溶胶-凝胶法制备的SiO2涂层抗原子氧侵蚀性能研穷

以正硅酸乙酯（TEOS）为原料，在乙醇共溶剂和盐酸催化剂条件下，采用溶胶-凝胶方法制备SiO2胶体溶液，通过旋涂法在Kapton基体上制备了SiO2薄膜。采用自己研制的空间综合环境地面模拟设备对试样进行了原子氧暴露实验，测试表明溶胶-凝胶制备的SiO2涂层抗原子氧侵蚀性能优异，抗原子氧侵蚀性能比聚酰亚胺基体提高了2个数量级以上。经FTIR和XPS分析表明在原子氧暴露后涂层表面生成了一层SiO2，它阻止了原子氧对基体材料的进一步侵蚀。涂覆涂层后基体的光学性能没有受到影响。实验证明溶胶-凝胶制备抗原子氧侵蚀的防护涂层是一种行之有效的方法。     

SiO2-TiO2-ZrO2涂层的制备及其特性

用溶胶-凝胶法(sol-gel method)在不锈钢表面制备了 SiO\-2-TiO\-2-ZrO\-2系无机氧化膜(STZ).用DTA/TG、IR、XRD和SEM等手段研究了涂层制备时由凝胶向玻璃态的转变以及涂层薄膜的显微结构特点,考察了涂层对基体的保护效果. 试验结果表明,在溶胶至凝胶最终转变为无机氧化物的过程中形成了无机网络,Si4+ 和Zr4+充当了网络骨架的形成离子.涂层为无定型玻璃态,其间混有石英、锐钛矿或金红石等微晶.     

SiO2—TiO2—ZrO2系涂层的制备及其特性

用溶胶－凝胶法（sol-gel method）在不锈钢表面制备了SiO2-TiO2-ZrO2系无机氧化膜（STZ）。用DTA／TG、IR、XRD和SEM等手段研究了涂层制备时由凝胶向玻璃态的转变以及涂层薄膜的显微结构特点，考察了涂层对基体的保护效果。试验结果表明，在溶胶至凝胶最终转变为无机氧化物的过程中形成了无机网络，Si^4 和Zr^4 充当了网络骨架的形成离子。涂层为无定型玻璃态，其间混有石英、锐钛矿或金红石等微晶。     

Zn-SiO2复合涂层在水介质中的耐冲刷腐蚀性能

渗锌钢不耐冲刷腐蚀,其应用受到了限制.在料浆渗锌涂层上采用溶胶-凝胶法研究了制备SiO2涂层的过程,获得了具有优异抗蚀性能的Zn-SiO2复合涂层的新技术.EDS和XRD分析证明,Zn-SiO2复合涂层的外层是一层较薄的非晶态SiO2薄膜,内层是与基体结合紧密的由FeZn11,FeZn9,FeZn7相组成的Zn-Fe合金层.在40℃自来水中冲刷腐蚀100h后,Zn-SiO2复合涂层的腐蚀速率约是渗锌层的1/20,20钢的1/170.在40℃,3.5%NaCl溶液中冲刷腐蚀100h后,Zn-SiO2复合涂层仍然保持光泽的表面.电化学测试结果表明,渗锌涂层涂覆一层SiO2薄膜后电极电位大幅度向正方向移动,是Zn-SiO2复合涂层提高抗腐蚀性能的主要原因.     

液态GaIn合金对铜的腐蚀机理与防腐蚀技术研究

为了提高Cu耐GaIn合金腐蚀的性能,采用多弧离子镀在纯Cu表面溅射Cr涂层和Al涂层.再利用原位反应和溶胶凝胶法制备出Cr/Cr2 O3/Al2 O3复合涂层、Cr/CrN/SiO2复合涂层以及Al/Al2 O3/Al2 O3复合涂层,将样品置于60℃和200℃的GaIn合金中进行腐蚀试验.GaIn合金会对Cu样表面造成严重的点状腐蚀,但在腐蚀过程中铜镓金属间化合物会附着在铜样表面,从而降低GaIn合金对铜块的腐蚀速率.GaIn合金会对Al/Al2 O3/Al2 O3涂层造成严重的腐蚀,使涂层大面积剥落.Cr/CrN/SiO2涂层在GaIn合金中较为稳定,腐蚀程度低,但最外层的SiO2出现开裂和剥落.Cr/Cr2 O3/Al2 O3涂层在GaIn合金中无明显腐蚀现象.随着腐蚀温度的升高,GaIn合金对样品的腐蚀速率也会有所提高.Cu在200℃时的腐蚀速率是在60℃时的269倍以上,黏附在Cu表面的腐蚀产物主要为CuGa2.Cr/Cr2 O3/Al2 O3涂层抗GaIn合金腐蚀性能最好,Cr/Cr2 O3/Al2 O3涂层在200℃的GaIn合金中腐蚀速率为0.0495μm/h,且对Cu的热导率影响在1％左右.     

硅酸钙及硅酸钠浓度对钛合金表面生物活性涂层的影响EI北大核心CSCD

使用微弧氧化技术,在恒压工作模式下,脉冲电压400 V,脉冲频率600 Hz,占空比15%,氧化时间10 min,电解液由CaSiO3,Na2SiO3·9H2O,EDTA-2Na和K2HPO4·3H2O组成,以不同浓度(0.0835-0.15 mol/L)的CaSiO3及不同浓度(0-0.06 mol/L)的Na2SiO3·9H2O,在3D打印基体钛片表面制备生物活性涂层。利用扫描电子显微镜、能谱仪、电化学工作站、涡流膜厚仪、Image-Pro Plus 6.0、轮廓仪、划痕仪等对涂层进行结构、性能及微观形貌表征,研究CaSiO3和Na2SiO3·9H2O浓度对涂层的影响。结果表明:随着CaSiO3浓度的增加,涂层厚度、粗糙度、微孔孔径及孔隙率、涂层钙磷元素比逐渐增大,耐腐蚀性能及膜基结合力变差;随着Na2SiO3·9H2O浓度的增加,涂层孔隙率及孔径先增大后减小,涂层厚度、粗糙度、涂层钙磷元素比逐渐增大,膜基结合效果和耐腐蚀性先变差后变好。当CaSiO3和Na2SiO3·9H2O的浓度分别为0.15 mol/L和0.015 mol/L时,涂层的性能最佳。     

溶胶-凝胶涂层增强锂云母微晶玻璃

对溶胶－凝胶涂层增强锂云母微晶玻璃进行了研究．结果表明：浸涂溶胶－凝胶涂层的锂云母微晶玻璃较未浸涂前,其抗弯强度增加８％～４８％借助扫描电子显微镜（ＳＥＭ）对涂膜前后锂云母微晶玻璃的表面显微结构进行了研究,发现锂云母微晶玻璃强度增加是由于溶胶粒子进入锂云母微晶玻璃内部,填充晶相与玻璃相之间的微孔,弥合内部微裂纹．     

金属基表面Al2O3-SiO2涂层耐冲蚀性能的研究

结合炼钢转炉用风机因炉气而导致叶片磨蚀较快的实际情况，从改善叶片材料的角度出发，采用溶胶-凝胶法制备Al2O3-SiO2涂层用在金属基体上进行试验。结果表明在含3％（质量分数）Si02磨粒的水介质中，单一三层的SiO2涂层、SiO2-Al2O3-SiO2涂层及混合溶胶制备的复合涂层的耐冲蚀性相近，均比单一三层的Al2O3涂层及A12O3-Sio2-Al2O3涂层好。混合溶胶制备的复合涂层在3％（质量分数）SiO2磨粒的酸性介质中表现出了良好的耐冲蚀性。     

隔板玻璃表面宽光谱增透膜的制备与性能

利用溶胶-凝胶提拉方法在隔板玻璃表面涂制得到由TiO2与SiO2组成的λ/2-λ/4型宽光谱增透膜。通过溶胶粘度、凝胶时间及红外光谱等研究了TiO2涂膜溶胶的稳定性与相应膜层性能，测试了双层增透膜的透过率、抗高能氙灯辐照性能及使用性能等。结果表明，控制合适的原料配比、降低薄膜烘烤升温速率，可得到适于大面积涂膜的稳定TiO2溶胶，有效改善TiO2膜层质量；隔板玻璃表面增透膜在450-900nm光谱范围内平均透过率高达约98％，使“神光-Ⅱ”第九路主放大器的实际增益提高5．5％-6．5％且具有良好的抗高能氙灯辐照性能。     

SiO2对Al2O3凝胶纤维相变的影响

以尿素催化硅酸乙酯水解制得SiO2溶胶。采用29Si NMR、27 Al NMR、FT-IR、TEM、DTA、XRD和SEM等对SiO2溶胶、Al2O3凝胶纤维化学结构和微观结构研究结果表明,该SiO2溶胶稳定性好,含有大量的单硅酸Si(OH)4,能和Al2O3表面的Al—OH反应生成Al—O—Si键而有效地将其包裹,从而阻止了过渡态Al2O3微晶的相互接触,抑制了α-Al2O3的成核和生长。     

牙科热压技术对新型玻璃陶瓷微观结构和化学稳定性的影响

实验的目的是分析牙科热压技术对新型二硅酸锂玻璃陶瓷微观结构和化学稳定性的影响.对Li2O-SiO2-K2O-Al2O3-Zr02-P2O2玻璃系统进行晶化热处理,应用牙科热压技术制备化学稳定性测试试件.X射线衍射(XRD)分析热压前后玻璃陶瓷的物相组成,扫描电镜(SEM)观察微观结构,根据ISO6872标准测试材料的化学稳定性.结果表明,热压前后玻璃陶瓷的晶相组成均以二硅酸锂(Li2Si2O5)为主,热压后,主峰强度增高,晶体尺寸增大,并且呈现沿热压方向的定向排列趋势.热压前后玻璃陶瓷的化学稳定性均符合ISO6872标准要求,热压组试件对化学腐蚀有较强的抵抗性.牙科热压技术能够改变实验玻璃陶瓷的微观结构,进而提高材料的化学稳定性.     

The effect of residual glassy phase in a bioactive glass-ceramic on the formation of its surface apatite layerin vitro

A bioactive glass containing (in wt%) SiO₂ 48, P₂O₅ 9.5, Na₂O 20 and CaO 22.5 was transformed into a glass-ceramic through a heat treatment. The apatite formation on the surface of this glass-ceramic was examined in a simulated physiological solution. The data from X-ray diffraction, infrared reflection spectroscopy, scanning electron microscopy together with energy-dispersive X-ray analysis and composition imaging of backscattered electrons showed that the formation of the surface apatite layer depends on the relative amount of residual glassy phase in the glass-ceramic. The apatite layer was found to formin vitro on its surface if the glass-ceramic contained a residual glassy phase in a relative proportion more than a limiting volume. It lay on a layer rich in silica. However, only, a silica-rich layer was developed within the surface region of the glass-ceramic during the interaction with solution if the glass was almost completely crystallized. It is proposed that the apatite formation on the surface of the glass-ceramic is mainly caused by its residual glass. The residual glass facilitating apatite formation is considered to provide a negatively charged surface developed during its corrosion in the surrounding solution. The negatively charged surface attracts calcium ions and creates a solution within the glass — solution interface that is highly supersaturated with respect to hydroxyapatite. This leads to the formation of apatite on the surface of the glass-ceramic.     

晶化热处理对新型牙科玻璃陶瓷微观结构和性能的影响

分析不同晶化热处理条件对新型牙科二硅酸锂玻璃陶瓷微观结构和性能的影响.对Li2O-SiO2-K2O-Al2O3-ZrO2-P2O5玻璃进行不同的晶化热处理,X射线衍射(XRD)分析玻璃陶瓷的物相组成,扫描电镜(SEM)观察材料的微观结构,根据ISO6872标准测试材料的弯曲强度,半透性分析采用对比度测试法.结果表明,随着晶化温度的升高,玻璃陶瓷的晶相组成由偏硅酸锂(Li2SiO3)为主转变为以二硅酸锂(Li2Si2O5)为主,晶体尺寸增大,由呈团簇状分布的球形晶逐渐转变成均匀分布的棒状晶,玻璃陶瓷的挠曲强度和对比度值均显著增大.通过调控晶化热处理条件,可实现基础玻璃的受控析晶,制备的玻璃陶瓷可获得较高的挠曲强度和适宜的对比度,能够满足牙科美学修复材料的要求.     

镀膜浮法玻璃的风化性能

采用人工加速风化的方法研究了镀有SiO2薄膜的浮法玻璃的风化性能,并与相同风化条件下的浮法玻璃原片的表面状态进行了比对,从风化机理上进行了分析。红外反射光谱和扫描电镜分析结果表明,镀有SiO2薄膜的浮法玻璃和未镀膜玻璃随着风化温度和风化时间的增加,均呈现风化现象逐渐加重的现象。但前者风化程度明显低于后者,尤其当风化条件(70℃,75%RH,风化15d)恶劣时,镀膜玻璃表面只出现了小块斑点和红外光谱的略微变化;而未镀膜玻璃表面则出现大面积的侵蚀斑块,在红外谱图上不仅≡Si—O—Si≡特征峰发生位移,而且出现了C?O的特征峰。说明SiO2膜层能够很好地阻挡玻璃表面Na+与空气中H+、H3O+的交换,有效地抑制玻璃表面风化的发生。     

热镀锌层上硅酸盐膜的耐蚀性和自愈性

热镀锌(HDG)钢片经SiO2∶Na2O摩尔比为1.00和3.50的硅酸钠溶液中处理后,在其表面获得硅酸盐转化膜。用中性盐雾(NSS)试验、塔菲尔极化和电化学阻抗谱(EIS)研究了硅酸盐膜试样的耐蚀性,将被刀片划伤的硅酸盐膜试样进行NSS腐蚀后,用扫描电镜(SEM)和能谱仪(EDS)观察和分析了划痕处的腐蚀,以探讨硅酸盐膜的自愈性。结果表明:在较高SiO2∶Na2O摩尔比溶液中获得的硅酸盐转化膜具有较好的耐蚀性和自愈性,腐蚀过程中硅酸负离子从膜层中迁移划痕处形成新的保护膜(由Zn,O和Si组成)抑制了划痕处锌的腐蚀。AFM观察发现,在摩尔比为3.50中获得的试样的膜层表面更加致密,这有利于阻止腐蚀介质的侵入和提供充裕的硅酸负离子迁移。并对硅酸盐转化膜试样的划痕的腐蚀过程的细节进行了分析和讨论。     

In vitro dissolution behavior of SiO<Subscript>2</Subscript>–MgO–Al<Subscript>2</Subscript>O<Subscript>3</Subscript>–K<Subscript>2</Subscript>O–B<Subscript>2</Subscript>O<Subscript>3</Subscript>–F glass–ceramic system

Herein, we report the results of the in vitro dissolution tests, which were carried out by immersing the selected glass-ceramic samples in artificial saliva (AS) for various time periods of up to 42 days. In our experiments, the SiO(2)-MgO-Al(2)O(3)-K(2)O-B(2)O(3)-F glass ceramics with different crystal morphology and crystal content were used and a comparison is also made with the baseline glass samples (without any crystals). The bioactivity of the samples was probed by measuring the changes in pH, ionic conductivity and ionic concentration of AS following in vitro dissolution experiments. High resistance of the selected glass-ceramic samples against in vitro leaching has been demonstrated by minimal weight loss (<1%) and insignificant density change, even after 6 weeks of dissolution in artificial saliva. While XRD analysis reveals the change in surface texture of the crystalline phase, FT-IR analysis weakly indicated the Ca-P compound formation on the leached surface. The experimental measurements further indicate that the leaching of F(-), Mg(2+) ions from the sample surface commonly causes the change in the surface chemistry. Furthermore, the presence of (Ca, P, O)-rich mineralized deposits on the leached glass-ceramic surface as well as the decrease in Ca(2+) ion concentrations in the leaching solutions (compared to that in the initial AS solution) provide evidences of the moderate bioactive or mild biomineralisation behaviour of investigated glass-ceramics.     

镁合金表面微弧氧化-SiO2复合膜层的微观结构和耐蚀性

采用有机醇盐水解法制备SiO2溶胶,用浸溃-提拉制膜技术在AZ31B镁合金微弧氧化陶瓷层表面制备SiO2膜层,研究了镁合金表面微弧氧化-SiO2复合膜层的微观结构和耐蚀性.结果表明:SiO2溶胶进入微弧氧化陶瓷层表面的微孔并形成了SiO2膜层;由微弧氧化陶瓷层和SiO2膜层组成的复合膜层的腐蚀电位比单一陶瓷层明显提高,...     

Chemical reaction of bioactive glass and glass-ceramics with a simulated body fluid

Glass-ceramic A-W containing crystalline apatite and wollastonite in an MgO-CaO-SiO₂ glassy matrix bonds to living bone through an apatite layer which is formed on its surface in the body. The parent glass G of glass-ceramic A-W and glass-ceramic A, which has the same composition as glass-ceramic A-W but contains only the apatite, also bond to living bone through the surface apatite layer, whereas glass-ceramic A-W(Al), which contains the apatite and wollastonite in an MgO-CaO-SiO₂-Al₂O₃ glassy matrix, neither forms the surface apatite layer nor bonds to living bone. In the present study, in order to reveal the mechanism of formation of the surface apatite layer, changes in ion concentrations of a simulated body fluid with immersion of these four kinds of glass and glass-ceramics were investigated. Bioactive glass G and glass-ceramics A and A-W all showed appreciable increases in Ca and Si concentrations, accompanied by an appreciable decrease in P concentration, whereas non-bioactive glass-ceramic A-W(Al) hardly showed any element concentration change. It was speculated from these results that dissolution of the Ca(II) and Si(IV) ions from bioactive glass and glass-ceramics plays an important role in forming the apatite layer on their surfaces in the body.     

TiNx/SiO2/Ag/SiO2低辐射膜耐H2S气体的腐蚀性能

为了提高玻璃片上SiO2/Ag/SiO2复合膜的耐腐蚀性能,用磁控溅射法在其上制备了TiNx薄膜.采用X射线衍射(XRD)、扫描隧道显微镜(STM)研究了TiNx薄膜的结构及表面形貌;参照GB/T 5137.3-2002电子产品硫化氢腐蚀的检验方法研究了TiNx/SiO2/Ag/SiO2低辐射膜耐H2S气体的腐蚀性能....     

多孔硅外延层转移制备SOI材料的研究

用多孔硅外延层转移的方法成功地制备出了SOI材料，卢瑟福背散射／沟道谱（RBS／C）和扩展电阻（SPR）的结果表明获得的SOI材料上层硅具有很好的单晶质量，电阻率分布均匀，上层硅与氧化硅埋层界面陡直。对制备多孔硅的衬底材料也作了研究，结果表明P型重掺杂的硅衬底在暗场下阳极氧化后仍保持很好的单晶性能，用超高真空电子束蒸发方法能外延出质量很好的单晶硅，并且，在一定浓度的HF／H2O2溶液中具有较高的腐蚀选择率，保证了上层硅厚度的均匀性。