混合胺修饰的介孔硅胶吸附CO2性能研究

以介孔硅胶为载体,采用"嫁接+浸渍"两步法制备了混合胺(APTS+TEPA)修饰的介孔硅胶吸附剂。在固定床中考察了3-氨丙基三乙氧基硅烷(APTS)和四乙烯五胺(TEPA)负载量、吸附温度、进气流量对CO2吸附性能的影响,并研究了吸附剂的循环稳定性。结果表明,当APTS负载量30%,TEPA负载量30%(TEPA30-APTS30-MSG),吸附温度为70℃,进气流量为30 m L/min时,该吸附剂表现出最好的吸附性能,饱和吸附量高达3.04 mmol/g,较纯TEPA浸渍提高了37.6%。该吸附剂经10次吸脱附循环后,饱和吸附量仅下降2.96%,具有较好的循环稳定性。     

苯酚在介孔材料上的吸附性能的研究

采用软模板剂方法分别合成了二维六方（p6mm）结构的有序FDU-15介孔聚合物和硅基介孔材料SBA-15。通过XRD、SEM、氮气吸脱附等测试手段对材料的结构、孔笼等进行了表征。考察了FDU-15和SBA-15吸附水溶液中苯酚的吸附行为,研究了不同温度下水溶液中苯酚的静态吸附,随着温度的升高吸附量增大。Langmuir和Freundlich方程能够对苯酚在FDU-15上的吸附性能进行很好的拟合。     

介孔吸附材料对甲醇的吸附行为研究

作为吸附法处理挥发性有机化合物(VOCs)技术的核心,吸附材料的选择及吸附行为研究至关重要.本文系统研究了3种介孔吸附材料对极性分子甲醇的吸附行为,实验测定了相应的吸附等温线,并基于Langmuir方程和Freundlich方程建立了吸附平衡方程.研究结果表明,3种介孔吸附材料均有典型的介孔孔道分布,平衡吸附量随平衡浓...     

介孔碳的合成及吸附性能研究

以SBA-15为模板,正丙胺为碳源,利用化学气相沉积将碳源引入SBA-15的孔道,采用纳米刻蚀路线合成介孔碳材料。通过X-射线衍射(XRD)、氮气吸附脱附和透射电镜(TEM)表征表明,介孔碳具有大的孔径和孔容。在初始质量浓度为200 mg/L的罗丹明B溶液中加入在不同碳化温度下制得的介孔碳1 mg/L,其中700℃下焙烧的介孔碳吸附180 min后,饱和吸附量为212 mg/g。通过离心可将吸附后的介孔碳与溶液分离。     

介孔Zn-Si材料对水中亚甲基蓝的吸附研究

采用化学沉淀法制备了一系列的Zn改性氧化硅(0.1Zn-Si、0.2Zn-Si和0.4Zn-Si)和纯氧化硅(0.0Zn-Si)介孔材料,并探讨了介孔Zn-Si材料对亚甲基蓝(MB)的吸附行为。详细的考察了p H、时间和温度对吸附量性能的影响。结果表明,在酸性条件下,Zn-Si样品的吸附容量高于纯的Si O2材料,特别是0.2Zn-Si样品的吸附量达到228.88 mg/g;实验数据表明,Zn-Si介孔材料对亚甲基蓝的吸附过程符合假二级动力学方程和Langmuir等温吸附模型。     

有序介孔炭吸附萘的研究

采用溶剂挥发诱导自组装合成了有序介孔炭(OMC).XRD和N2吸附测试表明,OMC具有有序的二维六方结构,平均孔径为3.4 nm,比表面积为504.9 m2·g-1,介孔率为67.6%.研究了OMC对萘的吸附机理,萘在OMC表面的吸附等温线表明,OMC对萘的吸附符合Langmuir吸附等温规律.由Vant Hoff方程计算得出OMC对萘的吸附焓变为-24.83 kJ·mol-1,说明吸附为放热过程,推测其吸附机理为氢键作用力.红外光谱分析进一步证明,萘与OMC表面之间主要以氢键作用产生吸附.吸附温度的升高使-OH伸缩振动峰的红移程度减小,氢键缔合作用力减弱,这可能是导致温度升高时OMC的萘平衡吸附量减小的主要原因.     

氧化铈-二氧化硅介孔材料制备及对铜离子的吸附性能

采用共沉淀法和沉淀浸渍法制备了纳米氧化铈-二氧化硅（CeO₂-SiO₂）介孔材料吸附剂,主要考察了其对水中铜离子（Cu²⁺）的吸附行为。通过X射线衍射（XRD）、扫描电镜（SEM）和氮吸附（BET）等手段对合成的介孔材料进行了性能表征,并通过静态吸附实验分析了溶液pH、溶液初始金属离子质量浓度、吸附剂用量、吸附时间等条件对介孔材料吸附Cu²⁺性能的影响。结果表明：共沉淀法制备的纳米CeO₂-SiO₂介孔材料对Cu²⁺的去除效果较沉淀浸渍法要好;当溶液pH=7.0时CeO₂-SiO₂介孔材料对Cu²⁺的吸附效果最好,20 min时基本达到吸附平衡;溶液初始Cu²⁺浓度增大Cu²⁺去除率降低,Cu²⁺累计吸附量增大;随着吸附剂用量增加Cu²⁺去除率增大,当CeO₂-SiO₂吸附剂用量为0.15 g/L时对Cu²⁺的去除率趋于稳定;CeO₂-SiO₂吸附剂对不同金属离子吸附性能由大到小的顺序为Cu²⁺、Fe²⁺、Mn²⁺,该吸附过程均符合准二级动力学模型。     

功能化介孔材料吸附性能与机理的研究进展

综述了功能化介孔材料的孔径结构、改性基团和吸附条件对废水中的有机污染物、染料分子和重金属离子以及生物大分子、药物分子、CO2和挥发性有机气体污染物的吸附脱除效果的影响,还介绍了功能化介孔材料对液晶材料中的微量无机离子和大极性有机杂质的吸附脱除效果,指出了新型功能化介孔材料的开发和吸附环境的研究是未来的研究热点和发展趋势。     

Ce-MCM-48介孔材料的合成与吸附性能研究

采用Ce2O3∶SiO2∶CTAB∶H2O∶NaOH=0.015∶1∶0.45∶60∶0.48的摩尔配比,用水热法合成了Ce-MCM-48介孔分子筛。试验结果表明,经550℃焙烧过的Ce-MCM-48分子筛吸附性能良好,投加量为1.2g/L,亚甲基蓝初始浓度5.0mg/L,吸附时间为3小时,溶液的pH值为7时,亚甲基蓝溶液的脱色率和降解率分别高达98.90%和86.89%。并采用XRD,TEM、EDS等方法对Ce-MCM-48样品进行了表征。     

载金属离子的介孔炭对噻吩吸附性能的研究

采用模板法制备了介孔炭,并利用浸渍法将金属离子Ni^2＋、Co^2＋负载在该介孔材料上。研究了不同吸附剂、温度和浓度对吸附的影响。结果表明,介孔炭负载Ni^2＋或Co^2＋比13X负载Ni^2＋脱硫效果好,Ni^2＋／介孔炭比Co^2＋／介孔炭脱硫效果好。当负载Ni^2＋的量为10％,温度为20℃时,介孔炭的脱硫效果最好。     

CO2 adsorption on amine-modified mesoporous silicas

Mesoporous silicas with enhanced pore structures were synthesized and polyethylenimine (PEI) was immobilized in them to produce adsorbents for CO₂. The prepared samples were characterized by N₂ adsorption–desorption isotherms and small angle X-ray diffraction, and their CO₂ adsorption performance were evaluated. CO₂ adsorption capacity increased with operating temperature initially and then decreased. Besides, CO₂ adsorption capacity increased due to the PEI loading with more amine sites. The results showed that the structure of support played an important role in the CO₂ adsorption capacity. High surface area and large pore volume also favored the CO₂ adsorption capacity.     

Synthesis, characterization and phenol adsorption of carbonyl-functionalized mesoporous silicas

Carbonyl-functionalized mesoporous silicas have been synthesized by co-condensation of tetraethoxysilane and varying contents of 3-(trimethoxysilyl)propyl methacrylate in acidic medium with the block copolymer Pluronic 123 as a structure directing agent. The functionalized materials were characterized by PXRD, TEM, SEM, IR, and N₂ adsorption?Cdesorption at 77?K. Adsorption of phenol in aqueous solution on the materials has been investigated. The experimental results showed that carbonyl-functionalized mesoporous silicas possess strong adsorption ability for phenol with interaction of O-H??O?=?C hydrogen bond. The adsorption data are fitted to Langmuir Isotherms and a maximum adsorption capacity calculated from the Langmuir equation can reach 0.87?mmol of phenol/g. The effect of the pH on phenol adsorption has been studied.     

Adsorption performance of mesoporous silicas towards a cationic dye. Influence of mesostructure on adsorption capacity

The dye adsorption performance of four mesoporous silicas with different structure and textural properties, MCM-41, MCM-48, SBA-15 and mesocellular silica foam (MCF), was studied and compared by using toluidine blue O (TBO) as dye model in aqueous solution. These materials were characterized by X-ray diffraction (XRD), small-angle X-ray scattering, nitrogen adsorption-desorption analyses, and transmission electron microscopy (TEM). The effect of some parameters such as adsorbent dosage, contact time, temperature, and pH on the TBO removal in aqueous solution was studied. Results showed that adsorption capacity raised when adsorbent dosage, contact time and pH solution were increased while an increase in temperature decreased the adsorption of TBO. Langmuir, Freundlich and Temkin isotherm models were employed to elucidate the adsorption mechanism while the adsorption rate data were analyzed according to the pseudo-first and second-order kinetic models. Results showed that adsorption of TBO onto MCM-48, SBA-15, and MCF fitted well the Freundlich isotherm model while the kinetic studies showed that adsorption process could be better described by the pseudo-second-order model for all mesoporous silicas. Finally, some solvents were evaluated to carried out dye desorption from the TBO-loaded mesoporous silicas founding that acetic acid was the most efficient.     

Hydrolysis of sugars catalyzed by water-tolerant sulfonated mesoporous silicas

Mesoporous silicas are modified with sulfonic acid groups either by one-pot or by grafting method. In the hydrolysis of sucrose and starch, the sulfonated mesoporous silicas work as water-tolerant recyclable solid acid catalysts, showing higher conversion and turnover frequency than conventional Amberlyst-15, Nafion-silica and HZSM-5 catalysts.     

新型介孔有机聚合物对氢气存储和染料快速吸附研究

采用二甲氧基甲烷对四苯基硼酸钠进行Friedel-Craft烷基化,得到了一种具有阴离子骨架的介孔材料MPTB-1。借助气体吸附仪和紫外分光光度计对该材料氢气存储性能和常见有机染料分子的吸附性能进行研究。结果表明,材料孔径分布在5.3 nm附近,属于介孔材料;在分压0.1 MPa时可以吸附1.19%(质量分数)的氢气;该材料对阳离子染料罗丹明B具有较高的吸附效率,对水中染料去除率30 min可达99%以上;MPTB-1对罗丹明B的吸附等温线符合Langmuir模型,吸附动力学符合准二级动力学模型。表明材料对罗丹明B的吸附为均匀的单分子层吸附,而且两者之间存在化学吸附作用。     

有序介孔碳和活性炭对阿莫西林的吸附研究

阿莫西林是废水中一类典型的药品与个人护理品类新型有机污染物,会对周围环境和人体健康造成潜在威胁。以蔗糖为碳源、以SBA-15为模板制备有序介孔碳（OMC）。采用动态吸附法研究其对阿莫西林的吸附行为,并与常规吸附材料商用活性炭（GAC）作对比。探讨了废水中阿莫西林的初始浓度、温度及流速对动态吸附的影响。结果表明：在同等条件下,OMC的吸附能力远强于GAC,以OMC为吸附剂可有效去除废水中的阿莫西林类新型有机污染物。     

Template synthesis of mesoporous silicas containing phosphonic groups

Mesoporous silicas containing the functional group ≡Si(CH₂)₂P(O)(OC₂H₅)₂ in the surface layer have been obtained using the template method (template—P123). Their treatment by a concentrated hydrochloric acid results in the formation of functional groups of the composition ≡Si(CH₂)₂P(O)(OH)₂ that is in agreement with the IR spectroscopy data. It has been shown that the above treatment causes an increase of the sample specific surface area (up to 605 m²/g), sorption capacity, and pore diameter. As established by means of the CP/MAS NMR spectroscopy on ³¹P nuclei, the sample drying in vacuum at 110°C results in the formation of fragments ≡Si(CH₂)₂P(O)(OH)—OSi≡ with the content of 10–15 wt %. However, according to the TEM data, the sample mesoporous structure is retained.     

有机-无机杂化介孔二氧化硅的合成及应用

有机-无机杂化介孔材料因其具有显著的活性中心、较高的机械和水热稳定性等特点,成为国内外学者广泛关注的热点研究材料。综述了有机-无机杂化介孔二氧化硅材料的主要合成方法,包括后合成法、共缩聚法和有序介孔有机硅法,并对3种方法存在的优缺点进行了比较。同时详细介绍了有机-无机杂化介孔二氧化硅材料在催化、环境保护、生物医药和光学领域的应用。并展望了有机-无机杂化介孔二氧化硅材料的发展及应用前景。     

有机-无机杂化介孔二氧化硅的合成及应用

有机-无机杂化介孔材料因其具有显著的活性中心、较高的机械和水热稳定性等特点,成为国内外学者广泛关注的热点研究材料。综述了有机-无机杂化介孔二氧化硅材料的主要合成方法,包括后合成法、共缩聚法和有序介孔有机硅法,并对3种方法存在的优缺点进行了比较。同时详细介绍了有机-无机杂化介孔二氧化硅材料在催化、环境保护、生物医药和光学领域的应用。并展望了有机-无机杂化介孔二氧化硅材料的发展及应用前景。     

Adsorption of phosphate and nitrate anions on ammonium-functionnalized mesoporous silicas

Surface modified mesostructured silica materials represent potential adsorbents offering an opportunity to remediate several important water pollutants. In the present work, ammonium-functionnalized MCM-41, MCM-48 and SBA-15 mesoporous silica materials were synthesized via post-synthesis grafting and co-condensation. Their efficiency to remove nitrate and phosphate anions in aqueous solutions was investigated. The adsorbent materials showed high adsorption capacities reaching 46.5 mg NO₃⁻/g and 55.9 mg H₂PO₄⁻/g under the operating conditions explored. The mesoporous silica materials functionalized via post-synthesis grafting method exhibited higher performances in terms of percentage pollutant removal and adsorption capacities if compared to their analogs synthesized according to the co-condensation strategy.