改性二氧化硅溶胶的制备及成膜过程

采用甲基三乙氧基硅烷(MEOS)和含有C=C双键的烷氧基硅(KH-570)与正硅酸乙酯(TEOS)共同水解,合成了改性的二氧化硅溶胶,并且用提拉法在不锈钢基材上镀膜.结果表明经MEOS及KH-570改性后二氧化硅溶胶粒子明显减小,粒径分布范围变窄,对涂层具有明显增韧性效果,MEOS涂层水接触角较大,而经KH-570改性的二氧化硅涂层在有引发剂存在下,120℃热固化时可发生C=C双键的聚合交联,形成机械强度更高的有机-无机复合网络结构.     

接枝改性硅丙复合涂层的制备及性能研究

以γ-甲基丙烯酰氧丙基-三甲氧基硅烷(KH-570)和甲基丙烯酸酯类(MMA)为原料,过氧化苯甲酰(BPO)为引发剂,在非水溶剂中聚合先制得丙烯酸酯和KH-570的预聚体,通过预聚体与正硅酸乙酯(TEOS)共同水解制得了稳定的改性二氧化硅溶胶,同时,用一步法由TEOS、KH-570及MMA共聚也制备了丙烯酸酯改性硅溶胶.2种接枝后的二氧化硅溶胶通过浸渍提拉法在金属或者玻璃基片上成膜.运用激光光散射,FTIR、UV分光光度仪、铅笔硬度测试仪和附着力试验等对改性二氧化硅硅溶胶及涂层样品进行了分析和表征.结果表明,丙烯酸酯预聚体水解法具有很高的接枝率,制备的溶胶粒径易于控制,随水解条件的改变,可得到纳米至亚微米粒度的改性二氧化硅溶胶,并且成膜性能好.丙烯酸酯接枝改性后的二氧化硅涂层光学透过率高,对上述基材具有较好附着力,铅笔硬度均达到4H以上,对基材具有较好保护作用.     

溶胶-凝胶法制备SiO_2/PMMA玻璃增强涂层（英文）

采用溶胶-凝胶法制备二氧化硅/PMMA涂层,研究复合涂层对玻璃强度的影响。以正硅酸乙酯和甲基丙烯酸甲酯、γ甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)为原料,制备出SiO_2/PMMA复合溶胶。将有机-无机复合溶胶采用提拉法涂覆在玻璃片上,经120℃热处理2 h制备了复合涂层。采用傅里叶红外光谱仪、原子力显微镜和扫描电镜表征了涂层的结构和形貌,同时采用双环强度测试仪和分光光度计对涂层前后玻璃的性能进行了测试。结果表明溶胶-凝胶法制备的二氧化硅/PMMA复合涂层中,PMMA含量在40%~70%之间时,二氧化硅粒子和PMMA形成了均匀的网络结构,两相相容性良好,形成了纳米级厚度的复合膜:玻璃的断裂强度提高了64.11%~97.85%:涂层后玻璃的透光率均在93%以上,高于末涂层玻璃。     

APTES改性蒙脱土对镁合金表面杂化溶胶-凝胶涂层防护性能的影响

针对蒙脱土与有机-无机杂化溶胶-凝胶体系较差的相容性,使用APTES对蒙脱土进行接枝改性,通过在蒙脱土表面引入氨基建立与溶胶-凝胶体系间较强的键合,在镁合金表面制备更加致密、稳定的复合涂层.对蒙脱土的表征结果表明APTES成功接枝到了蒙脱土片层上.结果 分析表明,相比于纯溶胶-凝胶涂层,添加AP-MMT的溶胶-凝胶涂层...     

改性纳米CaCO3复合粒子的制备、表征及性能

采用含有纳米硅溶胶的纳米碳酸钙悬浮液在超声波处理及加热条件下,硅溶胶发生缩合反应从而沉积在纳米碳酸钙粒子表面的溶胶-凝胶沉淀法,制备出性能稳定的纳米碳酸钙/二氧化硅复合粒子.通过红外光谱(FTIR)、TEM分析、zeta电位测定以及TGA分析,表征了硅溶胶与纳米CaCO3粒子之间的杂化作用,研究了改性纳米CaCO3复合粒子水分散液的稳定性和粒径、两种纳米粒子之间的包覆作用、杂化作用以及改性后纳米CaCO3复合粒子的热稳定性.同时研究发现,改性后的无机纳米CaCO3复合粒子在聚氨酯脲水分散液中具有很好的分散性.     

镍离子掺杂TiO2涂层的制备及亲水性研究

目的 研究不同含量的镍离子掺杂对TiO2纳米涂层亲水性能的影响.方法 采用溶胶-凝胶法制备不同含量Ni2+掺杂TiO2纳米复合溶胶,通过浸渍提拉法在载玻片上成膜,经过热处理后,得到不同含量Ni2+掺杂TiO2复合涂层.通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、紫外-可见光分光光度计(UV-Vis)、傅里叶变换红外光谱仪(FT-IR)和表面接触角仪,对掺杂不同浓度Ni2+后TiO2的晶型、涂层微观形貌、光吸收性能、结构组成和涂层亲水性等进行表征分析,从而确定最佳Ni2+浓度的复合涂层材料配方.结果 制备的TiO2主要由锐钛矿相和少量金红石相组成,Ni掺杂抑制了锐钛矿相向金红石相的转变.随着Ni含量的增加,TiO2晶粒尺寸逐渐降低.适量掺杂Ni2+制备的TiO2纳米涂层表面形貌光滑,粒子分布致密均匀.掺杂使吸收波长阈值向长波方向偏移,禁带宽度减小,在一定程度上提高了TiO2涂层的亲水性.当Ni2+掺杂质量分数为1.5％时,TiO2涂层亲水性最佳.结论 采用溶胶-凝胶法实现了镍离子掺杂TiO2的改性,掺杂Ni2+后,Ni2+/TiO2复合涂层的亲水性能明显提高.     

水性UV聚氨酯丙烯酸酯/二氧化硅复合材料的制备及涂膜性能

目的 制备光固化水性聚氨酯改性丙烯酸酯/二氧化硅（WPUA/SiO2）复合材料,提高水性光固化聚合物材料的涂膜性能。方法 制备含双键官能化的二氧化硅纳米粒子,将其引入到制备的可光固化聚氨酯改性丙烯酸酯乳液体系中,制备水性UV固化WPUA/SiO2复合乳液,研究复合材料制备方法,分析体系中官能化二氧化硅纳米粒子的分散稳定性及其对涂膜形貌、透光性、硬度等性能的影响。结果 由于WPUA和官能化二氧化硅纳米粒子均含有C==C,所制备的WPUA/SiO2复合材料可以用UV光进行固化,官能化二氧化硅纳米颗粒由于表面存在有机分子链,与水性聚氨酯改性丙烯酸酯相容性提高,使得二氧化硅纳米颗粒掺杂量达到10％（质量分数）时可存储稳定性达30天以上。固化后涂层的透光性和力学性能明显提升,涂层铅笔硬度达到3H,粘附性为1级,抗冲击强度大于50 kg?cm。结论 制备的WPUA/SiO2复合体系具有良好的稳定性,改性纳米粒子的掺杂对水性UV固化聚氨酯改性丙烯酸酯的力学性能有明显改善,且可提高复合涂层的透光性。     

TiO2对中空硅减反射涂层硬度的影响

目的 提高中空硅减反射(AR)涂层的硬度.方法 采用溶胶-凝胶法制备中空二氧化硅纳米微球(HSNs)胶体溶液,通过异丙醇钛(TTIP)的水解缩合作用,在HSNs表面沉积纳米TiO2后,制备HSNs@TiO2胶体溶液.将HSNs@TiO2胶体溶液与酸性硅溶胶(ACSS)复合,制备HSNs@TiO2/ACSS减反射液,通过旋涂法在玻璃基板上制备相应的AR涂层.通过特高分辨率场发射扫描电子显微镜、高分辨透射电子显微镜和原子力显微镜对HSNs和HSNs@TiO2纳米粒子的形貌进行分析,通过紫外-可见分光光度计和纳米压痕仪对HSNs/ACSS AR涂层和HSNs@TiO2/ACSS AR涂层的透射率、硬度和弹性模量分别进行分析.结果 纳米TiO2沉积在HSNs表面后,减反射液中HSNs@TiO2纳米粒子的粒径较HSNs粒径增大1～30 nm不等.由HSNs@TiO2/ACSS减反射液制备的AR涂层表面颗粒及团簇明显,表面粗糙度(RMS)可达9.61 nm,远高于HSNs/ACSS AR涂层的3.62 nm.含有较大粒径HSNs@TiO2纳米粒子的HSNs@TiO2/ACSS AR涂层使玻璃基板在550 nm波长处的透射率增加1.3％,低于HSNs/ACSS AR涂层的增加值2.8％.纳米TiO2沉积之前,HSNS/ACSS AR涂层的硬度和弹性模量分别为2.3 GPa和56.3 GPa,纳米TiO2沉积之后,HSNs@TiO2/ACSS AR涂层的硬度和弹性模量分别为3.3 GPa和55.2 GPa,AR涂层的硬度显著提高.结论 溶胶-凝胶法在HSNs上沉积纳米TiO2后,可有效提高AR涂层的硬度,因此AR涂层的环境适用性有望得到进一步提高.     

溶胶-凝胶高温氧化防护涂层

溶胶-凝胶方法是一种制备氧化物涂层的简单方法.在不同基体上，采用溶胶-凝胶法可以制备连续的对基体起保护作用的SiO2、Al2O3、ZrO2及它们间复合的涂层.本文系统介绍了溶胶凝胶过程的特点、原理，着重介绍溶胶凝胶法制备抗氧化性涂层的工艺过程，分析了该方法存在的缺点，指出未来要解决的问题.并简单介绍了一种新型无氧溶胶-凝胶制备陶瓷涂层技术.      

PDMS/Nano-SiO2改性SiO2基复合涂层制备及疏

采用溶胶-凝胶法,制备不同含量PDMS、Nano-SiO2改性的SiO2基有机-无机复合溶胶,涂覆于混凝土基底上。通过红外光谱(IR)、疏水角(CA)、扫面电镜(SEM)等测试研究不同含量的PDMS、Nano-SiO2对复合涂层疏水性能的影响。结果表明,PDMS和TEOS以化学键Si-O-Si的形式相互结合;复合涂层的疏水性能随着PDMS含量的增加而增加,文中疏水角最大提高了23°(PDMS为50%时);加入Nano-SiO2改性涂层的疏水性能只有在Nano-SiO2加入量较高时,才能有较为明显的差别,文中疏水角最大提高了26°(Nano-SiO2为8%时)。     

Influence of curing temperature, silica nanoparticles- and cerium on surface morphology and corrosion behaviour of hybrid silane coatings on mild steel

This work is aimed at developing and investigating silane based organic-inorganic hybrid coatings possessing unique properties, which can be used to improve the performance of steel structures subjected to marine corrosion. These silane based sol-gel coatings were prepared by dip coating planar samples of mild steel in solution of an organically modified silica sol made from hydrolysis and polycondensation of tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) in acid catalysis condition. Crack-free coatings were obtained on curing at 200 °C. On increasing the curing temperature to 400 °C, however, cracks developed in the plain organic-inorganic hybrid coatings. This observation was consistent with the visual observations where appearance of the coated specimen changed from colourless metallic to brownish grey on curing from 200 °C to 400 °C temperature. The coatings were further modified using SiO₂ nanoparticles and cerium. The effect of change in the - temperature as well as - composition on the microstructural properties of the coatings was determined using optical microscopy, scanning electron microscopy and atom force microscopy. Additionally, Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR/FTIR) was carried out to show the formation of the Si-O-Si structural backbone of the hybrid material with the organic CH₃ group incorporated into the silica network. The corrosion protection performance of these coatings was examined using potentiodynamic polarisation technique and electrochemical impedance spectroscopy in aerated 3.5 wt.% NaCl solution. The polarization curves and corrosion resistance as measured by the bode plots suggested that the plain hybrid coatings offer good protection against corrosion. However, the SiO₂ and cerium modified nano hybrid coatings exhibited superior performance to that displayed by plain hybrid coatings.     

Improved corrosion resistance of AA2024 alloys through hybrid organic-inorganic sol-gel coatings produced from sols with controlled polymerisation

In this work we present the development of a nanocomposite material composed by silica nanoparticles in a hybrid organic-inorganic sol-gel matrix for corrosion protection of aluminium alloys. The sol-gel matrix was produced from an inorganic precursor, tetraethoxysilane (TEOS), a hybrid precursor organically functionalized with CC groups, 3-metacryloxypropyltrimethoxysilane (MPS), and an organic bi-functional monomer, ethyleneglycol-dimethacrylate (EGDMA) used to increase the cross-linking network. Silica nanoparticles, on the other side, increase the density and provide a major mechanical performance through the reinforcement of the coating. The evolution of the sol, mainly the chemical structure, during the processes of hydrolytic condensation and organic polymerisation was studied as a function of the sol concentration through Fourier transformed infrared spectroscopy (FTIR), rheometry, laser diffraction analysis and contact angle. Mono and multilayer coatings were deposited by dipping onto AA 2024 substrates and characterised by profilometry. The corrosion behaviour was followed through potentiodynamic tests and Electrochemical Impedance Spectroscopy (EIS).     

改性硅溶胶-苯丙乳液复合涂层的制备及性能

目的 以硅溶胶、苯丙乳液为主要原材料,制备高性能有机-无机复合涂层,并为其应用提供一定价值的参考.方法 采用KH550、KH560以及KH570等3种硅烷偶联剂依次对硅溶胶进行接枝改性,选用改性效果较好的硅溶胶,制备改性硅溶胶添加量为0％、35％、70％、105％(相对于苯丙乳液的质量百分比)的4种涂层.用傅里叶变换红外光谱仪、马尔文Zeta电位仪以及扫描电子显微镜对硅溶胶的改性效果进行表征,用多功能材料表面性能试验仪等涂层力学测试仪、紫外/可见/近红外分光光度计、扫描电子显微镜分别对4种涂层的力学性能、隔热节能性能及微观形貌进行表征.结果 KH560对碱性硅溶胶的接枝改性效果最优.向苯丙乳液中添加一定量的改性硅溶胶可以显著提升涂层性能.当改性硅溶胶添加量为苯丙乳液质量的70％时,涂层综合性能提升最高,此时涂层太阳光反射比为0.683,近红外反射比为0.624,附着力为3.85 MPa,1000圈磨损后的质量损失率为53％,抗拉强度为5.4 MPa,但断裂伸长率降低较为明显,仅为49.8％.结论 KH560更适合对碱性硅溶胶进行接枝改性.添加KH560改性硅溶胶后,苯丙乳液涂层的力学性能、隔热节能性能得到了显著提升.实际使用时,建议改性硅溶胶添加量为苯丙乳液质量的70％.     

Durability of aminosilane-silica hybrid gas-barrier coatings on polymers

Aminosilane solutions with pH equal to 8 and to 11 were applied and cured on SiO₂-coated poly(ethylene terephthalate) (PET) films. The permeability of the silane-silica hybrid coating on PET was reduced twofold compared to that of the SiO₂/PET film, at solution concentrations as low as 1 wt.%, irrespective of the pH. This concentration level led to a dense silane monolayer crosslinked to the silica surface. The oxygen transport mechanisms in the hybrid coatings were determined based on the thermally activated rate theory. Permeation experiments were also performed under tensile loading, and the critical strain for loss of barrier performance was found to be improved by a factor of two, only in case of basic pH. The defect population and morphology of the hybrid coating subjected to hydrothermal aging were analyzed using a reactive ion etching method and atomic force microscopy, respectively. These experiments confirmed the defect healing action of the aminosilane at low concentrations in solution, through the formation of a densely crosslinked polysiloxane layer at the silane-silica interface for both pH8 and pH11. The influence of the silane treatment was emphasized in case of basic pH due to the dissolution of superficial oxide layers.     

The electrochemical study of corrosion resistance of silane-based hybrid films doped with rare earth salt on aluminum alloy

采用溶胶-凝胶法, 以γ-环氧丙氧丙基三甲氧基硅烷(γ-GPTMS)和正硅酸乙酯 (TEOS)为前驱体, 在2A12铝合金表面制备了稀土铈盐(Ce(NO3)3)掺杂的有机－无机杂化膜, 研究了铈盐掺杂浓度和涂层固化温度等工艺条件. 通过极化曲线和电化学阻抗谱(EIS), 比较了掺杂与未掺杂有机－无机硅烷杂化膜、铬酸盐转化膜和RE转化膜在3.5%NaCl (质量分数)溶液中的耐腐蚀性能. 测试结果均表明, 铈盐掺杂硅烷杂化膜的极化电阻比掺杂前增大了约13倍,并显著高于铬酸盐转化膜和RE转化膜.     

高能球磨法制备超细镍粉的研究

采用粒度测试、SEM和XRD等分析手段,系统研究了球磨时间和过程控制剂对制备超细镍粉的影响.结果表明:随着球磨时间的延长,镍粉的粒度在初期减小较快,后期的减小趋于平缓;过程控制剂KH-570的加入能有效加快超细镍粉的细化,提高分散性能、片状化程度和表面的洁净度.加入过程控制剂KH-570,球磨36 h,能获得粒度为5.76 μm的高纯镍粉.     

KH560改性纳米硅溶胶对苯丙涂层性能的影响

目的提高硅溶胶-苯丙复合涂层的综合性能,为有机-无机复合涂层的应用提供一定的参考意义。方法采用水浴加热机械搅拌/超声分散法,用KH560对硅溶胶进行表面改性,并将改性前后的硅溶胶与苯丙乳液共混,制备了含改性前后硅溶胶15%、30%、45%(质量分数,全文同)的硅溶胶-苯丙复合涂层。用红外光谱仪证实改性成功。用紫外/可见/近红外分光光度计、力学性能测试仪、扫描电子显微镜对改性前后硅溶胶-苯丙复合涂层综合性能及微观结构进行表征。结果含有改性后硅溶胶的复合涂层综合性能得到明显提高,当改性硅溶胶掺量为30%时,复合涂层综合性能最好,此时复合涂层磨耗值为0.078 g,附着力为1级,抗冲击性为62 mm,拉伸强度为4.74 MPa,断裂伸长率为215.90%,附着力、抗冲击性、拉伸强度和断裂伸长率分别比相同掺量下未改性硅溶胶复合涂层提高1级、6 mm、0.59 MPa和10.34%。结论 KH560可成功地对硅溶胶进行表面改性,将改性后的硅溶胶替代未改性的硅溶胶可提高硅溶胶-苯丙复合涂层的综合性能,实际应用时改性硅溶胶掺量以30%为宜。     

Corrosion performance of rosemary-extract-doped TEOS:TMSM sol-gel coatings on 304L stainless steel

Pure and rosemary-extract-doped hybrid nanostructure coatings have been generated using sols synthesized via acid catalyzed hydrolysis and condensation of methacryloxypropyltrimethoxysilane (TMSM) and tetraethoxysilane (TEOS) at the molar ratio of 1: 1, in combination with rosemary extract. Coatings have been deposited on stainless steel (SS) 304L substrates by spin coating followed by curing at room temperature for 24 h in air and characterized. The morphology, composition and adhesion of hybrid sol-gel coatings have been examined by SEM, EDX and pull-off test, respectively. Addition of high additive concentrations (0.1%) did not disorganize the sol-gel network. Direct pull-off test recorded a mean coating-substrate bonding strength larger than 23.21 MPa for the hybrid sol-gel coating. Corrosion testing of coatings on SS 304L was studied by potentiodynamic polarization measurements and electrochemical impedance spectroscopy after 1 h and 21 days exposure to the physiological saline solution. The corrosion resistances of hybrid rosemary-extract-doped coatings after 1 h and 21 days exposure to the physiological saline solution were higher than that of pure hybrid silica coatings, both of which had thicknesses ranging lower than 100 nm. Also the electrochemical beha-viors of doped coating were studied by potentiodynamic polarizations tests in 3.5% NaCl media and the results were shown that this system is applicable in industry.     

Preparation and characterisation of silica/epoxy hybrid nanocomposite coatings containing boehmite nanoparticles for corrosion protection

Abstract

A hybrid silica/epoxy nanocomposite film containing boehmite nanoparticles has been developed in this work through the sol–gel method to protect AA2024 alloy from corrosion. The hybrid sols were prepared by copolymerisation of 3-glycidoxypropyltrimethoxysilane, tetraethylorthosilicate and aluminium isopropoxide. The films were prepared by dip coating technique. The morphology and the structure of the hybrid sol–gel films were studied by scanning electron microscopy and atomic force microscopy. The corrosion protection properties of the films were investigated by potentiodynamic scanning and electrochemical impedance spectroscopy. The results indicate that the presence of the boehmite nanoparticles in hybrid structure of the silica/epoxy films, highly improved the corrosion protection performance of the coating system.     

玻璃表面二氧化硅基超疏水膜的研究进展

超疏水表面带来一些可贵的界面性质,包括防结冰、防污染、防氧化等。对于工业产品中常用的玻璃等无机材料,研究人员参照自然界超疏水物质的结构和成分,借助含碳、氟等元素的物质,通过各种方法,合成具有微米-纳米二重粗糙结构和低表面能的有机-无机杂化涂层与基材结合,从而制备超疏水表面。因玻璃表面亲水性的固有性质,在平板显示、触摸屏、太阳电池盖板、玻璃幕墙等领域,解决既能满足光学性能指标,又能实现疏水性和抗污染性的问题尤为重要。首先讨论了粗糙表面的固液复合接触和非复合接触两种理论模型,进而阐述了超疏水玻璃的实现要素和基于二氧化硅的超疏水膜的制备方法。梳理了以溶胶-凝胶法为基础的玻璃表面二氧化硅基透明超疏水膜的制备技术进展,根据涂膜次数、溶胶组成、膜层粗糙结构的实现方法等,将现有制备技术分类、归纳为三种制备路线：共前驱体合成改性二氧化硅溶胶制备单层超疏水膜,表面改性法制备多层结构超疏水膜,添加二氧化硅颗粒引入粗糙层法。指出了各种方法的超疏水原理、膜层特点,分析了部分制备实例的疏水性、粗糙结构、光学透过率等性质的影响因素。对于溶胶-凝胶法制备的SiO2基超疏水玻璃,实现超疏水性的同时,如何保持玻璃良好的透明性以及膜层的耐磨性、持久性,是需要重点研究的方向。