zeta potential of bioactive glass nanoparticles suspended in physiological saline was determined. The zeta potential was negative for acidic, neutral and basic pH values and was −16.18 ± 1.8 mV at pH 7.4. In summary, the sol–gel derived nanoparticles revealed in vitro bioactivity in SBF and had a negative zeta potential in physiological saline solution. This negative surface charge is due to the amount and kind of the ions in glass structure and according to the literature, promotes cell attachment and facilitates osteogenesis. The nanometric particle size, bioactivity and negative zeta potential make this material a possible candidate for bone tissue engineering.     

聚乙二醇对羟基磷灰石纳米晶粒形成的影响

用聚乙二醇(PEG)对羟基磷灰石(HA)进行不同的表面改性处理,考察PEG对HA纳米晶粒形成的影响。以PEG作为反应物媒介对HA进行物理修饰和在HA合成煮沸后加入PEG进行表面修饰。结果表明:以PEG作反应媒介合成HA得到的浆料在静置12 h后能够保持51%的高度,HA颗粒通过一条或多条链串在一起;合成煮沸后加入PEG改性处理得到的HA浆料保持45%的高度,相对于无改性的HA,晶粒明显地呈现针状,但长度相等。改性后均使PEG吸附在HA表面,低温烧结后晶粒结构趋同。PEG作反应媒介,能够阻止HA晶粒的生长,减少晶粒的大小。而合成煮沸后PEG的加入,不影响HA晶粒的生长发育。     

白云石制备的纳米氢氧化镁的性能及其影响因素

探讨了白云石碳化法制备纳米级氢氧化镁的工艺条件,研究了沉淀剂、反应温度对纳米级氢氧化镁形貌的影响,以及表面活性剂对纳米级氢氧化镁分散性的改善,并对反应机理进行了阐述.结果表明:以氨水为沉淀剂所得的纳米氢氧化镁近似六边形的薄片状,平均粒径为16nm,其结构稳定性优于以氢氧化钠为沉淀剂的产品.当反应温度为30℃时,Mg(OH)_2形成细小晶核,薄片的厚度为5～7nm,晶粒粒径为10～15nm;反应温度为50℃时,晶核开始生长为大晶粒,但排列无规则;反应温度为70℃时,Mg(OH)_2薄片的厚度增至10nm左右,晶粒粒径为10～20nm,具有规则排列的完整晶粒:反应温度为80℃时,Mg(OH)_2晶粒具有不规则排列.加入表面活性剂聚乙二醇或十二烷基硫酸钠可以提高纳米粒子的分散性.当表面活性剂聚乙二醇用量为氢氧化镁的3.0%(以质量计,下同)时,纳米氢氧化镁的分散性最好,片层的厚度约为10 nm,平均粒径为20 nm.当表面活性剂十二烷基硫酸钠用量为氢氧化镁的4.0%时,纳米氢氧化镁具有较好的分散效果,平均粒径为20nm.     

Preparation and Properties of Bioactive Composite Based on Bioactive Glass and Poly-L-Lactide

Bioactive and bioresorbable composite was fabricated based on poly-L-lactide (PLLA) and bioactive glass (average particle size: 4.24 µm) by the combination of solvent evaporation technique and hot pressing. Bioactive glass granules are distributed homogeneously in the composite. With the increasing of the amount of bioactive glass, the bending strength and shearing strength of composite decrease while the bending modulus increases. PLLA/bioactive glass composites present a typical morphology of brittle failure with a smooth fracture surface. The biocompatibility test shows that the bioactive glass existing in the composite facilitates both adhesion and proliferation of rat fibroblast on the PLLA/bioactive glass composite film.     

乳化法明胶亚微米粒子的制备

以A型明胶为原料,石蜡油为油相,采用乳化化学交联方法制备了明胶亚微米粒子. 用扫描电子显微镜(SEM)观察了明胶亚微米粒子的形貌和粒径. 研究了影响微球粒径的多种因素,包括明胶溶液浓度、乳化搅拌速度、乳化温度、乳化剂和固化剂. 结果表明,采用戊二醛为固化剂、增加明胶的浓度、提高乳化搅拌速度、使用混合性的乳化剂都有利于降低明胶粒子的粒径. 此外,对制备工艺进行了优化,并在7000 r/min左右高速搅拌的条件下,得到了成球性较好的粒径约为450 nm的明胶亚微米粒子.     

微乳法制备纳米二氧化钛及结构表征

以硫酸法钛白粉生产中间产物偏钛酸为原料,采用微乳法制备纳米二氧化钛粉体,研究表面活性剂加入量、沉淀剂加入量对颗粒粒径的影响,采用透射电镜（TEM）对颗粒的形貌进行表征,及X射线衍射仪（XRD）对制备颗粒的晶相成分进行分析。结果表明：制备的二氧化钛粉体晶型良好,粉体颗粒分布均匀,粒径为20-60nm。