共查询到19条相似文献,搜索用时 109 毫秒
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采用自行研制的成核晶化隔离法制备了不同Cu2+、Zn2+和Al3+物质的量比的层状双金属氢氧化物(LDHs)。通过X射线衍射(XRD)、红外光谱(FT-IR)、热重-差热分析(TG-DTA)、程序升温还原(TPR)及X光电子能谱(XPS)等研究手段对LDHs及其在500 ℃焙烧产物的组成、结构和表面化学状态进行了分析。结果表明,在焙烧产物中均存在一定形式相互作用的CuO-ZnO-Al2O3复合金属氧化物,Cu2+、Zn2+和Al3+之间的配比影响LDHs结构和热稳定性及其焙烧产物的组成和还原性能。 相似文献
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在[OH-]/[Al3+]=2.4的反应条件下,利用Al3+与碱液反应制备出Keggin离子,并由此制备出了无机、无机-有机柱撑膨润土,XRD-衍射数据表明,经柱撑后的膨润土层间距明显增大,达1.9 nm以上.研究了硝基苯在4种改性膨润土上的吸附行为,结果表明:经柱撑处理后的膨润土吸附能力明显大于钠基土,其吸附动力学行为遵循Bingham方程和Langmuir方程所描述的规律,平衡吸附量qe与平衡浓度Ce之间的关系符合Freundlich和Langmuir等温吸附方程,吸附表现为放热的物理吸附和有机质的分配作用. 相似文献
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以右旋布洛芬为原料,酸化蒙脱土为药物载体,制得右旋布洛芬/酸改性蒙脱土S(+)-IBU/acid-MMT干混悬剂。通过星点设计-效应面法优化右旋布洛芬/酸改性蒙脱土干混悬剂的制备工艺。以蒙脱土的载药量为考察指标,采用三因素五水平星点设计考察了盐酸浓度、酸化时间、酸化温度对干混悬剂制备工艺的影响,并对结果进行了二元多项式线性回归方程拟合,经效应面法预测最佳处方;借助XRD和SEM技术对干混悬剂进行了结构表征。结果表明,右旋布洛芬/酸改性蒙脱土干混悬剂最佳制备条件为:盐酸浓度3.3 mol/L,酸化时间5.2 h,酸化温度54℃,在该条件下,干混悬剂载药量可达443.7 mg/g,较优化前(352.4 mg/g)提高了25.9%。星点设计-效应面法适用于右旋布洛芬/酸改性蒙脱土干混悬剂制备工艺优化,以该方法建立的数学模型具有良好的预测性,所得干混悬剂具有更高的载药量。 相似文献
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采用水热法制备钛交联蒙脱土,SO2-4改性后作为载体,担载上铜,制成铜基SO2-4改性钛交联蒙脱土(Cu Ti PILM/SO2-4)催化剂,用C3H6作还原剂,考察了贫燃条件下不同空速、不同氧浓度以及H2O对催化剂活性的影响。结果表明,SO2-4用量w(SO2-4)为30%、Cu2+担载量w(Cu2+)为5%、500℃焙烧制得的Cu Ti PILM/SO2-4催化活性高,反应温度为250℃时,能使NO转化率高达70 6%,在水蒸气存在下,NO最大转化率仅下降7 0%。 相似文献
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采用低温沉淀陈化法经过滤、干燥、浸渍、再过滤、再干燥和焙烧制备了以ZrO2和TiO2为主要组分的固体超强酸催化剂,并添加镧系过渡金属氧化物进行改性。将所制备的催化剂应用于难以分离水分的乙酸乙酯的合成反应过程,得到该类型催化剂最适宜的制备条件为:n(ZrO2)∶n(TiO2)= 1.5∶1,LaCl3的添加量为催化剂中总质量的3%,硫酸浸渍液的浓度为1.0 mol·L-1,焙烧温度和时间为500 ℃和5 h。低温沉淀陈化法制备的催化剂催化活性高于常温制备的催化剂;改性的催化剂酸强度函数H0<-13.8;所制备的催化剂耐水性明显提高,乙酸乙酯的酯收率达到90%,选择性100%。 相似文献
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为了解决臭氧催化剂效率低、易流失等问题,采用焙烧法制备FeOx-CuOx-MnOx/活性炭-蒙脱土臭氧催化剂。通过扫描电子显微镜(SEM)、X射线能谱分析(EDS)等方法对所制备臭氧催化剂进行表征,并将该催化剂应用于臭氧催化氧化深度处理垃圾渗滤液实验。分别考察了臭氧催化剂载体中粉末活性炭与蒙脱土质量比、活性组分Fe2+、Cu2+、Mn2+物质的量比、载体与活性组分的质量比、焙烧温度与时间等因素对催化剂性能的影响。结果表明,当载体组分中粉末活性炭与蒙脱土质量比为1∶1,活性组分Fe2+、Cu2+、Mn2+物质的量比为3∶1∶1,载体与活性组分质量比为4∶1,焙烧温度为600℃,焙烧时间为60 min时,所制备臭氧催化剂孔道结构清晰,活性组分Fe2+、Cu2+、Mn2+负载率高且分布均匀;在深度处理垃圾渗滤液时,臭氧催化剂投加量为5 g/L,臭氧投加量为100 mg/L,垃圾渗滤液COD去除率达到67.46%,有较高的催化效率,且臭氧催化剂经过多次重复使用后,催化性能仍保持稳定。 相似文献
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酸化膨润土催化合成草酸二丁酯 总被引:4,自引:0,他引:4
以酸化膨润土(SO42-/Bentonite)固体酸为催化剂,草酸和正丁醇为原料,合成草酸二丁酯。考察焙烧温度对催化剂活性的影响。结果表明,焙烧温度500 ℃时催化剂活性较好。考察反应温度、原料配比、催化剂用量和反应时间等因素对酯化反应的影响,通过正交实验得到最佳酯化反应工艺条件:n(正丁醇)∶n(草酸)=3.5∶1,w(SO42-/Bentonite)=1.5%,反应温度130 ℃,反应时间3 h。最佳酯化反应条件下,草酸的转化率达到95.8%。催化剂重复使用6次后,草酸转化率达到93.6%。 相似文献
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钛交联蒙脱石纳米复合材料在化妆品中的应用 总被引:2,自引:0,他引:2
通过钛交联蒙脱石的各个成分在化妆品中所起的作用,论述了钛交联蒙脱石纳米复合材料在化妆品应用中具有防晒、保湿、去除异味、增稠等多种功效,比单独使用TiO2 和蒙脱石具有更大的优越性。 相似文献
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《Applied Clay Science》2010,47(4):346-350
To look for economic substitute of Laponite, two kinds of clay minerals purchased in China were chosen to prepare nanocomposite hydrogels. Structure, morphology, temperature-sensitivity and swelling behavior were investigated by XRD, SEM, DSC and gravimetric method. In comparison with hydrogel cross-linked by Laponite XLG, the hydrogel with hectorite (Lvjie trademark) or montmorillonite (G-105) as cross-linker exhibited higher swelling ratios as well as faster response rate. In the case of temperature-sensitivity, the volume phase transition temperature (VPTT) of the hydrogels cross-linked by hectorite (Lvjie trademark) and montmorillonite (G-105) was 31–33 °C, slightly different from hydrogels with Laponite XLG. The hydrogel with montmorillonite (G-105) was brown and fragile. The hectorite (Lvjie trademark) appeared as optimal substitute of Laponite in hydrogels because the prepared hydrogel exhibited high swelling ratio, rapid response rate, excellent thermal responsibility, good dispersion in hydrogel matrix and high storage modulus. 相似文献
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以临安钠基蒙脱土为原料,制备了铁交联和铁镧复合交联蒙脱土催化剂,利用物理吸附(BET)、扫描电镜(SEM)和X-射线衍射(XRD)对催化剂进行表征,并以铁镧复合交联蒙脱土(Fe/La-PILC)为催化剂,质量分数为30%的过氧化氢水溶液为氧化剂,考察反应时间、催化剂用量和过氧化氢用量对苯甲醇催化氧化制苯甲醛的影响.结果表明:铁镧复合交联蒙脱土形成了比较均一的中孔骨架结构;当苯甲醇与过氧化氢物质的量之比为1:2,Fe/La(200)-PILC(Fe与La物质的量之比为200)质量分数为4%,反应5 h时,苯甲醇转化率和苯甲醛选择性分别为62.1%和86.4%.研究铁镧交联蒙脱土催化剂的催化氧化机理,发现Fe/La-PILC催化氧化苯甲醇的活性氧来自于Fe/La-PILC所吸附的氧. 相似文献
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Lian Duan Ning Hu Tongqing Wang Hong Wang Lixia Ling 《Chemical Engineering Communications》2016,203(1):28-36
Adsorption removal of Cu (II) and Pb (II) on cross-linked chitosan/Al13-pillared montmorillonite (CCPM) was examined in solutions. The chitosan dosage was drastically reduced in the new nanocomposite, which is made from the treated clay (Al13-pillared montmorillonite). Several important parameters that influenced the adsorption of Cu (II) and Pb (II) ions, such as cross-linked chitosan-to-clay ratio, pH, temperature, initial concentration, dosage, and contact time effect, were systematically investigated. Result showed that in the nanocomposite with cross-linked chitosan-to-clay ratio of 0.45:1, the maximum removal efficiencies of Cu (II) [pH 6.5, dosage 10 g/L, initial Cu (II) concentration 100 mg/L, contact time 2 h, 298 K] and Pb (II) [pH 6.0, dosage 5 g/L, initial Pb (II) concentration 100 mg/L, contact time 2 h, 298 K] were 96.0% and 99.5%, respectively. Kinetic and isotherm studies have indicated that the adsorption process of Cu (II) or Pb (II) nanocomposites was better fitted by the pseudo-second-order equation and the Freundlich equation, with chemical adsorptions as the rate-limiting step. The metal–ion affinity to the functional groups of CCPM followed the order Pb (II) > Cu (II). The thermodynamic parameters ΔH and ΔS values showed that the sorption process of Cu (II) or Pb (II) was spontaneous (ΔG < 0), was endothermic (ΔH < 0), and had decreased entropy (ΔS < 0). HNO3 (0.1 M) could be a good desorbent in the recovery of metal ions after adsorption and regeneration of the adsorbent. 相似文献
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采用原位插层聚合法,制备了蒙脱土含量较高的共聚酯/蒙脱土纳米复合材料,意在做母料使用,含有该母料的聚合物复合材料的染色性能、吸湿浸润性能、抗静电性能及抗紫外性能等都有所改善。阐述了合适的共聚酯/蒙脱土纳米复合材料的制备工艺,讨论了制备过程中的影响因素,结果发现:在采用酯交换-缩聚反应釜进行原位插层聚合制备共聚酯/蒙脱土纳米复合材料的过程中,蒙脱土在缩聚釜中加入更符合生产实际;缩聚反应的实际过程证明了蒙脱土中含有的金属离子对缩聚反应有催化作用;另外,控制聚合的最终温度不超过278℃。最后,对共聚酯/蒙脱土纳米复合材料的结构进行了表征。 相似文献
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Gisèle Lecomte-Nana Amina Mokrani Nicolas Tessier-Doyen Kévin Boussois Hervé Goure-Doubi 《Ceramics International》2013,39(8):9047-9053
The present work aimed to investigate the processing of textural clay based materials using tape casting together with freezing. Two model raw materials were used, namely: BIP kaolin from France and ABM montmorillonite from Mediterranean region. The mixtures of both clays were studied, whereby, the amount of montmorillonite was 0, 5, 10, 20 or 50 mass%. After tape casting, the as-obtained green bands were frozen into liquid nitrogen, lyophilized and then fired at 1050 °C or 1200 °C.The amount of montmorillonite appeared as a critical parameter that controls the cohesion of the dry products. For montmorillonite content ≥20 mass%, the products exhibited multiple cracks after lyophilisation. With lower montmorillonite content, the cohesion of the dry products was satisfactorily and a macroscopic cross-linked surface texturation was observed. After calcination at 1050 °C or 1200 °C, the texturation appeared well defined. Moreover, calcination at 1200 °C increased the densification of products and the occurrence of a glassy phase was noted.The combination of both tape casting and freezing (freeze tape casting) is a promising way to develop various clay-based and composites materials exhibiting unique microstructure organization and characteristics with potential application in the field sustainable and environmentally friendly filtration, adsorption or catalysis. 相似文献