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1.
以板状和纤维状SBA-15为载体,采用正己烷为疏水溶剂、硝酸银的水溶液为亲水溶剂的双溶剂法制备了广谱抗菌剂板状Ag-SBA-15和纤维状Ag-SBA-15。以X射线衍射、扫描电子显微镜、透射电子显微镜和X射线能谱等手段表征了抗菌剂的结构和特性。通过试管稀释法考察了抗菌剂抗菌性能。结果显示,两种形貌SBA-15为载体制得的Ag-SBA-15都保持高度有序的二维六方相介孔结构,银颗粒在载体中均匀分散。试管稀释法测得由板状SBA-15制得抗菌剂对金黄色葡萄球菌的最小抑菌浓度达8ug/m L,而相应条件下由传统纤维状SBA-15为载体制得的抗菌剂最小抑菌浓度为32ug/m L。  相似文献   

2.
对介孔二氧化硅SBA-15进行氨基官能团化,制得NH2-SBA-15,通过溶液缩聚合成了一系列具有不同SBA-15质量分数的聚亚苯基苯并二噁唑/SBA-15(PBO/SBA-15)复合材料。利用红外光谱(FT-IR)、扫描电子显微镜(SEM)、热重分析(TG)和矢量网络分析仪(VNA)分别对复合材料的结构、微观形貌、热性能和电磁性能进行了表征与分析,研究了SBA-15对PBO/SBA-15复合材料介电参数的影响。研究表明:经过氨基官能团化之后,SBA-15能够均匀地分散在PBO基体中;当复合材料中SBA-15的质量分数小于8%时,PBO/SBA-15复合材料仍然保持着PBO优异的热稳定性;介孔二氧化硅SBA-15能够有效地降低PBO/SBA-15复合材料的复介电常数和介电损耗角正切,减弱PBO/SBA-15复合材料对电磁波的介电存储和损耗能力,使PBO/SBA-15复合材料表现出低介电损耗的性能。  相似文献   

3.
通过对介孔SBA-15孔壁氨基化(SBA-15-NH2),然后与C60反应形成化学键,成功地将C60组装进入SBA-15孔道中,合成了C60/SBA-15介孔复合材料,通过X射线衍射(XRD)、红外光谱(FTIR)、紫外-可见光谱(UV-Vis)和差热.热重分析(TG-DTA)等方法对其进行了表征,同时,对复合材料的荧光性质进行了研究。结果发现,SBA-15-NH2在575nm处出现发射峰,C60/SBA-15介孔复合材料在554nm处出现发射峰,峰位蓝移21nm。  相似文献   

4.
HCl对有序介孔氧化硅结构与形貌的影响   总被引:4,自引:0,他引:4  
赵春霞  陈文  刘琦  田高 《物理化学学报》2006,22(10):1201-1205
以三嵌段共聚物P123为有机模板导向剂、正硅酸乙酯TEOS为无机硅源, 在HCl存在的强酸性环境下, 采用水热法合成了有序介孔分子筛SBA-15. 采用XRD、SEM、TEM、N2吸附-脱附等手段对产物的结构与形貌进行了分析, 考察了HCl用量对有序介孔材料结构及形貌的影响. 结果表明, 在合成有序介孔氧化硅时, HCl发挥了催化和中间离子的双重作用, 促使棒状胶束形成六方有序排列, 降低SBA-15中微孔的数量, 而且对合成有序介孔氧化硅SBA-15的形貌有显著影响. 适宜的HCl用量对形成“珍珠链状”形貌的、热稳定性优良的SBA-15介孔材料具有重要作用.  相似文献   

5.
含钨SBA-15介孔分子筛催化剂的表面酸性和羟基分布   总被引:1,自引:0,他引:1  
分别以浸渍法和水热晶化法制备了SBA-15介孔分子筛孔中插入氧化钨和碳化钨的催化剂,采用NH3-TPD测定了表面酸性和总酸量,并采用FT-IR研究了它们的表面羟基分布情况.NH3-TPD结果表明,浸渍法制备的含氧化钨的SBA-15介孔分子筛催化剂表面只有SBA-15介孔分子筛的弱酸位,而含碳化钨的SBA-15介孔分子筛催化剂表面还出现了W2C的强酸位.水热晶化法制备的含氧化钨的SBA-15介孔分子筛催化剂表面SBA-15介孔分子筛的弱酸位随W含量的增大略有增强, W含量较高时还出现了钨物种的强酸位;含碳化钨的SBA-15介孔分子筛催化剂表面除了SBA-15介孔分子筛的弱酸位外, W含量较低时有W2C的强酸位, W含量较高时有W2C和WC两种强酸位.傅里叶变换红外光谱结果表明,浸渍法和水热晶化法制备的含氧化钨和碳化钨的SBA-15介孔分子筛催化剂除表面自由硅羟基外,还存在着α, β和γ三种不同类型的氢键羟基,并且氢键羟基和催化剂的制备方法以及催化剂的W含量都有一定的关系.  相似文献   

6.
氨基功能化SBA-15的直接合成及其对CO_2的吸附性能研究   总被引:1,自引:0,他引:1  
通过直接法合成了氨基功能化SBA-15介孔材料。使用X-射线粉末衍射法(XRD),N2吸-脱附,透射电子显微(TEM)等技术对氨基功能化材料进行了表征。实验结果表明:当反应原料中nAPTES/(nAPTES+nTEOS)≤0.20时,APTES功能化的材料都具有典型的介孔SBA-15结构;但当nAPTES/(nAPTES+nTEOS)≥0.225时,由于氨基对SBA-15结构的副作用导致SBA-15介孔结构坍塌。在氟离子辅助合成下可以获得高含量氨基(反应原料中nAPTES/(nAPTES+nTEOS)的比值为0.25)功能化的SBA-15材料,且此材料中的介孔孔径和BET比表面积都较大。CO2吸附结果表明,随着反应原料中APTES含量提高,所合成的材料对CO2的吸附量相应增加,同时在101kPa和25℃下,通过氟离子辅助合成的材料对CO2的吸附量远远优于无氟离子辅助合成材料的。本研究还对后嫁接法和直接合成法获得氨基功能化SBA-15介孔材料的优缺点进行了讨论。  相似文献   

7.
合成了一系列具有不同孔结构与性质的有序介孔二氧化硅材料SBA-15、MCM-41、SBA-16、KIT-6,同时通过改变水热温度制备了不同孔径大小的SBA-15,并利用小角X射线散射、透射电镜、扫描电镜和氮气吸附-脱附等手段,对其介孔结构进行了表征.以正丁醛为探针分子,考察了其对有机醛的吸附,并与Y-沸石的吸附性能做了对比.结果表明,材料的介孔比表面积与其对正丁醛的吸附量成正比,吸附等温线符合Langmuir模型,属于单层吸附,具有最大介孔比表面积的MCM-41对正丁醛的吸附量最大(484 mg·g-1).最后将SBA-15添加到卷烟滤嘴中,实验结果表明,SBA-15能显著降低卷烟烟气中巴豆醛的释放量.  相似文献   

8.
 采用浸渍法制备了Ni含量为2.5%~20%的系列Ni/SBA-15催化剂,在常压连续流动固定床反应器上考察了催化剂对二氧化碳重整甲烷制合成气的催化性能,并用X射线衍射和N2吸附法研究了Ni/SBA-15催化剂的结构特征. 结果表明, Ni/SBA-15催化剂具有很高的CH4和CO2转化率, 12.5%Ni/SBA-15催化剂在800 ℃反应600 h后活性没有明显下降,但反应710 h后CH4的转化率下降了约50%, CO2的转化率下降了约25%. 其活性下降的主要原因是催化剂积炭. 在高温条件下反应时, SBA-15的介孔结构也没有遭到破坏,分子筛的孔壁能有效阻止活性组分Ni的团聚. SBA-15孔中组装一定量的Ni活性组分后,除了SBA-15的介孔外,还会形成另外一种较小的孔,但这不影响SBA-15的有序介孔结构,只是其孔径、孔容和BET比表面积降低.  相似文献   

9.
合成了一系列具有不同孔结构与性质的有序介孔二氧化硅材料SBA-15、MCM-41、SBA-16、KIT-6, 同时通过改变水热温度制备了不同孔径大小的SBA-15, 并利用小角X射线散射、透射电镜、扫描电镜和氮气吸附-脱附等手段, 对其介孔结构进行了表征. 以正丁醛为探针分子, 考察了其对有机醛的吸附, 并与Y-沸石的吸附性能做了对比. 结果表明, 材料的介孔比表面积与其对正丁醛的吸附量成正比, 吸附等温线符合Langmuir 模型, 属于单层吸附, 具有最大介孔比表面积的MCM-41对正丁醛的吸附量最大(484 mg·g-1). 最后将SBA-15添加到卷烟滤嘴中, 实验结果表明, SBA-15能显著降低卷烟烟气中巴豆醛的释放量.  相似文献   

10.
基于Schiff碱功能单体的改性作用,采用共缩聚方法,制备了SBA-15型介孔分子筛负载的氧化镍纳米粒子.采用小角X射线散射(small angle XRD)、广角X射线衍射(wide angle XRD)、紫外-可见光谱(UV-Vis)、高分辨透射电子显微镜(HRTEM)和N2吸附-脱附测定对制得的样品进行了表征.结果表明,制得的样品具有SBA-15型介孔分子筛典型的二维六方有序结构,NiO纳米粒子主要分布于SBA-15型介孔分子筛的孔道内.当功能单体的含量不超过10%时,SBA-15型介孔分子筛的孔径在6~8nm范围内;而当功能单体的含量达到15%时,SBA-15型介孔分子筛的孔道被严重堵塞,孔径降为3.8nm.NiO纳米粒子的尺寸随着功能单体含量的增加而增大.  相似文献   

11.
A facile one-step method was proposed for the successful synthesis of Ag-nanoparticle-loaded mesoporous silica SBA-15 composites, where silver ions and their corresponding reductant aniline were added in the traditional synthetic system of mesoporous silica SBA-15 containing P123 as the surfactant and TEOS as the silica source. Mesoporous silica SBA-15 and Ag nanoparticles were spontaneously formed with Ag nanoparticles embedded in channels and even implanted in frameworks of mesoporous silica SBA-15. A tentative formation process was then proposed according to experimental observations. Furthermore, catalytic activities of Ag-nanoparticle-loaded silica SBA-15 composites toward the reduction of 4-nitrophenol in the presence of NaBH(4) and the reduction of H(2)O(2) were also investigated.  相似文献   

12.
Direct hydrothermal method is employed for incorporating iron into the pore structure of SBA-15. The resultant materials were analyzed by X-ray diffraction (XRD) patterns, N2 sorption isotherm and X-ray photoelectron spectroscopy (XPS). The characterizations of XRD patterns and XPS revealed that iron nanoparticles were present as highly dispersed nanoclusters in the well-ordered mesoporous channels of SBA-15. The characterizations of t-plot reveal only microporous channels of SBA-15 are confirmed to be filled with iron nanoparticles, leaving the mesopores unaffected. The supported material still maintained its ordered mesoporous structure similar to SBA-15 and possessed high surface area, large pore volume and uniform pore size.  相似文献   

13.
原位还原法制备SBA-15介孔分子筛负载纳米银颗粒   总被引:1,自引:0,他引:1  
利用一种温和的还原剂六亚甲基四胺(HMT)通过一步合成的方法制备了介孔Ag/SBA-15分子筛, 采用粉末X射线衍射(XRD)、透射电镜(TEM)和氮气吸附/脱附等手段对样品进行了表征. 样品的比表面积为525 m2/g, 平均孔径为5.4 nm. 用XPS、广角XRD和高分辨TEM等手段证实样品中的银为金属态的纳米颗粒. 研究结果表明, 以六亚甲基四胺为还原剂通过原位还原的方法能使银纳米颗粒较好地分散到介孔材料的孔道中.  相似文献   

14.
Highly dispersed gold nanoparticles have been incorporated into the pore channels of SBA-15 mesoporous silica through a newly developed strategy assisted by microwave radiation (MR). The sizes of gold are effectively controlled attributed to the rapid and homogeneous nucleation, simultaneous propagation and termination of gold precursor by MR. Diol moieties with high dielectric and dielectric loss constants, and hence a high microwave activation, were firstly introduced to the pore channels of SBA-15 by a simple addition reaction between amino group and glycidiol and subsequently served as the reduction centers for gold nanoparticles. Extraction of the entrapped gold from the nanocomposite resulted in milligram quantities of gold nanoparticles with low dispersity. The successful assembly process of diol groups and formation of gold nanoparticles were monitored and tracked by solid-state NMR and UV-vis measurements. Characterization by small angle X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicated that the incorporation of gold nanoparticles would not breakup the structural integrity and long-range periodicity of SBA-15. The gold nanoparticles had a narrow size distribution with diameters in the size range of 5-10 nm through TEM observation. The average particles size is 7.9 nm via calculation by the Scherrer formula and TEM measurements. Nitrogen adsorption and desorption isotherms gave further evidence that the employed method was efficient and gold nanoparticles were successfully incorporated into the pore channels of SBA-15.  相似文献   

15.
Formation of titanium nitride nanoparticles within mesoporous silica SBA-15   总被引:2,自引:0,他引:2  
We report the first synthesis of titanium nitride (TiN) nanoparticles inside the nanoscale channels of mesoporous silica SBA-15. The TiN precursor, Ti(NMe(2))(4) in toluene, was incorporated into the methyl group-modified channels of the SBA-15 powder. The functionalization of pore surfaces with methyl groups generates hydrophobic surfaces that facilitate impregnation with Ti(NMe(2))(4) and minimizes reactions between the TiN precursor and the hydroxyl groups on the surface of SBA-15. Formation of TiN nanoparticles inside the mesoporous channels of SBA-15 was carried out by subsequent ammonolysis at high temperatures (700-750 degrees C). The final products have been characterized by TEM and EELS images, powder XRD patterns, FTIR spectra, UV-vis absorption spectra, and nitrogen adsorption isotherm measurements to confirm the presence and distribution of TiN nanoparticles in the SBA-15 samples.  相似文献   

16.
以SBA-15为载体,采用浸渍法制备了不同Ag含量的Ag/SBA-15,通过N2吸附-脱附、X射线衍射、扫描电子显微镜、高分辨透射电子显微镜、X射线光电子能谱和电感耦合等离子体质谱对催化剂进行了表征。将Ag/SBA-15用于苯甲醇气相选择性催化氧化合成苯甲醛,研究了反应条件对转化率和选择性的影响。结果表明,Ag/SBA-15具有均一的一维孔道结构、较厚的孔壁(3-5 nm)及较大的比表面积(411-541 m2/g),其规整纳米空间的限域作用使一定负载量的Ag以纳米尺寸均匀分散于介孔SBA-15孔道内,增加了活性组分的比表面积。亲核性氧物种从Ag到SBA-15表面的氧溢流,提高了低温下Ag/SBA-15对苯甲醇气相选择性氧化合成苯甲醛的催化性能。5.3% Ag/SBA-15中的Ag粒径为5-6 nm,且均匀分散于载体孔道中,反应温度为220℃时,苯甲醇转化率为87%,苯甲醛选择性为95%;240℃时,苯甲醇转化率和苯甲醛选择性分别高达94%和97%;并在240-300℃范围内,其催化活性和选择性保持不变,表现出了良好的温度耐受能力。催化剂经活化再生可以连续使用40 h,选择性基本保持不变。  相似文献   

17.
采用三种氨基硅烷试剂(APTS: 3-氨丙基三甲氧基硅烷, TPED: N-(2-氨乙基)-3-氨丙基三甲氧基硅烷, TPDT: 3-[2-(2-氨基乙基氨基)乙基氨基]丙基-三甲氧基硅烷)对介孔SBA-15分子筛进行后嫁接表面功能化(分别记为APTS-SBA-15, TPED-SBA-15和TPDT-SBA-15), 然后利用氨基与氯金酸之间的静电作用及化学还原法, 将金纳米粒子引入分子筛的介孔孔道. 采用N2物理吸附、X射线衍射(XRD)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)等手段对催化剂的结构和电子性质进行了系统表征; 以巴豆醛液相加氢制巴豆醇反应比较了氨基硅烷的种类对催化性能的影响. 结果表明, 氨基硅烷的给电子能力是决定金催化剂上C=O键加氢选择性的主要因素, 氨基硅烷的给电子能力越强, 金活性位上的电子密度越高, 则巴豆醇的选择性和收率就越高.  相似文献   

18.
Three kinds of highly ordered SBA-15 mesoporous materials with different pore sizes and morphologies denoted as LPS-SBA-15 (stick-like with pore size 7.28 nm), CPS-SBA-15 (stick-like with pore size 5.96 nm) and T-SBA-15 (tablet-like with pore size 4.64 nm) have been prepared, characterized and employed as carrier materials. The release behaviors of the ibuprofen in a simulated body fluid from these mesoporous silica materials were studied. The influences of pore size and exterior morphologies of mesoporous silica on the release behaviors of ibuprofen have been investigated. It has been found that the release becomes fast with increasing of pore size and slow with extending of transport pathway, and that the release rate of ibuprofen from the three kinds of SBA-15 is LPS-SBA-15 > T-SBA-15 > CPS-SBA-15. The results show that the inner structure as well as the exterior morphologies of SBA-15 mesoporous silica can seriously affect the release behaviors of ibuprofen.  相似文献   

19.
We designed and synthesized a novel catalyst consisting of ordered mesoporous silica (SBA-15) functionalized with bis(thiourea) (BTU) linker. The regular and unique pore channels of BTU-SBA-15 ensure proper control of the size and homogeneous distribution of palladium nanoparticles. The physiochemical properties of the hybrid Pd@BTU-SBA-15 pre-catalyst were investigated using various techniques. The proposed catalyst is found to be very active, reusable, stable and scalable, and has excellent reactivity and selectivity for Suzuki and Heck coupling reactions under very mild and sustainable reaction conditions.  相似文献   

20.
陈志坚  李晓红  李灿 《催化学报》2011,32(1):155-161
以介孔材料SBA-15、经或未经Al2O3修饰的具有三维立方孔道结构的SiO2为载体,制备了负载型Pt催化剂,并用于催化α-酮酸酯底物2-氧代-4-苯基-丁酸乙酯(EOPB)和丙酮酸乙酯(Etpy)的不对称氢化反应中.结果表明,当SBA-15孔径由6.2,7.6和9.2nm依次增加时,EOPB不对称氢化的活性和手性选择...  相似文献   

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