甲醇对有序介孔氧化硅结构和形貌的影响

以三嵌段共聚物P123为模板剂、正硅酸乙酯TEOS为无机硅源,采用水热法合成了SBA-15介孔分子筛,并采用XRD、SEM、TEM、N_2吸附-脱附等表征手段研究了不同含量的甲醇对SBA-15分子筛的结构与形貌的影响.结果表明:甲醇对SBA-15介孔材料的形貌与结构影响较大,随着甲醇含量的增加,SBA-15介孔分子筛逐渐从纤维状变为球形,且在很宽的浓度范围内存在一个纤维状与球形共存的中间态,这主要是由于亲水性小分子的嵌入导致双胶束的形成,并最终形成两种形貌的共存;同时,随着甲醇含量的增加,介孔由有序向无序状态变化,N_2吸附-脱附实验表明平均孔径逐渐从10.2 nm降低到8.8 nm,孔径的分布逐渐变宽,孔容由1.003 cm~3/g逐渐增加到2.708 cm~3/g,比表面积由455.3 m~2/g增加到1063 m~2/g,说明随着甲醇添加量的增加,介孔逐渐向微孔方向扩展.     

介孔SiO2负载和包覆的纳米金属颗粒的制备与研究

制备了以SiO2为核、介孔SiO2为壳的核一壳颗粒负载纳米金属颗粒以及介孔SiO2壳层包覆SiO2负载的纳米金属颗粒。结果表明,十六烷基三甲基溴化胺（CTAB）作为模板剂,有助于介孔SiO2壳层包覆SiO2核的结构形成,介孔SiO2壳层的孔径方向垂直于SiO2核的表面;在聚乙烯吡咯烷酮（PVP）的稳定作用下,Pt纳米颗粒能均匀地分布在介孔SiO2壳层的表面。单分散SiO2颗粒经过3-氨丙基三乙氧基硅烷（APS）功能化后,可负载纳米金属颗粒。进一步研究表明,以SiO2负载纳米金属颗粒为核,NH3·H2O,乙醇和水为分散剂,CTAB为模板剂,正硅酸乙酯（TEOS）为硅源,还能制备介孔SiO2壳包覆SiO2负载的纳米金属颗粒,而且介孔SiO：壳层的厚度可通过TEOS的含量调节。     

Al掺杂TiO2介孔材料的合成、表征和光催化性能

以钛酸四丁酯为钛源、十八水硫酸铝为铝源、三乙醇胺为模板剂,采用研磨-溶胶技术合成了Al掺杂的TiO2介孔材料,并利用XRD、EDS、TEM、BET、UV-vis和IR等手段表征了材料的结构、形貌、比表面积、孔径分布及光学性能.结果表明:Al掺杂能够减小TiO2光催化剂的粒径,提高介孔TiO2的热稳定性;Al掺杂TiO2介孔材料的平均孔径为4.5 nm,比表面积达到110.2 m2/g;相比商用P25和介孔TiO2,Al掺杂介孔TiO2的吸收边发生红移,对初始浓度为20 mg/L的甲基橙进行催化降解1h后,其降解率达到92.5％.     

加水量与TEOS/MTES比例对有机-无机复合涂层防腐性能的影响

采用溶胶-凝胶法,以正硅酸乙酯(TEOS)和甲基三乙氧基硅烷(MTES)为前驱体,在钢片上制备有机-无机复合防腐薄膜。通过傅里叶红外光谱(FTIR)、扫描电镜(SEM)等测试手段研究薄膜材料的结构及性质的变化,并通过盐雾腐蚀试验和电化学阻抗谱测试对复合薄膜的防腐蚀性能进行检测,探讨加水量(R)、两种前驱体比例等溶胶凝胶过程工艺条件对防腐涂层结构及防腐性能的影响。结果表明,随加水量的增加,涂层防腐性能下降,随着TEOS/MTES比例由1:1到1:4,涂层防腐性能增强,涂层在R=2,TEOS/MTES=4时防腐性能最佳,较空白钢片阻抗提高2个数量级。     

设计与制备具有放射状介孔壳层的PS/_MSiO_2复合磨料及其抛光氧化硅片效果

以阳离子表面活性剂CTAB为牺牲模板、TEOS为硅源、硝酸铵/乙醇混合溶液为选择性溶剂,合成以表面经PVP修饰的聚苯乙烯(Polystyrene,PS)微球为内核、表面包覆介孔氧化硅(Mesoporous-silica,MSiO_2)壳层的新型PS/MSiO_2复合磨料。采用场发射扫描电镜(FESEM)、透射电镜(TEM)和原子力显微镜(AFM)测试,研究PS/MSiO_2复合磨料的核壳结构以及经复合磨料抛光后的表面粗糙度均方根值和抛光速率。结果表明:PS/MSiO_2复合磨料具有包覆完整的核壳结构,其PS内核尺寸为200~210 nm,介孔氧化硅壳层厚度约为30 nm,包覆层中存在大量放射状介孔孔道。氮气吸刚/脱刚测试表明:复合磨料的比表面积为612 m~2/g,介孔孔径为2~3 nm;经复合磨料抛光后衬底表面粗糙度均方根值(RMS)和抛光速率(MRR)分别为0.252 nm和141 nm/min,明显优于粒径相当的常规SiO_2磨料(0.317 nm,68 nm/min)。复合磨料中有机内核及壳层中的介孔孔道结构有利于降低颗粒的弹性模量和表面硬度,从而有助于减小磨料在衬底表面的压痕深度并降低抛光表面粗糙度。此外,复合磨料可借助其高比表面积提高对抛光液中有效化学组分的吸刚能力,从而增强接触微区内的化学反应活性以提高抛光速率。     

含镍和含钴介孔分子筛的稳定性和孔结构

以十六烷基三甲基溴化铵为模板剂,以硅酸钠、氯化镍、氯化钴等无机盐为原料,水热法合成出含Ni介孔分子筛和含Co介孔分子筛。采用XRD、FT-IR、TPR、TEM和比表面积孔径测定等方法对样品进行表征。结果表明:合成了长程有序性好的含Ni和含Co介孔分子筛;含Ni介孔分子筛的比表面积为753.3 m2/g,平均孔径为3.23 nm,750℃焙烧3 h,100℃水热处理5 d介孔结构仍然存在;含Co介孔分子筛的比表面积为744.1m2/g,平均孔径为4.44 nm,650℃焙烧后转变为虫蛀状介孔结构,750℃焙烧3 h后介孔有序性变得很差,100℃水热处理5 d后转变为虫蛀状结构。     

溶胶-凝胶法制备低折射率和低介电常数介孔二氧化硅薄膜

采用溶胶-凝胶技术,蒸发诱导自组装法(EISA)工艺制备了二氧化硅透明有序介孔薄膜.以十六烷基三甲基溴化铵(CTAB)作为模板剂,正硅酸乙酯(TEOS)为硅源前驱体,基片采用双面抛光的硅片,利用提拉法制备薄膜.经过表面修饰剂六甲基二硅胺烷(HMDS)修饰后,薄膜具有疏水性能,而且薄膜的二氧化硅骨架结构更稳定.由椭偏仪测得热处理后的薄膜的折射率低至1.18,而薄膜的介电常数为2.14.     

介/纳孔生物玻璃薄膜的孔结构调控及其BSA吸附

介/纳孔生物玻璃薄膜生物活性好,并且在药物和生长因子承载等方面发挥着重要的作用。本工作采用嵌段共聚物P123模板法合成介/纳孔生物玻璃薄膜,研究了十六烷基三甲基溴化铵(CTAB)和均三甲苯(TMB)添加剂,不同溶剂组分(乙醇和水)对介/纳孔生物玻璃薄膜的孔尺寸和分布的影响。实验结果表明:添加CTAB,薄膜形成小孔径介孔和大孔交互的孔形貌;TMB加入使薄膜介孔尺寸细微增大并产生略大尺寸的纳孔;而溶剂组分中水浓度增高,胶束尺寸分布均匀性和稳定性下降,大体积纳孔的含量明显增大。其中,介孔孔径均在10nm以内,而纳孔主要变化范围为20-200nm。添加剂和溶剂作用可归结于它们对胶束形成和与硅盐离子的组装影响;不同介/纳孔的薄膜可对蛋白质吸附量进行调节。     

溶胶凝胶法制备SiO2包覆Fe85Si9.6Al5.4软磁复合粉末

采用溶胶凝胶法,通过控制正硅酸乙酯(TEOS)和3-氨丙基三乙氧基硅烷(APTES)偶联剂的加入量,在Fe85Si9.6Al5.4粉末表面包覆SiO2绝缘层。采用X射线衍射(XRD)、傅氏变换红外光谱(FTIR)、X射线光电子能谱(XPS)、扫描电镜(SEM)和磁力显微镜(MFM)对粉末的微观结构及成分进行表征,采用振动样品磁强计(VSM)测试粉末的磁性能。结果表明:利用硅烷偶联剂对Fe85Si9.6Al5.4粉末表面改性后再加入TEOS,能在Fe85Si9.6Al5.4粉末表面包覆一层约1~2μm厚的絮状非晶SiO2;随着TEOS和APTES添加量的增多,SiO2包覆层的厚度也随之增加,饱和磁化强度Ms在0.86~0.90 T之间变化,Hci基本不变;当添加6 mLTEOS、1 mLAPTES时,得到的包覆粉末包覆效果及性能最佳,饱和磁化强度Ms达到0.90 T,矫顽力Hci为1 114A/m。     

原位Nb掺杂TiO_2薄膜的制备与光催化性能（英文）

采用微等离子体氧化法,在H2SO4溶液为电解液中以钛合金为基体制备原位生长的TiO2薄膜,并以罗丹明B溶液为目标污染物测试其光催化性能。为提高所得TiO2薄膜的光催化性能,向电解液中添加了不同浓度的草酸铌,制备了原位Nb掺杂TiO2薄膜。利用扫描电镜(SEM)和X射线衍射仪(XRD)分别对Nb掺杂前后的TiO2薄膜表面形貌、元素组成和晶体结构进行了分析。结果表明,Nb掺杂能使介孔TiO2晶粒细化,比表面积增大,Nb对TiO2晶相组成影响不大,但对晶胞参数有所影响,Nb掺杂可有效提高TiO2的光催化活性,其中当草酸铌为1.2g/L时,对初始浓度为10 mg/L罗丹明B溶液90min的降解率可达到85%,表现出最强的光降解能力。     

聚酰亚胺/SiO2杂化材料的溶胶-凝胶法合成、表征及电光性能

采用溶胶-凝胶技术,以4,4'-(六氟异丙基)-苯二酸酐(6FDA)、5,5'-(六氟异丙基)-二-(2-氨基苯酚)(6FHP)、非线性生色分子4-(N-2-羟乙基-N-甲基氨)-4'-[(6-硝基苯并噻唑-2-取代)二氮烯基偶氮苯(HNBDA)、偶联剂γ-氨丙基三乙氧基硅烷(APTES)和正硅酸乙酯(TEOS)水解液合成了系列的聚酰亚胺/SiO2杂化材料,其中TEOS的含量为0～22.5%.采用红外、热分析、扫描电镜、透射电镜和X射线衍射等进行表征.它们的玻璃化转变温度和热分解温度分别为216～366℃和321～438℃,表明具有较好的热稳定性.测定极化后材料832nm处的电光系数γ33为21～35 pm/V,且电光系数保持其初始值的85%以上(100 h),结果表明杂化材料在光器件上具有潜在的应用.     

Preparation of mesoporous silica thin films on polystyrene substrate by electrochemically induced sol-gel technique

The mesoporous silica thin films with an oriented hexagonal mesostructure were prepared on polystyrene (PS) substrate by electrochemically induced sol-gel technique using tetraethoxyorthosilicate (TEOS) as silica source and cetyltrimethyl-ammonium bromide (CTAB) as structure-directing agent. Prior to coating deposition, the PS substrate was made hydrophilic by sulfonation with concentrated sulfuric acid for 72 h to provide better adhesion of silica films to the substrate. The effects of synthesis parameters required to obtain well-ordered crack-free layers, such as deposition voltage and deposition time, were evaluated in detail. The samples were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared-Attenuated total reflectance (FT-IR-ATR), small-angle X-ray diffraction (SAXRD) and transmission electron microscopy (TEM). According to the experimental results, the deposition voltage of 3.6 V and the deposition time of 10 s were determined as the optimum conditions. The silica films with the thickness of ca. 1.5 μm obtained under this condition was crack-free smooth and had a hexagonally ordered pore array pattern nanostructure. The pore diameter was about 3 nm and the distance between the neighboring pore centers was ca. 4.6 nm.     

Microstructure characterization and photocatalytic activity of mesoporous TiO2 films with ultrafine anatase nanocrystallites

A series of mesoporous TiO₂ films on borosilicate glass with ultrafine anatase nanocrystallites were successfully synthesized using a non-acidic sol gel preparation route, which involves the use of nonionic surfactant Tween 20 as template through a self assembly pathway. The microstructure of these TiO₂ films was characterized by XRD, SEM, HR-TEM, UV-Vis spectroscopy, and N₂ adsorption-desorption isotherm analysis. Their photocatalytic activities were investigated by using creatinine as a model organic contaminate in water. It was found that all mesoporous TiO₂ films prepared with Tween 20 exhibited a partially ordered mesoporous structure. The photocatalytic activity of the TiO₂ films could be remarkably improved by increasing Tween 20 loading in the sol at the range of 50% (v/v), which yielded large amount of catalyst (anatase) on the glass support and enhanced specific surface area. The optimum Tween 20 loading was 50% (v/v) in the sol, above which good adhesion between TiO₂ films and borosilicate glass could not be maintained. The final TiO₂ film (Tween 20: final sol = 50%,v/v) exhibits high BET surface area (∼ 120 m²/g) and pore volume (0.1554 cm³/g), ultrafine anatase nanocrystallinity (7 nm), uniform and crack free surface morphology, and improved photocatalytic activity.     

On the porosity of polypyrrole films

Polypyrrole (PPy) films doped with anions of various size, charge and chemical nature (inorganic, surfactant, with aromatic ring) were electrochemically synthesized and investigated by low-temperature N₂ sorption experiments at −196 °C. The specific surface area, total pore volume, average pore radius, pore size distribution and other parameters for oxidized PPy films using dodecylsulfate, 2-naphthalene sulfonate, 1,5-naphthalene disulfonate, poly(4-styrenesulfonate), tosylate, perchlorate, nitrate and chloride as dopant ions, were calculated. The obtained data show that although the average pore radius of investigated mesoporous PPy films (17–19 Å) is practically independent of the dopant anion used, however the latter determines the total pore volume and specific surface area values in different PPy materials investigated. As the total pore volumes for PPy films doped with large amphiphilic anions show the smallest values, the corresponding values for PPy/small inorganic anions, are up to 2 times higher.     

Photocatalysis Performance of Nb-doped TiO2 Film in Situ Growth Prepared by a Micro Plasma Method

采用微等离子体氧化法,在H2SO4溶液为电解液中以钛合金为基体制备原位生长的TiO2薄膜,并以罗丹明B溶液为目标污染物测试其光催化性能。为提高所得TiO2薄膜的光催化性能,向电解液中添加了不同浓度的草酸铌,制备了原位Nb掺杂TiO2薄膜。利用扫描电镜(SEM)和X射线衍射仪(XRD)分别对Nb掺杂前后的TiO2薄膜表面形貌、元素组成和晶体结构进行了分析。结果表明,Nb掺杂能使介孔TiO2晶粒细化,比表面积增大,Nb对TiO2晶相组成影响不大,但对晶胞参数有所影响,Nb掺杂可有效提高TiO2的光催化活性,其中当草酸铌为1.2g/L时,对初始浓度为10 mg/L罗丹明B溶液90min的降解率可达到85%,表现出最强的光降解能力。     

Preparation of mesoporous titania particles using ionic liquid dissolving starch as templates

A mesoporous titania photocatalyst was prepared via calcining the solution of ionic liquid (1-methyl-3-butyl imidazolium bromide, [BMIM]Br) containing tetrabutyl titanate (TBT) and starch. The microstructure of the prepared mesoporous titania was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N₂ adsorption/desorption isotherm. The results indicate that the resulting mesoporous titania has a grain size of about 13.9 nm, a special surface area of 106 m²/g, and a pore volume of 0.22 cm³/g, and the pore size can be adjusted by the concentration of starch in ionic liquid. The photocatalytic activity of mesoporous titania in the degradation of methyl orange solution was determined. The effect of the specific surface area of mesoporous titania on the photocatalytic activity was also studied. The prepared mesoporous titania exhibits a high catalytic activity.     

钛掺杂介孔二氧化硅薄膜的制备与表征

采用溶胶-凝胶工艺,选用表面活性剂十六烷基三甲基溴化铵(CTAB)为模板剂,通过正硅酸乙酯(TEOS)和钛酸丁酯(TPOT)的分步水解得到均匀的SiO2-TiO2复合溶胶,制备了具有介孔结构的钛掺杂的二氧化硅薄膜.薄膜的折射率在1.20～1.236之间可调,介电常数在2.54～2.817之间.随着钛含量的增加,折射率和介电常数增大,而孔洞率降低.结果分析表明钛离子均匀的分散在SiO2-TiO2网络中形成了Si-O-Ti键的孤立四配位形态.     

低介电常数纳米氧化硅薄膜(英文)

介绍了一种新制备低介电常数 SiO2薄膜的方法。以 TEOS 为前躯体、盐酸为催化剂、CTAB 作为模版剂,采用溶胶-凝胶法制备硅溶胶,以浸渍提拉法制备薄膜。采用 FITIR、XRD 和 AFM 等方法表征了薄膜,并用阻抗分析仪测量介电常数。结果表明,通过调节 CTAB 的浓度和老化时间可以制得介电常数小于 2.2 的 SiO2 薄膜,薄膜拥有较好的机械强度和耐刮擦性,通过采用六甲基二硅胶烷(HMDS)对薄膜表面进行修饰,可以提高薄膜的疏水性能从而提高其在空气中的稳定性。     

Novel low temperature atmospheric pressure plasma jet systems for silicon dioxide and poly-ethylene thin film deposition

In this study, both low-density plasma quartz tube (QT) and high-density plasma metallic tube (MT) jet-electrodes with pulsed-type alternating-voltage (AC) generator were used to investigate the influences of the process parameters and electrode types on the microstructures and the corrosion behaviors of silicon dioxide (SiO₂) or poly-ethylene (PE, (CH₂CH₂)n) thin films. Tetraethoxysilane (TEOS) and ethylene (C₂H₄) were used as precursors for SiO₂ and PE thin film deposition. The TEOS precursor was vaporized by an ultrasonic oscillator and introduced into the AP plasma systems by argon (Ar) carrier gas. The main plasma working gas was Ar gas mixed with or without oxygen gas. The pulsed-type AC generator, with a frequency of 30 kHz, a voltage of 10 kV and a wattage of 300 W, was used to deposit SiO₂ and PE thin films on the silicon and AISI 1005 low carbon steel substrates at the room temperature, respectively. The high-density plasma MT jet-electrode with an Ar gas flow rate of 6 slm, a precursor flow rate of 40 sccm and an oxygen flow rate of 40 sccm revealed optimal plasma dissociation and chemical reaction efficiencies to synthesize effective atomic stoichiometry of SiO₂ (in-organic films) thin films. However, the low-density plasma QT jet-electrode with an Ar gas flow rate of 6 slm and an ethylene flow rate of 15 sccm appeared optimal plasma-induced polymerization efficiency to exhibit reasonable atomic stoichiometry of PE (organic films) thin films. Moreover, the optimal SiO₂ thin films deposited by MT jet-electrode possessed better corrosion resistant integrity than the optimal PE thin films synthesized by QT jet-electrode. It was also found that SiO₂ and PE thin films synthesized by the AP plasma method possess effective corrosion barrier characteristics like other deposition techniques.