纳米阳极氧化铝模板膜孔可控生长规律

采用新的二次阳极氧化工艺,制备了多孔纳米阳极氧化铝(anodized Al2O3,AAO)膜.对铝在草酸溶液中的二次阳极氧化过程进行了研究.利用扫描电镜、原子力显微镜、透射电镜等对其形貌进行了表征和分析.结果表明:用高纯铝所制备的纳米AAO膜孔大小一致,有序性强;膜的孔径随扩孔时间的增加而增大,随草酸浓度的增加而减少.进一步延长扩孔时间至1.5h,其孔径生长规律仍符合AAO膜孔径可控性动力学模型方程,使原模型的扩孔时间范围由1.0h拓展到1.5h.AAO膜的最佳制备工艺为:采用0.3mol/L草酸溶液,电压为40V,在40℃氧化9h和扩孔1 h.在最佳制备工艺条件下,制备的AAO膜厚为112.7 μm,孔径为70nm左右.     

孔间距和孔径连续可调的PAA模板的制备

在磷酸溶液中以二次阳极氧化制备的多孔阳极氧化铝(PAA)模板存在孔的规整低的缺点,文中提出了在磷酸/草酸混合溶液中采用二次阳极氧化法制备高规整(PAA)模板,利用图像处理软件(Image-Pro plus)对PAA膜的扫描电镜图进行分析处理,定量研究了阳极氧化电压、草酸含量和扩孔时间对PAA模板的孔径和孔间距的影响。由实验结果可知,在质量分数1%磷酸溶液中加入0.03 mol/L草酸溶液作为阳极氧化电解液,阳极氧化电压可以达到200 V。通过调节草酸添加量和阳极氧化电压可以得到孔间距在345—498 nm范围内高规整PAA模板。通过改变扩孔时间可以获得孔径在140-400 nm范围内高规整PAA模板,并且孔径与扩孔时间呈正线性相关关系,相关系数为0.99。这种高规整孔径、孔间距连续可调的PAA模板能够被用于制备规整金属纳米线阵列、纳米管阵列和高分子纳米柱等材料。     

AAO模板的制备及其应用

以多孔阳极氧化铝膜为模板制备纳米结构材料具有独特的优越性,得到了广泛的关注。本文介绍了在草酸溶液中制备的AAO模板的工艺过程,并用扫描电子显微镜（SEM）对阳极氧化铝膜的形貌和结构进行了表征,最后介绍了AAO组装体系的应用。     

在离子液体中用阳极氧化铝模板电沉积制备稀土镧纳米线

采用二次阳极氧化法获得纳米多孔阳极氧化铝(AAO)模板,在尿素-NaB r-KB甲r-酰胺离子液体中,用AAO模板电沉积稀土镧纳米线。扫描电子显微镜(SEM)结果显示,自制AAO模板孔洞分布均匀,孔径基本一致(约60~70 nm),孔口呈六边形。经过XRD、EDS和SEM对电沉积样品的成分和形貌进行表征和分析,显示在AAO模板中有镧纳米线的存在。     

纳米氧化铝膜孔径可控性动力学模型及其生长规律

采用新的二次阳极氧化工艺,制备了孔径为30～70nm的阳极氧化铝(anodizedAl2O3,AAO)膜.用扫描电镜和原子力显微镜观察了AAO膜孔洞的结构、形貌和它们的排列,发现制备的AAO铝膜的孔的纵横比大,孔分布有序,上下贯通,孔间相互平行,孔通道无交叉且有序.研究了电解液浓度、扩孔时间对膜孔半径的影响,建立了动力学模型,得出在一定时间内,孔径大小与电解液浓度之间呈对数关系,而与扩孔时间呈线性关系.根据电场理论,膜压应力值随扩孔时间增加趋向于表面张力值,当达到平衡后,膜孔孔径的大小随之确定.     

磷酸/草酸混合溶液中锥形多孔阳极氧化铝的制备和表征

提出了以磷酸/草酸混合溶液为电解液制备高度有序锥形多孔阳极氧化铝(PAA)模板的方法。首先采用二次氧化的方法,得到了孔洞排列高度有序且孔间距为495nm的PAA模板。在此基础上,采用阳极氧化过程和扩孔过程交替进行的方法,制备了不同长径比的有序锥形PAA模板。实验结果显示:锥形PAA模板的长径比与总氧化时间线性相关,可达到100以上;还说明了分段氧化时间和分段扩孔时间与锥形孔道形貌之间的关系。这种特殊结构的PAA模板可以大大拓展其在合成金属或半导体纳米线、光电材料以及高分子材料方面的应用范围。     

氧化铝模板制备氮化碳纳米管

利用二次阳极氧化方法制备了高度有序的多孔氧化铝(AAO)模板,利用这些模板通过溶胶-凝胶过程和高温后处理制备了氮化碳纳米管。分别用SEM、XRD和XPS表征了AAO模板和氮化碳纳米管的形貌、物相结构以及表面元素组成,发现所制备的氮化碳纳米管彼此平行、表面光洁,而且氮化碳纳米管的直径与所用AAO模板的孔径基本一致。     

多孔氧化铝模板的制备及应用

以磷酸溶液为电解液、以高纯铝为阳极,采用两步阳极氧化法制备氧化铝模板。扫描电子显微镜(SEM)对其表面形貌分析表明,氧化铝膜为多孔结构,膜孔径随着阳极氧化电压的增大而不断增大。对阳极氧化电流密度变化分析证实,铝的阳极氧化经历了三个阶段:阻挡层的生成、多孔层的形成和多孔层的稳定生长。以制备的氧化铝膜为阴极、锌片为阳极,以硝酸锌和硼酸的混合液为电解液,采用交流电沉积方法制备了针状氧化锌纳米线。     

铝基体超疏水表面的制备

先用二次阳极氧化法在纯铝表面制备出多孔阳极氧化铝(AAO)膜,再通过交流电沉积法在膜孔内沉积铜纳米线,制备出载铜AAO膜。然后用氢氧化钠溶液腐蚀除去部分AAO模板,裸露出的铜纳米线在其表面构造出柱状纳米粗糙结构,最后经过月桂酸乙醇溶液浸泡(低表面能修饰)。烘干后该表面与水滴的接触角为153.8°,滚动角小于1°,表现出超疏水性。     

铝阳极氧化膜多色彩电解着色工艺

简述了多色彩电解着色工艺的发展和特点,介绍了2种达到多色化显色的方法:阳极氧化膜底部扩孔处理和调整阳极氧化膜阻挡层。给出了扩孔处理过程中阳极氧化膜横断面的显微结构变化示意图,并给出了“阻挡层调整”实现多色化的工艺参数。描述了多色化阳极氧化膜的性能,并对比了电泳涂漆前后多色彩电解着色样品的颜色。     

软模板法制备单分散中空有机硅微球

通过硅氧烷单体在碱性条件下的水解-聚合反应,制备出了单分散乳液,研究了乳化剂HLB、反应时间、乳化剂用量、单体用量等因素对乳液的影响。然后以该乳液为模板、有机硅为壳层进行包覆,得到了中空微球。采用纳米粒度及Zeta电位分析仪、SEM、TEM、EDS、FTIR对乳液及中空微球进行表征。结果表明,在室温条件下,反应时间为6h时能够制备出单分散性较好的乳液,通过改变乳化剂用量、单体用量,能够实现对乳液粒径的调控,调控范围346～472 nm。以该乳液为模板进行缓慢包覆,当乳化剂质量分数低于0.003%时,能够得到形貌规整的单分散中空微球,中空微球的主要成分为有机硅。与硬模板法相比,该模板通过乙醇洗涤即可除去,制备过程较为简单。     

三维有序大孔二氧化钛光催化降解有机废水研究

以聚苯乙烯(PS)为胶晶模板,一定比例钛酸四丁酯、乙醇、醋酸、盐酸和水配制的溶胶溶液为前驱体,通过浸渍和低温固化过程,使溶胶在PS模板间隙内进行填充并原位凝胶,最后通过煅烧除去模板,得到三维有序大孔(3DOM) TiO2材料.将获得的3DOM TiO2材料作为一种新型光催化剂降解罗丹明B和甲基橙有机废水,同时对其降解过程中的反应动力学进行了分析.结果表明,3DOM TiO2材料具有良好的光催化降解性能,并且降解反应复合一级动力学方程.     

氧化钛纳米线阵列的溶胶凝胶模板合成与表征

采用二次阳极氧化工艺制备了高度规则排列的多孔氧化铝（PAA）模板,并利用模板法与溶胶-凝胶法结合的模板组装技术制备了氧化钛纳米线阵列,得到了直径在50 nm左右,线间距约为50 nm的纳米线阵列.研究了模板组装过程不同压力条件对溶胶向模板孔洞中填充度的影响,发现在一定的负压条件下,有利于PAA孔中气体的排出,得到高的溶胶填充度,进而制备出高质量的纳米线阵列.分别通过SEM及XRD技术表征了PAA模板及纳米线的形貌及相结构.SEM观察发现纳米线彼此平行,表面光洁,不存在龟裂,纳米线的长度和直径与所使用模板的厚度和直径一致,表明纳米线的生长受控于模板;XRD分析表明模板为单一的θ-Al₂O₃晶型,纳米线为锐钛矿型TiO₂.     

Preparation of Poly(acrylamide-maleic Acid) Resin by Template Polymerization and Its Use for Adsorption of Co(II) and Ni(II)

Poly(acrylamide-maleic acid) resin P(AAm-MA) was prepared by template polymerization. Polyacrylamide PAAm was used as a template for the polymerization of MA in an aqueous solution using gamma rays as the initiator. The effects on the capacity of P(AAm-MA), such as concentration of maleic acid and amount of template polymer, were investigated. P(AAm-MA) has been utilized as an adsorbent for the removal of Co(II) and Ni(II) ions from an aqueous solution. The effects of time of equilibrium, pH, temperatures, and dosage of the adsorbent on the removal of Co(II) and Ni(II) ions have been studied. The equilibrium data were analyzed using the Langmuir and Freundlich isotherm models. The equilibrium process was described well by the Langmuir isotherm model.     

超临界CO2萃取回收SBA-15中的有机模板剂

在200 mL高压萃取釜内,对含夹带剂的超临界CO2萃取回收SBA-15中有机模板剂P123(EO20PO70EO20)的最佳工艺条件进行了研究,考察了夹带剂种类、萃取温度、萃取压力、夹带剂流量对回收率的影响,确定最佳萃取工艺条件为：甲醇作夹带剂,温度45℃,压力27 MPa,夹带剂流量4 mL/min,萃取时间1.5 h,在此条件下P123回收率可达73.7%. 对不同方法脱除P123后的SBA-15进行了表征,结果表明,含甲醇夹带剂的超临界CO2萃取法是一种高效环保的方法,且得到的SBA-15保留了很好的骨架有序性,不会造成骨架硅羟基脱除,克服了高温焙烧脱除模板剂造成的孔道收缩问题.     

Synthesis of mesoporous alumina TUD-1 with high thermostability

Mesoporous alumina, TUD-1, was prepared via a sol-gel process by using tetraethylene glycol (TEG) as template. The effect of TEG and solvents on the pore structure of the final products was studied. A mechanism using non-surfactant template was proposed. It was found that TUD-1 has amorphous framework, high surface area, large pore volume and narrow pore size distribution together with high thermal stability upon prolonged heat treatment at high temperatures, which is essential for applications in adsorption and catalysis.     

Synthesis of mesoporous alumina TUD-1 with high thermostability

Mesoporous alumina, TUD-1, was prepared via a sol-gel process by using tetraethylene glycol (TEG) as template. The effect of TEG and solvents on the pore structure of the final products was studied. A mechanism using non-surfactant template was proposed. It was found that TUD-1 has amorphous framework, high surface area, large pore volume and narrow pore size distribution together with high thermal stability upon prolonged heat treatment at high temperatures, which is essential for applications in adsorption and catalysis.     

Configuration of molecular imprinted polymer for electrochemical atrazine detection

This paper addresses the specific ability of molecular imprinted polymers (MIPs) to bind the template. MIPs for atrazine with various monomer:template and crosslinker:template ratios were prepared using bulk polymerization process. In order to obtain conditions closer to real wastewater test cases, the degree of the imprinting factor by the selection of solvent (methanol and water) was studied and compared. The polymer tested in methanol did not demonstrate good recognition of atrazine. In addition, the imprinting factors increased significantly when the imprinted polymers were tested in water solvent by 45%. Based on Scatchard analysis, the MIP was dependent upon low atrazine concentration (up to 40 mg/L) as the cavities formed in the MIP proved the cavities effects. An electrochemical analysis was done in order to prove that the method can be used as a quantitative analysis of atrazine concentration detection in water solution.     

邻苯二甲酸二辛酯印迹吸附树脂的制备及其吸附性能

以大孔吸附树脂D101为载体,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯为交联剂,邻苯二甲酸二辛酯(DOP)为模板分子,制备了DOP分子印迹吸附树脂(DOP-MIP-D101),采用红外和扫描电镜等方法对其进行了表征。研究了DOP-MIP-D101对DOP的静态等温吸附性能、吸附动力学以及选择性吸附性能。结果显示,DOP-MIP-D101对DOP的吸附能力明显大于非印迹树脂(NIP-D101),且具有较高的选择性,吸附行为符合Freundilich方程。DOP-MIP-D101对DOP的吸附达到平衡的时间为100min左右。     

A density functional theory study on the mechanism of dimethyl ether carbonylation over heteropolyacids catalyst

Dimethyl ether(DME)carbonylation is considered as a key step for a promising route to produce ethanol from syngas.Heteropolyacids(HPAs)are proved to be efficient catalysts for DME carbonylation.In this work,the reaction mechanism of DME carbonylation was studied theoretically by using density functional theory calculations on two typical HPA models(HPW,HSiW).The whole process consists of three stages:DME dissociative adsorption,insertion of CO into methoxyl group and formation of product methyl acetate.The activation barriers of all possible elementary steps,especially two possible paths for CO insertion were calculated to obtain the most favorable reaction mechanism and rate-limiting step.Furthermore,the effect of the acid strength of Br?nsted acid sites on reactivity was studied by comparing the activation barriers over HPW and HSiW with different acid strength,which was determined by calculating the deprotonation energy,Mulliken population analyses and adsorption energies of pyridine.